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P:\2014JOBS\14031\Reports\14031-Crown Sydney Basement Design RPT-Rev 3-140620.doc
Basement Design Report Site 1C
Crown Sydney Hotel Resort
Issue: Rev 3
Prepared For: Crown Sydney Property Pty Ltd
Project No.: 14031
20th June 2014
Report No.: 14031_RPT0002
Basement Design Report Site 1C Crown Sydney Hotel Resort Project No. 14031 Issue: Rev 3 20th June 2014
P:\2014JOBS\14031\Reports\14031-Crown Sydney Basement Design RPT-Rev 3-140620.doc
Report Amendment Register
Issue Section & Page
No. Issue/Amendment
Author/
Initials Project
Engineer Reviewer/
Initials Date
1 DRAFT GW 7-04-14
2 Planning Submission GW CP 12-04-14
3 Final Planning
Submission GW CP 20-06-14
ISSUE ACCEPTED BY: AUTHOR: REVIEWER: ………………………………….. ………………………………….. GRANT WEIR CHRIS POTTER Signing for and on behalf of Signing for and on behalf of Robert Bird Group Pty Ltd Robert Bird Group Pty Ltd Date: 20th June 2014 Date: 20th June 2014
Basement Design Report Site 1C Crown Sydney Hotel Resort Project No. 14031 Issue: Rev 3 20th June 2014
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1 General ......................................................................................................................... 1
1.1 Introduction ........................................................................................................................................1
1.1.1 Document scope ...........................................................................................................................1 1.1.2 Project Description ........................................................................................................................1
1.2 Referenced documents .....................................................................................................................2
1.2.1 Standards and codes ....................................................................................................................2 1.2.2 Specifications ................................................................................................................................3 1.2.3 Consultant reports .........................................................................................................................3
2 Design Loads and Performance Criteria ................................................................... 3
2.1 BCA Structural Importance Level .....................................................................................................3
2.2 Design Life ..........................................................................................................................................3
2.3 Primary Loads ....................................................................................................................................3
2.3.1 Gravity loads .................................................................................................................................4 2.3.2 Wind Loads ...................................................................................................................................4 2.3.3 Earthquake Loads .........................................................................................................................5 2.3.4 Hydrostatic Loads .........................................................................................................................5 2.3.5 Serviceability .................................................................................................................................5
2.4 Ultimate Strength and Stability Performance Criteria ....................................................................5
2.5 Serviceability Performance criteria ..................................................................................................5
2.5.1 Floor design criteria ......................................................................................................................5
2.6 Structural Modelling ..........................................................................................................................6
2.7 Material Properties .............................................................................................................................6
2.7.1 Reinforcement properties ..............................................................................................................6 2.7.2 Concrete Properties ......................................................................................................................6 2.7.3 Reinforcement properties ..............................................................................................................6 2.7.4 Cover requirements ......................................................................................................................6
2.8 Crack control ......................................................................................................................................7
3 Footings ....................................................................................................................... 7
3.1 Tower footings....................................................................................................................................7
3.1.1 Concrete Properties ......................................................................................................................7 3.1.2 Reinforcement properties ..............................................................................................................7 3.1.3 Cover requirements ......................................................................................................................7
4 Basement Structure .................................................................................................... 8
Basement Design Report Site 1C Crown Sydney Hotel Resort Project No. 14031 Issue: Rev 3 20th June 2014
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1 General
1.1 Introduction
1.1.1 Document scope
This document outlines the basis for the structural engineering design for the basement on Site 1C for the Crown Sydney Hotel Resort Project.
This document is a live document and will be updated throughout the life of the project. Updates will only be made with the authority of the Project Engineer. At the end of the project this document will form part of Robert Bird Group record of the structural design and used in the validation of the as-installed work.
1.1.2 Project Description
The Crown Sydney Hotel Resort Project is a mixed use project made up of the following –
Three basement levels comprising car parking, circulation, plant and loading dock facilities.
