Preliminary Design Report - Auckland Council · 7.0 Typical Road Construction Details 27 ... The specific purpose of the Preliminary Design Report is to identify and document the

Appendix U

Preliminary Design Report

U

Auckland Transport26-Sep-2014

Redoubt Road - Mill RoadCorridor ProjectPreliminary Design Report

AECOM Redoubt Road - Mill Road Corridor Project

26-Sep-2014Prepared for – Auckland Transport – Co No.: N/A

Redoubt Road - Mill Road Corridor ProjectPreliminary Design Report

Client: Auckland Transport

Co No.: N/A

Prepared byAECOM New Zealand Limited121 Rostrevor Street, Hamilton 3204, PO Box 434, Waikato MC, Hamilton 3240, New ZealandT +64 7 834 8980 F +64 7 834 8981 www.aecom.com

26-Sep-2014

Job No.: 60317081

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AECOM Redoubt Road - Mill Road Corridor Project


Quality InformationDocument Redoubt Road - Mill Road Corridor Project

Ref60317081

\\nzakl1fp001\projects\603x\60317081\6. draft docs\6.1 reports\preliminary designreport\final\preliminary design report.docx

Date 26-Sep-2014

Prepared by Dawie Maritz

Reviewed by Greg Booth

Revision History

Revision RevisionDate Details

Authorised

Name/Position Signature

A 26 July 2013 Draft for Review Ian FonesProject Manager

B 26-Sept - Final Craig HindTechnical Director

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Table of ContentsIntroduction 11.01.1 General 11.2 Purpose of Preliminary Design Report 11.3 Identified Issues 2Options Considered 32.0Design Methodology 43.03.1 Functional Requirements 4Staging and Constructability 54.04.1 Staging 54.2 Constructability and Traffic Management 7

4.2.1 Constructability of Stage 1 (NOR1) 74.2.2 Constructability of Stage 2 (NOR2) 74.2.3 Constructability of Stage 3 (NOR2) 74.2.4 Constructability of Stage 4 (NOR2 and NOR3) 84.2.5 Constructability of Stage 5 (NOR3) 8

4.3 Future Proofing of the Corridor 84.3.1 Traffic forecasts 84.3.2 Public Transport 9

4.4 Safety Principles 10Geometric Design 115.05.1 General 11

5.1.1 Design Standards 115.1.2 Design Assumptions 11

5.2 Typical Cross Sectional Details 115.3 Design Speed 195.4 Superelevation 195.5 Horizontal Alignment 195.6 Vertical Alignment 195.7 Sight Distances 20

5.7.1 Stopping sight Distance (SSD) 205.7.2 Intersection sight distances 205.7.3 Roundabout diameter 24

5.8 Vertical Clearances to Overhead Services 245.9 Cross sections 24

5.9.1 Fill and Cut Slopes 245.9.2 Safe Roadsides 24

Safety Barriers 256.06.1 General 25


6.2 Lateral Clearance / Working Width to structures 256.3 Bridges 256.4 Transitions 256.5 End terminals 25Typical Road Construction Details 277.07.1 General 27

7.1.1 Design Standards 277.2 Kerb Criteria 27

7.2.1 Auckland Council’s Local Roads 277.2.2 Splitter Islands 277.2.3 Pram Crossings 27

7.3 Footpaths / Shared Paths / Cycle Paths 27Signage and Pavement Marking 288.08.1 Signage 28

8.1.1 Design Standards 28

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8.2 Pavement markings 288.2.1 Design Standards 28

Traffic Signals 299.09.1 Design Criteria 29

9.1.1 Design Standards 299.2 Signal Lanterns 299.3 Traffic Detection 299.4 Phasing 29Street Lighting 3010.010.1 General 30


10.2 Design Criteria 3010.2.1 Design Requirements 3010.2.2 Foundations 3110.2.3 Lighting Columns, Outreach Arms and Ground Stubs 3110.2.4 Luminaires 3110.2.5 Lamps 3210.2.6 Electrical Reticulation 3210.2.7 Distribution Pillar Cabinets 32

Fencing 3311.011.1 General 33Acoustics 3412.012.1 General 34


12.2 Detailed Design of Acoustic Attenuation 34Geotechnical (Earthworks) 3513.0Retaining Walls 3814.0Road Pavements and Surfacing 4015.015.1 General 4015.2 Design Traffic Loading 4015.3 Pavement and Material Design Standards 40

15.3.1 Pavement Design Criteria 4015.3.2 Pavement Material Standards 4115.3.3 Pavement Composition 4115.3.4 Pavement Surfacing 4115.3.5 Pavement Design Summary (Redoubt / Mill Road) 4215.3.6 Pavement Design Summary District Arterials and Local Roads 4215.3.7 Pavement Design Summary Intersections and Roundabouts 43

15.4 Test Pitting and Material Testing 4315.4.1 Laboratory Testing 4315.4.2 Estimated Field CBR 44

15.5 Constructability 4415.5.1 Pavement Widening 4415.5.2 Reworking of Existing Pavements 4415.5.3 New Pavements 4415.5.4 Construction of Intersections 4415.5.5 Construction of Roundabouts 4415.5.6 Granular Pavements 4515.5.7 Constructability 45

Utility Services 4616.016.1 General 46


16.2 Design Criteria 4716.2.1 Concept Design 4716.2.2 Transpower Assets 48

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16.2.3 Future Utility Service Betterment requirements 4816.2.4 Common Service Trenches 4816.2.5 Constructability 4816.2.6 Risk 49

Drainage 5017.017.1 General 50


17.2 Proposed Stormwater Drainage Works 5017.2.1 Areas of Existing Stormwater Infrastructure 5017.2.2 Un-serviced Areas 51

17.3 Detailed Design Considerations 5117.4 Erosion and Sediment Control 52Bridges 5318.018.1 General 53


18.2 Proposed Bridges 5318.3 Design Considerations 53Walking, Cycling and Public Transport Provisions 5519.0

19.1.1 Design Standards 5519.2 Walking 5519.3 Cycling 5519.4 Public Transport 55Scheme Design Stage Safety Audit 5620.0

20.1.1 Road Safety Audit (RSA) 56Intersections 5721.021.1 General 57

21.1.1 Design Standards 5721.1.2 Design Assumptions 5721.1.3 Signalised intersections 5721.1.4 Roundabouts 5721.1.5 Priority intersections 5721.1.6 Accessways 57

Departures from Standards 5822.0

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Introduction1.0

1.1 GeneralThis Design Report has been provided for Auckland Transport (AT) to detail the interpretation of the designrequirements with regard to the physical deliveries and the design standards, assumptions, materials andmethodology used in the development of the preliminary design and various elements of the project.

1.2 Purpose of Preliminary Design ReportThe specific purpose of the Preliminary Design Report is to identify and document the design parameters,standards and assumptions used in the Preliminary Design. The following construction elements are covered inthis report:

- Geotechnical.

- Existing services affected by the project, including relocation and/or protection works.

- Drainage both surface and sub-surface.

- Earthworks, including stability of cut/fill batters.

- Road geometrics, including speed environment, cross-sections, sight distances, vertical and horizontalalignment of all carriageways:

Structures, including bridges and retaining walls;

Super-structure form;

Specific structural design requirements;

Urban/rural design form and aesthetics;

Bridge cross-sections and traffic clearances;

Deck drainage;

Services;

Edge protection standard adopted.

- Road pavement, including surfacing:

Sub-grade improvements;

Rigid/flexible;

Types of surfacing.

- Footpaths / cycleways / busways / public transportation infrastructure.

- Median / edge barriers / crash cushions:

Concrete;

W-section steel;

End treatments.

- Lighting:

Power supply;

Electrical design;

Luminaire design;

Feature lighting.

- Intersections:

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Types;

Geometry;

Controls.

- Traffic signals.

- Signage and pavement markings.

- Fencing.

1.3 Identified IssuesThe project length between Redoubt Road and Manukau City’s southern boundary has District Arterial status inthe Manukau Operative District Plan and is shown as part of the future Regional Arterial network. In the ARTARegional Arterial Road Plan the Redoubt Road-Mill Road corridor is identified as a proposed Regional ArterialRoad. The corridor is shown as a Regional arterial route in the Auckland Plan. The route is also part of AucklandTransport’s Auckland Regional Cycle Network and notated on Map 13.3 of the Auckland Plan as a section of theregional cycle network. The corridor is shown in Appendix K of the Auckland Regional Policy Statement asforming part of the proposed Regional Arterial Road network being roads that link districts or urban areas withinthe region.

Following are the significant issues that are addressed in this design:

- Intersection safety and capacity of Redoubt and Mill Road and connecting side roads;

- Physical properties of the road and its substandard alignment and constraints;

- Current route not capable of handling the anticipated urban-based development of the region;

- Land-use growth combined with decreasing levels of service;

- Medium to long term demand will increase beyond the capacity of the current route;

- Provision of bus priority measures that will support the 15-minute bus headway (15 minutes between buses),including a westbound bus-only lane between Hollyford Drive and the motorway interchange;

- Provision of on road cycle lanes and shared path facilities. The cycle facilities proposed for the corridor arein accordance with the Regional Cycle Network and will form part of the consolidated Auckland CycleNetwork.

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Options Considered2.0Various previous options have been considered by others along this and adjacent networks. The Opus preferredoption, Option D Alternative (similar to Northern A and Eastern A), was used as the basis of our investigation.Using this option as a baseline, refinements were investigated resulting in the following options:

Eastern A, B, C and Northern A, B, C.

The combination of Eastern A and Northern A is similar to the previously preferred Opus option, howeveralternative alignments considered geometry, adverse environmental effects including but not limited to ecologyand slope stability, effects on privately owned property, and underground as well as overhead services. Therecommended options, as identified in the Scheme Assessment Report (SAR), are Eastern C and Northern B.

Refer to the SAR for details of the preferred option and outcome of the investigation.

Figure 1: Options considered

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Design Methodology3.0

3.1 Functional RequirementsThe proposed corridor study included sections of the road that differ in type, ranging from full urban with a publictransport requirements to a semi-rural regional arterial and rural collector. Table 1 is a summary of the functionalrequirements set out in the RFT.

The following table summarises the functional requirements as described in the RFT from AT:

Sections Route Description Location Functional Requirements

Section 1aand b

Redoubt Road – fromSH1 motorway to urbanfringe and,

Hollyford / EvergladeDrive – Either side ofRedoubt Road

Section 1a - CH0 to CH620(Redoubt Road)

Section 1b – CH50 to CH680(Everglade / Hollyford Road)

- Regional Urban Arterial (50km/h to60km/h)

- Includes Hollyford and EvergladeDrive

- 32m wide corridor (general)- Bus lane along Redoubt Road

Section 2 (2a,2b and 2c)

Redoubt Road west ofMurphys Road to SH1

Section 2a – CH620 to CH1290Section 2b – CH1290 to CH1690Section 2c – CH1690 to CH2560(Redoubt Road)

- Regional Urban Arterial (50km/h to60km/h) flowing into larger lifestyleblock sections (urban fringe)

- 32.4m wide corridorSection 3 (3a,3b and 3c)

Murphys Road north ofRedoubt Road to south ofFlat Bush School Road

Section 3a – CH0 to CH820Section 3b – CH820 to CH1680Section 3c – CH1680 to CH1900(Murphys Road)

- District Arterial (60km/h)- 30.8 to 35.8m wide corridor- Adequate capacity for projected

growthSection 4 (4a,4b, 4c, 4d and4e)

Redoubt Road and MillRoad east of MurphysRoad through to south ofAlfriston Road

Section 4a – CH2560 to CH2920(Redoubt Road)Section 4b – CH2920 to CH3400(Redoubt Road)Section 4c – CH3400 to CH5300(Mill Road)Section 4d – Ch5300 to CH5750Section 4e – CH5750 to CH6500

- Regional Rural Arterial (60km/h to80km/h)

- 32.4m wide corridor- Widening at intersections and

approaches

Section 5 Tie-in to existing MillRoad south of AlfristonRoad

Section 5 – CH6500 to CH7000(Mill Road)

- 32.4m wide corridor- Open drains instead of kerb and

channel

Table 1: Summary of functional requirements

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Staging and Constructability4.0

4.1 StagingThe recommended option as described in the Scheme Assessment Report (Eastern C and Northern B) can beconstructed in stages to maximise the Economic Efficiencies of the project. The project can be divided into fiveseparable construction stages. Within these stages are different sections (as described in Table 1), differentiatingbetween the functional requirements of each section as described in the RFT. The Stages are:

Stage 1: Redoubt Road CH0 – CH1620 (incl. Diorella, Hollyford, Everglade, Goodwood, Santa Monica,Bartells and Alexia Place) (NOR 1)

The intersection between Redoubt Road and Hollyford Drive is heavily trafficked and road users experiencesignificant delays during peak times. The proposed widening of Redoubt Road and Hollyford / Everglade Drive willensure delays are minimised. As a first priority stage, this separable portion can be constructed in isolation orwithout the requirements of other stage.

Stage 2: Redoubt Road CH1620 – CH3000 (incl. Hilltop and old Murphys Road) (NOR 2)

This stage follows the completion of Stage 1 and involves road construction opposite the Totara Park andMurphys Road intersection and includes a realigned Hilltop Road. Stage 2 should be constructed after or duringStage 1, but it is not essential to have Stage 3 completed.

Stage 3: Murphys Road CH0 – CH1900 (incl. Thomas Road) (NOR 2)

This stage includes some re-alignment of the top section of Murphys Road to connect with the new Redoubt Roadintersection and can be constructed in isolation. Murphys Road requires a large volume of fill not necessarilyobtained from other stages of the project and will therefore have to be imported.

Stage 4: Redoubt Road / Mill Road CH3000 – CH5500 (incl. Equestrian Park, old Redoubt and Mill Roadintersections) (NOR 3)

This stage is the most costly and involves large cuts and fills. There are two bridges or viaducts within thissection. Mill Road is severed by the new alignment and a new T-intersection is proposed at mid-block of thesevered section. The two bridges or viaducts traverse across two gullies.

Stages 5: Mill Road CH5500 – CH7100 (incl. Ranfurly and Alfriston) (NOR 3)

This stage includes two roundabouts, at the Mill / Ranfurly Road intersection and at the Mill / Alfriston Roadintersection. Stage 5 can be constructed to tie into Stage 4 at its northern end.

This staging plan is shown in Figure 2 below.

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Figure 2: Staging of Project

The staged implementation of the corridor is programmed to take place over several years and within separateNORs, with each stage likely to be constructed as separate projects. These stages will require preparation andlead in time for detailed design, project procurement and construction. The stages could be staggered, with thedetail design and procurement stages of the next stage overlapping with the construction of a previous stage. Asuggested staging programme that is in line with Auckland Transports’ programme is displayed in Table 2 below.

