GEOTECHNICAL INVESTIGATION AND LANDSLIDE RISK … rosebery wwtp - appendix q1... · 5 LANDSLIDE HAZARD The site is not within an area mapped for landslide hazards by MRT. However,

Geotechnical Consultants

GEOTECHNICAL INVESTIGATION

AND LANDSLIDE RISK

ASSESSMENT

TasWater

Proposed Sewer and Water Works in Rosebery

GL13098Ab 16 September 2013

Geotechnical Consultants Geoton Pty Ltd ABN 69 315 541 003

PO Box 522 Prospect TAS 7250 Office 3 Level 1 Images Centre

2 Trotters Lane Prospect TAS T (03) 6343 1900 F (03) 6343 1906

www.geoton.com.au

16 September 2013

Reference: GL13098Ab TasWater

PO Box 314DC

Ulverstone TAS 7315

Attention: Mr David Krushka

Dear Sir

RE: Geotechnical Investigation and Landslide Risk Assessment

Proposed Sewer and Water Works in Rosebery

We have pleasure in submitting herein our report detailing the results of the geotechnical

investigation and landslide risk assessment conducted at the above site.

Should you require clarification of any aspect of this report, please contact Tony Barriera at

this office on - (03) 6343 1900.

For and on behalf of Geoton Pty Ltd

Tony Barriera

Director

Geotechnical Investigation and Landslide Risk Assessment

Geoton Pty Ltd 1 GL13098Ab 16 September 2013

CONTENTS

1 INTRODUCTION 3

2 SCOPE OF WORKS 3

2.1 Scoping the study 3

3 GEOLOGY 3

3.1 Sewer Pipeline 4

3.2 Waste Water Treatment Plant 4

3.3 Outfall Pipeline 4

3.4 Water Treatment Plant 4

3.5 Water Pipeline 4

4 FIELD INVESTIGATION 4

5 LANDSLIDE HAZARD 5

6 SITE DESCRIPTION 5

6.1 Sewer Pipeline 5

6.1.1 Stirling Valley to Propsting Street 5

6.1.2 Propsting Street to Murchison Highway 6

6.1.3 Murchison Highway to Hollywood Street 7

6.1.4 Hollywood Street to Park Road Pump Station 7

6.1.5 Park Road Pump Station to Rosebery Park 8

6.1.6 Rosebery Park to Shackle Street 9

6.1.7 Shackle Street to the Railway Line 10

6.1.8 Railway Line to the Proposed WWTP 10

6.1.9 Corner of Park Road and Primrose Road 11

6.2 Waste Water Treatment Plant 11

6.2.1 Trenches 12

6.2.2 WWTP Foundations 12



6.3 Outfall Pipeline 12

6.3.1 Laboratory Testing 13

6.3.2 Slope Stability 14

6.4 Water Treatment Plant 14

6.4.1 WTP Foundations 15

6.5 Water Pipeline 15

7 DISCUSSION AND RECOMMENDATIONS 16

7.1 Excavation 16

7.2 Pipeline Foundation 17

7.3 Groundwater 17

7.4 Embedment and Backfilling 17

7.5 Erosion 18

8 LIMITATIONS 18

Limitations of Report

Figures

Figure 1: Site Plan – Proposed Sewer Pipeline

Figure 2: Site Plan – Proposed Waste Water Treatment Plant and Outfall

Figure 3: Site Plan – Proposed Water Treatment Plant and Pipeline

Figure 4: Geology Plan

Appendices

Appendix A: Borehole and Test Pit Logs

Appendix B: Qualitative Terminology for Use in Assessing Risk to Property

Appendix C: Some Guidelines for Hillside Construction

Appendix D: Site Photographs



1 INTRODUCTION

In response to a request by Mr David Krushka of TasWater, Geoton Pty Ltd has carried out a

geotechnical investigation for the Proposed Sewer and Water Works in Rosebery.

We understand that the Proposed Sewer and Water Works in Rosebery involves the

construction of the following:

A 3km long sewer pipeline with a nominal founding depth of 1.2m;

A Waste Water Treatment Plant (WWTP);

An outfall pipeline from the WWTP to the Stitt River;

A Water Treatment Plant (WTP), two alternative locations; and

A short 100m long water pipeline in the Stirling Valley.

A site plan showing the preliminary sewer alignment was provided showing the pipe running

from Stirling Valley Pump Station through the township of Rosebery to the new Waste Water

Treatment Plant above the Stitt River.

2 SCOPE OF WORKS

The purpose of the investigation is to assess the ground conditions along the proposed

pipeline routes (sewer pipeline, outfall and water pipeline) and the treatment plant sites.

This geotechnical assessment will be used as supporting information for tenderers to estimate

the treatment plant and pipeline installation costs (inclusive of excavation costs) and the

suitability of the excavated material for bedding and backfill.

In addition, a landslide risk assessment will be conducted along the proposed location of the

outfall pipeline.

The output of this survey work will provide TasWater with maps and estimate the proportion

and classifications of ground condition profiles (rock, clay, unconsolidated sediments etc) and

associated penetrability of the ground along the proposed pipeline route.

2.1 Scoping the study

Geoton identified 47 nominal test locations along the proposed pipeline routes, in addition to 7

test locations at each of the proposed treatment plants. The test locations were based upon

observations during fieldwork that were considered to be areas that may involve a potential

change in subsurface conditions. A site plan showing the test locations is provided as Figures

1 to 3.

3 GEOLOGY

An extract of the geology map showing all relevant areas is attached as Figure 4.



3.1 Sewer Pipeline

The Mineral Resources Tasmania (MRT) Geology 1:25,000 Scale Digital Sheets, indicates

that the proposed sewer pipeline is situated on either Quaternary aged glacial deposits or a

number of varying Cambrian aged volcaniclastic units (sandstone, siltstone, conglomerate or

porphyry), with this being generally confirmed by the field data.

3.2 Waste Water Treatment Plant


that the proposed WWTP is situated on Quaternary aged glacial deposits, with this being

generally confirmed by the field data.

3.3 Outfall Pipeline


that the proposed outfall pipeline is situated on Quaternary aged glacial deposits on the upper

slopes with Cambrian aged volcaniclastics located on the lower slopes towards the Stitt River,

with this being generally confirmed by the field data.

3.4 Water Treatment Plant


that the proposed WTP is situated on Cambrian aged volcaniclastics, with this being generally

confirmed by the field data.

3.5 Water Pipeline


that the proposed water pipeline is situated on Cambrian aged coarse grained volcaniclastic

sandstone, with this being generally confirmed by the field data.

4 FIELD INVESTIGATION

To aid in the field investigation, Geoton staff walked and reviewed the proposed route to

determine access and appropriate locations for the investigation.

The field investigated was conducted between 14 August 2013 and 10 September 2013 and

involved the subsurface investigation of 61 locations along the pipeline routes and at the

treatment plant locations. The investigation was conducted by drilling of boreholes by hand

and Drilltech auger rig and the excavation of test pits by a 5 tonne excavator to depths of

between 0.3m and 3.5m.

Insitu vane shear strength tests and pocket penetrometer tests were conducted in clay layers

encountered in the investigation. The results of the field tests are shown on the borehole and

excavation logs. The borehole and excavation logs are included in Appendix A.

The test locations were identified by hand-held GPS equipment and their locations are shown

on the site plans provided as Figures 1 to 3.



5 LANDSLIDE HAZARD

The site is not within an area mapped for landslide hazards by MRT. However, the steep

slopes at the location of the proposed outfall pipeline display past landslide characteristics. A

landslide risk assessment has been conducted on the outfall area with the results and

recommendations provided in Section 6.3.2 below. The remainder of the site is considered to

have a LOW landslide hazard risk provided the construction follows good hill practices.

The qualitative likelihood, consequence and risk terms used in this report for risk to property

are given in Appendix B. The risk terms are defined by a matrix that brings together different

combinations of likelihood and consequence. Risk matrices help to communicate the results

of risk assessment, rank risks, set priorities and develop transparent approaches to decision

making. The notes attached to the tables and terms and the comments on response to risk in

Appendix B are intended to help explain the risk assessment and management process.

In our experience, regulating authorities allow developments to proceed with VERY LOW to

LOW risk.

An information sheet entitled “Some Guidelines for Hillside Construction” adapted from the

Journal of the Australian Geomechanics Society, volume 42, Number 1, dated March 2007, is

presented in Appendix C.

6 SITE DESCRIPTION

6.1 Sewer Pipeline

6.1.1 Stirling Valley to Propsting Street

Through this section the pipeline runs from the Stirling Valley Pump station uphill through

dense native forest to the start of Propsting Street. This section is characterised by shallow

topsoil overlying volcaniclastic rock. Numerous rocky outcrops were identified along this

section (see Plate 1). The existing sewer pipeline through this section is partially above

ground possibly due to the shallow rock.

Test locations 1 to 7 were drilled/excavated along the proposed pipeline route within this

section, with the subsurface conditions being relatively uniform.

Borehole BH1 located at the base of the hill near the existing pump station encountered

uncontrolled fill to a depth 0.4m, overlying clayey silt to auger refusal on inferred rock at a

depth of 1.5m.

Test Pits TP2 to TP6 through the majority of this section encountered shallow topsoil and silt

to depths of 0.2m to 0.25m, overlying extremely/highly weathered rock (volcaniclastic) to

excavator refusal on slightly weathered rock at depths of 0.3m to 1.1m (see Plates 2 & 3).

Test Pit TP7 at the start of Propsting Street encountered uncontrolled fill to a depth of 1.1m,

overlying extremely/highly weathered rock (volcaniclastic) to excavator refusal on slightly

weathered rock at a depth of 1.8m.



Groundwater seepage was encountered in BH1 at a depth of 1.0m. In addition, minor

seepage was encountered in the low lying areas at the interface between the silty soils and

the rock.

Excavation along this section will only be partially achievable with a conventional excavator of

about 20 tonne. Due to the presence of shallow rock it is considered that larger excavating

equipment and possible rock breaking will be required.

We consider that the excavated materials would generally be suitable for trench backfilling.

Larger cobbles and boulders encountered in trench excavations may not be suitable to be

used within the trench backfill and will need to be disposed off-site.

Suitable pipe bedding material will need to be sourced off-site.

We consider the slopes within this section for the current pipeline alignment possess a LOW

slope stability risk.

Additional test locations were unable to be conducted due to the dense forest, with any

additional locations for an alternative route first requiring substantial clearing.

6.1.2 Propsting Street to Murchison Highway

Through this section the proposed pipeline route runs through the township of Rosebery

across ground with only gentle slopes.


section, with the subsurface conditions encountered being somewhat variable.

Test location 8 to 11 typically encountered uncontrolled fill to depths of 0.25m to 1.8m,

overlying extremely/highly weathered rock (volcaniclastic) to auger/excavator refusal on

slightly weathered rock at depths of 0.7m to 2.2m.

Boreholes BH12 to BH16 typically encountered uncontrolled fill to depths of 0.6m to 3.0m,

overlying medium dense sand or silt to the investigated depths of 2.0m to 3.5m.

Groundwater seepage was encountered in BH12 to BH16 at depths of 1.4m to 2.5m. The

groundwater seepage in Borehole BH15 and BH16 was interpreted as being a perched water

table within the uncontrolled fill.

An outcrop of rock is encountered near test location 14.

It is considered that trench excavations through this section should be readily achievable for

most of the alignment with an excavator of about 20 tonne, however due to the presence of

shallow rock at test location TP9 (see Plate 4) and outcropping rock near test location 14,

larger excavating equipment and possible rock breaking may be required.

The foundation of all trenches should be within the natural ground to minimise settlement, and

as such the trenches will be required to be substantially deeper than the nominal founding

depth of 1.2m at test locations B11 (1.8m of fill), BH15 (1.5m of fill) and BH16 (3.0m of fill).

Alternatively, additional bedding will be required from the natural ground depth to the

proposed design alignment depth.

We consider that trench support will be required in areas of deep uncontrolled fill (BH11, BH15

and BH16). In addition, where trench excavations encounter groundwater, in the vicinity of



test locations BH15 and BH16, this will require either dewatering or consideration should be

given for a wet installation.


Variable fill material and larger cobbles/boulders encountered in trench excavations may not

be suitable to be used within the trench backfill and will need to be disposed off-site.




