Technical Note – TN 008: 2019 · Track slab requirements shall be considered and implemented across the full life cycle of the asset including construction, operation, maintenance

Technical Note – TN 008: 2019

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Technical Note – TN 008: 2019

Subject: Amendment to T HR CI 12072 ST Track Slabs, v1.0

Issue date: 21 June 2019

Effective date: 21 June 2019

For queries regarding this document [email protected]

www.transport.nsw.gov.au

This technical note is issued by the Asset Standards Authority (ASA) to notify that the guard rails

requirements contained in T HR CI 12072 ST Track Slabs, version 1.0 are now superseded.

The ASA has published T HR CI 12071 Guard Rails, version 1.0 that covers the requirements for

guard rails. In this context, T HR CI ST 12072 ST has been amended as follows:

Delete the contents of Section 5.5 and replace with the following:

5.5 Approved configurations Guard rails on track slabs shall be in accordance with T HR CI 12071 Guard Rails.

Authorisation:

Technical content prepared by

Checked and approved by

Interdisciplinary coordination checked by

Authorised for release

Signature

Date

Name Joe Muscat Richard Hitch Peter McGregor Jagath Peiris

Position Principal Engineer Structures and Bridges

Lead Civil Engineer A/Chief Engineer A/Director Network Standards and Services

© State of NSW through Transport for NSW 2019 Page 1 of 1

Technical Note - TN 042: 2017

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Subject: Changes to durability requirements arising from the publication of T HR CI 12002 ST Durability Requirements for Civil Infrastructure

Issued date: 17 October 2017

Effective date: 17 October 2017

For queries regarding this document [email protected]

www.asa.transport.nsw.gov.au

This technical note is issued by the Asset Standards Authority (ASA) to notify that the durability

requirements for civil infrastructure contained in the following documents have been superseded.

• ESC 310 Underbridges

• ESC 340 Tunnels

• T HR CI 12030 ST Overbridges and Footbridges

• T HR CI 12040 ST Overhead Wiring Structures and Signal Gantries

• T HR CI 12060 ST Retaining Walls

• T HR CI 12065 ST Station Platforms

• T HR CI 12070 ST Miscellaneous Structures

• T HR CI 12072 ST Track Slabs

• T HR CI 12130 MA Track Drainage

• T HR CI 12130 ST Track Drainage

Durability requirements are now contained in T HR CI 12002 ST Durability Requirements for Civil

Infrastructure.


mailto:[email protected]


http://www.asa.transport.nsw.gov.au/


Authorisation:





Signature

Date

Name Richard Hitch Richard Hitch Jason R Gordon Jagath Peiris

Position Lead Civil Engineer Lead Civil Engineer Chief Engineer Director Network Standards and Services


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© State of NSW through Transport for NSW Page 1 of 1

For queries regarding this document

[email protected] www.asa.transport.nsw.gov.au

Technical Note - TN 082: 2016 Issued date: 21 December 2016

Subject: Revised reference to risk criteria This technical note has been issued by the Asset Standards Authority (ASA) to notify the

following.

• The risk criteria to be used by the Authorised Engineering Organisations (AEOs) providing

engineering services to TfNSW are contained in T MU MD 20002 ST Risk Criteria for

Organisations Providing Engineering Services, version 1.0.

• 30-ST-164 TfNSW Enterprise Risk Management (TERM) Standard provides the risk criteria

to be used by TfNSW.

• All references to the TERM standard in this document, where applicable to AEOs, shall read

as T MU MD 20002 ST.