Ground/Level 0 comprising; Hotel and Casino Lobby, Porte Cochere, Retail, Restaurant, Bars, Terraces, public space, landscaping and amenities, and BOH spaces.
Four main podium levels and three mezzanine podium levels above Ground comprising Restaurants, Gaming, Bars, Kitchens, BOH, Plant, Pool decks, recreation spaces and Function rooms.
A mixed use Tower to level 70 comprising Hotel, Villas, Sky Gaming, Apartments, Plant and Super Villas. Height to tip of roof is approximately 271m with the tip at RL275m
The tower is irregular in plan form and is tapered/curved and twisted in elevation
This report deals specifically with the basement elements located on the Site 1C area as illustrated below.
Basement Design Report Site 1C Crown Sydney Hotel Resort Project No. 14031 Issue: Rev 3 20th June 2014
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1.1.3 Existing Structures
The 1C Site contains some structure remnants and existing structures relating to its use as a maritime wharf area. There are existing sea wall caissons along the foreshore at the western edge that will remain post development. There is also a remnant section of this sea wall that returns into the 1C Site projecting in an easterly direction through the northern end of the basement and projecting into the 1B Site. The sea wall caissons are individual concrete units approximately 15m long by 12m wide by 13m high. They are reinforced concrete boxes with internal cells of approximately 4.5m square. The units were constructed off-site and floated into place and sunk. The cells were filled with river sand, rather than on site materials. This has been verified during demolition of caissons on Site 1A and at Barangaroo Headland Park. This also matches the original design documents. The basement construction will require demolition of approximately three caisson units.
The site also contains a section of reinforced concrete wharf deck. A new deck will be built over this deck with new supporting piles cut through the old deck which will remain in place.
1.2 Referenced documents
1.2.1 Standards and codes
The following standards and codes will be used for the structural design of the basements:
Building Code of Australia - 2013
AS1170.0 General Loading
AS1170.1 Imposed Loads
AS1170.2 Wind Code
AS1170.4 Earthquake Code
AS2159 Piling Design and Installation
AS2327.1 Composite Structures
AS3600 Concrete Structures
AS3700 Masonry Structures
AS3735 Concrete Structures Retaining Liquids
AS4100 Steel Structures
AS4671 Steel Reinforcing
AS4678 Earth-retaining structures
AS5100 Bridge Code
BS8002 Earth Retaining Structures
BS8081 Ground Anchorages
BS8110 Concrete Structures
BS8102 1990 Code of Practice for Protection of Structures Against Water from the Ground
ACI-318M – 02
Eurocodes
ISO 6897 - 1984
Basement Design Report Site 1C Crown Sydney Hotel Resort Project No. 14031 Issue: Rev 3 20th June 2014
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1.2.2 Specifications
The following specifications form part of the contract documents produced by Robert Bird Group:
Early works general requirements
Earthwork
Insitu concrete
Concrete formwork
Concrete reinforcement
Concrete finishes
Piling
Post tensioned concrete
Structural steel
Shotcrete
Temporary rock anchors
Permanent rock anchors
Masonry
Monitoring program
Structural Performance Brief Perimeter Earth Retention Systems
Structural Technical Brief Perimeter Earth Retention Systems
1.2.3 Consultant reports
The following reports will be used to obtain critical design information and provide guidance during structural design:
Geotechnical reports by Coffey Geotechnics Pty Ltd
2 Design Loads and Performance Criteria
2.1 BCA Structural Importance Level
The structural importance level assessed under the BCA-13 is:
Structural Importance Level 3.
2.2 Design Life
The design life for the Crown Sydney Project is 50 years.
2.3 Primary Loads
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2.3.1 Gravity loads
2.3.1.1 Dead Load
For the purpose of the design of slabs, beams and the strength design of walls and columns the self weight of concrete shall be taken as 24kN/m3.
For axial shortening calculations and vibration analysis concrete self weight may be taken as per the supplier’s recommendations but not less than 23.5 kN/m3.
The self weight of structural steel sections will be as per the manufacturers data. For fabricated sections the self weight of structural steel shall be taken as 78.5 kN/m3.
