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Cairns Performing Arts Centre – Feasibility Study Overview– May 2013

Appendix Appendix Appendix Appendix 13131313 – Structural Report

Cairns Performing Arts Centre – Feasibility Study Overview– May 2013

Cairns Regional Council Cairns Entertainment Precinct Structural Engineering Brief

222621-20

Draft 3 | 14 February 2013

This report takes into account the particular instructions and requirements of our client.

It is not intended for and should not be relied upon by any third party and no responsibility is undertaken to any third party. Job number 222621-20

Arup Singapore Pte Ltd Reg No 200100731M

Arup 10 Hoe Chiang Road #26-01 Keppel Towers Singapore 089315 www.arup.com

222621-20 | Draft 3 | 14 February 2013 | Arup J:\222000\222621-00 CEP\20 - CEP STRUCTURES\DOCUMENTS\CEP STRUCTURAL BRIEF 130214.DOCX

Document Verification

Job title Cairns Entertainment Precinct Job number

222621-20 Document title Structural Engineering Brief File reference

Document ref 222621-20 Revision Date Filename CEP Structural Brief 03-02-12.docx Draft 1 5 Feb

2012 Description Initial 35% Design Development issue (based on 23 January

2012 architectural drawings) for comment

Prepared by Checked by Approved by

Name Josh Neil Josh Neil Josh Neil

Signature

Draft 2 5 March 2012

Filename CEP Structural Brief 120305.docx Description Revised 35% Design Development issue (based on 23 January

2012 architectural drawings). To be provided to Managing Contractor Tenders for information.


Name Josh Neil Josh Neil Josh Neil

Signature

Draft 3 13 Feb 2012

Filename Description Scheme Design Report to the Revised Scope


Name Scott Rathie Mathew Vola

Signature

Filename Description


Name

Signature

Issue Document Verification with Document



Contents Page

Executive Summary 1

1 General 1

1.1 The Development 1 1.2 The Site 1 1.3 The Parties and Services 2 1.4 The Arup Design Team 2

2 Structural Description 3

2.1 Performing Arts Building 3 2.2 Main Entry 10

3 Design Standards and Sources of Reference 11

3.1 Codes of Practice and Standards 11 3.2 Specifications 12

4 Design Loads 13

4.1 Dead Loads 13 4.2 Superimposed Dead Loads 13 4.3 Live Loads 13 4.4 Wind Loads 15 4.5 Seismic Loading 16 4.6 Imposed movements 16 4.7 Dynamics 16 4.8 Barrier loads 17 4.9 Structural Robustness 17

5 Serviceability 18

5.1 Deflection Limits 18 5.2 Concrete 18

6 Materials 20

6.1 Concrete 20 6.2 Reinforcement 20 6.3 Tensioning Strands 20 6.4 Structural Steel 21 6.5 Concrete Block 21



Figures Figure 1: Layout of the site Figure 2: Section of the Performing Arts Building Figure 3: Current Basement Scheme Figure 4: Preliminary sketch illustrating tanked basement construction, and temporary works requirements for basement excavation (batter slope where possible, and temporary shoring where site boundary proximity precludes use of batters). Figure 5: Level A Floor Scheme Figure 6: Roof Type 3 Indicative Scheme from the Previous Site Location



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Executive Summary The Purpose of this design brief is to summarise the data, assumptions, principles and methods to be used in the structural engineering design of Cairns Entertainment Precinct.

This document is intended primarily to record all relevant design criteria, project data and other relevant references pertaining to the structural engineering of the project. The contents will be added to or revised as new information becomes available.

It is understood that this document will be issued with in-progress preliminary structural framing plans to provide an indication of the likely extent and nature of the building structures on the project, for input in a project feasibility report. It is emphasized that the structural design is not complete, and may change with architectural or client changes, and as the detailed structural analysis and design is carried out.



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1 General

1.1 The Development The client’s brief for Stage 1 of the development is a world-class performing arts centre and community space. Within the budget the following elements are currently included.

· 1000 + seat main auditorium, studio and rehearsal space

· 500 seat auditorium adjacent to the main auditorium

· Car parking (optional)

The precinct may be expanded in the future to include a hotel/ mixed use building and or a commercial tower (stages 2 and 3). Whilst design of the future facilities is not part of the current project, where these potential facilities are positioned over stage 1 structures, consideration will be given to including capacity in stage 1 foundations and columns to support future facilities.