Authorisation:





Signature

Date

Name Richard Adams Andy Tankard Andy Tankard Graham Bradshaw

Position Manager Safety and Risk Assurance

Principal Manager SQER

Principal Manager SQER

Director Network Standards and Services

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http://www.asa.transport.nsw.gov.au/

Track Slabs

T HR CI 12072 ST

Standard

Version 1.0

Issued date: 30 June 2015

Important Warning This document is one of a set of standards developed solely and specifically for use on public transport assets which are vested in or owned, managed, controlled, commissioned or funded by the NSW Government, a NSW Government agency or a Transport Agency (as defined in the Asset Standards Authority Charter). It is not suitable for any other purpose. You must not use or adapt it or rely upon it in any way unless you are authorised in writing to do so by a relevant NSW Government agency. If this document forms part of a contract with, or is a condition of approval by a NSW Government agency, use of the document is subject to the terms of the contract or approval. This document may not be current. Current standards are available for download from the Asset Standards Authority website at www.asa.transport.nsw.gov.au. © State of NSW through Transport for NSW

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T HR CI 12072 ST Track Slabs Version 1.0

Issued date: 30 June 2015 Standard governance

Owner: Lead Civil Engineer, Asset Standards Authority

Authoriser: Chief Engineer Rail, Asset Standards Authority

Approver: Director, Asset Standards Authority on behalf of the ASA Configuration Control Board

Document history

Version Summary of Changes

1.0 First issue.

For queries regarding this document, please email the ASA at [email protected] or visit www.asa.transport.nsw.gov.au

© State of NSW through Transport for NSW

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Preface The Asset Standards Authority (ASA) is an independent unit within Transport for NSW (TfNSW)

and is the network design and standards authority for defined NSW transport assets.

The ASA is responsible for developing engineering governance frameworks to support industry

delivery in the assurance of design, safety, integrity, construction, and commissioning of

transport assets for the whole asset life cycle. In order to achieve this, the ASA effectively

discharges obligations as the authority for various technical, process, and planning matters

across the asset life cycle.

The ASA collaborates with industry using stakeholder engagement activities to assist in

achieving its mission. These activities help align the ASA to broader government expectations

of making it clearer, simpler, and more attractive to do business within the NSW transport

industry, allowing the supply chain to deliver safe, efficient, and competent transport services.

The ASA develops, maintains, controls, and publishes a suite of standards and other

documentation for transport assets of TfNSW. Further, the ASA ensures that these standards

are performance-based to create opportunities for innovation and improve access to a broader

competitive supply chain.

This document details the design and performance requirements for track slabs on the TfNSW

heavy rail network.

This document has been developed from the RailCorp standard ESC 362 Track Slabs,

version 1.3 and has been reviewed and approved by the ASA Configuration Control Board.

This document replaces ESC 362 and is a first issue.


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Foreword This standard is intended to be used by competent personnel engaged in the provision of

services relating to rail infrastructure. Compliance with the requirements in this standard will not,

by itself, be sufficient to ensure that satisfactory outcomes will be produced. Personnel

providing services based on the standard need to bring appropriate expertise to the matters

under consideration.

In addition to the requirements of this standard, asset decisions shall take into account the life

cycle cost considerations specified in T MU AM 01001 ST Life Cycle Costing.

If, when using the standard, it is considered that the intent of stated requirements is not clear, a

clarification should be sought from the ASA.


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Issued date: 30 June 2015 Table of contents 1. Introduction .............................................................................................................................................. 6

2. Purpose .................................................................................................................................................... 6 2.1. Scope ..................................................................................................................................................... 7 2.2. Application ............................................................................................................................................. 7

3. Reference documents ............................................................................................................................. 7

4. Terms and definitions ............................................................................................................................. 9

5. General requirements for track slabs .................................................................................................. 10 5.1. Track slab design life ........................................................................................................................... 10 5.2. Approved materials .............................................................................................................................. 10 5.3. Clearances ........................................................................................................................................... 10 5.4. Prohibited configurations ..................................................................................................................... 10 5.5. Approved configurations ...................................................................................................................... 11 5.6. Environmental conditions ..................................................................................................................... 11 5.7. Heritage ............................................................................................................................................... 11 5.8. Services ............................................................................................................................................... 12 5.9. Width of track slab ............................................................................................................................... 12 5.10. Drawing standards ........................................................................................................................... 12

6. Construction requirements .................................................................................................................. 12 6.1. General construction requirements ..................................................................................................... 13 6.2. Drainage construction requirements .................................................................................................... 13 6.3. Slab construction ................................................................................................................................. 13