6.1.3 Murchison Highway to Hollywood Street

Through this section the proposed pipeline route runs down the walking track from the

Murchison Highway to Hollywood Street. The proposed alignment runs along a gully which is

characterised by deep fill (to create the walking track) and scattered rocky outcrops.

Test Pit TP17 was excavated in this section and encountered fill to a depth 0.3m, overlying

weakly cemented gravelly sand to a depth of 0.75m, underlain by highly weathered rock to

excavator refusal at a depth of 0.9m.

No groundwater seepage was encountered in the test pit.

Excavation along this section will only be partially achievable with a conventional excavator of

about 20 tonne. Due to the presence of shallow rock we consider that larger excavating

equipment and possible rock breaking will be required.

We consider that trenches within the natural ground should generally remain open over the

short term for pipe installation without the need for support.







6.1.4 Hollywood Street to Park Road Pump Station

Through this section the proposed pipeline route runs along the back of the houses along

Hollywood Street (above the Stitt River) and crosses Rosebery Creek. The test locations at

the back of Hollywood Street were conducted in the middle of the built up access track due to

the nearby existing services. Minor outcrops of rock and boulders were evident down towards

the proposed Rosebery Creek crossing.


section, with the subsurface conditions encountered being somewhat variable.

The boreholes/test pits typically encountered uncontrolled fill to depths of 0.8m to 2.0m,

overlying natural sandy silt or clayey sand to the investigated depths of 1.5m to 2.6m. Test Pit

TP22 was terminated at 1.5m due to excavator refusal on slightly weathered rock.



Groundwater seepage was encountered at the base of the fill in each borehole at depths of

0.7m to 1.8m.


most of the alignment with an excavator of about 20 tonne, however some areas of large

boulders and shallow rock (approaching Rosebery Creek) may require larger excavating

equipment or possible rock breaking.

The foundation of all trenches should be within the natural ground, and as such the trenches

will be required to be substantially deeper than the nominal founding depth of 1.2m at test

locations B18 (1.5m of fill) and BH21 (2.0m of fill). Alternatively, additional bedding will be

required from the natural ground depth to the proposed design alignment depth.

Where trench excavations encounter groundwater this will require either dewatering or

consideration should be given for a wet installation and possible shoring. In addition, trench

support will also be required in areas of deep uncontrolled fill. However, as the test locations

were conducted in the middle of the built up access track, the depth of fill is most likely

exaggerated and therefore if the proposed pipeline is set back into the bank the depth of fill

should be minimal with a corresponding decrease for the need for shoring.






slope stability risk, provided that the pipeline is founded within the natural ground.

6.1.5 Park Road Pump Station to Rosebery Park

Through this section the proposed pipeline route runs along Park Road crossing the Stitt River

and continues around to the back of Rosebery Park.


section, with the subsurface conditions encountered being variable.

Test locations 23 and 24 at the Stitt River Crossing encountered fill or topsoil to a depth of

0.25m, overlying medium dense or stiff soils to the investigated depths of 1.8m and 2.15m.

BH24 was terminated at 2.15m due to auger refusal on inferred rock.

Test locations 25 to 28 encountered uncontrolled fill to depths of 0.2m to 1.6m, overlying

varying units of silt, sand and weathered rock to the investigated depths of 0.9m to 2.2m.

BH26 was terminated at a depth of 0.9m due to auger refusal on inferred rock.

Groundwater seepage was encountered at the Stitt River crossing at depths of 1.5m and

1.75m. In addition, groundwater seepage was encountered towards the base of the fill at test

location BH25 (1.0m) and BH27 (1.5m).



boulders and shallow rock (BH26) may require larger excavating equipment or possible rock

breaking.



The foundation of all trenches should be within the natural ground, and as such the trenches

will be required to be substantially deeper than the nominal founding depth of 1.2m at test

locations B25 (1.5m of fill) and BH27 (1.7m of fill).

We consider that trench support will be required in areas of deep uncontrolled fill (BH25 and

BH27). In addition, where trench excavations encounter groundwater, in the vicinity of test

locations BH25 and BH27, excavations below the water level may collapse requiring

temporary trench support. In addition, excavations for the Stitt River crossing which encounter

water seepage will require either dewatering or consideration should be given for a wet

installation with trench support.





6.1.6 Rosebery Park to Shackle Street

Through this section the proposed pipeline route runs up the walking track from Rosebery

Park to Shackle Street.

A test pit/borehole investigation was not conducted in this area as the location of the existing

water and sewage pipe was unable to be determined. However the existing walking track is

cut down into the natural ground with the cut batter logged combined with shallow hand auger

holes.

The logs of the cut batter (test location 29) encountered sandy silt topsoil to a depth of 0.15m,

overlying clayey silt (with some cobbles and boulders) to a depth of 1.0m, underlain cobbles

and boulders in a clayey silt matrix, becoming weakly cemented at the base of the cutting at a

depth of 1.4m. The soil profile is interpreted as being glacial derived with this being confirmed

by the geology map.

No groundwater seepage was encountered over the investigated depth.



boulders and highly cemented soils may require larger excavating equipment or possible rock

breaking.

We consider that trenches should generally remain open over the short term for pipe

installation without the need for support.






slope stability risk, provided the alignment follows best practices, with the pipeline being

orientated up and down slope rather than across slope.



6.1.7 Shackle Street to the Railway Line

Through this section the proposed pipeline route runs from Shackle Street to the railway line.

Test locations 30 and 31 were excavated along the proposed pipeline route within this section,

with the subsurface conditions encountered being somewhat variable.

Test locations 30 and 31 encountered topsoil or uncontrolled fill to depths of 0.15m and 0.4m,

overlying sandy silt to depths of 0.6m and 0.9m, overlying clayey gravel to depths of 0.9m and

1.7m, underlain by highly weathered rock (volcaniclastic) to excavator refusal at depths of

1.1m and 1.9m.

No significant groundwater seepage was encountered over the investigated depths.



boulders and shallow rock (TP30) may require larger excavating equipment or possible rock

breaking.









6.1.8 Railway Line to the Proposed WWTP

Through this section the proposed pipeline route runs along the railway line, behind the house

along Chester Street and continues to the proposed WWTP.

Test locations 32 to 38 were excavated along the proposed pipeline route within this section,


The test locations all encountered glacial derived soils that were typically weakly cemented.

The test locations encountered topsoil or fill to depths of 0.15m to 0.4m, typically overlying

sandy silt or silty sand to depths of 0.25m to 1.5m, underlain by varying weakly cemented

units of sand and gravel to the investigated depths of 1.1m to 2.1m. Test location TP35 was

terminated at a depth of 1.1m due to excavator refusal on slightly weathered rock.

Groundwater seepage was encountered in TP36 at a depth of 0.3m. The test location was in

a small drainage depression. The remainder of the test locations did not encounter any

groundwater seepage over the investigated depths.



boulders, cemented soils and shallow rock (TP36) may require larger excavating equipment or

possible rock breaking.



We consider that trenches for the majority of this section should generally remain open over

the short term for pipe installation without the need for support. Where trench excavations

encounter groundwater, in the vicinity of test location TP36, excavations below the water level

may collapse requiring temporary trench support.







6.1.9 Corner of Park Road and Primrose Road

A small section of pipe is to be installed at the corner of Park Road and Primrose Road. The

area has been modified significantly with the placement of fill. In addition, insitu rock is seen

in nearby road cuttings.

Test location 34 was excavated along the proposed pipeline route within this section.

Test location 34 encountered roadbase fill to a depth of 0.3m, overlying landfill material to a

depth of 0.9m (see Plate 5), underlain by natural clayey sand to the investigated depth of

2.0m.

No groundwater seepage was encountered in the test pit.


most of the alignment with an excavator of about 20 tonne, however some areas of shallow

rock may be encountered (based on the site observations) and may require larger excavating

equipment or possible rock breaking.

We consider that trench support will be required in areas of deep uncontrolled fill.

We consider that the excavated natural material would generally be suitable for trench

backfilling. Landfill waste encountered in trench excavations will not be suitable to be used

within the trench backfill and will need to be disposed off-site.




6.2 Waste Water Treatment Plant

The proposed WWTP is located on the western side of the existing access road off Chester

Avenue. The site is generally covered with dense native forest and is relatively level with only

gentle undulation and minor drainage depressions.

The geology maps show the site of the proposed WWTP is located on Quaternary aged

glacial deposits.



Test locations 44 to 50 were excavated at the proposed site of the WWTP, with the

subsurface conditions encountered being somewhat variable.

The test pits typically encountered topsoil to depths of 0.1m to 0.2m, overlying sandy silt or

silty gravel to depths of 0.25m to 1.0m, underlain by varying weakly cemented units of sand,

gravel, silt and cobbles/boulders (see Plate 6) to the investigated depths of 1.0m to 2.0m.

Test locations 48, 49 and 50 were terminated at depths of 1.0m to 1.2m due to excavator

refusal on strongly cemented gravel and cobbles.

Minor groundwater seepage was encountered above the cemented soils (perched water table)

in test locations 44, 47 and 50.

6.2.1 Trenches



boulders and strongly cemented soils (Test locations 48, 49 and 50) may require larger

excavating equipment or possible rock breaking.




backfilling. Larger cobbles and boulders encountered in trench excavations may not be

suitable to be used within the trench backfill and will need to be disposed off-site.


We consider the slopes for the proposed WWTP possess a LOW slope stability risk.

6.2.2 WWTP Foundations

Insofar as it may be applicable, after allowing due consideration of the site geology, drainage

and soil conditions, the site has been classified as follows:

CLASS A (AS 2870)

This Classification is applicable only for ground conditions encountered at the time of this

investigation. If cut or fill earthworks are carried out, then the Site Classification will need to

be re-assessed, and possibly changed.

Insofar as it may be applicable, particular attention should be paid to the design of footings as

required by AS 2870 – 2011.

Conditions at this site dictate that the founding medium for all footings should extend through

the loose topsoil and sandy silt soils onto the weakly cemented soils or better.

Pad or bored pier footings founded within the weakly cemented soils at depths below 0.3m to

1.0m may be proportioned to an allowable bearing pressure of 250kPa.

6.3 Outfall Pipeline

The outfall pipeline runs from the proposed WWTP down a steep hillslope and discharges into

the Stitt River. The hill slope is densely vegetated with native forest and a track has been



cleared along the proposed alignment (see Plates 7 & 8). An Engineering Geologist walked

along the proposed alignment on 10 September 2013, in fine conditions. A site plan,

annotated with site observations is presented in Figure 2.

The upper slopes of the proposed outfall pipe alignment are situated on Quaternary aged

glacial deposits, with the lower slopes towards the Stitt River on Cambrian aged

volcaniclastics.

The hill slope typically has slope angles between 25 O and 38O and is undulating in the steeper

sections with evidence of several shallow landslide features. In addition, the proposed

alignment crosses two minor drainage depressions that show evidence of land instability with

shallow landslide features (see Figure 2).

The proposed alignment does not follow best practices in regards to land stability with the

alignment running across slope in some sections. However, the alignment chosen utilises the

gentler and more stable slopes than the adjacent surrounding area. The alignment chosen is

considered to be acceptable provided the recommendations below are adhered to.

Test locations 39 to 42 were drilled by hand auger along the proposed outfall pipeline route,


The test locations on the upper slopes (BH39 and BH42) encountered topsoil and sand to

depths of 0.2m and 0.3m, overlying sandy silt to auger refusal on inferred cemented soils at

depths of 0.6m and 1.1m. The test locations on the lower slopes (BH40 and BH41)

encountered topsoil to a depth of 0.2m, overlying clayey silt to depths of 0.5m and 0.6m,

underlain by gravelly clayey silt to auger refusal on inferred weathered rock at depths of 0.7m

and 0.75m.

No groundwater seepage was encountered over the investigated depths. However,

groundwater seepage is expected in the drainage depressions along the proposed alignment.

Subsoil drains will be required through the drainage depressions to discharge water

downslope of the pipeline. Also concrete encasement of the pipeline may be considered tp

prevent exposure of the pipe through erosion of the drainage depression.


most of the alignment with an excavator of about 20 tonne, however some areas of shallow

rock and strongly cemented soils may require larger excavating equipment or possible rock

breaking.




backfilling.


6.3.1 Laboratory Testing

The table below presents a summary of the test results.