2.3.1.2 Superimposed dead load
Unless noted otherwise the superimposed dead load allowances given here will include an allowance for floor finishes, ceiling finishes, light weight partitions, mechanical and hydraulic services, joinery and fixtures. Masonry partition weights and machinery plinths or supports are to be calculated separately. These loads are the minimum loads to be adopted for slab and beam design. These loads may be modified for column shortening calculations and frequency assessment of the building. A check calculation of the required floor load must be carried out to verify the load below is applicable. The check calculation should use the component base loads listed below.
Lobbies 2.5kPa
Porte Cochere 5.0kPa
Car park levels 0.5kPa
2.3.1.3 Live loads
Unless noted otherwise the following minimum live loads are to be used for design. These are derived from AS1170.1 and the client brief.
Lobby , public spaces 5.0kPa
Plant Rooms 5.0kPaMin.
Lime Street Roadway 15.0kPa
Planters Above Ground (assume min 600mm deep) 4.0kPa
Escape Stairs 4.0kPa
Porte Cochere 10.0kPa
Car park levels 2.5kPa
Car Stacker area 5.0kPa
Loads due to dynamic effects of machinery are to be verified separately. Impact loads in the car park are to be assessed in accordance with AS1170.
2.3.2 Wind Loads
Annual probability of exceedance 1:1000
Region A2
Terrain Category 3
Terrain Category 4 from East
V1000 = 46m/s (ultimate)
V100 = 41m/s (for serviceability)
Basement Design Report Site 1C Crown Sydney Hotel Resort Project No. 14031 Issue: Rev 3 20th June 2014
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V5 = 32m/s (for occupancy comfort)
Wind direction multiplier Md = 0.95
Shielding multiplier Ms = 1.0
Topographic multiplier Mt = 1.0
2.3.3 Earthquake Loads
Annual probability of exceedance, P= 1/1000
Kp = 1.3
Site Sub-Soil Class = Ce
Hazard Factor Z =0.08
Structural Ductility Factor, 2
Structural performance Factor, Sp = 0.77
2.3.4 Hydrostatic Loads
Annual probability of exceedance 1:50
Design Level RL2.2m
Ultimate Combination factor 1.2
2.3.5 Serviceability
Generally the load combinations for strength will be derived from AS1170.
2.4 Ultimate Strength and Stability Performance Criteria
The element capacities shall be greater than or equal to the design action effect.
Ru >= S*
2.5 Serviceability Performance criteria
2.5.1 Floor design criteria
2.5.1.1 Deflection
Incremental Deflection
General Span/500 or 25mm (whichever is less)
Supporting masonry Span/1000
Cantilevers Cantilever/250
Long Term Deflection
Slabs Span/250 or 25mm (whichever is less)
Beams Span/500 or 25mm (whichever is less)
Supporting Masonry Span/500
Cantilevers Cantilever/125 or 25mm (whichever is less)
Basement Design Report Site 1C Crown Sydney Hotel Resort Project No. 14031 Issue: Rev 3 20th June 2014
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Total allowable 30mm to end spans
(Slab + Beam) 25mm to internal spans
2.6 Structural Modelling
The lateral system for the building will be modelled using ETABS. The model will be a three dimensional model. Two separate models will be produced, a serviceability model and a strength model. The serviceability model will be used for frequency analysis to assess the building against the serviceability performance criteria. The strength model will be used for the structural strength design of the lateral system.
2.7 Material Properties
The following material properties will be adopted in the design.
2.7.1 Reinforcement properties
All reinforcing steel shall be in accordance with AS4671.
Normal ductility deformed bar grade 500 shall be used.
High strength stress bar shall have a minimum 0.1% proof stress of 810MPa. Modulus of elasticity shall be as per manufacturer’s data.
2.7.2 Concrete Properties
Characteristic (28 Days) Concrete Compressive Strength f’c (MPa)
Modulus of Elasticity Ec Mpa
25 27500 32 31000 40 34500 50 38000 60 41000 70 43400 80 44700
Creep coefficients – Code coefficients will be adopted.