7. Maintenance requirements for track slabs ......................................................................................... 14

8. Design requirements for track slabs ................................................................................................... 14 8.1. General design requirements .............................................................................................................. 14 8.2. Design loads ........................................................................................................................................ 16 8.3. Infill slab design ................................................................................................................................... 16 8.4. Allowable movements .......................................................................................................................... 17 8.5. Drainage design requirements............................................................................................................. 17 8.6. Track and track slab interface.............................................................................................................. 18 8.7. Noise and vibration .............................................................................................................................. 21 8.8. Transition section trackforms ............................................................................................................... 22

9. Decommissioning or disposal ............................................................................................................. 23


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1. Introduction A track slab is a reinforced concrete slab or slabs which has track directly attached.

The use of track slabs may be necessary in the following situations:

• locations with limited vertical clearance

• existing tunnels where clearances to the track need to be increased to allow the use of

larger rolling stock or to increase the clearance to the overhead wiring

• new tunnels where the use of non–ballasted track may enable a smaller tunnel profile to be

used, ongoing maintenance requirements to be minimised or where the attenuation of

noise and vibration is critical

• locations where vehicles may be regularly required to travel across the rails such as

maintenance depots

• locations where track is required to be directly fixed to a bridge deck

• locations where minimal noise impact is required

• locations where high-speed rail is required to be implemented

• locations at stations where the effect of tolerances on the gap between train and platform is

to be minimised

• locations where reduced maintenance over the life cycle of the asset is considered

essential.

Track slab requirements shall be considered and implemented across the full life cycle of the

asset including construction, operation, maintenance and decommissioning or demolition

stages.

The potential effects of any track slab work shall be considered and mitigated to ensure safety

so far as is reasonably practicable (SFAIRP) across the full life cycle in accordance with the

requirements of this document.

Designs of track slabs in tunnels are also to comply with the requirements of WorkCover NSW

Code of Practice – Tunnels under Construction: 2006.

2. Purpose The purpose of this document is to provide technical requirements for track slabs within the rail

corridor.


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2.1. Scope This document specifies the technical requirements for track slabs within the rail corridor. This

includes technical requirements for track slabs at maintenance centres. It also includes

requirements for both rigid and floating slabs, the interface with track, the transition between

rigid and floating slabs, and the transition to other forms of track support.

The document covers track slabs where the track is fixed directly to a concrete slab. For the

purpose of this document, track fixed directly to a bridge deck is also considered as a track slab.

The document does not address the design requirements for slabs supporting ballasted tracks.

2.2. Application The requirements of this document apply to new track slabs and to upgrades of existing

portions of the network.

3. Reference documents The following documents are either cited in the text or may provide additional information. For

dated references, only the cited edition applies. For undated references, the latest edition of the

referenced document applies.

International standards

BS 6177 Guide to selection and use of elastomeric bearings for vibration isolation of buildings

ISO 14837-1 Mechanical Vibration – Ground-Borne Noise and Vibration arising from Rail

Systems – Part 1: General guidance

Australian standards

AS 1085.1 Railway track material – Steel rails

AS 1170 Structural design actions

AS 1726 Geotechnical site investigations

AS 2159 Piling – Design and installation

AS 3600 Concrete structures

AS 7513 Railway Rolling Stock Interior Environment

AS 5100 Bridge design

Transport for NSW standards

ESC 100 Civil Technical Maintenance Plan

ESC 200 Track System

ESC 210 Track Geometry and Stability © State of NSW through Transport for NSW Page 7 of 23

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ESC 215 Transit Space

ESC 220 Rail and Rail Joints

ESC 230 Sleepers and Track Support

ESC 302 Defect Limits

ESC 310 Underbridges

ESC 340 Tunnels

ESG 100 Signal Design Principles

T HR CI 12130 ST Track Drainage

T MU AM 01003 ST Development of Technical Maintenance Plans

SPC 234 Resilient Fastenings

SPC 235 Resilient Baseplates

SPC 301 Structures Construction

ESG 100.17 Signal Design Principles Track Circuits

30-ST-164/4.0 TfNSW Enterprise Risk Management Standard (available on request – contact