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Stage Length

Detail design, land purchaseand procurement Construction

Start / End Date Duration Start / End Date Duration

1 Redoubt Road CH0-CH1620(incl. Hollyford, Everglade,Goodwood, Santa Monica andBartells Drive)

±2,420m 2015 / 16 12 months 2017 / 18 24 months

2 Redoubt Road CH1620 – CH3000(Incl. Hilltop Drive)

±1,580m 2016 / 17 12 months 2019 / 20 12 months

3 Murphys Road CH0 – CH1900(incl. Thomas Road)

±2,100m 2017 / 18 12 months 2020 / 22 24 months

4 Redoubt / Mill Road CH3000 –CH 5500 (incl. Old Redoubt andMill Road)

±2,900m 2018 / 19 12 months 2022 / 23 36 months

5 Mill Road CH5500 – CH7700(incl. Ranfurly and Alfriston)

±3,400m 2020 / 21 12 months 2025 / 2026 15 months

Table 2: Indicative Staging Programme

4.2 Constructability and Traffic ManagementEach stage will need to be constructed in such a way as to maintain existing traffic and meet a practical approvedTemporary Traffic Management Plan (TTMP) that may cater for traffic diversions of some or all traffic during itsconstruction period. Below by construction section are key constructability and traffic management issues thathave been taken in to consideration with the proposed alignment design. These need to be refined during thedetailed design phase following consultation with AT and other stakeholders.

4.2.1 Constructability of Stage 1 (NOR1)

Following is a brief constructability description of Stage 1:

- Redoubt Road CH0 – CH620: the intersection of Redoubt Road with SH 1 off ramp - enabling to maintainexisting traffic flows while widening on the southern side first. TMP involves maintaining access to asignificant number of properties.

- Everglade / Hollyford CH 50 – CH680: Redoubt Road / Hollyford Road / Everglade Drive intersection –enabling off road widening on all sides while working around a major intersection while maintaining existingtraffic flows. TMP involves maintaining access to a significant number of properties.

- Redoubt Road CH620 – CH1620: the intersection of Redoubt Road north of Hollyford / Bartells Drive /Alexia Place / Totara Park entrance (excl. Hilltop Road) – enabling to maintain existing traffic flows whilewidening on the southern side first while maintaining existing traffic flows. TMP involves maintaining accessto a significant number of properties.


Sections tying in at practical locations including into the existing carriageway:

- Redoubt Road CH1620 – CH2550: Redoubt Road, north of and including Hilltop Road / New MurphysRoad connection – essentially a green fields section built in Totara Park with temporary link at western endto the existing Redoubt Road carriageway. TMP involves maintaining access to Totara Park off road users.


- Murphys Road CH0 – CH820: Murphys Road, Flat Bush School Road / south end of Murphys Bush –widening one side then switching to the other side. TMP involves maintaining access to a small number ofproperties.

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- Murphys Road CH820 – CH1640; Murphys Road, south end of Murphys Bush / first bend near top of hill –significant earthworks, WSL services protection in the southern part with traffic diversions:

The northern section to Thomas Road involves widening one side then switching to the other side.TMP involves maintaining access to a small number of properties.

The southern section from Thomas Road is likely to involve substantial closure of the top section due toearthworks. It will also require several TMPs that look to divert traffic along Thomas Road and or FlatBush School Road / Chapel Road / Matthews Road / Hilltop Road Redoubt Road. To enable this tohappen, Hilltop Road Intersection needs to have already been completed and a set of temporary trafficsignals installed there to cater for the traffic movements.

- Murphys Road CH1640 – CH1900: Murphys Road, extension to new Redoubt Road – This section can beundertaken in isolation as each end with little impact on the existing carriageway. It has been designed toconnect into the existing carriageway with temporary connections at both ends. TMP involves maintainingaccess to a small number of properties at the southern end outside the proposed retaining walls.

4.2.4 Constructability of Stage 4 (NOR2 and NOR3)

- Redoubt Road CH2550 – CH3000: New Road, Murphys Road extension / west of Pony Club entrance –This section is essentially a green field section that can be built off line with a temporary connect as requiredat the southern end back to the existing carriageway before the Pony Club entrance. TMP involvesmaintaining access to Totara Park off road users.

- Redoubt Road CH3000 – CH3500: New Road, west of Pony Club entrance / new Kinnard Lane connection– This section is essentially a green field section that can be built off line but with a new connection toRedoubt Road. TMP involves maintaining access to several properties most likely to the junction with the topend of Mill Road around the end of the constructed.

- Redoubt Road CH3500 – CH5500: New Road, new Kinnard Lane / south existing Mill Road – This sectionis mostly a green field section that can be built off line with a temporary connect at the northern end back toeast of the existing Redoubt Road / Mill Road intersection to allow construction over the existing Mill Road.This section at the southern end needs to finish short of the existing Mill Road to enable existing Mill Roadtraffic to flow. Temporary access is requiring for the small number of properties at the southern end of thissection back to the existing Mill Road. TMP involves maintaining temporary access to a small number ofproperties.


- Mill Road CH5500 – 5800: New Road, south existing Mill Road / south Ranfurly Road – This section ismostly a green field section that can be built off line with a temporary connect at the northern end back to theexisting Mill Road to allow construction of the final section of section 4c. Temporary access is required forthe small number of properties at the southern end of this section and for construction of the roundaboutback to the existing Mill Road. TMP involves maintaining temporary access to a small number of properties.

- Mill Road CH5800 – 7100: New Road, south Ranfurly Road / Alfriston Road roundabout – This section ismostly a green field section that can be built off line with a temporary connect at the southern end back tothe existing Alfriston Road on the southern side to allow construction of the roundabout. TMP involvesmaintaining temporary access to a small number of properties.

4.3 Future Proofing of the CorridorThe Preliminary Design takes in to account the planned growth in land use by allowing for and managing theexpected impacts of that development.

4.3.1 Traffic forecasts

Traffic modelling carried out on the corridor confirms that the capacity recommended for the corridor caters for theforecast growth over the next 30 years without over-supplying capacity. This is reflected in forecast travel timesand levels-of-service that are better than the do minimum scenarioi1. The typical road cross section includes twothrough lanes in each direction, with additional lanes provided at the busiest intersections located at Murphys

1 The Do Minimum option represents the scenario where no improvements were proposed to the corridor over and above usualor routine maintenance

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Road and Hollyford Drive. This additional road capacity provides immediate relief to a currently congestedcorridor, whilst also allowing for the planned development growth in the Southern Sector.

In addition to performance of traffic on the corridor, the additional capacity provides relief to the wider network byremoving bottlenecks formed by existing intersections and by balancing travel over parallel routes such as ChapelRoad, Te Irirangi Drive, and especially SH1. The additional capacity will improve travel time for vehicles travellingto key destinations via State Highway (example: to/from Auckland CBD) during the peak and off peak periods.Traffic flows on the wider network operate under improved levels of service, providing positive transportationimpacts to travel time, congestion relief, and trip reliability.

4.3.2 Public Transport

The Frequent Service Network between Botany Downs and Manukau will deliver at least a 15-minute serviceoperating all day and will be complemented by a network of connector routes that operate all day at half-hourlyfrequencies. In addition, a supporting network of local services, peak-only services, and targeted services willcater for specific market needs.

The Hollyford Drive / Redoubt Road and Diorella Drive / Redoubt Road intersections have both been designed toprovide bus priority measures that will support the 15-minute bus headway, including a westbound bus-only lanebetween Hollyford Drive and the motorway interchange. The bus lane develops immediately north of the HollyfordDrive / Redoubt Road intersection, providing a Bus only right turn lane at the signalised intersection with adedicated Bus only phase in the signal timing. All existing bus stop locations are to remain.

The capacity of these bus priority measures is far in excess of the demand created by the Frequent ServiceNetwork and is suitable also for connector services to use.

The remainder of the corridor does not form part of the planned public transport network. The small number ofcontrolled intersections on the corridor will therefore allow any future services to run on the corridor with minimaldelays on the through movements, and especially during off peak periods will not be subject to any significantdelays.

The public transport provisions are therefore in accordance with strategic public transport planning for futureservices in excess of those considered in the 10 year horizon of the current Auckland Regional PassengerTransport Network Plan and proposed Integrated Transport Plan.

4.3.2.1 Cycling

The cycle facilities provided for the corridor are in accordance with the existing Regional Cycle Network and willform part of the consolidated Auckland Cycle Network. The Auckland Cycle Network will form part of the ‘OneNetwork’ of transport options in Auckland, adding to the range of travel choices along the corridor.

On and off-road cycle lanes as well as off-road shared facilities are provided throughout the project length, andare supplemented with off-road paths where the environment is more suitable, for example adjacent Totara Parkand along the old Mill Road. A segregated cycle lane is provided along the west bound bus lane betweenHollyford and the Motorway to separate cyclists from the bus lane.

The road corridor has sufficient width for the proposed facilities. All intersections are to have appropriate cyclemarkings in accordance with the design guidelines and standards.

4.3.2.2 Walking

Footpaths and/or shared facilities are provided for the length of the project. Refer to section 5.2 of this report forthe typical cross sections and walking and cycling facilities proposed. The low trafficked old Mill Road will improvepedestrian facility by providing off road facilities for recreational walking and cycling.

Traffic signal intersections at Diorella Drive, Hollyford Drive, Goodwood Drive and Murphys Road will all havepedestrian facilities incorporated into the signals, providing safe and certain crossing opportunities.

The free left turn from Redoubt Road into Hollyford Drive (north bound) contains a signalised pedestrian crossing.

The left turn out of Murphys Road into Redoubt Road (southbound) and left turn into Murphys Road from RedoubtRoad (eastbound) is marked as a “zebra” crossing.

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4.4 Safety PrinciplesThis Preliminary Design for the corridor takes into account the government's strategy to guide improvements inroad safety over the period 2010 to 2020. This strategy is the Safer Journeys strategy. The strategy's vision is:

“A safe road system increasingly free of death and serious injury”

The Safe System recognises that people make mistakes and are vulnerable in a crash and aims for the entireroad system to improve safety by creating safer roads and roadsides, safer speeds, safer vehicles and safer roaduse.

The safety principles for the design of the roadway are to include:

- Safe roads and roadsides: To significantly reduce the likelihood of crashes occurring and to minimise theconsequences of crashes of the highest risk types of head-on, run-off road, intersection crashes, andcrashes involving pedestrians and cyclists.

- Safe road use: A design is required where road users comply with road rules, take steps to improve roadsafety and expect safety improvements.

- Safe speeds: The result of all crashes is strongly influenced by impact speed. The number of speed-relatedcrashes and the severity of crashes are to be reduced by implementing safer travel speeds. This requires:

drivers to understand safe speeds,

speed limits that reflect the use, function and safety of the network, and

travel speeds that support both safety and economic productivity.

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Geometric Design5.0

5.1 General5.1.1 Design Standards

The primary standards used in the preliminary design are listed below in order of precedence:

- Austroads Guide to Road Design (AGRD) Parts 1 to 8

- Manual of Traffic Signs and Markings (MOTSAM) Part I: Traffic Signs

- Manual of Traffic Signs and Markings (MOTSAM) Part II: Markings

- NZTA State Highway Geometric Design Manual (SHGDM - draft), December 2000

- Austroads Guide to Traffic Management Part 6: Intersections, Interchanges and Crossings

- Austroads Guide to Traffic Management Part 9: Traffic Operations

- Austroads Guide to Traffic Management Part 10: Traffic Control and Communications Devices

For local roads, the geometric standards are listed below.

- AGRD Parts 1 to 8

- Auckland Council Standard Engineering Details: 2008

- Auckland Traffic Management Unit Traffic Signals Design Guidelines Version 2.0

5.1.2 Design Assumptions

The project RFT provided some design direction and where applicable, these design directions have beenincorporated in the design.

5.2 Typical Cross Sectional DetailsThe following cross sections form the alignment of the Preliminary Design:

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Section 1A – Redoubt Road, Chainage 0 – 620 (MC00)Cross sectional makeup:

- Design speed – Regional Urban Arterial 60km/h (posted 50km/h).

- Traffic Signals replace current give way at Diorella Drive.

- Diorella Drive is widened to allow for separate left and right turn lanes.

- The central, flush median is retained.

- Lane widths – 3.3m (four lanes, two in either direction and a west bound bus lane).

- A 3.4m bus only lane west bound to minimise PT delays (shared with cyclists).

- On-road Cycle lane (east bound) – 1.5m inclusive of a 300mm channel and 400mm buffer and No Parking.

- Off–road Cycle lane (west bound) – 1.6m segregated cycle lane on the proposed shoulder and a 2.0mfootpath separated with a 1.5m grassed berm.

- Flush median width – 3.0m.

- Existing west bound footpath remains, while a new 2.0m footpath is provided on the west bound side.

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Section 1B – Everglade / Hollyford Drive, Chainage 45 - 690 (MC10)Cross sectional makeup:


- Lane widths – 3.3m (two inner lanes, opposing directions) 3.3m (two opposing outer lanes).

- A 3.4m bus only lane developing on the southbound approach only.

- An initial 1.2m raised median develops into a 3m flush median to accommodate future pedestrian crossings.

- Grass berms as shown.

- Off–road Cycle lane (north bound) – 1.8m segregated cycle lane on the proposed shoulder with a 2.0mfootpath separated by a 1.15m grassed berm.

- Shared pedestrian facility (south bound) – 3.0m shared facility provided.

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Section 2 A & B – Redoubt Road, Chainage 600 – 2550 (MC00)Cross sectional makeup:


- Redoubt Road / Hollyford intersection: Existing signalised intersection replaced.

- Redoubt Road / Hilltop Road: Un-signalised T-intersection provided.

- Lane widths – 3.5m (four lanes, two in either direction) and No Parking.

- On-road Cycle lane – 1.6m plus 0.4m buffer between traffic lane (including 300mm channel).

- Flush Median width – 3.0m.

- Grass berms as shown.

- 2.0m Footpath east bound and a 3.0m shared facility west bound.

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Section 3A – Murphys Road, Chainage 0 – 820 (MC20)Cross sectional makeup:

- Design speed – District Arterial 90km/h (currently posted at 80km/h).

- Lane widths – 3.2m (four lanes, two in either direction).



- 2.2m Footpath north bound and a 3.0m shared facility south bound.

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Section 3B – Murphys Road, Chainage 820 - 1900 (MC20)Cross sectional makeup:

- Design speed – Horizontal Design Speed achieved is 90km/h, while a design speed of only 80km/h wasachieved for the vertical alignment due 9% vertical grade from CH 1212 (currently posted at 80km/h).

- Lane widths – 3.2m (four lanes, two in either direction).



- 2.2m Footpath north bound and a 3.0m shared facility south bound.

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Section 4 – Redoubt / Mill Road, Chainage 2550 – 5500 (MC00)Cross sectional makeup:

- Design speed – Horizontal Design Speed achieved is 90km/h, while a design speed of only 80km/h wasachieved for the vertical alignment due to the sag curve at chainage 3914 (posted 60km/h-80km/h).

- Intersection between Redoubt Road and Murphys Road signalised.



- Raised Median – 2.0m (0.5m shoulders) and 3.0m where flush.

- 3.0m Shared path south bound.

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Section 5 – Mill Road, Chainage 5500 – 7100 (MC00)Cross sectional makeup:

- Design speed – Regional Rural Arterial 90km/h (posted 80km/h).


- On-road Cycle lane – 2.0m plus 0.6m buffer between traffic lane (including 300mm channel). Within thetransition to the existing Mill Road (Stage 5b), the cycle lanes becomes the existing shoulder.

- Raised Median – 2.0m (0.5m shoulders) and 3.0m where flush.

- 3.0m Shared path south bound.

- 2 laned Roundabouts at the Ranfurly and Alfriston Roads’ intersections.