Summary of Laboratory Test Results

Sample Liquid Limit (%)

Plastic Limit (%)

Plasticity Index (%)

Class

BH40 – 0.3 to 0.5m 41% 33% 8% ML (Clayey Silt)

BH41 – 0.3 to 0.5m 39% 31% 8% ML (Clayey Silt)

BH42 – 0.5 to 0.7m Not Obtainable

Not Obtainable

Non Plastic ML (Sandy Silt)

An assessment of the plasticity characteristics of the materials encountered indicates that the

clayey silt soils at this site possess a low/moderate shrink/swell potential.

Published correlations between Plastic Index and angle of internal friction indicated that the

laboratory tested clayey silt soils would have a peak strength angle of internal friction values of

about 32O to 37O and residual strength value of about 27O.

6.3.2 Slope Stability

Large Scale Failure:

In light of the findings of this investigation (shallow rock and cemented soils) and

topographical features of the site the likelihood of large scale failures occurring with its

head scarp being within the outfall area is considered RARE, with the potential

consequences assessed to be MAJOR.

Therefore the corresponding qualitative risk for a large scale failure occurring on the site is

assessed as LOW.

Small to Medium Scale Failure:

In light of the findings of this investigation (shallow rock and cemented soils, undulating

ground, existing shallow landslides on steep slopes and within drainage depressions) and

topographical features of the site the likelihood of small to medium scale failures occurring

on the site affecting the proposed outfall is considered POSSIBLE, with the potential

consequences assessed to be MEDIUM.

Therefore the corresponding qualitative risks for small to medium scale failures occurring

on the site are assessed as MODERATE.

MODERATE risk may be tolerated in certain circumstances but requires the planning and

implementation of treatment options to reduce the risk to LOW. In this case the founding

of outfall pipeline within the weathered rock or cemented soils and providing

subsoil drains within the drainage depressions will reduce the consequences of

landslide failures effecting the pipeline to INSIGNIFICANT and therefore the

landslide risk will reduce to LOW.

6.4 Water Treatment Plant

The proposed WTP is located off the south eastern end of Propsting Street above the Stirling

Valley. Two separate sites were assessed for the location of the proposed WTP. A site plan

showing the two locations is provided as Figure 3.



The first site assessed (“Site 1”) is a small hill located on the north eastern side at the end of

Propsting Street. The hill is sparsely vegetated and displays numerous rocky outcrops.

The second site assessed (“Site 2”) is located along a ridge directly south of Site 1. Site 2 is

only gently sloping and is predominantly densely vegetated.

The geology maps show that both sites are located on Cambrian aged volcaniclastics.

Test locations 51 to 54 were excavated at Site 1 and test locations 55 to 57 were excavated at

Site 2, with the subsurface conditions encountered being relatively uniform.

At Site 1 the test pits on the hill TP52 to TP54 encountered topsoil/sandy silt to depths of 0.1m

to 0.5m, overlying highly weathered rock to excavator refusal at depths of 0.25m to 0.9m (see

Plates 9 & 10). Test location TP51 located on the flat area at the base of the hill encountered

fill to a depth of 1.3m, overlying highly weathered rock to excavator refusal at a depth of 1.6m.

At Site 2 the test pits encountered topsoil or fill to depths of 0.1m to 0.4m, overlying

extremely/highly weathered rock to excavator refusal at depths of 0.5m to 1.1m (see Plate 11).

Groundwater seepage was encountered within the fill of test location 51. The remainder of

the test locations did not encounter any groundwater seepage over the investigated depths.

We consider the slopes for the proposed WTP possess a LOW slope stability risk.

6.4.1 WTP Foundations

Insofar as it may be applicable, after allowing due consideration of the site geology, drainage

and soil conditions, both Site 1 and Site 2 have been classified as follows:

CLASS A (AS 2870)

This Classification is applicable only for ground conditions encountered at the time of this

investigation. If cut or fill earthworks are carried out, then the Site Classification will need to

be re-assessed, and possibly changed.

Insofar as it may be applicable, particular attention should be paid to the design of footings as

required by AS 2870 – 2011.

Conditions at this site dictate that the founding medium at both sites for all footings should

extend through the loose topsoil and sandy silt soils onto the extremely/highly weathered rock

or better.

Pad or bored pier footings founded to depths below auger/excavator refusal of 0.25m to 1.1m

may be proportioned to an allowable bearing pressure of 500kPa.

6.5 Water Pipeline

The proposed water pipeline is located in the Stirling Valley and is approximately 100m long

running along the Stitt River between the two existing pump stations. Anecdotal evidence

suggest that the area along the Stitt River has been substantially modified by the placement of

fill to create the access road and working area (see Figure 3).



The field investigation was required to be conducted using hand tools as MMG were unable to

locate their existing water pipe. Test locations 58 to 61 were drilled by hand auger, with the

subsurface conditions encountered being somewhat variable.

Boreholes BH58, BH59 and BH61 encountered topsoil or fill to depths of 0.15m to 0.5m,

overlying clayey silt or sandy silt to auger refusal on inferred rock at depths of 0.9m to 1.8m.

Borehole BH60 was unable to penetrate the fill and was terminated within the fill at a depth of

0.5m.

Groundwater seepage was encountered at depths of 0.75m to 1.5m within the Boreholes

BH58, BH59 and BH61.


most of the alignment with an excavator of about 20 tonne.


installation without the need for support. Where trench excavations encounter groundwater it

is considered that excavations below the water level will collapse requiring temporary trench

support. Excavations which encounter water seepage will require either dewatering or

consideration should be given for a wet installation with trench support.





7 DISCUSSION AND RECOMMENDATIONS

7.1 Excavation

Excavation along the section from the Stirling Valley to Propsting Street will only be partially

achievable with a conventional excavator of about 20 tonne. Due to the presence of shallow

rock larger excavating equipment and possible rock breaking will be required through this

section.

The remainder of the proposed pipeline alignment (Propsting Street to the WWTP) should be

readily achievable, to the nominal founding depth of 1.2m for the pipeline, with a conventional

excavator of about 20 tonne. Of the test locations investigated from Propsting Street to the

WWTP only 5 locations as stated in the sections of the report above encountered excavator

refusal at depths less than 1.2m.

It is recommended that at the watercourse crossings and in areas where deep uncontrolled fill

and potentially collapsible soils are encountered as stated in the sections of the report above

that shoring be provided for the trench excavation.

All trenches should be maintained in a stable condition to prevent movement or collapse and

the length of trench open at any one time should be minimised.

The minimum width of the trench shall be sufficient for the placement and compaction of

embedment materials, particularly below the pipe spring line (width) and in the haunch support



area, to ensure complete filling with material to the specified relative compaction and the

making and inspection of joints.

7.2 Pipeline Foundation

The foundation of all trenches should be within the natural ground. The test pits and

boreholes generally revealed suitable founding conditions along the route. Due to the

presence of deep uncontrolled fill in numerous scattered locations the foundation of the

trenches in these locations will be required to be deeper than the nominal founding depth of

1.2m and possible backfilling with bedding material to the design alignment depth.

For stability reasons the pipeline foundation for the outfall is required to be within the

cemented soils or weathered rock.

Soft soils and/or uncontrolled fill may be encountered in areas not covered by the investigation

in particular in low lying areas where water may pond or within water way crossings. In areas

where soft or loose soils are encountered, some improvement works such as providing a

geotextile and/or coarse rock fill should be considered to bridge across these areas of soft or

loose soils.

It is recommended that the base of trench excavations be inspected to ensure that suitable

founding conditions exist, in particular at locations where the pipeline changes direction and

thrust block structures are proposed.

7.3 Groundwater

Groundwater was encountered in some of the boreholes and test pits over their investigated

depths.

Where groundwater is encountered in trench excavations, de-watering of the trench will be

required during construction, to maintain the stability of the surrounding soil and to provide

suitable working conditions. The trench should be kept free of water until the pipeline is

installed and embedded with fill materials placed and compacted to the required height to

prevent flotation.

Alternatively, wet installation and the use of shoring may need to be considered in some

areas.

The use of heavier granular backfill may also be considered in areas where a high water table

is likely to occur along the route.

7.4 Embedment and Backfilling

Compaction of the insitu clay soils around the pipes may be problematic.

AS/NZS2566.2 recommends that material in the embedment zone should ideally consist of:

Selected cohesionless soils;

Controlled low strength materials (CL/SM); and

Stabilised soils.



It is considered that the subsurface conditions encountered in the boreholes and test pits

would be suitable for use as general backfill. Compaction of backfill will be difficult where it is

saturated or placed in trenches that have standing water. It is recommended that a free

draining granular fill be used within water filled trenches.

In soft and water logged areas, alternative encasement methods around the pipeline may be

considered through the areas of soft ground, such as placing gravel around the pipeline

wrapped in a geofabric.

7.5 Erosion

No areas of deep gully erosion were observed along the proposed pipeline route. Where the

outlet pipe passes through drainage depressions concrete encasement should be considered

to prevent possible erosion of these drainage depressions exposing the pipe. We consider

that the potential for soil erosion along the pipeline route would be minimal, provided that best

pipeline practices and the recommendations below are followed:

The upper layers of the trenches should be compacted to at least 98% standard

compaction;

The backfill should be mounded along the trench to allow for settlement and prevent

channels forming that may concentrate surface water flows causing erosion;

Where long and steep slope runs of the pipeline occur, shallow cut off drains should be

installed at about 20m spacings; and

The area should be vegetated as soon as possible or alternatively mulch should be

provided until vegetation becomes established.

8 LIMITATIONS

Although the borehole and test pit data provides an indication of subsurface conditions along

the proposed pipeline route, variations in soil conditions may occur in areas of the site not

specifically covered by the field investigation. To the best of our knowledge, they represent a

reasonable interpretation of the general condition along the proposed route. Under no

circumstances, however, can it be considered that these findings represent the actual state of

the proposed route at all points. The base of all trench excavations should therefore be

inspected to ensure that the founding medium meets the requirements of the project.

Geoton Pty Ltd ABN 69 315 541 003

Geotechnical Consultants - Limitations of report

These notes have been prepared to assist in the interpretation and understanding of the limitations of this report.

Project specific criteria

The report has been developed on the basis of unique project specific requirements as understood by Geoton and applies only to the site investigated. Project criteria are typically identified in the Client brief and the associated proposal prepared by Geoton and may include risk factors arising from limitations on scope imposed by the Client. The report should not be used without further consultation if significant changes to the project occur. No responsibility for problems that might occur due to changed factors will be accepted without consultation.

Subsurface variations with time

Because a report is based on conditions which existed at the time of subsurface exploration, decisions should not be based on a report whose adequacy may have been affected by time. For example, water levels can vary with time, fill may be placed on a site and pollutants may migrate with time. In the event of significant delays in the commencement of a project, further advice should be sought.

Interpretation of factual data

Site assessment identifies actual subsurface conditions only at those points where samples are taken and at the time they are taken. All available data is interpreted by professionals to provide an opinion about overall site conditions, their likely impact on the proposed development and recommended actions. Actual conditions may differ from those inferred to exist, as it is virtually impossible to provide a definitive subsurface profile which includes all the possible variabilities inherent in soil and rock masses.

Report Recommendations

The report is based on the assumption that the site conditions as revealed through selective point sampling are indicative of actual conditions throughout an area. This assumption cannot be substantiated until earthworks and/or foundation construction is almost complete and therefore the report recommendations can only be regarded as preliminary. Where variations in conditions are encountered, further advice should be sought.

Specific purposes

This report should not be applied to any project other than that originally specified at the time the report was issued.

Interpretation by others

Geoton will not be responsible for interpretations of site data or the report findings by others involved in the design and construction process. Where any confusion exists, clarification should be sought from Geoton.

Report integrity

The report as a whole presents the findings of the site assessment and the report should not be copied in part or altered in any way.

Geoenvironmental issues

This report does not cover issues of site contamination unless specifically required to do so by the client. In the absence of such a request, Geoton take no responsibility for such issues.