[email protected])

Legislation

Environmental Planning and Assessment Act 1979

Heritage Act 1977 (NSW)

Other reference documents

WorkCover Code of Practice – Tunnels under Construction 2006

RMS QA Specification R82 Lean-Mix Concrete Sub-base

B80 RMS Specification Concrete Work for Bridges

Environment Protection Authority NSW – Interim Guideline for the Assessment of Noise from

Rail Infrastructure Projects

NSW Environmental Protection Authority – Rail Infrastructure Noise Guideline (RING)

NSW Heritage Office State Agency Heritage Guide


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4. Terms and definitions The following terms and definitions apply in this document:

AEO Authorised Engineering Organisation

ASA Asset Standards Authority

ballasted trackform consists of ballast, sleepers, rail fastening assemblies and rails

DLA dynamic load allowance the dynamic load allowance for railway live load effects is a

proportion of the static railway live load calculated in accordance with AS 5100

derailment containment device an approved configuration installed to prevent a high

consequence event arising from a train derailment. Such events include a train impacting

structure or structural elements and a train falling off a bridge

embedded rail system a form of track construction where the rails are set into a concrete slab

with the crown of the rails level with the upper surface of the slab. Embedded track is generally

specified for maintenance depots

floating track slab track slab which is isolated from the ground or supporting structure using

resilient bearings

non–ballasted trackform consists of concrete slabs, rail fastening assemblies and rails

rail corridor comprises the full volume, both above and below ground, between the outer face

of opposing boundary fences. If no boundary fences are present, the extent of the rail corridor

shall be taken as 15 m from the centre-line of the outermost rail.

rigid track slab track slab which is directly fixed to the ground or supporting structure

RMS Roads and Maritime Services

SFAIRP so far as is reasonably practicable

TfNSW Transport for New South Wales

trackform type of track structure. May be ballasted or non–ballasted

track slab concrete slab or slabs with directly fixed track including where track is directly fixed

to a bridge deck

white rail Category 1 recycled rail in accordance with ESC 220


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5. General requirements for track slabs Section 5.1 through Section 5.10 explains the general requirements for track slabs.

5.1. Track slab design life The minimum design life of all structural track slab components shall be 100 years in

accordance with AS 5100.

5.2. Approved materials The approved construction material for the structural elements of track slabs is reinforced

concrete.

Fibre reinforced concrete shall not be used without the prior approval of the Lead Civil Engineer,

ASA.

The use of polymer concrete sleepers embedded into track slabs is approved. Polymer concrete

sleepers shall be in accordance with the requirements of ESC 230.

Lean mix concrete is a permissible sub-base material for track slabs. Lean mix concrete used

as a sub-base material shall be in accordance with the requirements of RMS QA Specification

R82.

Timber and masonry shall not be used as construction material for track slabs.

Materials for track slabs in tunnels shall be non–flammable and shall comply with specific

requirements for fire safety detailed in ESC 340.

5.3. Clearances Horizontal and vertical clearances from track slabs to structures adjacent to and over the track

shall comply with the requirements of ESC 215.

5.4. Prohibited configurations Embedded rail systems are prohibited except for sidings and at maintenance depot locations.

Concrete upstands located between running rails shall not be used as an alternative to

derailment containment devices.


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5.5. Approved configurations Single or twin arrangement guard rails are approved derailment containment devices for use on

track slabs.

The normal arrangement for guard rails comprises two parallel guard rails (that is twin guard

rails) with a tapered 'vee' section on the train approach side. Standard details for single guard

rail installations have not been developed at this stage. Details for single guard rail installations

shall be approved by the Lead Civil Engineer, ASA.

5.6. Environmental conditions The design of track slabs shall consider environmental impacts and sustainability opportunities

across the life cycle of the asset. Considerations relating to track slabs include the following:

• embodied energy in construction materials

• use of recycled and recyclable construction materials

• stormwater management

• air quality – particularly during construction

• noise and vibration – particularly during construction

Environmental management is governed by the Environmental Planning and Assessment Act,

1979. This Act requires that environmental impacts resulting from development shall be

appropriately assessed. All relevant environmental factors shall be considered at a sufficiently

early stage to be satisfactorily addressed in concept designs.