1.2 The Site The site is adjacent to the existing Cairn Convention Centre, separated by Grafton St as shown in Figure 2.

Figure 1: Layout of the site



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1.3 The Parties and Services Title Pen Portrait

Client Cairns Regional Council

Project Manager Savills

Managing Contractor TBC

Architect Cox Rayner CA Architects

Certifier Certis

Fire Safety Engineer Arup

Structural, Mechanical, Facade and Traffic

Arup

Theatre Planning Schuler Shook

Acoustics Acoustic Studio

Planning Urbis

Civil Engineering Cardno

Heritage Consultant Converge

Hydraulics Steve Paul and Partners

Geotechnical TBC

Wind Tunnel Testing and Wind Engineer

Windtech

Electrical Steensen Varming

Landscape Tract

ESD Cundall

1.4 The Arup Design Team The current Arup structural engineering team leaders for this project are:

Title Pen Portrait

Project Director Ian Ainsworth

Project Manager Josh Neil

Project Structural Engineer Mat Vola and Scott Rathie

Project Structural Technician Jason McKenzie

Cairns Regional Council Cairns Entertainment PrecinctStructural Engineering Brief


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2 Structural Description

General description and status The revised scope of works entails the performing arts building. This is currently at the scheme design phase.

2.1 Performing Arts Building

General Description The six level building provides theatre seating for 1000 patrons, together with associated front and back of house facilities, including public foyer spaces, orchestra pit, stage, rehearsal space, loading docks and car parking.

Figure 2: Section of the Performing Arts Building

There are currently two design options considered. The structural concept that has been documented is based on the scheme for Option 1 with the Foyer at Level 5.35m. Please note that Option 2 is still under consideration and is structurally similar to Option 1 excluding the basement slab and columns supporting Level A1.



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Design Status The functional and architectural design of the performing arts building had undergone several iterations during the concept, scheme, DA and early design development phases on an adjacent site. Now on this current site the project is at scheme design and incorporates a significantly different car park configuration and theatre spaces.

On the previous site at end of design phase 3 (February 2012), the basic form and framing systems and materials of the building structures have been defined. In the balance of the design development (phase 4) and detailed design/construction documentation (phase 5), detailed analyses of the structural framing, design and documentation of concrete reinforcement and post-tensioning and steel framing sizing and connection design will be completed. An alternative building configuration identified by the architect in late February 2012 involving a reduced basement extent, a single level loading dock and a modified back of house arrangement is currently being reviewed, and if adopted the structural framing changes arising from the alternative will be quantified and plans updated in the early part of design phase 4.

The new scheme on the current site incorporates design elements that were developed for the previous site.

Stability Acoustic requirements dictate that the theatre, stage and fly tower be surrounded by concrete walls. In addition there are several stair and lift cores that also need to have concrete walls to provide the acoustic performance specified by the acoustic consultant. Using reinforced concrete walls around the theatre, stage and fly tower in conjunction with reinforced concrete stair and lift shafts provides the building with adequate resistance to lateral loading from wind and seismic events. It is noted that several of the walls do not extend down to foundation level at the underside of the basement, and thus some structural transfers are required.

Foundations Whilst the appointment of a geotechnical consultant and the results of a site specific geotechnical investigation are still awaited, the preliminary geotechnical desktop report provided in the concept design phase and experience on the nearby Cairns Convention Centre site strongly suggests that there is no option but to fully support all significant structures on piled foundations due to the presence of weak and compressible marine alluvium. For the purpose of initial cost estimation commonly used “Frankipiles” average 20m long founding in stiff layers underlying the soft alluvium have been indicated on preliminary foundation plans (subject to confirmation when geotechnical information is available), but the final construction documentation will be on a performance basis to allow suppliers to utilise their proprietary systems to maximum efficiency. It is noted that there is likely to be some contamination of the site due to previous industrial uses, and also that there may be acid sulphate soils present. Refer to Civil Engineering Brief and reports, and geotechnical investigations (where available) for details of extent of contamination and acid sulphate soils, and the planned site remediation and mitigation measure to be adopted during excavation of the site.



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Basement For option 1 as shown in Section 2.1, Figure 2, a single level basement is located under the performing arts building. The ground level or above ground parking was recommended to be at a level of RL 2.1 AHD by Cardno. Taking into the self-weight of the slab on ground a floor level of RL 1.9 is acceptable when considering the small hydrostatic pressures with a bund around the car park of RL 2.1 to meet the flooding requirement. The performance arts building also requires ARI 100 year immunity and should therefore have its minimum floor level of RL 3.35 AHD. When a flood level reaches this level it is assumed that the car park would overflow and relieve the hydrostatic pressures.