Shrinkage strain – Code coefficients will be adopted.
2.7.3 Reinforcement properties
All reinforcing steel shall be in accordance with AS4671.
Normal ductility deformed bar grade 500 shall be used.
2.7.4 Cover requirements
The exposure classification shall be as follows:
Basements A1
FRL shall be as follows:
Basements 90/90/90
Plant rooms 90/90/90
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Cover Schedule
The following are minimum covers and where greater are required by AS3600 for fire or durability the code shall govern.
Characteristic (28 Days) Concrete Compressive
Strength f’c (MPa)
Cover to outer most reinforcement layer
(mm) internal general
Cover to outer most reinforcement layer
(mm) Commercial and Retail internal
Cover to outer most reinforcement layer
(mm) external general
25 25 40 n.a. 32 25 40 40 40 25 40 30 50 25 40 25 60 25 40 25 70 25 40 25 80 25 40 25 90 25 40 25 100 25 40 25
2.8 Crack control
The minimum degree of crack control adopted for the basement will be moderate as defined in AS3600. Generally all external slabs shall have a continuous top mat of reinforcement. Slabs that have significant restraint may require more stringent crack control.
All post tensioned slabs shall have a minimum P/A of 1.4MPa in the secondary direction for crack control calculations.
3 Footings
3.1 Tower footings
The tower footings are proposed as a series of barrette elements socketed into class II sandstone. These will be further refined in size and socket depth as the structure design progresses. Large diameter bored piers may also be considered for the lighter loaded helical columns. These will also be socketed into class II sandstone.
Foundations will be further covered in a performance specification.
3.1.1 Concrete Properties
Characteristic (28 Days) Concrete Compressive Strength f’c (MPa)
Modulus of Elasticity Ec MPa
40 34500 50 38000 60 41000
3.1.2 Reinforcement properties
All reinforcing steel shall be in accordance with AS4671.
Normal ductility deformed bar grade 500 shall be used.
3.1.3 Cover requirements
Minimum cover shall be 75mm bottom and sides, 50mm top. 100mm to barrettes
Basement Design Report Site 1C Crown Sydney Hotel Resort Project No. 14031 Issue: Rev 3 20th June 2014
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4 Basement Structure
The Basement structure comprises two main areas, site 1B to the East and Site 1 C to the West, each with a different construction methodology proposed. A permanent movement joint is proposed between site 1B and site 1C. The basement accommodates parking, Loading Dock and some plant areas and is three levels below ground. This report specifically covers the Site 1C area. The basement shoring system is proposed as a perimeter diaphragm wall (D wall) which will act as the temporary and permanent retaining wall. The wall will be a design and construct package let as an early works item. The D wall will be constructed in 6m panel widths under bentonite and panels will be 800mm – 1200mm thick as determined by the wall contractor. The panels will extend a minimum of 0.5m into class IV or better sandstone and some will extend further based on the individual panel design loads. The D wall is covered by separate specifications covering performance and technical requirements as referenced above. The wall will be designed as a waterproof element in the basement zone in accordance with relevant design codes. The performance specification defines the level of water tightness. A maximum inflow through the wall of 0.75 litres per minute is specified for the entire 1C site D wall. The Brief contains additional watertightness requirements: No more than ten per cent of the wall can appear damp. No free flowing water is acceptable, and there is to be no ponding of water at the joint between the wall and the B 3 Hydrostatic slab. Occurrence of any of these would be regarded as a defect and rectification is required under the brief. These requirements are set at a level higher than the environmental analysis of vapour generation to ensure the quality of watertightness expected from the design and construct D wall Contractor. The sequence of work is such that temporary anchors are not required for lateral support however some vertical anchors may be adopted for overturning and shear resistance to in plane forces if required by the contractor. The basement to Site 1 C which is under the main tower is proposed to be constructed using a top down top up construction sequence to reduce total construction time. The proposed sequence is detailed in the Basis of Design Report but essentially it has ground floor slab cast first followed by the B1 slab, then B3 slab and finally the B2 slab. The tower will be constructed above ground floor simultaneously with excavation and construction of the basements. Tower foundations will be a mix of barrette piles and bored piles socketed into class II or better sandstone. The podium columns and basement columns beyond the tower footprint will be bored piles socketed into rock with a cast in steel plunge column section required to suit the top down top up construction sequence.