- Where Stage 5b begins to taper in order to “tie in” to the pre-existing Mill Road alignment, this section haslane widths of 3.5m (one in either direction) with 2.0m shoulders and a 2.5m berm.

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5.3 Design SpeedThe design speed allowed for in each section reflects the existing scenario and functional location, i.e. urban,semi-rural or rural locations.

SectionHorizontal Design Speed Vertical Design Speed

Design Posted Design Posted

Section 1a and b 60km/h 50km/h 60km/h 50km/h

Section 2 (urban) 60km/h 50km/h 60km/h 50km/h

Section 2 (rural) 70km/h 60km/h 70km/h 60km/h

Section 3 80km/h 80km/h 80km/h 80km/h

Section 4a 90km/h 60km/h 80km/h 60km/h

Section 4b & 4c 90km/h 80km/h 80km/h 80km/h

Section 5 90km/h 80km/h 90km/h 80km/h

Table 3: Design speed achieved

5.4 SuperelevationSuperelevation transitions have been designed to avoid areas of flat carriageway and to ensure adequate surfacedrainage to reduce the possibility of aquaplaning.

The maximum superelevation used is 4.5%. The maximum rate of rotation used is 2.5% per second.

Superelevation has been designed in accordance with SHGDM (Draft 2000) as per the Austroads (2009) Guide toRoad Design Part 3: Geometric Design recommendations.

Superelevation development and curve k-values have are included in the long sections for reference.

5.5 Horizontal AlignmentSection 1a, b and 2 follow the existing horizontal alignment where possible. At Section 1a and 2 the wideningoccurs primarily along the southern boundary and along the western boundary along section 1b.

The Horizontal alignment design is in accordance with Austroads (2009) Guide to Road Design Part 3: GeometricDesign.

5.6 Vertical AlignmentSections 1a, 1b and 2 follow the existing vertical alignment where possible with widening primarily along thesouthern boundary. The end of section 2, which deviates from the existing alignment, has a 70km/h verticalalignment.

Sections 3a and 3b (Murphys Road) both have a 60km/h vertical alignment. A maximum vertical grade of 9% ismaintained to the intersection with Redoubt Road as agreed with Auckland Transport.

Sections 4a, 4b and 4c all have a 90km/h vertical alignment, maintaining an 8% max vertical grade.

Vertical design is in accordance with the Austroads (2009) Guide to Road Design Part 3: Geometric Design. Thetable below states the design criteria achieved.

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Section DesignSpeed

Min SSD(m)

Minimum K-Value:Crest / Sag

MaximumGrade

MinimumGrade

Section 1a and b 60km/h 64 N/A 5.8% 1.6%

Section 2 (urban) 60km/h 64 N/A 7.7% 5.6%

Section 2 (rural) 70km/h 81 39.6 / 16 4.5% 0.4%

Section 3a and b 80km/h 99 39.1/21 9% 0.26%

Section 4a 80km/h 99 101.8 / NA 6.2% 0.4%

Section 4b – 4e 80km/h 99 60.8 / 22 7% 0.78%

Section 5 90km/h 132 54.5 / 75.9 5.5 0.3%

Table 4: Vertical design criteria achieved

5.7 Sight Distances5.7.1 Stopping sight Distance (SSD)

The midblock vertical design is based on Austroads Part 3: Table 8.7.

- Posted speed = 50kp/h, Design speed = 60kp/h, minimum crest K-value 11.8 (2.0s reaction time).



- Posted Speed = 80kp/h, Design speed = 90kp/h, minimum crest K-value 51.0 (2.0s reaction time).

5.7.2 Intersection sight distances

Intersection stopping distances are based on Austroads Part 4A: tables 3.1 and 3.2.

- Approach sight distance (ASD) - Driver eye height to pavement marking (object height 0m).

- On Redoubt road (CH 0.00 – 1400m), the design is matching the existing vertical alignment, a minimum K-value of 18.8 has been selected from table 3.1.

- 60kph design speed minimum k-value = 18.8 (1.5s reaction time).

The remainder of the main alignment (CH 1400m to project end) there are no signalised intersections, thereforemidblock K-values have been applied.

Table 5 (below) summarises the design criteria required and achieved for the Preliminary Design. The table alsoindicates the Approach Sight Distances (ASD) as well as the Safe Intersection Stopping Sight Distances (SISD)required and achieved.

Where the standards could not be achieved, they are marked in RED. A short comment is provided to list thereason for the non-conformance. Section 22 of this report identifies all the items where the standards have notbeen met and provides mitigation measures or an explanation why the standards have not been met.

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Intersection DesignSpeed

Approach Sight Distance(ASD)

Safe Intersection StoppingDistance (SISD) Reaction

time(RT)

Grade CommentRequiredDist./k-value

AchievedDist./k-value

RequiredDist./k-value


Redoubt Road / Diorella Drive Intersection

Redoubt RdEast bound

60kph 64m / 18.8 >64m / NA 114m / 14 >114m / NA 1.5sec -1% No crest curve

Redoubt RdWest bound

60kph 69m / 18.8 >69m / 18.8 119m / 14 >119m / 18.8 1.5sec -3.6% Grade corrected

Diorella DriveSouth bound

60kph 64m / 18.8 64m / NA NA NA 1.5sec +0.5% Existing alignment. No Crest curve on side road

Redoubt Road / Hollyford Drive / Everglade Drive Intersection


60kph 57m / 18.8 >57m / 18.8 107m / 14.0 >107m / 18.8 1.5sec +8.9% Grade corrected


60kph 72m / 18.8 >72m / 18.8 122m / 14.0 >122m / 18.8 1.5sec -4.5% Grade corrected

Hollyford DrSouth bound

60kph 64m / 18.8 >64m / 51.0 114m / 14.0 95m / 18.8 1.5sec +0.6 SISD non-critical on signalised intersection. Standardnot achieved due to horizontal curve and existing RW

Everglade DrNorth bound

50kph 50m / 13.8 55m / 13.8 92m / 10.0 97m / 13.8 2.0sec +10% Lowered design speed to match existing road profile

Redoubt Road / Goodwood Drive / Santa Monica Place Intersection


60kph 69m / 24.0 >69m / NA 119m / 16.0 >119m / NA 2.0sec +3.8% Grade corrected


60kph 84m / 24.0 >84m / 119.4 134m / 16 >134m / 119.0 2.0sec -8.6% Grade corrected

Santa Monica PlSouth bound

40kph 34m / 5.3 >34m / 3.5 67m / 4.9 >67m / 3.5 1.5sec -3.9% Lowered design speed to match existing road profile.Design following existing alignment.

Goodwood DrNorth bound

60kph 53m / 24.0 >53m / NA 112m / 16 >112m / NA 2.0sec +10% Grade corrected

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time(RT)





Redoubt Road / Hilltop Road Intersection


60kph 78m / 18.8 >78m / NA 128m / 16 >128m / NA 2.0sec -4.5% Grade corrected


60kph 78m / 18.8 >78m / NA 128m / 16 >128m / NA 2.0sec -4.5% Grade corrected

Hilltop RoadSouth bound

50kph 47m / 13.8 >47m / 16 89m / 10 >89m / 13.8 2.0sec +13.5% Grade corrected

Redoubt Road / Murphys Road Intersection


80kph 114m / 59.5 >114m / NA 181m / 35 >181m / NA 2.0sec +0.4%


80kph 114m / 59.5 >114m / NA 181m / 35 >181m / NA 2.0sec -0.4%

Murphys RdSouth bound

80kph 90m / 48.5 >90m / 51 NA NA 1.5sec +9.0% Grade corrected

Redoubt Road / Old Redoubt Road / Kinnard Lane staggered Intersection


80kph 114m / 59.5 >114m / NA 181m / 35 >181m / NA 2.0sec +0.4%


80kph 104m / 59.5 >104m / NA 181m / 35 >181m / NA 2.0sec +6.1% Grade corrected

Old Redoubt RdSouth bound

40kph 42m / 7.2 42m / 7.2 NA NA 2.0sec -4.2% Grade corrected

Kinnard LaneNorth bound

40kph 32m / 5.3 32m / 5.3 NA NA 1.5sec +6% Grade corrected

Redoubt Road / Old Mill Road Intersection


80kph 110m / 59.5 >110m / NA 177m / 35 >177m / NA 2.0sec +3.4% Grade corrected

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time(RT)






80kph 123m / 59.5 >123m / NA 190m / 35 >190m / NA 2.0sec -3.4 Grade corrected

Mill RdNorth bound

40kph 42m / 7.2 >42m / 7.2 NA NA 2.0sec -4.2 Grade corrected

Redoubt Road / Ranfurly Road Roundabout

Redoubt RdSouth bound

80kph 137m / 59.5 >137m / NA NA NA 2.0sec -7.0% Grade corrected

Redoubt RdNorth bound

80kph 113m / 59.5 >113m / NA NA NA 2.0sec +2.9% Grade corrected

Ranfurly RdWest bound

50kph 55m / 13.8 >55m / 16.2 NA NA 2.0sec +3.0%

Ranfurly RdEast bound

50kph 52m / 13.8 52m / 13 NA NA 2.0sec +3.8% Grade corrected

Redoubt Road / Alfriston Road Roundabout

Redoubt RdNorth bound

80kph 114m / 59.5 <114m / 51 NA NA 2.0sec -0.5% Final design to be adjusted to achieve designstandard.

Redoubt RdSouth bound

80kph 114m / 59.5 >114m / NA NA NA 2.0sec +0.5%

Alfriston RdWest bound

50kph 55m / 13.8 >55m / NA NA NA 2.0sec +0.0%

Alfriston RdEast bound

50kph 52m / 13.8 >52m / NA NA NA 2.0sec +4.1% Grade corrected

Table 5: Sight Distances Required and Achieved

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5.7.3 Roundabout diameter

Austroads Part 4B: table 4.1:

The Preliminary Design is based on a posted speed of 80kph, and an absolute minimum suggested value of 20mRadius for a dual lane roundabout.

5.8 Vertical Clearances to Overhead ServicesA summary of the agreed clearances (with Transpower) is summarised in the table below.

Link Design (m)

Murphys Road (@ overhead cables) 8.46m

Table 6: Clearance achieved

5.9 Cross sectionsRefer to Section 5.2 for a description of the cross sectional characteristics of each section.

5.9.1 Fill and Cut Slopes

The following table summarises the design elements achieved for the Preliminary Design:

Parameter Recommendation

Cuts 3H:1V

Fills 3H:1V

Table 7: Cut and Fill used in Preliminary Design

Cuts exceeding 5m in height are to be benched. These benches will be designed to intercept debris spills and willbe sloped backwards to a drain at a 1.5% slope.

Retaining walls are used to reduce the overall footprint and to accommodate the widening while maintaining land-use where possible.

5.9.2 Safe Roadsides

Clear zones will be designed in accordance with the AGRD Part 6, Section 4 - Table 4.1. Where clear zonescannot be achieved, appropriate treatment based on Austroads Part 6: Roadside Design, Safety and Barriers willbe provided. The proposed road safety barrier locations have been indicatively shown on the drawings, range60317081-SHT-30-000-CD-0501 to 0516. For further detail, refer to Section 6.0 below.

Wire rope along the raised medians is to be considered during the Detailed Design Phase. The proposed wirerope barrier locations have been indicatively shown on the drawings.

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Safety Barriers6.0


All roadside safety barriers will be designed to comply with the following relevant design standards:

- AGRD Part 6 Roadside Design Safety and Barriers

- NZTA Specification for Road Safety Barrier Systems, M/23; 2009

- NZTA Bridge Manual

- NCHRP Report 350 (previously accepted systems) or MASH-1 (new systems)

- AS/NZS 3845


Test Level 3 (road and walls) and five (bridges) safety barriers have been allowed for based on the requirementsof the above design guidelines. It is proposed that further investigation be carried out in the Detailed DesignPhase to confirm the barrier type(s), level, and transition requirements.

Safety barriers are considered appropriate alongside all traffic lanes where there is insufficient clear zone widthbased on the design speed in accordance with the AGRD Part 6 Roadside Design Safety and Barriers.

Leading and trailing terminal ends will be provided at all safety barrier ends meeting the above standards inconjunction with the barrier types used. Wire rope along the raised medians has been included in the PreliminaryDesign drawings.

6.2 Lateral Clearance / Working Width to structuresThe minimum lateral clearances to the faces of Permanent Works structures will be designed to comply withSection 6 of AGRD Part 6.

Dynamic deflection and Vehicle roll allowance is addressed in AGRD Part 6, Section 6.3.15 and Section 6.3.16respectively. To calculate vehicle roll allowance we propose to use Table 6.8 AGRD Part 6.

6.3 BridgesThe requirements for bridge edge protection, including footpaths and approach requirements, are set out inVolume 2: Appendix B of the NZTA Bridge Manual (2013). The design process for bridge edge protection isspecified in the Bridge Design Statement.

Rigid concrete barriers at Test Level 5 (TL-5) impact barriers are required for both the Puhinui Creek Gully Bridgeand the South Mill Road Gully Bridge. Further investigation needs to be carried out in the Detailed Design phaseto confirm the barrier level and transition requirements.

With the geometry proposed, a TL 5 concrete barrier extending 10 m onto the road will provide adequatediscontinuity between the roadside and the bridge barriers.

Bridge side protection (traffic face and outside face along the whole length) shall be coated with anti-graffiticoating to the manufacturers specification and requirements.

6.4 TransitionsWhere barriers transition from one type to another, an approved proprietary device or NZTA standard detail will beprovided which complies with M/23 Specification Appendix A: 2009. This needs to be investigated as part of thedetailed design phase.

6.5 End terminalsBarrier end terminals will be an approved proprietary device by NZTA, which complies with M/23 SpecificationAppendix A: 2009.

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Proprietary re-directive, non-gating end terminals (such as a CSP X-350) will be used on this project. This type ofend terminal smoothly redirects a vehicle, without pocketing or penetration of the barrier, when a vehicle impactsthe barrier at, or near the nose of the device, or downstream of the nose.

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Typical Road Construction Details7.0


The road construction details are based, where applicable, on standard construction details obtained from thefollowing documents:

- AGRD Parts 1 to 8

- Manukau City Council – Engineering Quality Standards and Manukau Approved Requirements

- Australian / New Zealand Standards

- AS/NZS 3661 – Slip Resistance of Pedestrian Surfaces

- NZS 3109 – Concrete Construction

- AS/NZS 2053 – Conduits and Fittings for Electrical Installations

7.2 Kerb Criteria7.2.1 Auckland Council’s Local Roads

The kerb profile that will be used is vertical kerb and channel on the outside kerbs, mountable kerbs for splitterislands and traffic kerbs for median islands and traffic islands. Kerb dimensions are as follows:

- Vertical kerbs (130mm high) and Channel (300mm wide)

- Mountable kerb (90mm high) and Channel (300mm wide)

7.2.2 Splitter Islands

Splitter islands will be designed to comply with AGRD Part 4 Intersections and Crossings.

7.2.3 Pram Crossings

Pram crossings are located at all pedestrian crossing facilities. Pram crossings will be designed to comply withPDC Development Code; drawing number June 2009/R21.

7.3 Footpaths / Shared Paths / Cycle PathsAll paths are designed in accordance with the following standards:

- Manukau City Council – Engineering Quality Standards

- Auckland Transport – ATCOP Chapter 11 Cycling Infrastructure Design

- MCC District Plan

- NZTA’s Pedestrian Planning and Design Guide

All paths are 100mm thick using 20Mpa concrete. Paths are to have a non-slip surface texture.