Figures

approved

date

scale title:

project no:

project:

client:

figure no.originalsize

drawn

revA3

MS11/09/13

As Shown SITE PLAN - PROPOSED SEWER PIPELINE

Figure 1

Approximate Scale (m)

3002001000 400

BH 1Approximate borehole location

DCP 2

DCP 3

DCP 5

BH 7

BH 9

BH 8

TB

TASWATER

PROPOSED NEW SEWER AND WATER WORKSROSEBERY

GL13098A

Legend

Proposed Sewer - Rising Main

Approximate test pit locationTP 1

!RS208

RS207

RS203

Park Road SPS

Stirling Valley SPS

Proposed Sewer - Gravity Main

TP 2

TP 3

TP 5

TP 6

TP 4

TP 7

TP 57

TP 55

TP 56

TP 52

TP 51TP 53

TP 54

BH 1

BH 8

TP 9

BH 10

BH 11

BH 12

BH 13

BH 14

BH 15

BH 16

TP 17

BH 18BH 19

BH 20

BH 21

TP 22

TP 23

BH 24

BH 25

BH 26

BH 27

BH 28

C 29 (cutting)

BH 30

BH 31

C 32 (cutting)

C 33 (cutting)TP 34

TP 35

TP 36

TP 37

TP 38

BH 39

BH 40

BH 41

TP 43

SEE FIGURE 2(Wastewater TreatmentPlant and Outfall)

SEE FIGURE 3(Water Treatment Plant)

C 1Approximate cutting exposure

BH 42

approved

date

rev

scale title:

project no:

project:

client:


drawn

A4

Legend

2

MS11/09/13

SITE PLAN - PROPOSED WASTEWATER TREATMENT PLANT AND OUTFALL

TB

TASWATER


GL13098A

As Shown

N


Approximate test pit location

TP 46

TP 49

TP 45

TP 44

TP 48

TP 47

TP 50

TP 1

PROPOSED WASTEWATERTREATMENT PLANT

BA

RK

ER

CR

EE

K

STITT RIVER

Proposed Outfall Pipeline

AC

CE

SS

RO

AD

BH 41

BH 40

BH 39

BH 42

Approximate slopeo12

Drainage channel

Break of slope - well defined

Approximate Scale (m)100500

o

38

SMALL SHALLOWLANDSLIDE WITHINMINOR DRAINAGEDEPRESSION

PIPELINE FALLALONG BARKER

OCREEK APPROX 5-10

o

30-35

MINOR DRAINAGEDEPRESSION

o

25-30

o

25

o

18

PIPELINE FALLAROUND BEND

OAPPROX 15-19

PIPELINE FALLNEAR LEVEL - ALONG CONTOURLINE

approved

date

rev

scale title:

project no:

project:

client:


drawn

A4

Legend

3

MS11/09/13

SITE PLAN - PROPOSED WATER TREATMENT PLANT AND PIPELINE

TB

TASWATER


GL13098A

As Shown


Approximate test pit locationTP 1

Proposed Sewer Pipeline

Approximate Scale (m)2001000

TP 2

TP 3

TP 4

TP 5

TP 6

TP 7

TP 57

TP 56

TP 55

TP 54

TP 53

TP 52

TP 51

BH 1

SITE 1 - PROPOSED WATERTREATMENT PLANT

SITE 2 - PROPOSED WATERTREATMENT PLANT

N

SEWER PUMP STATION

WATER PUMP STATION

FILTER PLANT

BH 58 BH 59

BH 61

BH 60

Approximate area of fill built upalong the river

approved

date

scale title:

project no:

project:

client:


drawn

revA3

MS11/09/13

As Shown GEOLOGY PLAN

Figure 4

Approximate Scale (m)

3002001000 400Geology Legend

N

TB

TASWATER

PROPOSED NEW SEWER PIPEROSEBERY

GL13098A

Cambrian felsic volcaniclastic and pyroclastic rocks, usually feldspar phyric (Cdvt)

Cambrian units of coarse-grained crystal rich volcaniclastic sandstone (Cdsvx)

Quaternary glacial and glaciogene deposits (Qpgg)

Cambrian volcanicalstic sandstone, with minorsiltstone and conglomerate (Cdtss)

Cambrian feldspar-quartz porphyry (Cdfs)

Legend

Proposed Sewer

Cambrian felsic to intermediate volcaniclastic (Cdt)

Appendix A Borehole & Excavation Logs

ENGINEERINGBOREHOLE LOG

Geotechnical Consultants Borehole no. BH1

PO Box 522 Prospect TAS 7250 Sheet no. 1 of 1

3/1, 2 Trotters Lane Prospect TAS Job no. GL13098A

T (03) 6343 1900 F (03) 6343 1906

Date : 10/9/13

Logged By : MS

Drill model : -90O RL Surface :

- Datum :

M L FILL

0.25 D/M MD

ML M F NATURAL

0.50

St V-60kPa

0.75

1.00 W Water seepage at 1.0m

V-62kPa

1.25

1.50

1.75

2.00

2.25

HA N

Structure, additional

observations

Penetr

ation

Co

nsis

ten

cy

de

nsity,

ind

ex

Mo

istu

re c

on

ditio

n

Auger refusal due to inferred rock

(grading towards rock)

Borehole terminated at 1.5m

Client :

Project :

Location : Rosebery

Proposed New Sewer Pipe

TasWater

CLAYEY SILT - low plasticity, light

grey

Becoming orange, becoming medium

FILL - Sandy Gravel (rock fill), fine to

coarse angular gravel, brown, with

plasticity

a trace of cobbles

FILL - Sandy Silt, low plasticity, fine

grained sand, brown

Hole diameter :

Material Description

Cla

ssific

atio

n

Sym

bo

l

Depth

(m)

Inclination:

Bearing:

Me

thod Notes

Samples

Tests

Gra

phic

log

Suppo

rt

Wate

r

Easting:

Northing:

Hand Auger

80mm

With some gravel/cobbles

ENGINEERINGEXCAVATION LOG

Geotechnical Consultants Test Pit no. TP2



T (03) 6343 1900 F (03) 6343 1906

Date : 5/9/13

Logged By : MS

450mm -90O RL Surface :

2.0m - Datum :

ML M F Topsoil - organic matter

M MD

0.25

Massive

0.50

0.75

1.00

1.25

1.50

1.75

2.00

2.25

E

N

Excavator:

on slightly weathered rock

Co

nsis

ten

cy

de

nsity,

ind

ex


observations

TOPSOIL - Clayey Silt, low plasticity,

dark grey, with some sand

HIGHLY WEATHERED ROCK

(Volcaniclastic), fine grained, medium

strength, blocky, light grey/white

Test Pit terminated at 0.3m

Excavator and ripper refusal

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests

5 Tonne Bucket: Inclination:

Length: Bearing:

Client : TasWater

Project : Proposed New Sewer Pipe

Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 5/9/13

Logged By : MS


2.0m - Datum :

ML M L Topsoil - organic matter

ML M MD

0.25 M/W Minor seepage

D/M D

VD

0.50

0.75

1.00

1.25

1.50

1.75

2.00

2.25

E

N



strength, blocky, light grey

Becoming high strength

Test Pit terminated at 0.5mM

ois

ture

co

nd

itio

n

Co

nsis

ten

cy

de

nsity,

ind

ex


observations

TOPSOIL - Sandy Silt, low plasticity,

fine grained sand, dark grey

SANDY GRAVELLY SILT - low

plasticity, fine to coarse gravel, grey



Length: Bearing:

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l



Location : Rosebery

Excavator: 5 Tonne Bucket: Inclination:

Client : TasWater





T (03) 6343 1900 F (03) 6343 1906

Date : 5/9/13

Logged By : MS


2.0m - Datum :

M L Topsoil - organic matter

0.25

D/M D

D/M D Highly fractured (blocky)

0.50

VD

Massive

0.75

1.00

1.25

1.50

1.75

2.00

2.25

E

N


sandy clay between fractures




light brown, sandy silt properties



strength, blocky, light grey/grey, M

ois

ture

co

nd

itio

n

Co

nsis

ten

cy

de

nsity,

ind

ex


observations


dark brown/dark grey, with some

fine grained sand

EXTREMELY WEATHERED ROCK

(Volcaniclastic), low strength,

Length: Bearing:

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l



Location : Rosebery


Client : TasWater





T (03) 6343 1900 F (03) 6343 1906

Date : 5/9/13

Logged By : MS


2.0m - Datum :


0.25 D/M D Highly fractured (blocky)

VD

Massive

0.50

0.75

1.00

1.25

1.50

1.75

2.00

2.25

E

N



on slightly weathered rockM

ois

ture

co

nd

itio

n

Co

nsis

ten

cy

de

nsity,

ind

ex


observations




(Volcaniclastic), fine grained, high

strength, blocky, white mottled green

Length: Bearing:

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l



Location : Rosebery


Client : TasWater





T (03) 6343 1900 F (03) 6343 1906

Date : 5/9/13

Logged By : MS


2.0m - Datum :


ML D/M D

0.25

D D

VD

0.50

0.75

1.00

1.25

1.50

1.75

2.00

2.25

E

N


Excavator refusal on slightly

weathered rock


strength, highly fractured, white/

light brown/orange

Mo

istu

re c

on

ditio

n

Co

nsis

ten

cy

de

nsity,

ind

ex


observations



SANDY SILT - low plasticity, fine

grained sand, light grey/orange



Length: Bearing:

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l



Location : Rosebery


Client : TasWater





T (03) 6343 1900 F (03) 6343 1906

Date : 5/9/13

Logged By : MS


2.0m - Datum :

M L

M L

0.25

0.50

0.75

1.00

D/M D NATURAL

1.25 D VD

1.50 D VD

1.75

2.00

2.25

E

N



weathered rock


light brown/orange


(Volcaniclastic), fine grained, high


(Volcaniclastic), fine grained, low


orange, sandy silt soil properties

Mo

istu

re c

on

ditio

n

Co

nsis

ten

cy

de

nsity,

ind

ex


observations


grained sand, dark grey

FILL - Mixture of sand, silt, cobbles

and gravel, orange/brown

(predominantly subangular/angular

gravel and cobbles)

Length: Bearing:

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l



Location : Rosebery


Client : TasWater





T (03) 6343 1900 F (03) 6343 1906

Date : 29/8/13

Logged By : MS


- Datum :

M L FILL


0.50

D/M D NATURAL

0.75

D VD

1.00

1.25

1.50

1.75

2.00

2.25

Auger refusal on inferred rock




strength, highly fractured, light grey/

light green




light grey, sandy silt soil properties

Mo

istu

re c

on

ditio

n

Co

nsis

ten

cy

de

nsity,

ind

ex


observations

AD

V

N

FILL - Mixture of Silty Sand and

Sandy Clay, fine grained, medium

plasticity, orange and grey, with

some gravel/cobbles

Hole diameter : 130mm Northing: Bearing:

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Location : Rosebery

Drilltech Easting: Inclination:

Client : TasWater






T (03) 6343 1900 F (03) 6343 1906

Date : 5/9/13

Logged By : MS


2.0m - Datum :

M L FILL

0.25

D/M VD

D

0.50

0.75

1.00

1.25

1.50

1.75

2.00

2.25

Excavator and ripper refusal on

slightly weathered rock




light green/cream

plasticity, orange and grey, with

some gravel/cobbles


Co

nsis

ten

cy

de

nsity,

ind

ex


observations

FILL - Mixture of Silty Sand and

Sandy Clay, fine grained, medium

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests

E

N


Length: Bearing:

Excavator:

Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 29/8/13

Logged By : MS


- Datum :

M L

0.25

M/W Minor seepage

0.50

D/M D NATURAL

D

0.75

1.00

D VD

1.25

1.50

1.75

2.00

2.25

AD

V

N





strength, highly fractured, light brown/

white



strength, highly fractured, light

brown, sandy silt soil properties

cobbles

Co

nsis

ten

cy

de

nsity,

ind

ex


observations


grained sand, grey, with some

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests



Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 29/8/13

Logged By : MS


- Datum :

M L FILL

0.25

M L

0.50

M L

0.75

1.00

1.25

1.50

1.75 (possible old topsoil layer)

SM M MD NATURAL

2.00

D VD

2.25

AD

V

N



strength, highly fractured, light brown/

white, low plasticity fines


SILTY SAND - fine grained, light

brown/light green, with a trace of

cobbles

With some cobbles

Becoming dark grey

FILL - Clayey Sand, fine/medium

grained sand, low plasticity fines,

light brown, with a trace of organic

matter


clay


Co

nsis

ten

cy

de

nsity,

ind

ex


observations

FILL - Gravelly Sand, fine to coarse

grained, orange/brown, with some

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests



Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 29/8/13

Logged By : MS


- Datum :

M L FILL

MD

0.25

0.50

SM M MD NATURAL

0.75

1.00

ML M MD

1.25

1.50

W Water seepage at 1.5m

1.75

2.00

2.25


Becoming light brown

Becoming light green, with a trace

of clay

SANDY GRAVELLY SILT - low

plasticity, fine sand, light green/light

brown

SILTY SAND - fine grained, brown/

grey, with some clay and a trace of

gravel

Co

nsis

ten

cy

de

nsity,

ind

ex


observations

FILL - Sandy Gravel, fine to coarse

gravel (subangular, bluestone), grey

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests

AD

V

N



Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 29/8/13

Logged By : MS


- Datum :

M MD Bitumen Seal

0.25 D/M

M MD NATURAL?