5.7. Heritage The Heritage Act, 1977 is designed to protect, maintain and manage environmental heritage in

NSW. The Heritage Act, 1977 also includes for items of archaeological significance. If changes

are proposed to items that have heritage significance, the following shall apply:

• for items listed on the State Heritage Register, the provisions of the Heritage Act 1977 shall

be met

• for items listed on a state agency Section 170 Heritage and Conservation Register, the

principles and relevant guidelines contained within the State Agency Heritage Guide shall

be followed

Where new track slabs are proposed within a heritage listed precinct and in the vicinity of a

heritage listed item, the identified significance of heritage items shall not be compromised.

Heritage fabric shall be protected from damage during and following construction activities. If

unrecorded or unexpected heritage finds are made during works, the works shall cease


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immediately. In this event, heritage advice shall be sought and notification shall be made in

accordance with existing legislation.

5.8. Services Provision shall be made in the design and installation of track slabs for services as required

such as signalling, electrical and communications.

The Automatic Train Protection (ATP) project team shall be consulted for guidelines and

requirements on all projects where a track slab requires to be installed.

Track slab design shall facilitate the future installation of balises where required by the ATP

project team.

Services shall be positioned in accordance with the following requirements:

• transit space standard ESC 215

• clear of any walking areas where they may present a trip hazard

• not to interfere with or obstruct emergency walkways

• not to obstruct access to or reduce the capacity of refuge areas

• not to obstruct drainage

• not to obstruct track control marks

The location of any services shall also be selected so that future access for maintenance of the

services is facilitated.

5.9. Width of track slab The track slab shall extend a minimum width of 500 mm beyond the outermost edge of the base

plate on each side of the running rails at the level of the slab under the rails.

5.10. Drawing standards Construction drawings shall detail the design loadings, horizontal and vertical clearances, and

any other information that is relevant to ensuring that the new structure is constructed and

maintained in accordance with the design.

6. Construction requirements Section 6.1 through to Section 6.3 explains the construction requirements for track slabs.


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6.1. General construction requirements Construction methods include top down, bottom up or a combination of both.

Top down construction involves setting the rails in place with temporary supports and then

casting the concrete track slab in-situ.

Bottom up construction involves installing a track slab and then attaching the rails after the

concrete has been poured and has set.

ASA has a suite of technical specifications covering various aspects of civil construction. The

specifications are detailed in SPC 301 and shall be incorporated in design and construction

documentation.

Track slab configurations include the following:

• monolithic slab

• base slab and top slab

• sleepers embedded in or on a slab

• base slab with kerb walls and an infill slab

• concrete monoblock sleepers embedded in or on a slab

• floating slab

The finished surface of the track slab shall be constructed to a tolerance of +0 mm, –5 mm from

the design level.

The construction method shall ensure that track fastenings are fully supported with no voids

under the track fastenings. This is particularly important when top down construction is used.

6.2. Drainage construction requirements The track drainage system shall be constructed as specified in T HR CI 12130 ST.

6.3. Slab construction The construction joint between base and top slabs shall be in accordance with the requirements

stated in section 11 of SPC 301 Structures Construction. Refer to Figure 1 for more information.


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7. Maintenance requirements for track slabs The design of track slabs shall take into account the ability to access key components for

inspection and maintenance purposes.

Maintenance requirements shall be specified in a technical maintenance plan for track slabs.

Requirements shall include examination tasks and frequencies, damage limits, and repair

standards, and be supported by documentation showing the basis for these requirements.

Technical maintenance plans shall be produced in accordance with T MU AM 01003 ST.

8. Design requirements for track slabs Section 8.1 through to Section 8.8 explains the design requirements for track slabs.