Handrails will need to be provided on retaining walls and reinforced earth embankments, where protection fromfalling is required by the NZ Building Code. Handrails will be designed to comply with the requirements of the NZBuilding Code. The minimum desirable height of pedestrian/cycle safety rails is 1.4m.

No signs or street furniture will be installed within the footpaths and any signage overhanging these paths willneed to have a minimum vertical clearance of 2.4m.

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Signage and Pavement Marking8.0

8.1 Signage8.1.1 Design Standards

All road signage will be designed in accordance with the following documents:

- NZTA Traffic Control Devices (TCD) Manual

- MOTSAM - Part I: Traffic Signs

- MOTSAM - Part II: Markings

- MOTSAM - Part III: Motorways And Expressways

All retro reflective sheeting will comply with AS/NZS 1906.1:1993.

Each sign will be labelled with both a MOTSAM or TCD reference number (in accordance with the aboveacronyms) and a unique sign reference number, so that they can be individually identified.

8.2 Pavement markings8.2.1 Design Standards

The pavement markings will be designed in accordance with the following design standards:

- NZTA TCD Manual

- MOTSAM - Part II: Markings

- MOTSAM - Part III: Motorways And Expressways

- NZTA P/30 Specification for High Performance Road marking

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Traffic Signals9.0

9.1 Design Criteria9.1.1 Design Standards

During detailed design, the design of traffic signals is to be in accordance with:

- Auckland Traffic Management Unit (TMU) Traffic Signals Design Guidelines Version 3.0 August 2010

- The National Traffic Signal Specification Rev 2 September 2005 produced by the Signals New Zealand UserGroup (SNUG)

- Austroads Guide to Traffic Management Parts 6, 9 and 10, and the Traffic Control Devices Rule 2004.

Traffic signal design and operation will be developed in consultation with Auckland Transport and the TMU duringthe Detailed Design phase, ensuring network management strategies such as coordination and mode prioritiesare incorporated. Other elements including new power connections, provision of new SCATS, bus detection,communication lines and controller software preparation requires some time to implement so early liaison withthese parties is critical.

9.2 Signal LanternsLED displays are to be used for all signal lanterns in the project (including pedestrian signal lanterns).

9.3 Traffic DetectionAdvance vehicle loops and cycle loops are to be used where necessary to optimise signal operation. If controllercapacity allows, detector loops will be included in uncontrolled left turn lanes for traffic counting purposes.

9.4 PhasingPhasing for the signalised intersections will be confirmed in consultation with the TMU / Auckland Transport.

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Street Lighting10.0Street lighting is to be provided along all roads within the project corridor.


The primary design standards are listed below in order of preference.

- Electricity Act & Electrical (Safety) Regulations 2010

- AS / NZS 3000: Electrical Installations

- Local Authority Bylaws, Conditions and Standards

- Auckland Council District Plan (Manukau and Papakura sections)

- NZ Radio Interference Regulations and Interference Notices (Radio and Television)

- Vector Standards in relation to work in their network adjacent to NZTA’s network

- AS/NZS1158: Road Lighting

- NZS 5902: Building and Civil Engineering Drawing Practice

- Electrical Code of Practice NZECP:34

- NZTA Standard M / 19 – Tubular Steel lighting Columns Specification


The design assumptions need to be taken in to consideration with the design criteria below when completing thedetailed design.

- Design of all lighting within the corridor will be in accordance with the prescribed lighting standards.

- Obtaining all required agreements including cabling, supply, distribution points and connection will bedesigned and undertaken by the lines company Vector.

- The interrelationship of this design is based on complementing the landscaping and urban design treeswhere by the trees are positioned around the required lighting column positions.

- At signalised intersections Traffic signal poles where possible have been used as the first choice positionsupplemented by infill lighting.

10.2 Design Criteria10.2.1 Design Requirements

The proposed lighting is designed to comply with Auckland Council’s street lighting policy and is based on thelighting technical parameters of Category V1 (AS/NZS 1158.1.1.2005 Table 2.2) estimate for >20,000 VPD. Thedesign utilises the luminance method based on the SAASTAN lighting programme or similar approved designprogramme for New Zealand conditions, as well as the luminance method for any intersections and changes inroadway width and areas below bridge structures.

Upgrading, replacing and / or relocating existing lighting within the corridor shall comply with the AucklandTransport (ATCOP) lighting standards. It does not include dimmable lamps.

Column spacings are typically to be designed in a staggered arrangement on either side of the carriageway andlocated in the front berm. Approaching major intersections which widen out, poles are generally to be opposingeach other. A copy of the street lighting concept design is shown on the existing services and concept designdrawings.

Outdoor distribution cabinets will be provided, including lighting control and facilities for remote metering.

Cable selections and voltage drop calculations will need to take into account relevant start up currents ofluminaries as well as the lowest striking voltage for the number of luminaries per circuit.

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10.2.2 Foundations

All lighting support column foundations will be designed and constructed to suit the individual site conditions.

All shear bases will need to be installed strictly in accordance with the manufacturer’s recommendations, and onflat ground shall have 75mm clearance from finished ground level and on a slope 100mm clearance from finishedground level to the back underside of the flange.

Shear bases will need to be rotated 15 degrees from the horizontal outreach arm, in the direction of travel as permanufacturer’s recommendations.

10.2.3 Lighting Columns, Outreach Arms and Ground Stubs

All lighting columns located within the traffic clear zones will either have frangible supports, or be protected byroad safety barriers.

All columns are typically octagonal lighting columns either ground planted in areas under 70km / hr or standardflange base and shear bases for speeds over 71km / hr or special bridge connections. They will be designed tocomply with the “NZTA Standard M / 19” standard. All shear stubs will be further protected with a continuousbarrier coating (epoxy-mastic or similar) at least 150 microns thick to 100mm above finished surface level to aminimum of 400mm below surface level.

Outreach arms will be mitred, and have a 5 degree tilt angle from the horizontal for luminaires on the carriagewayand 5-10 degrees for local roads and bridges. Tilts up to 10 degrees may be used in exceptional cases. A typicalmounting height of 12m with a 2m outreach arm or 3m in special circumstances will be used. Pole spacings willbe based on the following:

- urban areas, non-intersections at 42-45m centres alternate sides with specimen trees between;

- urban areas, intersections and approaches on traffic signal poles and when approaching widenedintersections at 42-45m centres opposing each other; and

- rural areas, at 42-45m centres alternate sides.

The actual pole type and approved supplier need to be considered at the design stage.

10.2.4 Luminaires

This luminaires will be based on using the Auckland Transport approved AEC KAOS 2 with flat glass protectors.

The luminaires will be fitted with a removable control gear assembly, equipped with the appropriate igniters. Theunderside of each luminaire shall carry the identification of the lamp size using letters readable from the ground.

Intersections will be designed to comply with the illuminance based lighting technical parameters (AS/NZS1158.1.1.2005 Table 2.2) in accordance with clause 3.4.3.3 where it states that, the illuminance requirements forthe higher lighting subcategory shall apply.

Intersections where the intersecting road is deemed Category P will be treated in accordance with clause 3.4.3.4,where a luminaire has been located within 12m of the intersecting road.

Pedestrian Refuges will be lit to comply with the horizontal illuminance based lighting technical parameters(AS/NZS 1158.1.1.2005 Table 2.2) in accordance with clause 3.4.3.6.

Signalised Pedestrian crossings will be lit to meet a minimum of 20 lux as per Auckland Council’s requirements.

Non Signalised pedestrian crossings (Amber globe type zebra crossings) will be lit to comply with the horizontaland vertical illuminance based lighting technical parameters (AS/NZS 1158.4.2009 Table 3.4 and 3.5) inaccordance with clause 3.3 and Sub-category X1.

The smaller bridge (chainage 4800 – 4900) can be lit from either end as the spans are short enough to undertakethis however the long bridge (chainage 3900 – 4100) will require lighting on each side with poles opposing eachother to comply with the required standards.

Road lighting in Rural Areas is addressed in AS/NZS 1158. Since the ambient light and sky glow in Rural Areas issignificantly less than that in built-up areas, the impact of obtrusive light is much more pronounced.AS 4282-1997(Control of the Obtrusive Effects of Outdoor Lighting), will be used as a guide in these areas.

The following design guidelines will be applied during detailed design:

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- Keep road lighting to the minimum applicable standard at intersections and road terminations.

- Minimize lighting beyond these areas (intersections and terminations). Only provide sufficient lights such thata pedestrian walking along the road always has a light in view, for orientation and guidance.

- Priority shall be given to roads that are designated for traffic detours from main highways.

Consideration should be given in the detailed design phase to investigate the potential of using the LED lanternson the approved list to determine if they can meet the required standards.

10.2.5 Lamps

Lamps will be from the Auckland Transport approved list being the GE TT 250 W Metal Halide Lamp.

10.2.6 Electrical Reticulation

All electrical work will need to comply with the Electrical Regulations 2010 and the Electrical Codes of Practice.

Clearance between lighting columns and adjacent distribution lines will need to conform to requirements ofElectrical Code of Practice NZECP: 34. The design will need to include power supply to all traffic signals.

Cable systems will be designed in accordance with AS/NZS 3000. The cable will be 16mm, PVC insulated,neutral screened, with soft drawn copper conductors, having a sheath radial thickness of no less than 3.2mmscreened with the screen connected as the earth.

Cable is to be connected directly to the Vector network providing continuous supply (24/7) into the street lightcolumn and undertaken during the design stage. In some sections of road it may be more cost effective toconnect more than one light to a single feed from the LV network connection. Selections and voltage dropcalculations will take into account relevant start up currents of luminaries as well as the lowest striking voltage forthe number of luminaries per circuit.

Vector Networks will supply and install their own cables from the network to the connection point in the base ofthe street light column. No more than four columns will be supplied by each phase on each cable.

Outdoor distribution cabinets will be provided, including lighting control and facilities for remote metering.

Miniature circuit breakers (MCBs) will be used for circuit protection. HRC fuses will be provided in the base ofeach pole for isolation purposes.

All cables will have mag slab protection where not located in ducts. Where cables cross trafficked carriagewaysthey will not cross at 90 degrees and be installed in appropriately sized PVC ducts at a minimum 1m cover fromtop of the wearing course to the obvert of the duct with a SN8 stiffness rating.

Each pole will be earthed by means of 10mm2 copper insulated wire exothermically welded to a 16mm copperbonded steel earth rod 300mm from the pole base.

10.2.7 Distribution Pillar Cabinets

Power supplies will be from existing distribution pillars and any new distribution points will be provided as requiredby Vector.

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Fencing11.0

11.1 General11.1.1 Design Assumptions

Replacement fencing is to be provided where privately owned property and reserves are affected. The type anddesign is to be undertaken during the Detailed Design phase.

The type of fencing needs to be designed to meet the strategy outlined in the Urban Design and Landscapingreport for particular technical details, which is summarised below.

- Fences for residential properties along the corridor are to balance the privacy and safety needs of residents,consider an appropriate level of attenuation and consider issues of built character, budget and futuremaintenance.

- Rural property boundaries will also need treatments which consider rural activities, natural character andlandscape attributes (e.g. biophysical and cultural patterns and processes) and the open views and vistasthat are commonly attributed to rural landscape character.

- A ‘family of design’ hardscape materials palette will be developed to provide a consistent identity andcharacter that is specific to the Redoubt / Mill Road corridor.

- Scoria from site could be salvaged, stored and reused on wall facings, low walls and paving features.

- Facing treatments for walls and structures that are integrated with the overall design theme of the corridorand consider the use of natural stone found in the locality such as scoria, or external concrete finishes thatuse tone and texture in a creative or appropriate way.

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Acoustics12.0


The acoustic assessment has been carried out in accordance with the following standards and design guides:

- NZS 6806:2010 Acoustics – Road-traffic noise – New and altered roads

- NZS 6803:1999 – Acoustics – Construction Noise

- NZTA Traffic Noise Guidelines

- NZTA’s Environmental Plan


Refer to the Noise and Vibration report for all design assumptions.

12.2 Detailed Design of Acoustic AttenuationA noise assessment has been undertaken to determine the impact of traffic noise from the upgrade on the nearbynoise-sensitive properties (refer Appendix L of the Assessment of Environmental Effects (AEE)).

The noise impact assessment indicates that noise mitigation will be required to achieve suitable noise levels atthe noise sensitive properties in the project area. An extensive assessment of noise mitigation options has beenundertaken in accordance with the method set by NZS 6806:2010. For each area of the project a number ofoptions have been developed.

Mitigation options include the use of a low noise road surface and building modifications.

When the project proceeds to the detailed design phase, the preliminary mitigation options will need to beassessed to determine the best practicable option for noise mitigation.

An assessment of construction noise and vibration has also been undertaken as referred to in Appendix L of theAssessment of Environmental Effects (AEE ).

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Geotechnical (Earthworks)13.0


The primary design standards are listed below:

- NZTA Bridge Manual (including Provisional Amendment, Dec 2004).

- NZS 1170:5 (2004), New Zealand Standards NZS 1170:5, Structural Design Actions, Part 5: EarthquakeActions – New Zealand, 2004.

- NZS 4402:1986 (Incorporating Supplement No. 1). Methods of Testing Soils for Engineering Purposes.

- NZTA F/1:1997. Specification for Earthworks Construction


Refer to the Geotechnical Interpretive Report (Appendix N of the AEE) for any design assumptions.

13.2 ReferencesPrevious geotechnical investigation information and interpretation is documented in the following reports:

- AECOM (2013). Redoubt to Mill Road Corridor, Geotechnical Interpretive Report, February 2013.

- AECOM (2013). Redoubt to Mill Road Corridor, Geotechnical Factual Report, February 2013.

- AECOM (2012), Redoubt to Mill Road Corridor, Preliminary Geotechnical Assessment Report, July 2012.

- Opus (2011), Mill Road Realignment – Alfriston to Hollyford Drive, Manukau, Geotechnical Factual Report,April 2011.

- Opus (2010), Ormiston Road to Redoubt Road, Scheme Assessment Report, November 2010.

- GHD (2010), Hollyford to Ronwood Corridor Study, PGAR, October 2010.

- GHD (2010), Mill Road Corridor Study, Scheme Assessment Report, October 2010

- Opus (2008), Mill Road to Redoubt Road Corridor Study, Preliminary Geotechnical Appraisal, July 2008.

- Worley Consultants Ltd (1989), Redoubt Road Reservoir Complex, Stability Assessment, September 1989.

Other references:

- Lunne et al (1997). Cone Penetration Testing in Geotechnical Practice. Blackie Academic & Professional.

- Stark & Olson (2002).Liquefied strength ratio from liquefaction flow failure case histories. CanadianGeotechnical Journal, 39: 629-647.

- NCEER (1997). Proceedings of the NCEER Workshop on Evaluation of Liquefaction Resistance of Soils.Technical Report NCEER-97-0022.

- Idriss, I. M., and Boulanger, R. W. (2008). Soil liquefaction during earthquakes. Monograph MNO-12,Earthquake Engineering Research Institute, Oakland, CA, 261 pp.

- CivilTech (2008). LiquefyPro V5. Liquefaction and Settlement Analysis Program.

- Geologismiki (2012). CLiq v.1.7.1.14. Liquefaction and Settlement Analysis Program.