0.50

ML M St NATURAL

0.75

1.00 V-70kPa

1.25

ML M St

1.50


1.75

2.00

2.25 Borehole terminated at 2.2m

AD

V

N


grained sand, light grey

SANDY CLAYEY SILT - low plasticity,

light grey mottled orange

FILL? - Sandy Gravel Silt, low

plasticity, fine to coarse gravel, brown

silt

Co

nsis

ten

cy

de

nsity,

ind

ex


observations

FILL - Sandy Gravel Roadbase, fine

to coarse gravel, grey, with some

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests



Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 29/8/13

Logged By : MS


- Datum :

M MD FILL

0.25

M MD

0.50

0.75

ML M F NATURAL

1.00 V-40kPa

1.25

1.50 W St V-54kPa

1.75

2.00 V-60kPa

2.25

Client :


AD

V

N

Becoming light grey/light brown


grained sand, light grey, with a

trace of clay

with some cobbles

FILL - Clayey Sand, fine grained,

low plasticity fines, orange/brown,

Co

nsis

ten

cy

de

nsity,

ind

ex


observations


to coarse gravel, brown

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests



TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 29/8/13

Logged By : MS


- Datum :

M MD FILL

0.25

0.50

0.75

1.00

1.25


(perched water table)

1.50

ML M/W F/S NATURAL

1.75

W

2.00 F V-40kPa

St

2.25

Me

thod

Suppo

rt

Penetr

ation

Wate

r


grained, dark grey

AD

V

N

and a trace of clay

Co

nsis

ten

cy

de

nsity,

ind

ex


observations


gravel, orange, with some cobbles,

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Notes

Samples

Tests



Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 29/8/13

Logged By : MS


- Datum :

ML W St

2.50

2.75

3.00

3.25

3.50

3.75

4.00

4.25

4.50

Client :



Co

nsis

ten

cy

de

nsity,

ind

ex


observations


grained, dark grey

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests



AD

V

N

TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 29/8/13

Logged By : MS


- Datum :

M MD FILL

0.25

D/M

0.50

0.75 D/M MD/

L

1.00

1.25

1.50

1.75

2.00

2.25

Me

thod

Suppo

rt

Penetr

ation

Wate

r

AD

V

N

grained, light grey, with some silt


and a trace of clay

Co

nsis

ten

cy

de

nsity,

ind

ex


observations


gravel, orange, with some cobbles,

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Notes

Samples

Tests



Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 29/8/13

Logged By : MS


- Datum :

D/M MD FILL



2.75

3.00

ML M St NATURAL

3.25

3.50

3.75

4.00

4.25

4.50

Client :



GRAVELLY SILT - low plasticity,

fine to coarse gravel, light grey/

light green

Co

nsis

ten

cy

de

nsity,

ind

ex


observations


grained, light grey, with some silt

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests



AD

V

N

TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 4/9/13

Logged By : MS


2.0m - Datum :

M L FILL


above natural

SW M D NATURAL

0.50

0.75

D VD

1.00

1.25

1.50

1.75

2.00

2.25

Me

thod

Suppo

rt

Penetr

ation

Wate

r

E

N



(Volcaniclastic Sandstone), high

strength, light green



GRAVELLY SAND - fine to coarse

grained, brown/light green, with some

cobbles/boulders, weakly cemented

cobbles

Co

nsis

ten

cy

de

nsity,

ind

ex


observations



Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Notes

Samples

Tests


Length: Bearing:

Excavator:

Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 29/8/13

Logged By : MS


- Datum :

M L

0.25

M F

0.50

0.75

1.00 M/W F/S V-30kPa



1.50

ML M St NATURAL

D/M

1.75

2.00

2.25


grained sand, light green/grey, with

some gravel

grading towards rock?

FILL - Clayey Silt, medium plasticity,

orange mottled grey, with some

with a trace of cobbles



Co

nsis

ten

cy

de

nsity,

ind

ex


observations

FILL - Clayey Gravel, fine to coarse

gravel, low plasticity fines, brown,

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests



AD

V

N

Becoming brown/dark brown

gravel

TasWater


Location : Rosebery

Client :





T (03) 6343 1900 F (03) 6343 1906

Date : 29/8/13

Logged By : MS


- Datum :

M F

0.25

0.50 V-44kPa

M/W Minor seepage above

0.75 the natural ground

ML M St NATURAL

1.00 V-64kPa

1.25

1.50


2.00 V-refusal

2.25


With some gravel

Becoming light grey, no clay

Becoming orange, with some clay

Co

nsis

ten

cy

de

nsity,

ind

ex


observations

FILL - Clayey Silt, low plasticity, dark

grey, with some gravel

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests

AD

V

N


grained sand, light brown, with a

trace of gravel



Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 29/8/13

Logged By : MS


- Datum :

M MD FILL

M/W S

0.25

0.50 V-20kPa

0.75 W Minor seepage above the

natural ground

SC M/W L NATURAL

1.00

1.25

1.50 M MD

ML M St

1.75

2.00

2.25 Borehole terminated at 2.2m


grained sand, light brown mottled

orange, with a trace of clay

AD

V

N

Becoming medium dense

CLAYEY SAND - medium grained,

medium plasticity fines, orange


grained sand, dark grey, with some

gravel

Co

nsis

ten

cy

de

nsity,

ind

ex


observations

FILL - Sandy Clayey Gravel, fine to

coarse, orange, with some cobbles

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests



Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 29/8/13

Logged By : MS


- Datum :

M MD FILL

M S

0.25

0.50

0.75

1.00

1.25

1.50

1.75

W Minor seepage above the

2.00 natural ground

SC M MD NATURAL

2.25

AD

V

N


medium plasticity fines, orange/

yellow

Becoming dark grey

Becoming light grey


grained sand, dark grey, with some

gravel

Co

nsis

ten

cy

de

nsity,

ind

ex


observations

FILL - Sandy Clayey Gravel, fine to

coarse, orange, with some cobbles

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests



Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 29/8/13

Logged By : MS


- Datum :

SC M MD

2.50

2.75

3.00

3.25

3.50

3.75

4.00

4.25

4.50


observations



Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Notes

Samples

Tests



Client : TasWater


Location : Rosebery


yellow

Co

nsis

ten

cy

de

nsity,

ind

ex

AD

V

N

Me

thod

Suppo

rt

Penetr

ation

Wate

r





T (03) 6343 1900 F (03) 6343 1906

Date : 5/9/13

Logged By : MS


2.0m - Datum :

M L FILL

M St

0.25

0.50 V-80kPa

0.75

W Minor seepage above the

natural ground

SC M MD NATURAL

1.00

D

1.25

D/M

1.50

1.75

2.00

2.25



weathered rock (Volcaniclastic

sandstone)

clay, with some cobbles/boulders

Grading towards rock

brown, weakly cemented

Becoming light grey, decrease in

some organic matter


grained sand, light grey, with some

gravel/cobbles/boulders

Co

nsis

ten

cy

de

nsity,

ind

ex


observations

FILL - Topsoil, Sandy Silt, low

plasticity, fine grained, dark grey, with

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests


Length: Bearing:

Excavator:

E

N



Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 4/9/13

Logged By : MS


2.0m - Datum :

M MD FILL

0.25

SC M MD NATURAL

0.50

0.75

M D

1.00

1.25

1.50 M/W Water seepage at 1.5m

1.75

2.00

2.25

some cobbles



Becoming light brown

Co

nsis

ten

cy

de

nsity,

ind

ex


observations


to coarse gravel, grey/orange, with

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests

E

N

COBBLES & BOULDERS in a

clayey sand matrix, subrounded,

medium plasticity fines, orange

medium plasticity fines, orange,

with some cobbles/boulders


Length: Bearing:

Client : TasWater


Location : Rosebery

Excavator:





T (03) 6343 1900 F (03) 6343 1906

Date : 29/8/13

Logged By : MS


- Datum :

ML M L Topsoil - grass roots

Disturbed

0.25

ML M St NATURAL

0.50

ML M St

0.75

1.00 V-80kPa

1.25

1.50


SW W MD

2.00 V-refusal

D

2.25

Grading towards rock

Borehole terminated 2.15m, Auger

refusal on inferred rock

GRAVELLY SAND - fine to coarse

grained, brown, with a trace of clay

CLAYEY SILT - medium plasticity,

orange, with some fine grained

sand

grained sand, light grey/cream, with

a trace of clay

some gravel


Co

nsis

ten

cy

de

nsity,

ind

ex


observations


fine grained sand, dark grey, with

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests

AD

V

N



Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 29/8/13

Logged By : MS


- Datum :

M L FILL

M L

0.25

0.50

0.75

M/W


1.25

1.50

ML W L NATURAL

1.75

SP W L

2.00

2.25 Borehole terminated 2.2m

SAND - medium grained, light grey,

with a trace of silt



AD

V

N


gravel, low plasticity fines, orange

Co

nsis

ten

cy

de

nsity,

ind

ex


observations



Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests



Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 29/8/13

Logged By : MS


- Datum :

ML M L

0.25 SC M MD

D/M D

0.50

D

0.75

VD

1.00

1.25

1.50

1.75

2.00

2.25



grained, low strength,


with some cobbles/boulders


(Volcaniclastic Sandstone), medium



Co

nsis

ten

cy

de

nsity,

ind

ex


observations



Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests



E N

Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 29/8/13

Logged By : MS


- Datum :

M L

0.25

M L

0.50

M L

0.75

1.00

1.25


GW W MD NATURAL

1.75

2.00

2.25

AD

V

N


SANDY GRAVEL - fine to coarse

gravel, subrounded, grey/brown


gravel, brown



Co

nsis

ten

cy

de

nsity,

ind

ex


observations

FILL - Sand, fine/medium grained,

light grey

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests



Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 29/8/13

Logged By : MS


- Datum :

M MD

0.25

0.50

ML M F

0.75

1.00 St V-70kPa

1.25

SC M MD


M D

D/M

1.75

VD

2.00

2.25

AD

V

N





grained, low strength,




with some gravel

CLAYEY SILT - low plasticity, brown/

light grey, with some fine grained

sand

Co

nsis

ten

cy

de

nsity,

ind

ex


observations

FILL - Silty Gravel Roadbase, fine

to coarse gravel, light blue

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests



Client : TasWater


Location : Rosebery

ENGINEERING LOG

Geotechnical Consultants Test no. C29



T (03) 6343 1900 F (03) 6343 1906

Date : 29/8/13

Logged By : MS


- Datum :

M L Top of cutting along walking

track

ML M St

0.25

0.50

0.75

1.00

M D Glacial

1.25

1.50

1.75

2.00

2.25

N

Becoming weakly cemented

Bottom of cutting at 1.4m

Hand auger refusal

COBBLES & BOULDERS in a clayey

silt matrix, subrounded, orange

some clay


orange mottled grey, with some

cobbles/boulders

Co

nsis

ten

cy

de

nsity,

ind

ex


observations


fine grained sand, dark brown, with

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests

Easting: Inclination:

Hole diameter : Northing: Bearing:

Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 4/9/13

Logged By : MS


2.0m - Datum :

M L Topsoil

ML M MD NATURAL

0.25

GC M MD Glacial

0.50

0.75

D

D VD

1.00

1.25

1.50

1.75

2.00

2.25

E

N

Weakly cemented

grained, medium strength, light grey

CLAYEY GRAVEL - fine to coarse,





With some cobbles/boulders


(Volcaniclastic Sandstone), fine

with some cobbles

some clay


grained sand, light brown, with a

trace of gravel

Co

nsis

ten

cy

de

nsity,

ind

ex


observations


fine grained sand, dark grey, with

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests


Length: Bearing:

Excavator:

Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 4/9/13

Logged By : MS


2.0m - Datum :