The sub-stage basement floor slab set at approximately RL +1.35m will be subjected to large hydrostatic uplift pressures during extreme flood events (approximately 2m head of water). During normal service conditions the basement floor slab set at approximately RL +1.35m will be subjected to large hydrostatic uplift pressures in the order of 0.75 m head of water assuming ground water level close to the existing ground level of approximately RL+2.0m.

Figure 3: Current Basement Scheme

In order to resist uplift pressures, a heavily reinforced suspended concrete slab will be required to span between columns and or walls. A banded slab has been adopted to simplify reinforcement placement and to integrate pilecaps within the slab.

Control of water ingress to the basement at RL+1.35 could be achieved by use of membranes, or by design of the concrete floor as a water-resisting structure with limits on reinforcement service stresses and design crack widths. The use of a membrane is a more reliable method, and this has been indicated on preliminary drawings together with a blinding layer under the slab to support and protect the



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membrane. It is noted that whichever system is adopted, it is likely that there will be some degree of water ingress into the basement, and prudent precautions should be taken such as incorporation of perimeter spoon drains, falling of slab to drains, provision of a sump with pump, and provision for a lining to perimeter walls to hide damp or stained walls

The carppark is likely to require 0-0.5m of fill due to the fall of the site. Where the perimeter wall is likely to be too close to the site boundary allow the use of temporary cut batter slopes a temporary shoring system to be designed and provided by the contractor. It is also likely that measures such as temporary dewatering and placement of a crushed rock working platform over a geotextile layer will be required to facilitate construction activities in the excavation for the lower sub stage basement.

It is noted that there is potential scope for the costs of the basement structure to be somewhat reduced by considering the adoption of a lower flood protection level for the carpark entry – i.e. if the crest of the entry was lowered to a level with a lower average recurrence interval than the current 100 year level of RL+3.35m which was selected in the concept design phase (either 20 year or 50 year), the magnitude of the maximum possible uplift pressure would be reduced, resulting in reductions in concrete and reinforcement quantities in the basement slab. Any change in the level of flood immunity to be provided for the basement would require client approval.

Figure 4: Preliminary sketch illustrating tanked basement construction, and temporary works requirements for basement excavation (batter slope where possible, and temporary shoring where site boundary proximity precludes

use of batters).

Structural Scheme for Stage Pit for scheme with Foyer at RL3.35

[TdoanpoanUchpu



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Floors All structural floors within the Performing Arts Building are expected to be concrete slabs supported by walls or concrete beams. Beams are likely to be a combination of reinforced and post tensioned construction, with tensioning used where required by limitations on available depth (e.g. transfer beams), and where required for deflection control (e.g. cantilever beams supporting balcony seating). Within the auditorium, acoustic and air-conditioning supply requirements dictate that “double slabs” are required in some areas, with upper tiered floors supported off the structural slabs below. Detailed review of buildability, architectural, acoustic and building services considerations will be required to finalise the most appropriate materials and form for the non-structural tiered floors.

Rigging platforms and the like above stage level within the fly tower are expected to be steel framed.

Figure 5: Level A Floor Scheme

Vertical structure The vertical structure of the building will be concrete columns and walls supporting floor structure.



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Roof Roof Type 1 (Lobby): A lower soffit lining is expected to be required in the lobby area to create a ceiling space to accommodate services (sprinklers, airconditioning ductwork, lights etc) and the more substantial acoustic insulation and mass layers required to ensure that the lobby is acoustically protected from break-in of external noise. The lobby roof framing is still to be confirmed but based off the original scheme be a single layer steel supported on the walls of the lobby spaces and possibly off the glass wall mullions. The lobby roof will be designed to support the various mechanical installations (AHU and Chiller) required.

Roof type 2 (Auditorium and Fly Tower): The roof over the auditorium and fly tower are expected to be multi-layer constructions to achieve the high level of acoustic performance specified by the acoustic consultant. The lowest layer will be the structural roof, which is envisaged to be a concrete slab cast on permanent profiled steel formwork (bondek) supported on and acting compositely with steel beams and trusses spanning between the perimeter structural concrete walls of the auditorium and fly tower. Some of these trusses will also form and support catwalks for rigging and maintenance access. The selection of this form for the structural roof has been driven by buildability and safety considerations, and removes the need for any temporary propping or formwork in the high spaces above the auditorium seating and the stage. The final layer will be a a standard steel roof sheeting supported off purlins. The framing in this area will however be lighter than the plaza and foyer roof framing due to the ability to support this upper roof layer directly off the structural roof slab. Waterproofing of the layered roof is still under development by the architect, but it is likely that the primary waterproofing will be at the top layer, with a second layer on top of the upper concrete slab.