- Rocscience (2012). SLIDE V6. 2D Limit Equilibrium Slope Stability Analysis Program.

- Tensar (2012). TensarSoil V2.06.14. Reinforced Fill Wall and Steep Slope Design Program.

- Rocscience (2012). Settle3D V2. 3D Settlement Assessment Analysis Program.

- Geologismiki (2012). CPeT-IT v.1.7.5.17. Interpretation of Cone Penetration Test (CPTu) Data.

- GeoStru (2012). LoadCap v.8.20.0.623 Ground Load Bearing Capacity Assessment Program.

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- ATC/MCEER (2003), ATC/MCEER-49-1 Liquefaction study report. Recommended LRFD Guidelines for theSeismic Design of Highway Bridges. Applied Technology Council / Multi-disciplinary Centre for EarthquakeEngineering Research.

- Jibson, RW (2007). Regression models for estimating coseismic landslide displacement. EngineeringGeology, Vol 91, p209-218.

- Ambraseys, N.N. and Menu, J.M. (1988), Earthquake-Induced Ground Displacements, EarthquakeEngineering and Structural Dynamics, Vol. 16, pp. 985 – 1006.

- New Zealand Geotechnical Society (2005). “Field Description of Soil and Rock, Guidelines for the FieldDescription of Soils and Rocks for Engineering Purposes”.

- Robertson, P. K., (2012), Guide to Cone Penetration Testing, 5th Edition.

13.3 Design Criteria13.3.1 Soil Properties

The proposed design soil strength properties are presented in Table 8. The material properties are generallyderived from the in situ and lab test data and supplemented by our knowledge of similar soil in the area.

Material Unit Weight(kN/m3)

Effective stress parametersTotal stress(undrained)parameters

- c' (kPa) - Phi (degrees) - Cu (kPa)

Engineered Fill 18 2 30 100

Colluvium 18 0 30 80

Alluvium 17 0 28 50

CW to HW Waitemata Group 18 2 32-35 100

MW,SW & UW Waitemata Group 18 20 35 -

Table 8: Proposed Design Soil Strength Parameters

Notes: CW = completely weathered, HW = highly weathered, MW = moderately weathered, SW = slightly weathered, UW = un-weathered

13.3.2 Seismic Loading

Seismic accelerations used for slope design will be based on peak ground accelerations derived from the currentNZTA Bridge Manual (including Provisional Amendment, Dec 2004) and return periods, hazard factors andrepresentative soil profiles derived from NZS 1170.5:2004.

The return period for bridge, retaining wall and embankment fill adopts Table A4 in the Provisional AmendmentDecember 2004 of the NZTA Bridge Manual 2003.

13.3.3 Liquefaction Assessment

Susceptibility of the natural ground to liquefaction will be assessed using updated NCEER, Robertson 2009method. The assessment for ‘sand like’ soil (includes clay like soils) will be carried out using CPT data in the CLiqsoftware V.1.7.1.14 (Geologismiki, 2006).

The liquefaction analysis will be carried out for three levels of PGA associated with SLS 1, SLS 2 and ULSearthquake for the bridge and earthworks.

13.3.4 Cut / Fill Slope Batter and Embankment Fill

13.3.4.1 General

Temporary cuts/fills for construction will be designed to ensure adequate factors of safety at all times.

All cut/fill slopes will be stabilised to prevent any fretting or erosion after construction.

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13.3.4.2 Slope Batter

Grassed slope batters will be designed at a 1V:3H maximum to be traversable by mechanical plant used fornormal highway maintenance purposes. Any slope steeper than this will be planted.

13.3.4.3 Slope Stability Criteria

The load cases and the required level of stability design criteria considered in the slope stability assessment arepresented in Table 9.

CaseNo Load Case Groundwater FOS min Max. Permanent

Displacement (mm)

1 Static, short term1 Design long term GWL 1.3 -

2 Static, long term Design long term GWL 1.5 -

3 Static, short term Design elevated GWL 1.2 -

4 Seismic, SLS 1 Design long term GWL 1.0 -

5 Seismic, SLS 2 Design long term GWL - 100

6 Seismic, ULS Design long term GWL - 100

Table 9: Load case for slope stability assessment and the associated ground conditions

1 The un-drained shear strength is applied for the fine-grained (cohesive) material in Load Case No. 1, 4, 5 and 6.

Traffic loading of 12 kPa will be applied for static load case. No traffic loading is assumed for the seismic loadcase.

Un-drained shear strength and liquefied shear strength will be applied when appropriate to a particular soil unit forboth the static and seismic loading case. For the short term case, fine grained soils are modelled as un-drained.

Suitable drainage measures will be incorporated to ensure the cut slopes and fill embankments does not becomefully saturated.

13.3.4.4 Slope Stability Analysis

Analyses for detailed design will be undertaken using the 2D ‘Slide’ analysis software V.6 to model the stability ofthe proposed cut and fill slopes under both static and seismic conditions using circular failure paths. The GeneralLimit Equilibrium Method will be used.

13.3.5 Earthworks Construction

All work shall be carried out in accordance with specification NZTA F/1, and the requirements of the AucklandRegional Council Technical Publication No 90 (ARC TP90). This will be defined in the earthworks specification.

13.3.6 Compaction Standard Requirements

Compaction standards will be specified to meet strength and deformation assumptions in the design. Currentpractice is to use compacted soil strength and air voids to comply with the requirements of Clause 10.5 ofNZTA/F1.

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Retaining Walls14.0


- NZ Building Code

- NZTA New Zealand Bridge Manual Second Edition, 2003 (including Amendment December 2004)

- NZTA RRU Bulletin 84 Volume 2: Seismic Design of Bridge Abutments and Retaining Walls, 1990

- NZS1170 Structural Design Actions

- Other Standard Specifications (subject to requirement and approval)

- Earth Retaining Walls: AS 4678-2002 Earth-retaining structures (with the NZTA Bridge Manual for trafficloadings)


Refer to the Geotechnical Interpretive Report (Appendix N of the AEE) for any design assumptions.

14.1.3 Foundation and Materials Properties

The foundation soil properties of the retaining structures will adopt the soil properties of the natural groundpresented in Table 8 above of the earthworks design criteria. The materials used to form the retaining structureswill be dependent on the type of structure being constructed.

In the case of significant fill heights (10m), MSE slopes and walls for earth reinforcement will be Tensar geogrid(or similar approved). The material strength and properties will adopt those presented in the Manufacturerspecifications.

For lower cut / fill heights the use of timber pole, gravity wall, concrete pile or concrete crib walls may beconsidered. Soil nailing may also be used to stabilise cut slopes formed within the upper colluvial and completelyweathered Waitemata materials.

The design of any retaining structures will be required to accommodate the presence or re-location ofunderground services and be undertaken during the next stage of design.

14.1.4 Seismic Loading and Displacement

The seismic loads and performance of the new retaining walls will be designed to accord with the requirements ofthe NZTA Bridge Manual Clause 5.7 (including Provisional Amendment, Dec 2004). The return period of ULSearthquake for the retaining wall design will adopt Table A4 in the NZTA Bridge Manual 2nd 2003.

14.1.5 Retaining Wall Stability

The minimum factors of safety (working stress), in accordance with Table 4.3 of NZTA Bridge Manual, will be asfollows:

ConditionNormal Loading Seismic LoadingFactor of Safety Factor of Safety

Sliding 1.5 *

Overturning 2.0 1.5

Bearing 3.0 2.0

Overall stability against soil failure 1.5 1.25

Table 10: Minimum Factors of Safety (working stress)

*Permanent displacement under design earthquake loading is allowed; adopt Table 5.9 of the NZTA BridgeManual, as discussed in the previous section.

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Temporary cuts and fills for construction will be designed to have a minimum factor of safety against all modes offailure of 1.2 at all times. If the Contractor judges that it cannot accept the cost and time consequences of failure,a higher factor of safety that is acceptable to the Contractor will be achieved.

Suitable drainage will be installed behind retaining structures to prevent the development of excess porepressures.

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Road Pavements and Surfacing15.0

15.1 GeneralThis Preliminary pavement design comprises the design of road widening, reworking of existing pavements andpavement structures on new alignments.

The traffic loading is such that granular pavements will require modified pavement layers to prevent early rutting.

Intersections will be designed with modified base and subbase layers to accommodate the additional loading dueto turning movements.

Roundabouts will be designed as structural asphalt pavements to prevent permanent deformation and to ensurelong-term pavement performance.

A primary asphalt surfacing (regulating layer) will be placed on all road sections requiring a final OGPA surface.This layer is deemed necessary to ensure long-term integrity of the pavement and to facilitate milling andreplacement of the OGPA as a future maintenance strategy.

15.2 Design Traffic LoadingTraffic loading was calculated from Annual Average Daily Traffic (AADT) as predicted by traffic modelling. Thepredicted AADT, assumed a percentage of Heavy Commercial Vehicles (%HCV) and design traffic loading interms of equivalent standard axles are summarised in Table 11 below.

Section AADT 2011 AADT 2026 AADT 2041 % HCV DESA X106

Redoubt Road East of SH1 22,000 34,000 36,500 5 12.36

Redoubt Road East of Hollyford Dr 10,000 22,000 25,500 5 7.5

Mill Rd South of Redoubt Rd 13,500 24,500 28,500 5 8.68

Mill Rd North of Alfriston Rd 9,000 17,000 23,000 5 6.27

Mill Rd South of Alfriston Rd 11,000 19,500 25,000 5 7.23

Murphys Rd North of Redoubt Rd 10,500 22,500 24,500 5 7.60

Table 11: Predicted AADT and design traffic loading (DESA)

The data indicates that the average traffic growth rate for the first 15 years (2011-2026) will be in the order of4.5% and for the following 15 years (2026-2041) the growth rate will be in the order of 1%.

The calculation of the design traffic loading is further based on the following assumptions:

- Directional factor of 0.5

- Lane distribution factor of 1

- Number of heavy vehicle axle groups per heavy vehicle 2.4

- ESA per heavy vehicle is 0.6

15.3 Pavement and Material Design StandardsThe pavement design has been carried out in accordance with the AUSTROADS Pavement Design Guide (APDG2004), the NZTA 2007 Supplement to AUSTROADS and the Auckland Transport Development Code.

15.3.1 Pavement Design Criteria

The pavement structural design life will be 25 years and the pavement will be designed to the following criteria:

- Design reliability of 95%

- The subgrade CBR will be based on 4 day soaked values

- For all modified material design, moduli will be as per granular material in accordance with APDG 2004 andthe NZ Supplement

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- Granular material will be modelled in CIRCLY as anisotropic and sub layered

- Subgrade improvement layers will be sub layered and limited to a CBR of 15

- Reworked existing pavements will meet the design requirements of new pavements

15.3.2 Pavement Material Standards

All materials will meet the AUSTROADS, NZTA and Auckland City Criteria requirements. Performance tests suchas the following will be carried out:

- Structural asphalt mix design in accordance with TNZ TM 6002 v1 and relevant AUSTROADS documents.

- Basecourse aggregate will comply with NZTA M/4 AP40 and Manukau MR8 Specification, except for specificmodified mixes.

- Subbase aggregate will meet Manukau MR9 and NZTA Specifications.

- Cement stabilised, foam bitumen and cement modified materials will represent good practice andcompliance with current Draft NZTA T/19 and NZTA B/4 specifications.

15.3.3 Pavement Composition

The following pavement compositions are proposed for the widening and the reworking of the existing structures:

- Foam bitumen stabilised basecourse layers on the most heavily trafficked section (East of SH1 to HollyfordRoad).

- Cement stabilisation of existing and widened pavement (Hollyford Road to Hilltop Road).

For the new road alignment from Hilltop Road to the tie-in with Mill Road (CH 6950), a granular pavement withcement modified basecourse layer is proposed. In sections where the road is in cut, it is proposed to modify thesubbase layer or in-situ stabilise the subgrade material. Subsoil drains will also be provided at the edge of thepavement structure in these areas.

Roundabouts will be constructed in structural asphalt on cement stabilised subbase layers and the pavementcomposition of intersections will be cement modified basecourse and subbase layers.

All private entrance roads will be granular pavements.

15.3.4 Pavement Surfacing

The following surfacings are proposed in accordance with the skid resistance requirements as specified in NZTAT10: 2012 and is summarised in Table 12 below:

Road SectionPostedSpeed(km/h)

RequiredMPD (mm) Surfacing Type Noise Abatement

Requirement

SH1 to Hilltop Rd 50 >0.7 OGPA or SMA OGPA

Hilltop Rd to Murphys Rd 50 >0.7 Grade 3/5 seal or SMA Not required

Murphys Rd to north of RedoubtRd

60 >0.7 Grade 3/5 seal or SMA Not required

Murphys Rd to tie-in of Mill Rd 80 >1.0 Grade 2/4 seal Not required

Murphys Rd from FlatbushSchool Road to Redoubt Rd

60 >0.7 Grade 3/5 seal or SMA Not required

Hollyford/Everglade Drive 60 >0.7 Grade 3/5 seal or SMA Not required

Private Entrance Roads N/A N/A Grade 3/5 seal Not required

Table 12: Skid resistance requirements in accordance with NZTA T10: 2012

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15.3.5 Pavement Design Summary (Redoubt / Mill Road)

Pavement structures for Redoubt Road and Mill Road are summarised in Table 13 below.

SectionChainage

Surfacing RegulatingLayer Base Subbase

SubgradeImprovement

LayerStart End

SH1 to Hollyford -Existing Widening

00

700700

30 OGPA30 OGPA

40 AC1440 AC14

200 FBS200 FBS

Existing200 GAP65

Existing150 AP65

Hollyford toHilltop - ExistingWidening

700700

13001300

30 OGPA30 OGPA

40 AC1440 AC14

200 CemAP40200 CemAP40

Existing200 GAP 65

Existing150 AP65

Hilltop to Mill -ExistingWidening

13001300

41004100

40 SMA1440 SMA14

200 CemAP40200 CemAP40

Existing200 GAP 65

Existing150 AP65

Murphys Road toEnd

4100 6950 Grade 4/2 200 CemAP40

200 GAP 65 150 AP65

Table 13: Pavement design for Redoubt and Mill Road (SH1 to CH 6950)

15.3.6 Pavement Design Summary District Arterials and Local Roads

Pavement structures for district arterial and local roads are summarised in Table 14 below.