M L FILL

M L

0.25

ML M L NATURAL

0.50

GC M MD Glacial

0.75

D

1.00

1.25

1.50 M/W Minor seepage above

rock

1.75 D VD

2.00

2.25

E

N

weathered rock


grained, medium strength, light grey




Weakly cemented

Becoming light brown/yellow

trace of gravel



with some cobbles


grained sand, grey, with a


gravel, low plasticity fines, orange/

white/grey, with some cobbles and

a trace of organic matter

Co

nsis

ten

cy

de

nsity,

ind

ex


observations

FILL - Sandy Silt topsoil, low plasticity,


Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests


Length: Bearing:

Client : TasWater


Location : Rosebery

ENGINEERING LOG




T (03) 6343 1900 F (03) 6343 1906

Date : 4/9/13

Logged By : MS


- Datum :

M L Top of cutting along

railway line

ML M MD NATURAL

0.25

0.50

GC D/M D Glacial

0.75

1.00

1.25

1.50

1.75

2.00

2.25

N


cemented


medium plasticity fines, orange/grey,

with some cobbles, weakly


grained sand, light grey, with a

trace of gravel and clay

Co

nsis

ten

cy

de

nsity,

ind

ex


observations



Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests



Client : TasWater


Location : Rosebery

ENGINEERINGLOG




T (03) 6343 1900 F (03) 6343 1906

Date : 4/9/13

Logged By : MS


- Datum :

M L Top of cutting along

railway line

GC D/M D Glacial

0.25

0.50

0.75

1.00

GW D/M D

1.25

1.50

1.75

2.00

2.25

N



gravel, grey, subrounded, with some

cobbles, weakly cemented

cemented


medium plasticity fines, orange/grey,


Co

nsis

ten

cy

de

nsity,

ind

ex


observations

TOPSOIL - Sandy Gravel, fine to

coarse gravel, grey

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests



Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 4/9/13

Logged By : MS


2.0m - Datum :

M L FILL

0.25 ML M MD NATURAL

0.50 SW M MD Glacial

0.75

1.00

GW D/M D

1.25

1.50

1.75

2.00

2.25

E

N



gravel, grey, subrounded, with some

cobbles, weakly cemented

light grey, with a trace of cobbles,

weakly cemented

of gravel/cobbles

GRAVELLY SAND - fine to coarse,


grained sand, light grey, with a trace

Co

nsis

ten

cy

de

nsity,

ind

ex


observations



Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests


Length: Bearing:

Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 4/9/13

Logged By : MS


2.0m - Datum :

D/M D FILL

0.25

M VL

0.50

ML D/M MD NATURAL

0.75

D

D VD

1.00

1.25

1.50

1.75

2.00

2.25

E

N

grained, high strength, light grey








cobbles/boulders

ORGANIC LAYER - tree branches

up to 15cm diameter

with a trace of cobbles, boulders and

clay

Co

nsis

ten

cy

de

nsity,

ind

ex


observations


to coarse gravel, orange and grey,

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests


Length: Bearing:

Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 4/9/13

Logged By : MS


2.0m - Datum :


ML M/W L

0.25


Minor test pit collapse

0.50

ML M MD

0.75 D

1.00

1.25

1.50

SC M D Glacial

1.75

2.00

2.25

E

N



orange, with a trace of cobbles,

weakly cemented

Becoming light grey/light blue


grained sand, light grey, with a trace

of gravel

GRAVELLY SANDY SILT - low

plasticity fines, brown/grey, with

some cobbles, subrounded

Co

nsis

ten

cy

de

nsity,

ind

ex


observations



Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests


Length: Bearing:

Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 4/9/13

Logged By : MS


2.0m - Datum :


0.25

ML M MD

0.50 V-refusal

0.75

1.00 V-refusal

1.25

SC M D Glacial

1.50

1.75

2.00

2.25

E

N




weakly cemented


subrounded cobbles


Co

nsis

ten

cy

de

nsity,

ind

ex


observations



Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests


Length: Bearing:

Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 4/9/13

Logged By : MS


2.0m - Datum :


SM M MD

0.25

SC M MD Glacial

D

0.50

0.75

1.00

1.25

1.50

1.75

2.00

2.25

E

N



weakly cemented

SILTY SAND - fine grained, light grey,

with some cobbles


Co

nsis

ten

cy

de

nsity,

ind

ex


observations



Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests


Length: Bearing:

Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 10/9/13

Logged By : MS


- Datum :


0.25 ML M MD

0.50 D/M D

0.75

1.00

1.25

1.50

1.75

2.00

2.25

HA N


Auger refusal on inferred weakly

cemented glacial soils

Becoming light brown/light yellow

SANDY SILT - non plastic, fine


Co

nsis

ten

cy

de

nsity,

ind

ex


observations



Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests

Hand Auger Easting: Inclination:


Client : TasWater

Project : Proposed New Sewer Pipe (outfall)

Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 10/9/13

Logged By : MS


- Datum :


0.25 ML M St

D

LL=41%

PL=33%

PI=8% 0.50 V-84kPa

ML D/M VSt

grading towards rock

0.75

Auger refusal on inferred highly

weathered rock (vocaniclastic)

1.00

1.25

1.50

1.75

2.00

2.25

HA N


GRAVELLY CLAYEY SILT - low

plasticity, light grey, with some

weathered rock


orange, with a trace of fine sand

Co

nsis

ten

cy

de

nsity,

ind

ex


observations



Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests



Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 10/9/13

Logged By : MS


- Datum :


0.25 ML M St

D

LL=39%

PL=31%

PI=8% 0.50 V-90kPa

ML D/M VSt

grading towards rock

0.75

1.00

1.25

1.50

1.75

2.00

2.25

HA N

Auger refusal on inferred highly

weathered rock (volcaniclastic)


plasticity, light brown/orange, with

some weathered rock



orange, with a trace of fine sand

Co

nsis

ten

cy

de

nsity,

ind

ex


observations



Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests



Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 10/9/13

Logged By : MS


- Datum :


SM M MD

0.25

ML M MD

0.50 V-90kPa

D

LL=NO

PI=NP

0.75 D/M D V-refusal

1.00

1.25

1.50

1.75

2.00

2.25


Auger refusal on inferred weakly

cemented glacial soils

Becoming light brown/light yellow

SANDY SILT - non plastic, fine


SILTY SAND - fine grained, light

grey, with a trace of gravel/cobbles

Co

nsis

ten

cy

de

nsity,

ind

ex


observations



Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests



HA N

Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 4/9/13

Logged By : MS


2.0m - Datum :

D/M MD FILL

0.25

M L

0.50

0.75

SC M MD NATURAL

1.00

1.25

1.50

1.75

2.00

2.25

LANDFILL - Mixture of rubbish, sand,

gravel, cobbles and organic matter.

Rubbish consisting predominantly

of metal


Co

nsis

ten

cy

de

nsity,

ind

ex


observations

FILL - Clayey Gravel Roadbase, fine

to coarse gravel, orange, with some

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests

E

N

orange, with a trace of cobbles

CLAYEY SAND - fine/medium

grained, low plasticity fines, red/

Length: Bearing:

Client : TasWater


Location : Rosebery

cobbles






T (03) 6343 1900 F (03) 6343 1906

Date : 4/9/13

Logged By : MS


2.0m - Datum :


W Minor seepage

0.25 ML M MD

0.50 V-refusal

0.75

1.00 W Minor seepage

SW M D

1.25

1.50 V-refusal

1.75

2.00

2.25


E

N

GRAVELLY SAND - fine to coarse,

orange/brown, with some cobbles,

trace of clay, weakly cemented

subrounded cobbles



Co

nsis

ten

cy

de

nsity,

ind

ex


observations


brown, with some sand

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests


Length: Bearing:

Client : TasWater

Project : Proposed Wastewater Treatment Plant

Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 14/8/13

Logged By : MS


2.0m - Datum :


ML M MD

0.25

ML M St

0.50 V-66kPa

0.75 GC D/M D V-refusal

1.00

1.25

1.50

1.75

D/M D

2.00

2.25


silt matrix, subrounded, orange/brown

weakly cemented


plasticity, fine to coarse gravel,

orange, with some cobbles/boulders



subrounded cobbles


COBBLES & BOULDERS in a sandy

Co

nsis

ten

cy

de

nsity,

ind

ex


observations



Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests


Length: Bearing:

E

N

medium plasticity fines,orange/cream


cemented

Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 14/8/13

Logged By : MS


2.0m - Datum :


ML M MD

0.25

ML M St

0.50 V-90kPa

0.75 H V-refusal

1.00 V-refusal

1.25

SW M MD

1.50

D/M D

1.75

2.00

2.25

Becoming weakly cemented


plasticity, fine to coarse gravel,

light grey, with some cobbles/

boulders


Becoming cemented, dark orange, with

a trace of subrounded gravel/cobbles

SAND - medium grained, orange/

yellow, with some clay/silt

SILTY GRAVEL - fine to coarse gravel,

low plasticity fines, grey, with some

subrounded cobbles

Co

nsis

ten

cy

de

nsity,

ind

ex


observations



Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests

E

N


Length: Bearing:

Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 4/9/13

Logged By : MS


2.0m - Datum :


ML M/W L

0.25

W Water seepage above

cemented gravels

0.50 D/M D V-refusal

VD

0.75

D/M VD Weakly cemented

1.00

1.25

1.50

1.75

2.00

2.25

Near excavator refusal


E

N

GRAVEL & COBBLES in a sandy

silt matrix, subrounded, light grey

weakly cemented

sand matrix, weakly cemented,

light grey

GRAVEL & COBBLES in clayey



subrounded cobbles

Co

nsis

ten

cy

de

nsity,

ind

ex


observations


fine grained sand, brown

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests


Length: Bearing:

Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 14/8/13

Logged By : MS


2.0m - Datum :


ML M/W L

0.25

0.50

M D Weakly cemented

0.75

D/M VD

1.00

1.25

1.50

1.75

2.00

2.25


Excavator refusal - strongly cemented

brown/orange



subrounded cobbles

Co

nsis

ten

cy

de

nsity,

ind

ex


observations



Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests


Length: Bearing:

E

N



Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 14/8/13

Logged By : MS


2.0m - Datum :


ML M MD

0.25

D/M D Weakly cemented

0.50

0.75

1.00

1.25

1.50

1.75

2.00

2.25





brown/orange

SILTY GRAVEL - fine to coarse gravel,

low plasticity fines, grey, with some

subrounded cobbles

Co

nsis

ten

cy

de

nsity,

ind

ex


observations



Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests

E

N


Length: Bearing:

Client : TasWater


Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 4/9/13

Logged By : MS


2.0m - Datum :


ML M MD

0.25

W Minor seepage

M D

0.50 D/M

VD

0.75

1.00

1.25

1.50

1.75

2.00

2.25



Becoming light grey/cream



brown/orange



subrounded cobbles

Co

nsis

ten

cy

de

nsity,

ind

ex


observations



Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests


Length: Bearing:

Client : TasWater


Location : Rosebery

E

N





T (03) 6343 1900 F (03) 6343 1906

Date : 5/9/13

Logged By : MS


2.0m - Datum :

M L FILL


0.50

0.75

1.00

1.25

D VD NATURAL

1.50

1.75

2.00

2.25







light blue

orange, with a trace of organic

matter

Co

nsis

ten

cy

de

nsity,

ind

ex


observations

FILL - Mixture of clay, gravel, cobbles

and boulders, subangular, brown/

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests


Length: Bearing:

TasWater

Project : Proposed Water Treatment Plant

Location : Rosebery

E

N

Client :





T (03) 6343 1900 F (03) 6343 1906

Date : 5/9/13

Logged By : MS


2.0m - Datum :

ML M F/S

0.25 ML M MD

0.50

D/M D

D

0.75

VD

Massive

1.00

1.25

1.50

1.75

2.00

2.25


Becoming light grey/light blue






light brown

gravel/cobbles

sand



Co

nsis

ten

cy

de

nsity,

ind

ex


observations


dark brown, with some fine grained

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests


Length: Bearing:

Client : TasWater


Location : Rosebery

E

N

Excavator:





T (03) 6343 1900 F (03) 6343 1906

Date : 5/9/13

Logged By : MS


2.0m - Datum :