Roof Type 3 (Back of House Roof): The roof to back of house areas is expected to be a series of relatively simple skillion roofs with steel rafters, steel purlins and conventional profiled steel roof sheeting. A ceiling will be suspended under the roof, but given the high internal pressures corresponding to the cyclonic wind environment and the depth of the ceiling void that will be several meters deep in parts, it is expected that the ceiling will need to be provided with secondary framing and ceiling purlins rather than relying upon a conventional suspended ceiling.



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Figure 6: Roof Type 3 Indicative Scheme from the Previous Site Location



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2.2 Main Entry

General The majority of the plaza is a paved surface set above the 100 ARI flood level of RL+3.35m (corresponding with the Performing Arts building), with ramps and stairs leading down to street level at approximately RL+1.35-2m.

Plaza slab and Foundations Whilst the appointment of a geotechnical consultant and the results of a site specific geotechnical investigation are still awaited, the preliminary geotechnical desktop report provided in the concept design phase and experience on the nearby Cairns Convention Centre site strongly suggests that there is no option but to fully support all significant structures on piled foundations due to the presence of weak and compressible marine alluvium. In order to accommodate the complex arrangement of hard paving, steps, ramps, planters without risking the development of differential settlements and resulting trips hazards and damage to floor finishes; a suspended slab supported by ground beams on piles has been specified for the majority of the plaza area. It is also noted that to try and form the plaza slab as a slab-on-ground construction would require the placement of more than a meter of fill over this area to bring the current ground level of approx RL + 2.0m up to the finished level of RL +3.35m. The placement of this fill could be expected to generate substantial settlements due to consolidation of the soft underlying alluvium. For the purpose of initial cost estimation, commonly used “Frankipiles” average 20m long founding in stiff layers underlying the soft alluvium have been indicated on preliminary foundation plans (subject to confirmation when geotechnical information is available), but the final construction documentation of the piles will be on a performance basis to allow suppliers to utilise their proprietary systems to maximum efficiency. It is noted that there is likely to be some contamination of the site due to previous industrial uses, and also that there may be acid sulphate soils present. Refer to Civil Engineering Brief and reports, and geotechnical investigations (where available) for details of extent of contamination and acid sulphate soils, and the planned site remediation and mitigation measure to be adopted during excavation of the site.



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3 Design Standards and Sources of Reference The design and documentation of the building and associated works shall comply with the Design Brief Documents as well as the project BIM plan provided by Cox.

3.1 Codes of Practice and Standards

3.1.1 Design Standards The following codes and standards will form the basis for the structural design:

AS/NZS 1170 Pt 1 Loading Code - Dead and Live Loads

AS/NZS 1170 Pt 2 Loading Code - Wind Loads

AS/NZS 1170 Pt 4 Loading Code - Earthquake Loads

AS 2121 Cold Formed Steel Structures Code

AS 2327 Pt 1 Composite Construction Code - Simply Supported Beams

AS 3600 Concrete Structures Code

AS 3700 Masonry Code

AS 4100 Steel Structures Code

BCA Building Code of Australia (relevant extracts below)

Table B1.2a Importance Levels of Buildings and Structures Importance Level Building Types

1 Buildings or structures presenting a low degree of hazard to life and other property in the case of failure.

2 Buildings or structures not included in Importance Levels 1, 3 and 4.

3 Buildings or structures that are designed to contain a large number of people.

4 Buildings or structures that are essential to post-disaster recovery or associated with hazardous facilities.

Table B1.2b Design Events for Safety

Importance Level

Annual probability of exceedance

Wind Snow

Earthquake Non-cyclonic Non-cyclonic Cyclonic

1 1:100 1:200 1:100 1:250

2 1:500 1:500 1:150 1:500

3 1:1000 1:1000 1:200 1:1000

4 1:2000 1:2000 1:250 1:1500



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3.2 Specifications Specifications are to be provided for:

Piling Concrete (Reinforcement, Formwork, Material inc. Precast) Structural Steel

Outline specifications have been produced during design phase 3 to provide prospective Managing Contractors with an indication of likely specification extent and content.



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4 Design Loads

4.1 Dead Loads The assumed dead loading for this project is listed below

Description Assumed loading Comments

Concrete 24 kN/m3 (25kN/m3 for heavily reinforced sections).