SectionChainage

Surfacing Base SubbaseSubgrade

ImprovementLayerStart End

Murphys Rd 0 1900 Grade 3/5 200 Cem AP40 200 GAP 65 150 AP65

Everglade Dr 50 200 Grade 3/5 200 Cem AP40 200 GAP 65 150 AP65

Hollyford Dr 250 650 Grade 3/5 200 Cem AP40 200 GAP 65 150 AP65

Diorella Dr 0 70 Grade 3/5 150AP40 200 GAP 65 N/A

Santa Monica Pl 0 25 Grade 3/5 150AP40 200 GAP 65 N/A

Goodwood Dr 0 60 Grade 3/5 150AP40 200 GAP 65 N/A

Bortell Dr 0 50 Grade 3/5 150AP40 200 GAP 65 N/A

Alexia Pl 0 50 Grade 3/5 150AP40 200 GAP 65 N/A

Totara Park 0 60 Grade 3/5 150AP40 200 GAP 65 N/A

Hilltop Rd 0 150 Grade 3/5 150AP40 200 GAP 65 N/A

Redoubt Link 2400 0 90 Grade 3/5 200 Cem AP40 200 GAP 65 150 AP65

Pony Club Entr Rd 0 140 Grade 3/5 150AP40 200 GAP 65 N/A

Redoubt Link 3250 0 290 Grade 3/5 200 Cem AP40 200 GAP 65 150 AP65

Kinnard Lane 0 230 Grade 3/5 150AP40 200 GAP 65 N/A

Link 3100 0 100 Grade 3/5 100AP40 200 GAP 65 N/A

Link 5020 0 200 Grade 3/5 200 Cem AP40 200 GAP 65 150 AP65

Ranfurly 0 120 Grade 3/5 200 Cem AP40 200 GAP 65 150 AP65

Alfriston Rd 0 120 Grade 3/5 200 Cem AP40 200 GAP 65 150 AP65

Table 14: Pavement design for District Arterial and Local Roads

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15.3.7 Pavement Design Summary Intersections and Roundabouts

Pavement structures for Intersections and Roundabouts are summarised in Table 15 below.

Intersection Chainage Surfacing Base SubbaseSubgradeImprovementLayer

Hollyford Dr 600 SMA14 200 Cem AP40 200 Cem GAP 65 150 AP65

Murphys Rd 2550 SMA14 200 Cem AP40 200 Cem GAP 65 150 AP65

Ranfurly RdRoundabout

5550 SMA14 200 StructuralAsphalt

200 Cem GAP 65 150 AP65

Alfriston RdRoundabout

3650 SMA14 200 StructuralAsphalt

200 Cem GAP 65 150 AP65

Table 15: Pavement design for Intersections and Roundabouts

15.4 Test Pitting and Material TestingA total of seven test pits were excavated in order to confirm the existing pavement depth and to obtain samplesfor laboratory testing. Test pits were excavated at the following positions and referenced to the proposed newalignment:

- Test Pit 1 in Redoubt Rd, CH150

- Test Pit 2 in Hollyford Dr, CH250

- Test Pit 3 in Redoubt Rd, CH3150

- Test Pit 4 in Alfriston Rd, CH6300

- Test Pit 5 in Mill Rd, CH7000

- Test Pit 6 in Murphys Rd, CH2550

- Test Pit 7 in Murphys Rd, CH2550

The test pits revealed deep granular pavement structures in the order of 500 mm, with cement modified pavementlayers in test pits 2, 4 and 7.

15.4.1 Laboratory Testing

Material sampled from the basecourse layer, subbase and subgrade was tested in the laboratory. Sand equivalent(SE), particle distribution (PSD) and CBR test results are summarised in Table 16 below:

PositionBasecourse Subbase Subgrade

CommentsSandEquivalent

PSD%passing 75µm

SandEquivalent

PSD%passing 75µm

CBR 4 daysoaked

TP 1 61 7 42 6

TP2 62 7 4 Cem

TP3 45 5 1

TP4 71 3 Cem

TP5 27 3 42 5

TP6 62 3

TP7 70 1 2.5 Cem

Note: Cem = Cemented modified materials

Table 16: Laboratory test results

The sand equivalent values are generally much higher than expected and is probably due to cement modificationof the materials and well within the limits for basecourse and subbase materials.

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The particle size distribution of the base and subbase materials are generally within the requirements for thesematerials. The dust fractions are slightly high for crushed basecourse materials in test pits 1 and 2, but are ideallysuited for FBS recycling.

Laboratory CBR samples of the subgrade materials were compacted at field moisture and returned relatively lowvalues.

15.4.2 Estimated Field CBR

Scala tests were conducted on the subgrade layers encountered in each of the seven test pits. The Scala derivedCBR values ranged from CBR 2 to 8 immediately below the pavement structure and all values increased withdepth. 95thpercentile design CBR of 3 was adopted for the pavement design purposes.

15.5 ConstructabilityPavement reworking and widening will involve the following standard activities as described for each pavementtype.

15.5.1 Pavement Widening

- Subgrade preparation in accordance to TNZ F/1

- Widen existing pavement structure by benching into each layer in a stepwise manner

- Modify basecourse across the total width of widening and existing pavement

- Provide appropriate surfacing

15.5.2 Reworking of Existing Pavements

- Rework existing basecourse to a depth of 200 mm and modify with FBS or cement in accordance with TNZB/5

- Provide Grade 5 membrane seal and resurface as required in accordance with TNZ TM 6002 v1.

15.5.3 New Pavements

- Subgrade preparation in accordance to TNZ F/1(consider subgrade stabilisation in cuts)

- Construction of subgrade improvement layers

- Construct subbase in accordance with TNZ B/2

- Construct basecourse in accordance with TNZ B/5

- Construct asphalt and sealed surfaces in accordance with TNZ TM 6002 v1 and TNZ P/3 respectively.

15.5.4 Construction of Intersections

- Construct widening of intersections up to subbase level

- Remove basecourse from existing pavement

- Cement modify subbase across the total width of the intersection

- Construct new cement modified basecourse over total width of the intersection

- Provide appropriate surfacing

15.5.5 Construction of Roundabouts

- Subgrade preparation in accordance to TNZ F/1(consider subgrade stabilisation in cuts)

- Construction of subgrade improvement layers

- Construct cement stabilised subbase in accordance with TNZ B/4

- Construct structural asphalt basecourse in accordance with TNZ TM 6002 v1

- Construct SMA surfacing in accordance with TNZ TM 6002 v1

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15.5.6 Granular Pavements

- Construct granular pavements on subgrades prepared according to TNZ B/2

- Provide sealed surface in accordance with TNZ P/3

15.5.7 Constructability

It is proposed that the FBS and cement modified pavements be constructed as per the proposed pavementdesigns. The FBS option is proposed on the section east of SH1 to Hollyford Drive due to the high traffic loading.For the rest of the project cement modified base courses are proposed in order to curb early rut formation and toprovide a competent base layer for asphalt and chip seal surfaces. It is further recommended that the base andsubbase layers be cement modified on the intersections and that structural asphalt pavements be provided on thetwo roundabouts. For local roads, chip sealed granular structures are proposed.

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Utility Services16.0

16.1 GeneralThe project will impact on existing Services Authorities assets to varying degrees. The design has been producedto a conceptual level and identifies the existing services, street lighting and outlines consultation on key affectedassets. Further detailed investigations and design is required on all affected services during the detailed designstage. Where noted by the Services Authority, any future service or betterment provisions are included in theirresponse.

In developing the conceptual design additional consultation was undertaken with the Service Authorities to betterunderstand their requirements, priorities and likely effects of the proposed design on their assets. The followingService Authorities were consulted as they had services within the corridor.

- Vector – Power, Communication and gas

- Chorus/Telecom/Spark - Telecommunications

- Telstra Clear (Vodafone) - Telecommunications

- Transpower – Pylons (2)

- Watercare Services Limited (WSL) – Watermains, wastewater mains and stormwater mains

- Nova Energy - Gas

As part of the consultation process AECOM undertook the following procedure:

- Provided Service Providers with a set of drawings showing all existing services and a link to AT’s projectwebsite which provided them with further information.

- Provided a scope of service which included a request for a rough order of cost (ROC) estimate + / - 100%and indicative design, contingency percentages and likely cost increases from 2015 to 2022, and wherepossible to identify any betterment they may wish to include.

- Held at least one meeting with each affected Service Provider to present and discuss the project, its keydrivers, timeframe, preferred option, agree the level of information required, and betterment.

- Where possible obtained a letter of support covering the information they supplied for use in the preliminarydesign.

16.1.1 Design Standards

The primary design standards relating to utility services are listed below:

- Draft Auckland Transport code of Practise (ATCOP)

- Code of Practice for working in the Road, Auckland Council

- Utility Services standards, codes, supply and installation requirement for construction

- Electricity Act & Electrical (Safety) Regulations 2010

- AS / NZS 3000: Electrical Installations

- Local Authority Bylaws, Conditions and Standards

- Auckland Council District Plan (Manukau and Papakura sections)

- NZ Radio Interference Regulations and Interference Notices (Radio and Television)

- Vector Standards in relation to work in their network adjacent to AT’s network

- NZECP 34:2001 New Zealand Electrical Code of Practice for Electrical Safe Distances


The following design assumptions have been taken into consideration with the concept design and need to befully reviewed during the detailed design phase.

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- Each Service Authority has outlined their assumptions and any clarifications in their response. A summary ofthe commonly found items are as follows:

All estimates are provided at a set date.

Estimates are generally to a concept level with contingency and funding contingency supplied and byagreement with AECOM.

AT is responsible for undertaking the Civil works (trench excavation, duct laying and backfill)component using their main physical works contractor while the Service Authority will supply, lay andconnect their asset.

Any betterment has been noted.

Generally most services are preferred to be relocated to the new berm unless otherwise stated.

Most are in favour of using a common utility trench were possible.

16.2 Design Criteria16.2.1 Concept Design

Existing services drawings were prepared using the service provider provided services information with theproposed alignment superimposed upon them in the Preliminary Design Drawings. Using these drawings majorkey services that conflicted with the proposed features such as kerb lines, carriageway and structures wereidentified.

Utilities service trenches undertaken at these key locations determined cover, position and asset type and wereadded to the existing services drawings.

Site inspections along with discussions with the affected service Provider were undertaken to present findingsincluding indicative clearances, to discuss their requirements and agree any preferred and recommendedrelocation or protection treatments. These form the basis of the conceptual design and have been added to theservices drawings.

Also taken into consideration was the relative risk to service Providers services, the continuity of supply tocustomers, traffic management, costs, safety and construction methodology during the conceptual design.

While several key major affected services have been identified all services need to be investigated in muchgreater detail once the final alignment has been confirmed during the detailed design phase of the project toconfirm which can be protected or require relocation.

It is recommended that further detailed utility trenches and piloting at key points needs to be undertaken early onduring the detailed design phase to confirm more accurately the extent and effect on all services. This will thenassist the utility services providers with their design requirements.

The service provider as part of their scope has provided the following information in support of the conceptualdesign.

- Vector: Power, Communication and Gas – letter of support and cost estimate.

- Chorus: Telecommunications – letter of support and cost estimate.

- Telstra Clear (Vodafone): Telecommunications – letter of support, cost estimate and concept design.

- Transpower: high level response only.

- Watercare: Watermains, wastewater mains and stormwater mains – Meeting minutes. AECOM conceptdesign covering local services.

- Nova Energy: Gas – letter of support, cost estimate and concept design.

With regards to Watercare, local services in particular local sanitary sewers, watermains and protection formaintenance of large bulk watermains, a desk top assessment has been undertaken to quantify the likely extentof relocation and or protection required and allowance made in the cost estimate. This includes making allowancefor cast in-situ retaining walls with precast road loading strength roofs around the bulk watermains so as to enableaccess for maintenance. With regards to the stormwater lines this is covered in section 17, Drainage.

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16.2.2 Transpower Assets

Transpower has provided a high level response but were unable to supply a conceptual design and estimate.They require AT to enter in to a Detailed Solution Development Agreement (DSD) before proceeding any further.AT has advised that they will not be proceeding with the DSD during this stage and are looking to undertake itduring the detailed design phase of the project.

As the proposed design stands, the existing pylon (HYL-OTA-A_A0195) on Redoubt Road (CH1735m) identifiedwould be within the new carriageway and would require relocation. Initial indications from Transpower are that thisis possible with clearances likely to meet Transpower’s Crossing Policy clearance standards for the proposedalignment.

Murphys Road pylon (OTA_WKM_B0474) (CH 990m) is not affected due to the alignment being moved eastward.

The other two lines crossing Murphys Road, pylons OTA_WKM_A0493-0494 and OTA_WKM_C0472-0473, initialindications from Transpower are that clearances meet the require policy standards for the proposed alignment.

16.2.3 Future Utility Service Betterment requirements

Consultation undertaken with the service providers has indicated to date the following Service provider bettermentor upgrades.

Chorus: Redoubt Road two large and small manholes and Murphys Road, two new ducts

The following betterment works are proposed:

a) (Redoubt Rd at SH1 to start Mill Rd)

- Construction of two large manholes and four small manholes

b) Mill Rd intersection with Redoubt Rd to Alfriston

- No betterment works

c) Murphys Rd

- Installation of two ducts the entire length of the new Murphys Rd.

Any betterment included in agreements needs to be reviewed in conjunction with the respective Service providerand included in the detailed design phase.

16.2.4 Common Service Trenches

All services that require relocation works need to be relocated in accordance with the following approach.

- Urban areas: where possible install a common service trench in the back berm (in front of the boundary)and where additional area is available under the footpath (excluding areas for stormwater attenuation units)on either side of the carriageway.

- Other areas: the back berm and where additional area is available under the footpath on either side of thecarriageway.

The use of a common service trench is dependent on many factors such as availability due to existing services,carriageway position and level which need to be clearly identified once the alignment is finalised during thedetailed design stage. The service configuration and clearances within a common service trench needs to beidentified and determined for each construction stage during the detailed design phase. This includes serviceprovider liaison, temporary diversions / connections and acceptance by all affected service providers to ensurethat all minimum clearances and design requirements are able to be met.

16.2.5 Constructability

It is recommended that an advanced enabling service physical works contract be undertaken prior to the maincontract for each construction stage and include:

- the relocation / removal of existing services as required,

- temporary diversions / connections, and

- making allowance for excavation / disposal of soil / rock and backfilling.

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16.2.6 Risk

A risk register was prepared in accordance with the NZTA’s Risk Management Process Manual AC/MAN/1.

Potential utility services risks include:

- Determining how Transpower Pylon (HYL-OTA-A_A0195) on Redoubt Road can be relocated to a suitableposition clear of the carriageway; and

- Major utility services affected or damaged during construction.

All listed utility service risks need to be actively managed during the next project phase (detailed design).

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Drainage17.0


The following standards apply to stormwater drainage design and are to be used as design progresses:

- Peak Flow and Volume Estimation: ARC TP108 Guidelines for Stormwater Modelling in the AucklandRegion.

- Stormwater Management System Design: ARC TP10 Design Guideline Manual: Stormwater TreatmentDevices (2003) and relevant Catchment Management Plans.

- Collection and Conveyance: Austroads Guide to Road Design Part 5:Drainage Design.

- The Proposed Auckland Unitary Plan.


- Stormwater management allowance to be provided only for runoff from the road corridor, based upon designroad cross sections.

- Rainfall depths and stormwater runoff characteristics taken from ARC TP108 Guidelines for StormwaterModelling in the Auckland Region.

- Allowance for Climate Change of 2.1 degrees temperature increase and 8% rainfall increase per degree.

- Batter slopes of 3H:1V suitable for the formation of stormwater wetland areas.

17.2 Proposed Stormwater Drainage WorksThe following stormwater management systems have been investigated for the road corridor. The designphilosophy has taken into consideration that the majority of the urban section of the corridor is subject to aStormwater Management Area Flow 1 (SMAF 1) overlay (as part of the PAUP). The SMAF 1 overlay also coversland in Rural sections including the pocket of Mixed Housing Suburban zoned land that has three hundred metresof frontage to the southern side of Mill Road (approximately 480m south of the current intersection of Mill andRedoubt Roads) and the Future Urban Zoned land which extends from Ranfurly Road to the end of the corridornorth of Popes Road.