M L

D/M D

Highly fractured

0.25

D VD

0.50

0.75

1.00

1.25

1.50

1.75

2.00

2.25

Becoming light blue




strength, blocky, light grey/orange



strength, cream/light orange,

clayey sand soil properties

Co

nsis

ten

cy

de

nsity,

ind

ex


observations


fine grained sand, grey

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Notes

Samples

Tests


Length: Bearing:

Client : TasWater


Location : Rosebery



Me

thod

Suppo

rt

Penetr

ation

Wate

r

E

N





T (03) 6343 1900 F (03) 6343 1906

Date : 5/9/13

Logged By : MS


2.0m - Datum :

M L

D VD

0.25

0.50

0.75

1.00

1.25

1.50

1.75

2.00

2.25





strength, blocky, light grey


Co

nsis

ten

cy

de

nsity,

ind

ex


observations


fine grained sand, grey

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests


Length: Bearing:

TasWater


Location : Rosebery

Client :

E

N





T (03) 6343 1900 F (03) 6343 1906

Date : 5/9/13

Logged By : MS


2.0m - Datum :

M L FILL

0.25

ML M St NATURAL

0.50

D/M D

Highly fractured

0.75 D VD

1.00

1.25

1.50

1.75

2.00

2.25




weathered rock

(Volcaniclastic Sandstone), coarse

grained, medium strength, orange/

pink/white, blocky



grained, low strength, light

brown, clayey sand soil properties


CLAYEY SILT - low plasticity, white/

orange, with some sand

dark grey

Co

nsis

ten

cy

de

nsity,

ind

ex


observations

FILL - Mixture of clay, gravel, cobbles

and boulders, subangular, grey/

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests


Length: Bearing:

Client : TasWater


Location : Rosebery

Excavator:

E

N





T (03) 6343 1900 F (03) 6343 1906

Date : 5/9/13

Logged By : MS


2.0m - Datum :

M L

0.25 D D

Highly fractured

D VD

0.50

0.75

1.00

1.25

1.50

1.75

2.00

2.25


weathered rock

pink/white, blocky


grained, low strength, light brown



grained, medium strength, orange/



Co

nsis

ten

cy

de

nsity,

ind

ex


observations



Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Penetr

ation

Wate

r Notes

Samples

Tests


Length: Bearing:

Client : TasWater


Location : Rosebery

Me

thod

Suppo

rt

E

N





T (03) 6343 1900 F (03) 6343 1906

Date : 5/9/13

Logged By : MS


2.0m - Datum :

M L

D VD

0.25

0.50

0.75

1.00

1.25

1.50

1.75

2.00

2.25







grained, medium strength, light

brown/light green

Co

nsis

ten

cy

de

nsity,

ind

ex


observations



Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests


Length: Bearing:

Client : TasWater


Location : Rosebery

E

N





T (03) 6343 1900 F (03) 6343 1906

Date : 10/9/13

Logged By : MS


- Datum :

0.25

0.50

ML M F NATURAL

St V-70kPa

0.75

1.00

V-90kPa

1.25


V-54kPa

1.75

2.00

2.25


grey, with a trace of fine grained sand

Becoming orange, medium plasticity



Becoming grey, low plasticity, with

some gravel (grading towards rock)

gravel

Co

nsis

ten

cy

de

nsity,

ind

ex


observations


grained sand, grey, with a trace of

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests

AD

V

N



Client : TasWater

Project : Proposed Water Treatment Plant (Pipe)

Location : Rosebery





T (03) 6343 1900 F (03) 6343 1906

Date : 10/9/13

Logged By : MS


- Datum :

ML M L

W

ML M F

0.25

St

0.50 V-64kPa

0.75


1.00

1.25

1.50

1.75

2.00

2.25


Auger and crowbar refusal on inferred

rock

Becoming grey, low plasticity, with

some gravel (grading towards rock)

Becoming orange, medium plasticity


grey, with a trace of fine grained sand

Co

nsis

ten

cy

de

nsity,

ind

ex


observations


fine grained sand, grey/brown

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests



Client : TasWater


Location : Rosebery

HA N





T (03) 6343 1900 F (03) 6343 1906

Date : 10/9/13

Logged By : MS


- Datum :

MD D/M

0.25

D

0.50

0.75

1.00

1.25

1.50

1.75

2.00

2.25



cobbles/boulder

cobbles and boulders

Co

nsis

ten

cy

de

nsity,

ind

ex


observations

FILL - Clayey Gravel, fine to coarse,

low plasticity fines, with some

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests



Client : TasWater


Location : Rosebery

AD

V

N





T (03) 6343 1900 F (03) 6343 1906

Date : 10/9/13

Logged By : MS


- Datum :

ML M L

0.25 W Minor seepage

M/W MD

M

0.50


1.00

1.25

1.50

1.75

2.00

2.25

boulder



Becoming grey

grained sand, grey/light grey, with

some cobbles/boulders


Co

nsis

ten

cy

de

nsity,

ind

ex


observations


fine grained sand, grey/brown

Depth

(m)

Gra

phic

log

Cla

ssific

atio

n

Sym

bo

l


Mo

istu

re c

on

ditio

n

Me

thod

Suppo

rt

Penetr

ation

Wate

r Notes

Samples

Tests



Client : TasWater


Location : Rosebery

AD

V

N

Borehole Log Explanation Sheet Method

TERM Description

AS Auger Screwing*

AD Auger Drilling*

RR Roller / Tricone

W Washbore

CT Cable Tool

HA Hand Auger

DT Diatube

B Blank Bit

V V Bit

T TC Bit * Bit shown by suffix e.g. ADT

Support

TERM Description

M Mud

N Nil

C Casing

Notes, samples, tests

TERM Description

U50 Undisturbed sample 50 mm diameter


D Disturbed sample

N Standard Penetration Test (SPT)

N* SPT – sample recovered

NC SPT with solid cone

V Vane Shear

PP Pocket Penetrometer

P Pressumeter

BS Bulk sample

E Environmental Sample

R Refusal

Penetration

1 2 3 4

No resistance ranging to refusal

Water

Symbol Description

Water inflow

Water outflow

17/3/08 water on date shown

Classification symbols and soil description Based on unified classification system

Moisture

TERM Description

D Dry

M Moist

W Wet

WP Plastic Limit

WL Liquid Limit

Consistency/Density index

TERM Description

VS very soft

S soft

F firm

St stiff

VSt very stiff

H hard

Fb friable

VL very loose

L loose

MD medium dense

D dense

VD Very dense

Excavation Log Explanation Sheet Method

TERM Description

N Natural exposure

X Existing excavation

BH Backhoe bucket

B Bulldozer blade

R Ripper

E Excavator

Support

TERM Description

S Shoring

N Nil

Penetration

1 2 3 4

No resistance ranging to refusal

Water

Symbol Description

Water inflow

Water outflow

17/3/08 water on date shown

Notes, samples, tests

TERM Description



D Disturbed sample

PP Pocket Penetrometer

V Vane Shear

BS Bulk sample

E Environmental Sample

R Refusal

Classification symbols and soil description Based on unified classification system

Moisture

TERM Description

D Dry

M Moist

W Wet

WP Plastic Limit

WL Liquid Limit

Consistency/Density index

TERM Description

VS very soft

S soft

F firm

St stiff

VSt very stiff

H hard

Fb friable

VL very loose

L loose

MD medium dense

D dense

VD Very dense

Soil Description Explanation Sheet(1of 2)

DEFINITION:

In engineering terms soil includes every type of uncemented or partially cemented inorganic or organic material found in the ground. In practice, if the material can be remoulded or disintegrated by hand in its field condition or in water it is described as a soil. Other materials are described using rock description terms.

CLASSIFICATION SYMBOL & SOIL NAME

Soils are described in accordance with the Unified Classification System (UCS) as shown in the table on Sheet 2.

PARTICLE SIZE DESCRIPTIVE TERMS

NAME SUBDIVISION SIZE

Boulders >200 mm Cobbles 63 mm to 200 mm Gravel coarse 20 mm to 63 mm

medium 6 mm to 20 mm fine 2.36 mm to 6 mm

Sand coarse 600 µm to 2.36 mm

medium 200 µm to 600 µm

Fine 75 µm to 200 µm

MOISTURE CONDITION Dry Looks and feels dry. Cohesive and cemented soils

are hard, friable or powdery. Uncemented granular soils run freely through hands.

Moist Soil feels cool and darkened in colour. Cohesive

soils can be moulded. Granular soils tend to cohere.

Wet As for moist but with free water forming on hands

when handled.

CONSISTENCY OF COHESIVE SOILS

TERM UNDRAINED STRENGTH

su (kPa) FIELD GUIDE

Very Soft

<12 A finger can be pushed well into the soil with little effort.

Soft 12 - 25 A finger can be pushed into the soil to about 25mm depth.

Firm 25 - 50 The soil can be indented about 5mm with the thumb, but not penetrated.

Stiff 50 - 100 The surface of the soil can be indented with the thumb, but not penetrated.

Very Stiff

100 - 200 The surface of the soil can be marked, but not indented with thumb pressure.

Hard >200 The surface of the soil can be marked only with the thumbnail.

Friable – Crumbles or powders when scraped by thumbnail.

DENSITY OF GRANULAR SOILS

TERM DENSITY INDEX (%)

Very loose Less than 15

Loose 15 - 35

Medium Dense 35 - 65

Dense 65 - 85

Very Dense Greater than 85

MINOR COMPONENTS

TERM ASSESSMENT GUIDE

PROPORTION OF MINOR

COMPONENT IN: Trace of Presence just

detectable by feel or eye, but soil properties little or no different to general properties of primary component.

Coarse grained soils: <5% Fine grained soils: <15%

With some Presence easily detected by feel or eye, soil properties little different to general properties of primary component.

Coarse grained soils: 5 - 12% Fine grained soils: 15 - 30%

SOIL STRUCTURE

ZONING CEMENTING Layers Continuous across

exposure or sample.

Weakly cemented

Easily broken up by hand in air or water.

Lenses Discontinuous layers of lenticular shape.

Moderately cemented

Effort is required to break up the soil by hand in air or water.

Pockets Irregular inclusions of different material.

GEOLOGICAL ORIGIN

WEATHERED IN PLACE SOILS

Extremely weathered material

Structure and fabric of parent rock visible.

Residual soil Structure and fabric of parent rock not

visible.

TRANSPORTED SOILS

Aeolian soil Deposited by wind.

Alluvial soil Deposited by streams and rivers.

Colluvial soil Deposited on slopes (transported downslope by gravity).

Fill Man made deposit. Fill may be significantly more variable between tested locations than naturally occurring soils

Lacustrine soil Deposited by lakes.

Marine soil Deposited in ocean basins, bays, beaches and estuaries.

Soil Description Explanation Sheet (2 of 2)

SOIL CLASSIFICATION INCLUDING IDENTIFICATION AND DESCRIPTION FIELD IDENTIFICATION PROCEDURES (Excluding particles larger than 60 mm and basing fractions on estimated mass)

USC PRIMARY NAME

CO

ARS

E G

RAI

NED

SO

ILS

M

ore

than

50%

of m

ater

ials

less

than

63

mm

is

larg

er th

an 0

.075

mm

(A 0

.075

mm

par

ticle

is a

bout

the

smal

lest

par

ticle

vis

ible

to th

e na

ked

eye)

GR

AVE

LS M

ore

than

hal

f of

coar

se fr

actio

n is

larg

er th

an

2.0

mm

CLE

AN

GR

AVE

LS

(Litt

le

or n

o fin

es) Wide range in grain size and substantial

amounts of all intermediate particle sizes. GW GRAVEL

Predominantly one size or a range of sizes with more intermediate sizes missing. GP GRAVEL

GR

AVE

LS

WIT

H F

INE

S (A

ppre

ciab

le

amou

nt

of fi

nes)

Non-plastic fines (for identification procedures see ML below) GM SILTY GRAVEL

Plastic fines (for identification procedures see CL below)

GC CLAYEY GRAVEL

SA

ND

S M

ore

than

hal

f of

coar

se fr

actio

n is

sm

alle

r th

an 2

.0 m

m CLE

AN

SA

ND

S (L

ittle

or

no

fines

) Wide range in grain sizes and substantial amounts of all intermediate sizes missing SW SAND

Predominantly one size or a range of sizes with some intermediate sizes missing. SP SAND

SA

ND

S

WIT

H F

INE

S (A

ppre

ciab

le

amou

nt

of fi

nes)

Non-plastic fines (for identification procedures see ML below). SM SILTY SAND

Plastic fines (for identification procedures see CL below). SC CLAYEY SAND

FIN

E G

RAI

NE

D S

OIL

S M

ore

than

50%

of M

ater

ial l

ess

than

63

mm

is s

mal

ler t

han

0.07

5 m

m

IDENTIFICATION PROCEDURES ON FRACTIONS <0.2 mm.