Steel 78.50 kN/m3

Concrete masonry 21.4 kN/m3 Also allow for render or plasterboard finishes as required.

Sheeting and secondary supporting steel work

0.25 kPa (max) 0.75 kPa (max)

Roof specification

Figure 9 - Dead Load Unit Weights

4.2 Superimposed Dead Loads Block work partitions: To be calculated, but not less than 2.5 kPa on elevation Cavity Walls: To be calculated, but not less than 3.5 kPa on elevation Cladding sheeting and fixings: To be calculated, but not less than 0.5 kPa on

elevation

4.3 Live Loads

4.3.1 Typical Floor Live Loads Refer Structural Loading Plans, and Theatre Consultant drawings for rigging loads.

The live load values for use in analysis and design are summarised below.

General Area Specific Area Use Uniformly distributed load (kPa)

Common Public Spaces Theatre Main Lobby Mezzanine

5.0 5.0 5.0

Roof Access for maintenance 0.25

Plant Rooms General 5.0

Stage and Back of House 7.5

In the interests of clarity, structural loading plans will be produced to define the magnitude and extent of design loads for all floors. Samples of preliminary loading plans are attached below. These will be updated as the design develops.



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4.3.2 Live Load Reduction Live load reduction is a statistical concept which recognizes the fact that the

larger an area supported by an element, the less likely that the full design load is likely to act over the entire area.

Where appropriate, live load reduction should be used for Column design Piles Pile caps Pad footings Core walls

0.5 < ψa < 1.0 ψa = 1.0 for the following

areas covered by activity or occupancy C3, C4 and C5 (T 3.1) Storage areas on which imposed floor actions exceed 5 KPa Light and medium traffic areas Imposed actions for machinery and equipment One way slabs and beams

The critical loading case for the ultimate limit state occurs when an area of 18 m2 (the maximum area for which ψa = 1.0) is loaded and adjacent areas are loaded with an arbitrary point in time load. (AS1170.1 supp)

4.4 Wind Loads All design wind loading is to be confirmed by the Wind Engineer.

For the purpose of preliminary design in phases 2 and 3, Design Wind Loads have been assessed in accordance with AS/NZS 1170.2

Importance Level III

Annual Probability of exceedance 1:1000

Region C

Regional wind speed V1000 (ult) 73.5 m/s

Basic wind speed V20 (serv) 45 m/s

Wind Direction Multiplier Md 0.95 for Trusses and Frames, 1.0 for cladding

Terrain Category 2

Terrain / Height Multiplier Mz,cat 0.83 to 0.94 (10 to 20m Height range)

Shielding Ms 1.0



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4.5 Seismic Loading Earthquake loading applied to the structural elements will be assessed in accordance with AS 1170.4 - 2007 Earthquake Code.

Importance Level III

Probability of Exceedance 1:1000

Probability Factor, kp 1.3

Hazard Factor, Z 0.06

Soil Classification De – Deep or soft soil site (to be confirmed by Geotechnical Engineer)

Earthquake Design Category II

4.6 Imposed movements The effect of imposed movements on the structure will be considered in the calculations. These include the following types of movement:

Settlement either absolute of differential Heave either absolute or differential Temperature range either absolute of differential Shrinkage when restrained between stiff elements Creep of axially loaded members and flexural members Elastic shortening under prestressing, shrinkage and temperature

Consideration should be given to the provision of joints in the structure to limit the effects of imposed movements.

Recommended design parameters:

Design Concrete Shrinkage : 650 microstrain Design Temperature Range: +/- 15 deg C

(To be reviewed for any exposed steel structure)

4.7 Dynamics Consideration has to be given to the dynamic performance of the seating structure.

Concrete modulus, for initial dynamic investigation

Use 1.3 E

Initial suggested frequencies;

Min frequency of 6Hz for concerts Frequency for roof of 1Hz



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4.8 Barrier loads In accordance with AS1170.1, design loads applied at handrail level

Handrails (generally) 1.5 kN/m in any direction Handrails for areas subject to crowd loads 3.0 kN/m in any direction Handrails for non-public back of house areas 0.75kN/m in any direction

Refer AS1170.1 for infill loads

4.9 Structural Robustness The Structure will be designed in accordance with Section 6 of AS1170.0 and commentary. In particular general provisions will be:

The structure will be designed so that it can adequately survive the accidental removal of an individual element or a limited part of the structure or acceptable localised damage.