The Stormwater Management Area: Flow overlay seeks to protect and enhance Auckland's rivers, streams andaquatic biodiversity in urban areas. SMAF 1 areas are those catchments which discharge to sensitive or highvalue streams (Puhinui in this instance) that have relatively low levels of existing impervious area. In these SMAFareas, future development and redevelopment is still enabled, but it is subject to controls to reduce stormwaterrunoff to protect aquatic biodiversity and other values from further decline and enhance them where possible.

In addition, a High Use Stream Management Area Overlay applies to Totara Park and to land adjacent to thecurrent intersection of Redoubt and Mill Roads. The overlay extends for approximately 1.2 km in an easterlydirection from this intersection and includes Watercare’s reservoir facility.

This overlay seeks to manage streams which are under pressure from demands to take water, or use water for anumber of purposes. The high use of these streams creates conflicts between the amount of water beingabstracted, the amount of water needed to be left in the stream for other uses, such as assimilating the adverseeffects of discharges, and the amount of water required to maintain ecological values and base flows.

17.2.1 Areas of Existing Stormwater Infrastructure

The areas of road corridor with existing stormwater infrastructure (i.e. the section from SH1 to Totara Park) havebuildings located on each side of the existing road and numerous services located within the road reserve. Assuch there are constraints on space available for stormwater management systems.

Road widening works in this section will retain the existing vertical alignments and incorporate kerb and channelstormwater collection for the carriageway.

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The above constraints, including the limited capacity of the existing stormwater network in these areas, limits theoptions available for stormwater management. Soakage to ground has been excluded due to the unsuitablenature of the soils.

The proposed approach is to utilise the existing connections into the reticulated system. Stormwater treatment isproposed via either proprietary treatment devices, or rain gardens at specific locations where land is available.

If, during detailed design, and as a result of subsequent discussion with Council, peak flow reduction is required,then this will be provided either in underground detention, or in conjunction with the rain garden areas. Again, dueto the developed, urban nature of this area, there are limited areas available for above-ground storage.

17.2.2 Un-serviced Areas

Sections of the road corridor that do not currently have stormwater infrastructure will need new stormwatermanagement systems and suitable discharge locations.

Collection and conveyance along the road is to be achieved by both kerb and channel, and swales. While swalesare the preferred method of collection (via sheet flow), in some areas grades are too steep or topography doesnot permit their use and kerb/channel will be required. Swales will also be designed to achieve treatmentobjectives and TSS removal as per ARC TP10.

The proposed approach to managing stormwater quality and quantity in these areas is via a combination ofswales, wetlands and in some constrained locations, proprietary devices. Where possible, a treatment train will beprovided consisting of both vegetated swales and wetlands.

Vegetated swales: These will be designed in accordance with ARC's TP10 Design Guideline Manual forStormwater Treatment Devices (2003) and will generally provide water quality treatment only. In most cases theswales will discharge to wetlands where additional treatment will be provided, along with provision of extendeddetention volume (EDV) and peak flow attenuation. During detailed design, confirmation will be sought fromCouncil in terms of the appropriate ARI events for attenuation.

In some locations, it is proposed to utilise wider ‘wet’ swales with check dams to provide extended detention, andpeak flow attenuation (if required).

It is understood that vegetated swales will also provide the ‘retention’ requirements established in the PAUP.

Wetlands: Wetland areas will be designed in accordance with ARC's TP10 Design Guideline Manual forStormwater Treatment Devices (2003) and will provide water quality treatment, extended detention volume (EDV)and peak flow attenuation. During detailed design, confirmation will be sought from Council in terms of theappropriate ARI events for attenuation.

Erosion control is especially important in the headwater gullies of the Puhinui Stream. The wetlands will bedesigned with appropriate energy dissipation and erosion protection measures at outfalls to watercourses, which,in conjunction with the EDV, will help mitigate potential erosion downstream of the wetlands.

It is understood the wetlands will not provide the ‘retention’ requirements established in the PAUP.

Proprietary devices: While it is understood that these are not preferred by Auckland Council, in some cases theymay be the best practical option, due to topographical (or other) constraints. During detailed design, effort will bemade to avoid constructing these and to use alternative ‘end-of-pipe’ treatment such as a rain garden. Thesedevices will generally provide water quality treatment only. They will generally not provide extended detentionvolume (EDV), retention or peak flow attenuation.

17.3 Detailed Design ConsiderationsA summary of items for further consideration during the next phase of the design of the stormwater systems forthe road corridor are provided below.

- Check updated CMPs and Flood Hazard areas at the time of design to ensure the design takes account ofcurrent requirements/information.

- Consideration of current Climate Change recommendations at the time of design.

- Provide suitable water quality treatment and retention and detention where feasible.

- Provide for separation of clean and dirty waters where feasible.

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- Assess and design for slope stability for wetland areas.

- Limit permanent open water depth in wetlands (for safety).

- Flow velocities are to be adequately controlled for erosion/slope protection.

- Provide fish passage for any in-stream culvert works.

- Allow for collection or diversion of upstream flows where required.

- Consider the benefits of subsoil drainage.

- Accurately establish levels on existing pipe connections (especially where back-of-kerb attenuation systemsare to be used).

- Design all systems for safe access and maintenance.

17.4 Erosion and Sediment ControlErosion and sediment control measures will need to be adopted during construction and must be in accordancewith the requirements of Auckland Regional Council Technical Publication No 90 (ARC TP90). Theserequirements are aimed at reducing the amount of sediment leaving construction sites, as the construction periodis when most sediment runoff can occur.

Erosion and sediment control plans will need to be developed as part of detailed design and construction planningphases. Appropriate sediment control practices are likely to include (but not be limited to): sediment retentionponds, silt fences, clean water diversion channels, decanting earth bunds and flocculation.

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Bridges18.0


The design is based on various New Zealand codes and standards including Transit New Zealand (presently NewZealand Transport Agency) Bridge Manual (2013). Some of these codes are:

- NZS 3101:2006 Concrete structure standards

- AS/NZS 1160 (Different Parts) Loading standards

- NZS 3404.1:2009 Steel Structures Standards

- NZS 3404:1997 Steel Structures Standards

These codes and standards are to be followed for any changes and future design work.

Any departures from the New Zealand design codes and standards or use of any other international standardsneed to be discussed with Auckland Transport together with valid reasons for necessary approval.


The following assumptions were made in the development of the proposed bridge arrangements.

- Lateral load coming from the embankment is carried mainly by the proposed MSE wall.

- Any services through the MSE walls will need to be carefully arranged to avoid any adverse effect to thefunction of the wall and bridge.

- The proposed bridge arrangements will be refined during detailed design. Such refinements will have noeffect on the present footprints of the bridges.

- Design will be refined considering any hydraulic effect, if any, found in the hydraulic studies planned fordetailed design.

- The currently proposed 30m long 1.5m deep super-T beams can be easily transported and placed inposition using suitable equipment.

18.2 Proposed BridgesTwo bridging structures are required to traverse two gully systems within the rural section of the alignment atCH3875 and CH4847.

BridgeLocation Bridge Approx. Length (m)

Ch. 3875 – 4057 Puhinui Creek GullyBridge

170m overall length consisting of 6 No spans

Ch. 4847 – 4889 South Mill Road Bridge 28m single span

Table 17: Bridge Information

As far as possible locally available materials and beam sections will be used for these structures.

18.3 Design Considerations Preliminary design work has confirmed the footprints of the bridges. Sufficient work has been undertaken to:

- Prove the designs are viable;

- Support consenting requirements;

- Identify land requirements;

- Refine cost estimates;

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- Clearly convey the design intent to suppliers; and

- Identify design constraints which are fixed and cannot change.

Sufficient design flexibility has been retained to encourage designer and contractor innovation. It does not preventalternative solutions being proposed by others, subject to specific Principal’s Requirements being met wherenecessary. As such the information provided in this report is intended to support any future work.

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Walking, Cycling and Public Transport Provisions19.019.1.1 Design Standards

Walking, Cycling and Public Transport facilities will be designed in accordance with:

- Austroads Guide to Road Design Part 6A Pedestrian and Cyclist Paths

- Auckland Transport – ATCOP Chapter 11 Cycling Infrastructure Design

- Auckland Transport – ATCOP Public Transport.

Refer to Section 4.1 for a description of the cross sectional provisions along each section.

19.2 WalkingFootpaths and or shared facilities are to be provided on both sides of Redoubt Road from the Motorway junctionto the Murphys Road intersection and on the southern side of Redoubt Road and Mill Road for the entire length ofthe project. Footpaths are also to be provided on both sides of the side roads to tie into existing facilities wherethey exist. Pedestrian crossing facilities are to be included at traffic signals. Future mid-block crossings utilisingthe 3.0m flush median could be included during the detailed design phase.

A shared use facility is proposed from Hollyford Drive to Alfriston Road (L = 5,680m). A safe crossing facility is tobe included near the Totara Park entrance, and could include a pedestrian / cycling refuge island or a pedestriantraffic signal. This would help provide connectivity for recreational cyclists using the park. This is to be determinedduring the detailed design stage.

A footpath and a shared facility are proposed on Murphys Road between Redoubt Road and Flatbush SchoolRoad.

A shared pathway for walking and cycling could be provided off-road on the east side of Mill Road on theredundant sections of Redoubt – Mill Roads from Murphys Road to the southern extent of the project (south ofAlfriston Road) at a later date should demand require it. This pathway will make use of the redundant portions ofRedoubt / Mill Roads (with no new pathway formed).Should this eventuate, a tunnel or underpass will need to beprovided under the corridor located 120 metres east of Kinnard Lane.


19.3 CyclingRedoubt Road and Mill Road are part of the consolidated Auckland Cycle Network, which is still underdevelopment. Under this new network there are two types of cycle network included in Redoubt Road-Mill Roadcorridor – a Cycle Highway and a Cycle Connector.

Cycle facilities have been included on the entire length of the corridor including dedicated lanes with cycle specificmarkings, particularly at intersections as well as shared facilities. On road cycle lanes have been includedthroughout the project length, with the exception of Redoubt Road west bound between Hollyford and theMotorway and north bound on Hollyford Drive.

On Redoubt Road, A cycle lane, segregated from the west bound bus lane, has been included, separated fromthe 2.0m footpath by a 1.5m grassed berm.

All intersections will have appropriate cycle markings in accordance with the NZ Supplement to the AustroadsGuide to Traffic Engineering Practice Part 14: Bicycles. This is to include advanced stop boxes generally andhook turn boxes where this facility would be advantageous. Once Auckland Transport formally adopts the DRAFTATCOP Chapter 11 Cycling Infrastructure Design, the roundabouts and the cycleway design will be amended toreflect their preferred high speed roundabout treatment of shared off road paths through splitter islands (Fig. 27).


19.4 Public TransportFrequent Service Network bus facilities will be provided on Hollyford Drive and on Redoubt Road betweenHollyford Drive and the Motorway.

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The bus lane develops immediately north of the Hollyford Drive / Redoubt Road intersection in the southbounddirection, providing a bus only right turn lane at the signalised intersection. The intersection will have a dedicatedBus Only phase in the traffic signal phasing.

A dedicated bus lane has been included in the preliminary design westbound along Redoubt Road west of theHollyford Drive / Everglade Drive intersection through to the Motorway junction. The bus lane does not have aseparate Bus Only phase at the new Diorella traffic signals.

It is intended that bus stops remain in their current locations, with future additional stops considered on a case bycase basis. In addition, buses are expected to stop in the live lanes supported with appropriate line marking.Recessed bus bays are not favoured due to the delays imposed on the service due to the difficulty in merging intothe live travel lanes.

Scheme Design Stage Safety Audit20.020.1.1 Road Safety Audit (RSA)

An independent Scheme Design Road Safety Audit (RSA) was undertaken by Traffic Planning Consultants in lateMay, early June 2013 and September 2014. The Auditors were Jos Vroegop (TPC - lead) Keith Weale (MWH)and John Niell (Opus).The Safety Audit report, recommendations, Designer Response, Client Decisions and Actions Taken have beenincorporated ,where appropriate, into the preliminary design and will be finalised as a requirement of the detaileddesign stage.

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Intersections21.0


- Preliminary intersection design has been carried out in accordance with Austroads Guide to Road DesignPart 4A: Unsignalised and Signalised Intersections.

- Roundabout design during the detailed design phase is to be carried out in accordance with AustroadsGuide Road Design Part 4B: Roundabouts.

- Austroads Guide to Traffic Engineering Practice Part 7: Traffic Signals.


Traffic modelling and growth forecasts were used to determine the performance of each movement atintersections and to confirm acceptable intersection design along the corridor. Refer to the SAR (Appendix A) fordetailed specifics.

21.1.3 Signalised intersections

Signalised intersections need to be provided at the following intersections:

- Redoubt Road / Diorella Drive

- Redoubt Road / Hollyford Drive-Everglade Drive (upgrade of existing, including bus lane)

- Redoubt Road / Goodwood Drive-Santa Monica Place

- Redoubt Road / Murphys Road

21.1.4 Roundabouts

Dual lane roundabouts need to be provided at the following intersections:

- Mill Road / Ranfurly Road

- Mill Road / Alfriston Road

21.1.5 Priority intersections

A number of priority intersections have been included in the preliminary design. In addition, some accesses anddriveways are consolidated to reduce direct access to Redoubt Road and Mill Road.

The Redoubt Road / Kinnard lane and Redoubt Road / Mill Road priority intersections were initially assessed asone combined cross road priority intersection. The assessment resulted in significant delays and was consideredto be unsafe for the right turn traffic movement into Mill Road. This resulted in discarding the cross roadintersection alignment and designing it as two separate intersections.

21.1.6 Accessways

Private accessways are maintained to all existing properties. Some driveways require re-grading into the propertyto maintain access. Some accessways are combined to ensure a limited number of accesses on the maincorridor.

Some “no exit” lanes are generated due to severance by the Redoubt Road/Mill Road corridor. Accesses from theservices lanes are retained where practical. Refer to the Preliminary Design drawings for details of the specificaccesses.

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Departures from Standards22.0In each of the design disciplines or subsections in this report, the design standards used have been listed. Veryfew of these listed design standards have not been met. These primarily relate to the geometric design. Thedesign utilises the existing alignment throughout the urban section of the alignment and therefore some departurefrom the standards are unavoidable. Departures from the listed standards are summarised below (refer also toTable 5 of this report):

i) Hollyford Drive / Redoubt Road Intersection (south bound) – Due to the location of the existing retainingwall along the left hand shoulder, the Safe Intersection Stopping Distance of 114m for the most eastern lanecannot be met. A Safe Intersection Sight Distance (SISD) of 95m has been achieved, however SISD is notas critical at a signalised intersection compared to a stop or give-way type intersection as the traffic signalscan be mounted at height. We recommend the traffic signals at this intersection are placed on a mast arm tomitigate the lack of appropriate forward sight distance.

ii) Santa Monica Place / Redoubt Road Intersection (south bound) – Due to the proximity of RosewoodPlace to Redoubt Road a complete re-grade of Santa Monica cannot be achieved. The existing alignmentcannot be modified to achieve the required k-values for Approach Sight Distance (ASD) and SISD. Thevalues required and achieved are as follows:

a) ASD (required): k-value - 5.3 and ASD 34m.

b) ASD (achieved): k-value - 3.5 and ASD 28m.

c) SISD (required): k-value – 4.9 and SISD 67m.

d) ASD (achieved): k-value – 3.5 and SISD 45m.

iii) Redoubt Road / Alfriston Road Roundabout (north bound) – The design contains a vertical crest curveat CH6500 with a k-value of 51. As a result an ASD of 105m has been achieved compared to the required k-value of 59.5 and ASD of 114m. The design should be adjusted during the Detailed Design Stage and thecrest curve modified to achieve the required standard.

iv) No curve widening has been applied to curves with a radius of less than 300m. The detailed design shouldaccount for either:

a) Curve widening where the alignment uses radii of less than 300m (CH1078; CH1364 and CH1505) or,

b) Increase the curve radii from 200m to 300m with no curve widening required.