SIL

TS &

CLA

YS

Liqu

id li

mit

less

than

50

DRY STRENGTH DILATANCY TOUGHNESS

None to Low Quick to slow None ML SILT

Medium to High None Medium CL CLAY

Low to medium Slow to very slow Low OL ORGANIC SILT

SIL

TS &

C

LAY

S

Liqu

id li

mit

gr

eate

r tha

n 50

Low to medium Slow to very slow Low to medium MH SILT

High None High CH CLAY

Medium to High None Low to medium OH ORGANIC CLAY

HIGHLY ORGANIC SOILS Readily identified by colour, odour, spongy feel and frequently by fibrous texture. Pt PEAT

● Low plasticity – Liquid Limit WL less than 35%. ● Medium plasticity – WL between 35% and 50%.

COMMON DEFECTS IN SOIL

TERM DEFINITION DIAGRAM TERM DEFINITION DIAGRAM PARTING A surface or crack across which the

soil has little or no tensile strength. Parallel or sub parallel to layering (eg bedding). May be open or closed.

SOFTENED ZONE

A zone in clayey soil, usually adjacent to a defect in which the soil has a higher moisture content than elsewhere.

JOINT A surface or crack across which the soil has little or no tensile strength but which is not parallel or sub parallel to layering. May be open or closed. The term 'fissure' may be used for irregular joints <0.2 m in length.

TUBE Tubular cavity. May occur singly or as one of a large number of separate or inter-connected tubes. Walls often coated with clay or strengthened by denser packing of grains. May contain organic matter

SHEARED ZONE

Zone in clayey soil with roughly parallel near planar, curved or undulating boundaries containing closely spaced, smooth or slickensided, curved intersecting joints which divide the mass into lenticular or wedge shaped blocks.

TUBE CAST Roughly cylindrical elongated body of soil different from the soil mass in which it occurs. In some cases the soil which makes up the tube cast is cemented.

SHEARED SURFACE

A near planar curved or undulating, smooth, polished or slickensided surface in clayey soil. The polished or slickensided surface indicates that movement (in many cases very little) has occurred along the defect.

INFILLED SEAM

Sheet or wall like body of soil substance or mass with roughly planar to irregular near parallel boundaries which cuts through a soil mass. Formed by infilling of open joints.

Appendix B Qualitative Terminology for Use in Assessing Risk to Property

Geoton Pty Ltd (adapted from Australian Geomechanics Vol 42 No 1 March 2007) 1

QUALITATIVE TERMINOLOGY FOR USE IN ASSESSING RISK TO PROPERTY QUALITATIVE MEASURES OF LIKELIHOOD Approximate Annual Probability Implied Indicative Landslide

Recurrence Interval

Description Descriptor Level Indicative

Value Notional

Boundary 10-1

5x10-2

5x10-3

5x10-4

5x10-5

5x10-6

10 years20 years

200 years

2000 years

20,000 years

200,000 years

The event is expected to occur over the design life. ALMOST CERTAIN A

10-2 100 years The event will probably occur under adverse conditions over the design life. LIKELY B

10-3 1000 years The event could occur under adverse conditions over the design life. POSSIBLE C

10-4 10,000 years The event might occur under very adverse circumstances over the design life. UNLIKELY D

10-5 100,000 years The event is conceivable but only under exceptional circumstances over the design life. RARE E

10-6 1,000,000 years The event is inconceivable or fanciful over the design life. BARELY CREDIBLE F Note: (1) The table should be used from left to right; use Approximate Annual Probability or Description to assign Descriptor, not vice versa. QUALITATIVE MEASURES OF CONSEQUENCES TO PROPERTY Approximate Cost of Damage Description Descriptor Level

IndicativeValue

Notional Boundary

200%

100%

40%

10%

1%

Structure(s) completely destroyed and/or large scale damage requiring major engineering works for stabilisation. Could cause at least one adjacent property major consequence damage.

CATASTROPHIC 1

60% Extensive damage to most of structure, and/or extending beyond site boundaries requiring significant stabilisation works. Could cause at least one adjacent property medium consequence damage.

MAJOR 2

20% Moderate damage to some of structure, and/or significant part of site requiring large stabilisation works. Could cause at least one adjacent property minor consequence damage.

MEDIUM 3

5% Limited damage to part of structure, and/or part of site requiring some reinstatement stabilisation works. MINOR 4

0.5%

Little damage. (Note for high probability event (Almost Certain), this category may be subdivided at a notional boundary of 0.1%. See Risk Matrix.)

INSIGNIFICANT 5

Notes: (2) The Approximate Cost of Damage is expressed as a percentage of market value, being the cost of the improved value of the unaffected property which includes the

land plus the unaffected structures. (3) The Approximate Cost is to be an estimate of the direct cost of the damage, such as the cost of reinstatement of the damaged portion of the property (land plus

structures), stabilization works required to render the site to tolerable risk level for the landslide which has occurred and professional design fees, and consequential costs such as legal fees, temporary accommodation. It does not include additional stabilisation works to address other landslides which may affect the property.

(4) The table should be used from left to right; use Approximate Cost of Damage or Description to assign Descriptor, not vice versa

Geoton Pty Ltd (adapted from Australian Geomechanics Vol 42 No 1 March 2007) 2

QUALITATIVE TERMINOLOGY FOR USE IN ASSESSING RISK TO PROPERTY (CONTINUED) QUALITATIVE RISK ANALYSIS MATRIX – LEVEL OF RISK TO PROPERTY

LIKELIHOOD CONSEQUENCES TO PROPERTY (With Indicative Approximate Cost of Damage) Indicative Value of

Approximate Annual Probability

1: CATASTROPHIC200%

2: MAJOR60%

3: MEDIUM20%

4: MINOR5%

5:INSIGNIFICANT

0.5%

A – ALMOST CERTAIN 10-1 VH VH VH H M or L (5)

B - LIKELY 10-2 VH VH H M L C - POSSIBLE 10-3 VH H M M VL

D - UNLIKELY 10-4 H M L L VL

E - RARE 10-5 M L L VL VL

F - BARELY CREDIBLE 10-6 L VL VL VL VL Notes: (5) For Cell A5, may be subdivided such that a consequence of less than 0.1% is Low Risk.

(6) When considering a risk assessment it must be clearly stated whether it is for existing conditions or with risk control measures which may not be implemented at the current time.

RISK LEVEL IMPLICATIONS

Risk Level Example Implications (7)

VH VERY HIGH RISK Unacceptable without treatment. Extensive detailed investigation and research, planning and implementation of treatment options essential to reduce risk to Low; may be too expensive and not practical. Work likely to cost more than value of the property.

H HIGH RISK Unacceptable without treatment. Detailed investigation, planning and implementation of treatment options required to reduce risk to Low. Work would cost a substantial sum in relation to the value of the property.

M MODERATE RISK May be tolerated in certain circumstances (subject to regulator’s approval) but requires investigation, planning and implementation of treatment options to reduce the risk to Low. Treatment options to reduce to Low risk should be implemented as soon as practicable.

L LOW RISK Usually acceptable to regulators. Where treatment has been required to reduce the risk to this level, ongoing maintenance is required.

VL VERY LOW RISK Acceptable. Manage by normal slope maintenance procedures.

Note: (7) The implications for a particular situation are to be determined by all parties to the risk assessment and may depend on the nature of the property at risk; these are only given as a general guide

Appendix C Some Guidelines for Hillside Construction

PRACTICE NOTE GUIDELINES FOR LANDSLIDE RISK MANAGEMENT 2007

Australian Geomechanics Vol 42 No 1 March 2007

APPENDIX - SOME GUIDELINES FOR HILLSIDE CONSTRUCTION

GOOD ENGINEERING PRACTICE POOR ENGINEERING PRACTICE ADVICE

GEOTECHNICAL ASSESSMENT

Obtain advice from a qualified, experienced geotechnical practitioner at early stage of planning and before site works.

Prepare detailed plan and start site works before geotechnical advice.

PLANNING SITE PLANNING Having obtained geotechnical advice, plan the development with the risk

arising from the identified hazards and consequences in mind. Plan development without regard for the Risk.

DESIGN AND CONSTRUCTION

HOUSE DESIGN Use flexible structures which incorporate properly designed brickwork, timber or steel frames, timber or panel cladding. Consider use of split levels. Use decks for recreational areas where appropriate.

Floor plans which require extensive cutting and filling. Movement intolerant structures.

SITE CLEARING Retain natural vegetation wherever practicable. Indiscriminately clear the site. EARTHWORKS Retain natural contours wherever possible. Indiscriminatory bulk earthworks.

CUTS Minimise depth. Support with engineered retaining walls or batter to appropriate slope. Provide drainage measures and erosion control.

Large scale cuts and benching. Unsupported cuts. Ignore drainage requirements

FILLS

Minimise height. Strip vegetation and topsoil and key into natural slopes prior to filling. Use clean fill materials and compact to engineering standards. Batter to appropriate slope or support with engineered retaining wall. Provide surface drainage and appropriate subsurface drainage.

Loose or poorly compacted fill, which if it fails, may flow a considerable distance including onto property below. Block natural drainage lines. Fill over existing vegetation and topsoil. Include stumps, trees, vegetation, topsoil, boulders, building rubble etc in fill.

ROCK OUTCROPS & BOULDERS

Remove or stabilise boulders which may have unacceptable risk. Support rock faces where necessary.

Disturb or undercut detached blocks or boulders.

RETAINING WALLS

Found on rock where practicable. Provide subsurface drainage within wall backfill and surface drainage on slope above. Construct wall as soon as possible after cut/fill operation.

Construct a structurally inadequate wall such as sandstone flagging, brick or unreinforced blockwork. Lack of subsurface drains and weepholes.

FOOTINGS Found within rock where practicable. Use rows of piers or strip footings oriented up and down slope. Design for lateral creep pressures if necessary. Backfill footing excavations to exclude ingress of surface water.

Found on topsoil, loose fill, detached boulders or undercut cliffs.

SWIMMING POOLS

Engineer designed. Support on piers to rock where practicable. Provide with under-drainage and gravity drain outlet where practicable. Design for high soil pressures which may develop on uphill side whilst there may be little or no lateral support on downhill side.

DRAINAGE

SURFACE

Provide at tops of cut and fill slopes. Discharge to street drainage or natural water courses. Provide general falls to prevent blockage by siltation and incorporate silt traps. Line to minimise infiltration and make flexible where possible. Special structures to dissipate energy at changes of slope and/or direction.

Discharge at top of fills and cuts. Allow water to pond on bench areas.

SUBSURFACE Provide filter around subsurface drain. Provide drain behind retaining walls. Use flexible pipelines with access for maintenance. Prevent inflow of surface water.

Discharge roof runoff into absorption trenches.

SEPTIC & SULLAGE

Usually requires pump-out or mains sewer systems; absorption trenches may be possible in some areas if risk is acceptable. Storage tanks should be water-tight and adequately founded.

Discharge sullage directly onto and into slopes. Use absorption trenches without consideration of landslide risk.

EROSION CONTROL &

LANDSCAPING

Control erosion as this may lead to instability. Revegetate cleared area.

Failure to observe earthworks and drainage recommendations when landscaping.

DRAWINGS AND SITE VISITS DURING CONSTRUCTION DRAWINGS Building Application drawings should be viewed by geotechnical consultant SITE VISITS Site Visits by consultant may be appropriate during construction/

INSPECTION AND MAINTENANCE BY OWNER OWNER’S

RESPONSIBILITY

Clean drainage systems; repair broken joints in drains and leaks in supply pipes. Where structural distress is evident see advice. If seepage observed, determine causes or seek advice on consequences.

PRACTICE NOTE GUIDELINES FOR LANDSLIDE RISK MANAGEMENT 2007

Australian Geomechanics Vol 42 No 1 March 2007

Documents

GEOTECHNICAL INVESTIGATION AND LANDSLIDE RISK … rosebery wwtp - appendix q1... · 5 LANDSLIDE HAZARD The site is not within an area mapped for landslide hazards by MRT. However,