Avoidance of structural systems that collapse without warning. Provision of alternate load paths so that failure and collapse of critical

structural members is averted. Provision of ductile connections that allow for large deformations of members

under abnormal conditions.



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5 Serviceability

5.1 Deflection Limits The following deflection limits are proposed for the building structure:

Element Long Terms Deflection under Total Load

Beams and slabs Spans Cantilevers

Generally L/250 L/125

Supporting masonry L/500 L/250

Storey drift under wind H/500

Overall sway under wind H/500

Differential settlement L/500

5.2 Concrete

5.2.1 Durability The requirements of AS 3600 will be applied to all reinforced concrete. The following exposure classification and minimum concrete strengths will be adopted:

Exposure classification B2 for external exposed and wash down internal elements

Exposure Classification A2 for Internal non-exposed elements Min Concrete strength f’c = 32MPa

5.2.2 Crack Control The degree of crack control to be provided in concrete elements (refer AS 3600 Clause 9.4.3) generally will be as follows:

Moderate where contained within enclosed non wash down areas of the building

Strong degree of crack control for external or internal wash down slabs.

Special attention will be given to location of crack control joints in long runs of wall and upstands, at points of stress concentration, and in external elements.

5.2.3 Steelwork Corrosion Protection The corrosion protection for the structural steelwork will be dependent on the location of the steel elements within the building. Internal steelwork which is in marginally damp areas where occasional condensation may occur, such as around the building perimeter and in the vehicle and plantroom areas, will require a higher level of protection that inside air-conditioned space which is permanently dry.



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For both these internal environments it is assumed that there is no access for maintenance.

A high standard corrosion protection scheme is required for all exposed steelwork

Min requirement = long term protection to AS 2312.

The paint scheme for corrosion protection must be compatible with the Fire Protection.

All exposed steelwork will require maintenance during the life of the building.

5.2.4 Fire Resistance Levels for Structural Elements Fire resistance levels for structural elements shall be determined in accordance with the Building Code of Australia and any subsequent approved relaxations as advised by the Fire Engineer for the project.

Concrete covers are to be in accordance with AS 3600 Section 5. The fire rating of blockwork walls is to be shown on the architect’s schedule.



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6 Materials For preliminary design purposes, concrete grades in core walls and columns up to a concrete cylinder strength f'c of 80MPa have been used. Steel grades of 300/350MPa for structural steel members and 500MPa for reinforcing steel have been adopted.

These values represent readily available materials. There is certainly scope to test the economy of using higher strength materials during later design phases.

The following structural materials are used in the works unless noted otherwise on the drawings. Typical values for the properties of these materials are listed. These values are to be adjusted where appropriate.

6.1 Concrete Concrete Material Properties will be assumed to be:

Concrete Material Properties

Grade f’c (MPa) 25 30 40 50 65 80 100

Young Modulus E (MPa)

25x10³ 26x10³ 28x103 30x10³ 37.4x10³ 39.6x10³ 42.2x10³

Co-efficient of thermal expansion

10x10-6 per oC

Basic shrinkage strain

Refer AS3600

Basic Creep Factor Refer AS3600

Poisson’s Ratio 0.2

Density 24kN/m³ (plain concrete) 25kN/m³ (reinforced concrete)

6.2 Reinforcement Reinforcing Steel properties will be assumed to be:

Bar Type Elastic Modulus [MPa] Yield Strength, fy [MPa]

Stirrups and Ties 200,000 500

Longitudinal Bars 200,000 460

6.3 Tensioning Strands Stressing Strand properties will be assumed to be:

Stressing Tendon Properties

Strand Type 12.7mm 15.2mm

Minimum Breaking Load [kN] 184 kN 256 kN

Modulus of Elasticity [MPa] 195 x 103 MPa



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Wedge Slip 6 mm

Basic Relaxation 2 %

Friction Curvature Coefficient 0.20

Wobble Factor 0.020 rad/m

6.4 Structural Steel Structural steel properties will be assumed to be:

Structural Steel Properties

Steel Grade 300 (open sections and plate), 350 (Hollow sections)

Elastic Modulus 200,000 MPa

Poisson’s Ratio 0.2

Co-efficient of Thermal Expansion 0.000010

6.5 Concrete Block The Structural properties of concrete block will be assumed to be:

Concrete Block Properties

Block characteristic compressive strength, f’uc 15 MPa

Mortar Mix General 1:1:6

Retaining Walls 1:0.25:3

Core fill grout compressive strength, f’c 20 MPa

Compressive Strength of Unit of Masonry, f’m 8.06 MPa