The basement structure requires the B3 slab to be designed as a hydrostatic slab to resist uplift from ground water. The groundwater level fluctuates tidally and is generally between RL0.5m and RL 1.0m. The basement 3 slab and piles will be designed to resist Groundwater to RL2.2m being the flood level based on a minimum annual probability of exceedance of 1:50. An ultimate load factor of 1.2 will be taken for hydrostatic action. The B3 slab is generally 1200mm thick with local thickenings or drop panels 1600mm thick at columns and wall supports to increase punching shear capacity. The slab is heavily reinforced due to the extremely high uplift loads. The slab will be cast on a waterproof membrane system which will be laid on a blinding slab. The membrane will be protected by a protection board as required prior to placement of the B3 slab reinforcement. The membrane system will be specified by the Project Architect and is the primary waterproofing defence for the B3 slab. We understand that a Perfrufe cold fusing membrane system is proposed. The B3 slab will also be designed as a waterproof element using the provisions of BS8102 as a second line of defence against water ingress. All joints will contain waterstops and construction joints will include hydrophilic waterstops as well as re-injectable seals.
Basement Design Report Site 1C Crown Sydney Hotel Resort Project No. 14031 Issue: Rev 3 20th June 2014
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Temporary dewatering is required to excavate and cast the basement slab and the groundwater and excavated material are subject to existing contamination. Refer the environmental consultant for contamination and remediation treatments. The hydrostatic uplift after de-watering is turned off exceeds the self-weight of the basement and ground floor structure and so permanent tension piles will be required to hold the structure down in zones outside the tower footprint. These will be bored piles socketed into rock to provide sufficient uplift resistance as well as being capable of resiting downwards loads from dead and live loads. Suitable measures will be required to prevent issues of heat of hydration and differential heat of hydration when casting the B3 slab. Measures such as chilled water, low heat cement and insulation may be required to ensure heat of hydration and differential temperatures are controlled in the B3 slab. The B 2 slab is proposed to be cast on conventional formwork and comprises a reinforced slab and band beams. Some of the larger spans have post tensioning in the band beams. The B1 slab is largely a flat slab to Site 1C to suit easier top down construction. The slab will be mainly conventionally reinforced with only a few post tensioned band beams adopted in large span areas near the loading dock. The Ground floor slab is to be cast on conventional formwork and as such a banded slab has been adopted. Post tensioning is used in heavy load areas and long span areas. Basement columns will comprise barrettes piles and steel lined bored piers in the tower area and concrete encased fabricated steel plunge columns in the areas outside the tower footprint. The encased columns will also contain conventional reinforcement. The fabricated section is designed for a temporary load suited for the construction sequence and is embedded below founding level and encased in a reinforced concrete bored pier. The bored pier is sized for the permanent load case and will socket into class II sandstone or better. The steel section is encased in stabilised sand/ weak-mix grout from the underside of pile cap level to ground level. This is removed during top down excavation. The slabs are attached to welded steel seats on the way down and the column is ultimately concrete encased after the lowest basement is cast. Plunge column sizing will be detailed after a further program session with Lend Lease so as to establish steel column load demands based on the actual program. Sizing can vary considerably depending on the percentage of final load the steel section is required to carry. The final concrete column sizes in the top down basement area are impacted by the required steel plunge sections and will be advised after plunge column sections are calculated.
Brisbane Office Robert Bird Group Pty Ltd ABN 67 010 580 248 ACN 010 580 248 Level 5 333 Ann Street Brisbane Qld 4000 PO Box 7035 Riverside Centre Brisbane Qld 4001 Australia
P: +61 (0) 7 3319 2777 F: +61 (0) 7 3319 2799
www.robertbird.com
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