In relation to the above, curve widening and increased curve radii can be accommodated within the proposeddesignation footprint without affecting adjacent properties. The effect on the berm widths is similar for bothoptions.

Addendum 1

to

the Preliminary Design Report

AECOM New Zealand Limited8 Mahuhu CrescentAuckland 1010PO Box 4241Auckland 1140New Zealandwww.aecom.com

+64 9 967 9200 tel+64 9 967 9201 fax

\\nzakl1fp001\projects\603x\60317081\4. tech work area\4.3 engineering\geotechnical\ch 1700 retaining wall\mill road - murphys road proposed retaining wall assessment rev 12031015.docx

Richard

This memo describes the outcome of the preliminary assessment to evaluate the feasibility of the retaining wall(RW) option at the new Murphys Road –Redoubt Road intersection from CH1680 to CH1840.

Executive Summary

As is common at this initial route protection (NOR) stage of the project there has been limited ground investigationundertaken. Given this data limitation the approach of the project is to adopt the least favourable of that data i.e.the `worst case’. Hence stability analyses of a proposed 9m high bored pile anchored (anchor embedment limitedto road reserve) retaining wall (RW) at the criterial section at CH1765 was carried out for both long term (Static)and short term (static and seismic) conditions.

The stability analysis was carried out using finite element analysis (FEA) in Rocscience software Phase2 ver 8.0considering a homogenous soil profile comprised of firm SILT (DH10).

Due to lower inferred shear strength of firm silt, RW performance in terms of wall displacement and global stabilityis unsatisfactory under short term static and seismic conditions. For both cases wall displacements and globalstability factors are not in compliance with NZTA Bridge Manual performance criteria.

A ground improvement layer with thickness of around 3m in front of wall below the formation level is proposed tocontrol wall displacement and enhance global stability. The results of FEA show that both wall displacements andglobal stability factors will be in compliance with NZTA Bridge Manual performance criteria with the groundimprovement in place.

It is recommended that additional site investigations be undertaken to confirm ground and groundwater conditionsthrough the proposed road cutting zone for use at the detailed design stage It is possible that ground conditionless favourable than that assumed in this preliminary assessment may be encountered. This may lead toincreased ground improvement demand to enable construction works to remain outside of private properties.

Based on this preliminary assessment and limitations as noted, it is our opinion that retaining wall betweenCH1680 to CH1840 with and without anchors and ground improvement as required will meet NZTA BridgeManual performance criteria and can be constructed wholly within the NOR footprint.

Memorandum

To Richard Black - Auckland Transport Page 1 of 10

CC Craig Hind, Graham Blakeley, Sam Harris, Dawie Maritz

Subject Redoubt Road Mill Road Corridor - Murphys Road Proposed Retaining Wall Assessment

From Sajjad Anwar

File/Ref No. 60317081/1.4 Date 1-Mar-2015Rev: 1

\\nzakl1fp001\projects\603x\60317081\4. tech work area\4.3 engineering\geotechnical\ch 1700 retaining wall\mill road - murphys road proposed retaining wall assessment rev 12031015.docx2 of 10

1.0 Site and Ground Conditions

The existing site topography is hilly where the new Mill Road alignment needs to cut through (Figure 1). Therequired cut height varies along the proposed alignment from CH1680 to CH1840 but is up to 9m maximum atCH1765. Current site investigation comprised one AECOM drill hole DH10 and one Opus borehole BH02 and onehand auger hole (HA14).

Figure 1 Site Layout Plan

The boreholes are located at either end of the proposed cutting, meaning there is no borehole information of theactual cut material or foundation. The AECOM borehole is located near CH1680 whereas Opus borehole and HAare located around CH1840 i.e. at the proposed intersection with Redoubt Road.

From the drilling data, ground conditions are significantly different at either end of the proposed cutting. DH10encountered firm Silt over the full drilling depth to approximately 20m below ground level with inferred shearstrength of 25 to 50kPa (40kPa adopted for design).

BH02 and HA14 encountered stiff to very stiff Silt (Shear strength >100kPa) with rock (ECBF) level at 9.5m depth.

Based on this available investigation data the worst ground conditions are represented by DH10 (full depth firmSilt to 20m) located at the start of the RW at CH1680, whereas much better ground conditions are present at theend of the RW i.e. CH1840 (BH02 and HA).

It is therefore difficult to infer ground conditions at the cutting in between these investigation locations where wallheights are the maximum and will control the design.

To address the high degree of uncertainty in ground conditions we have assumed the poorer ground conditionsrepresented by drill hole DH10 for this preliminary assessment. Both static and seismic load case with effectiveand total stress parameters are analysed.

2.0 Proposed Retaining Wall (RW) Geometry

Review of the proposed RW height versus clearance distance back to the existing property boundaries wasundertaken to determine the least favourable combination for the preliminary assessment of RW design, with thecritical combination being a high wall (requiring anchors) but with limited clearance distance to the existingproperty boundaries in which to install anchors.

236

246

242


Based on that data in Table 1 the critical section lies at CH1765 at property 246 side, i.e. 9m retained height with11.3m clearance distance to the existing property boundary.

With these dimensions it is not viable to use a battered slope (a slope of 1H: 1V would be needed, which is notpossible in the poor ground). Other forms of walls may be possible, but for preliminary analysis and to testviability we have assumed a vertical bored pile concrete type retaining wall, which needs to be anchored toremain stable in the poor ground conditions represented by DH10. Because the clearance distance, relative towall height, is small and ground conditions are poor, conventional strand or bar type grouted anchors are notviable as they would need to be long to generate sufficient capacity and would extend into the neighbouringproperty. Instead steel screw anchors (steel shaft with large diameter steel end plate) are proposed as these cangenerate load resistance capacity in poor ground within a shorter installed length; these are adopted for theanalysis.

Table 1 Analyses of the Proposed RW Height vs Clearance Distance to The Existing Property Boundaries

3.0 Retaining Wall (RW) Analysis

3.1 Model Inputs

Finite Element Analysis (FEA) analyses of the selected section were carried out using 2D plane strain model inRocscience software Phase2 ver. 8.0. Retaining wall type considered in the analyses was reinforced concretebored pile wall supported by anchors.

For the wall height of 9m, 4 rows of anchors at 2m centre horizontal spacing are installed with a length of 11m andinstallation angle of 20 degrees to avoid private property encroachment. A wall embedment of 5m is consideredfor global stability. A uniform soil profile comprised of firm silt is considered for the analyses (DH10). The slope atthe back and the top of the RW is modelled as 3(H):1(V). The top back slope modelled as a uniform surchargerather than soil element is to minimise its impact on retaining wall analysis. A single excavation stage analysiswith no construction sequence is modelled. The FEA model is shown in Figure 2.


Figure 2 Phase 2 FEA Model – Static Case (to 246 Redoubt Road Boundary)

Both effective and total stress analyses are carried out to assess the stability of the RW. Effective stress analysesare carried out to assess RW stability under long term static loading conditions, whereas total stress analyses arecarried out to assess RW stability under short term static and seismic loading conditions. The design parametersused for effective and total stress analyses are summarized in Table 2.

Table 2 Design Parameters for FEA Analysis

Long Term Static Load Case Short Term Static & Seismic Load Case

- Unit Weight, = 17kN/m3

- Effective cohesion, c’ = 3kPa

- Effective friction resistance, ’ = 28 degrees

- Elastic Modulus, E = 20MPa

- Poisson’s ratio, = 0.3

- Stress Ratio, k = 0.5

- Unit Weight, = 17kN/m3

- Shear Strength, Su = 40kPa

-

- Elastic Modulus, E = 20MPa

- Poisson’s ratio, = 0.3

- Stress Ratio, k = 0.5

246

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oper

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unda

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Seismic loading in the analysis is considered by assuming stiff wall dynamic pressure distribution as shown inFigure 3.

Figure 3 Stiff Wall Seismic Pressure Distribution

A lateral uniform rectangular pressure ( x) of 23kPa [0.75 x 0.14 x 17 x 12.8m (height of wall with slope height)] isapplied behind the wall to simulate seismic loading (Figure 4) for the ultimate limit state case (ULS). The peakground acceleration coefficient (Co) of 0.14g is estimated using the NZTA Bridge Manual as summarized below.

Co = 1.33 x 0.1 x 1.3 x 0.8 = 0.138 ~ 0.14

1.33 (Class C)

0.1

1.3 (1/1,000)

0.8 (Class C)

Figure 4 Phase 2 FEA Model – Seismic Case

3.2 Analysis Results

Case A): Effective Stress Analysis – Long Term Static Load Case

Effective stress analysis results show the RW will undergo a maximum lateral deformation of 25mm to resist longterm static earth pressure. Based on analysis results the mode of deformation is translational and maximum

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induced anchor load is around 200kN/anchor. The global stability factor is more than 3.0. These RW stabilityanalysis results are acceptable. The output of the analyses is shown in Figure 5 and Figure 6.

Figure 5 Analysis Output of Effective Stress Analysis – Long Term Static Load Case

Figure 6 Global Stability - Long Term Static Load Case

Case B): Total Stress Analysis – Short Term Static Load Case

Total stress analysis results show the RW will undergo maximum lateral deformation of 190 to 300mm (maximumbeing at toe level) to resist short terms static earth pressure (e.g. during construction). Based on analysis resultsthe mode of deformation is rotational and maximum induced anchor load is around 480kN/anchor. The globalstability factor is less than 1. These results are not acceptable and indicate excessive wall deformation/failureduring construction. The output of the analyses is shown in Figure 7 and Figure 8.


The low shear strength of the ground causes failure at the base of the wall which has insufficient passive capacityat the toe, causing the wall toe to move more than the top. The low soil shear strength also means there isinsufficient anchor bond strength resulting in anchors unable to control greater wall lateral movement. This implieslonger anchor lengths are required, which will encroach into private property.

Figure 7 Analysis Output of Total Stress Analysis – Short Term Static Load Case

Figure 8 Global Stability - Short Term Static Load Case

Case C): Total Stress Analysis – Short Term Seismic Load Case

Total stress analysis results show the RW will undergo maximum lateral deformation of 300 to 500mm (maximumbeing at toe level) to resist short terms combined static and seismic earth pressure. Based on analysis results themode of deformation is rotational and maximum induced anchor load is around 640kN/anchor. The global stabilityfactor is less than 1. These results are not acceptable and indicate excessive wall displacement during seismicloading including ground displacement developing within the private property as a result of wall movement. Theoutput of the analyses is shown in Figure 9 and Figure 10.


The lower shear strength of the ground material has caused greater wall deformation at toe level by providinginsufficient passive capacity. The ground heaving has caused the wall toe to move outward as shown in Figure 9.

The lower shear strength of the ground has also made anchor bond strength ineffective and as a result anchorsare unable to hold excessive wall movement. This implies longer anchor lengths are required, which wouldencroach into the private property.

Figure 9 Analysis Output of Total Stress Analysis – Short Term Seismic Load Case

Figure 10 Global Stability - Short Term Seismic Load Case

Case D): Addition of Ground Improvement

The RW fails in cases B and C (i.e. excessive deformation during construction stage and under seismic loading).In order to comply with NZTA Bridge Manual Performance criteria (Table 6.4 maximum allowable displacementlimits) and to have adequate global stability factor for both short term static and seismic loads conditions, it isrecommended to enhance passive resistance of the RW. The greater passive resistance can be achieved byimproving the ground in front of the RW below the formation level before full RW excavation is complete.


In order to demonstrate the improvement in RW performance additional stability analyses for both short termstatic and seismic loads conditions are undertaken and considering a 3m thick improved ground layer in front ofthe RW below the formation level as shown in Figure 11.

Figure 11 Phase 2 FEA Model – With Improved Ground

The analyses results show significant reduction in RW displacement and improved global stability factor.

- The wall displacement for short term static load conditions is around 25mm with controlled toe movementcompare to unimproved ground conditions at toe. The induced anchor load is around 180kN/anchor. Theglobal stability factor is more than 2 (Figure 12). These results are acceptable.

- The wall displacement for short term seismic load conditions is around 30mm with controlled toe movementcompared to unimproved ground conditions at the toe. The induced anchor load is around 220kN/anchor.The global stability factor is more than 2 (Figure 13). These results are acceptable.

Figure 12 Short Term Static Load Case - With Improved Ground


Figure 13 Short Term Seismic Load Case - With Improved Ground

4.0 Conclusion

Based on the ground investigation data available at this stage of the project and adopting the least favourable ofthat data, stability analyses of a proposed 9m high bored pile anchored (anchor embedment limited to roadreserve) retaining wall (RW) at the criterial section at CH1765 was carried out for both long term (Static) and shortterm (static and seismic) conditions.

The stability analysis was carried out using finite element analysis (FEA) in Rocscience software Phase2 ver 8.0considering a homogenous soil profile comprised of firm SILT (DH10).

Due to lower inferred shear strength of firm silt, RW performance in terms of wall displacement and global stabilityis unsatisfactory under short term static and seismic conditions. For both cases wall displacements and globalstability factors are not in compliance with NZTA Bridge Manual performance criteria.

A ground improvement layer with thickness of around 3m in front of wall below the formation level is proposed tocontrol wall displacement and enhance global stability. The results of FEA show that both wall displacements andglobal stability factors will be in compliance with NZTA Bridge Manual performance criteria with the groundimprovement in place.

It is recommended that additional site investigations be undertaken to confirm ground and groundwater conditionsthrough the proposed road cutting zone for use at the detailed design stage. It is possible that ground conditionless favourable than that assumed in this preliminary assessment may be encountered. This may lead toincreased ground improvement demand to enable construction works to remain outside of private properties.

Based on this preliminary assessment and limitations as noted, it is our opinion that retaining wall with and withoutanchors and ground improvement as required will meet NZTA Bridge Manual performance criteria and can beconstructed wholly within the road reserve full length of the wall from CH180 to CH1840.

5.0 Limitation

The recommendations contained in this design memorandum are based on limited previous ground investigationdata. Inferences about ground conditions across the site are made using geological principles and engineeringjudgement, however it is possible that conditions may vary at the RW location during construction and therefore itis not possible to guarantee the continuity of ground conditions away from the location of the investigations.Further geotechnical investigations are recommended to address this uncertainty at the appropriate project stage.

This design memorandum has been prepared for the particular project and purpose described in this designmemorandum and no responsibility is accepted for the use of any part of this design memorandum in any othercontext or for any other purposes.

Detailed design of the RW is required to confirm actual construction requirements.

Documents

Preliminary Design Report - Auckland Council · 7.0 Typical Road Construction Details 27 ... The specific purpose of the Preliminary Design Report is to identify and document the