8.1. General design requirements Track slab design is a system design taking into account the stiffness of the following:

• slab (including base and infill slabs)

• sub-base

• sub-grade

• rail fastening assemblies

• rail

The sub-base shall be designed based on the results of a geotechnical investigation to ensure it

provides a continuous uniform support of the track structure. The sub-base shall satisfy

settlement requirements stipulated in Section 8.4 of this document. The sub–base shall be

designed to prevent the infiltration of water under the track slab and to mitigate against the

adverse effects of high water tables.

Track slab designs shall ensure the following:

• be capable of adoption throughout varying configurations of the structure, for example, in

tunnels where configurations may vary between the running tunnel, crossover caverns and

underground stations

• take into account the seepage forces at foundation level

• take into account the presence of bedding planes in rock foundation within the influence

zone

• minimise the risk of derailment owing to track irregularities


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• not be skewed at either track slab end relative to the line of the rail in plan

This is to avoid twisting of the rail under loading.

• provide uniform transmission of all rail borne forces to the trackform

• provide continuous rail with no mechanical joints

• provide appropriate electrical insulation and electrolysis mitigation measures

• incorporate rail lubrication systems where maintenance requirements dictate

• provide for future track maintenance, including rail replacement, in–situ rail welding and

emergency rail clamping

In addition to the above, the design and installation of floating slabs shall ensure the following:

• dynamic deflections shall not cause the transit space to be compromised

• dynamic behaviour of the floating slab shall not act adversely with the vehicle suspension

modes, resulting in increased wear of any component or a reduction in ride quality

• provide for positive drainage of the track slab in accordance with Section 8.5 of this

document

• bearing materials shall minimise the increase in dynamic stiffness as the frequency rises

Bearings shall be designed and tested in accordance with the requirements of AS 5100.4

Bridge design – Bearings and deck joints and BS 6177:1982 – Guide to selection and use

of elastomeric bearings for vibration isolation of buildings

• adequate air gap is provided beneath the floating slab to avoid acoustic coupling effects

• resilient direct fixation of the rails is provided on top of the floating slabs

The maximum height of grout bed under the rail baseplates shall be 60 mm. Packers may be

used in conjunction with screw spikes.

High impact epoxy grouts/mortars or specially developed grouts shall be used under the

baseplates to accommodate the high dynamic effects and movement of the slab. There shall be

no metallic elements in the epoxy. Standard cementitious grouts shall not be used.

The grout bed shall provide sufficient edge distance to the bolt hole to avoid cracking of the

grout.

Where different trackforms are used on a particular project, the geometric tolerances specified

at the wheel and rail interface should be the same.

The design of track slabs shall provide for easy access to bearings for inspection, maintenance

and replacement.

The design shall mitigate against debris getting into gaps around floating slabs. All gaps shall

be effectively sealed to prevent debris from entering gaps between structural elements. © State of NSW through Transport for NSW Page 15 of 23

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Non–resilient fastening assemblies shall not be used on track slabs.

Where the track slab consists of a base slab and an infill slab, the infill slab shall be positively

anchored to the base slab.

The maximum vertical drop at the edges of the track slab shall be 150 mm unless guard rails

are provided.

8.2. Design loads Track slabs shall be designed to accommodate the minimum train loadings as specified in Table

1.

Table 1 – Train loadings

Operating class Train loading

Main lines

Passenger main line 200 LA plus DLA

Mixed passenger freight main line 300 LA plus DLA

Freight line 300 LA plus DLA

Light line 200 LA plus DLA

Heavy freight option 350 LA plus DLA

Sidings

General yard 300 LA plus 50% DLA

Passenger operations or maintenance 180 LA plus 0% DLA

The loading in Table 1 is based on the railway traffic load specified in AS 5100. The ‘Reference

Load’ is 300 LA.

Operating classes are defined in ESC 200.

For all other loadings, all axles shall be proportioned by the ratio of the nominated LA load

divided by 300.

Where track is directly fixed to a bridge deck, DLA shall be derived from Table 8.4.2 of

AS 5100.2. For track slabs on ground the DLA shall be taken as 1.0.

Track slabs shall also be designed for the derailment load requirements of AS 5100.

Track slabs shall be designed for earthquake forces in accordance with AS 5100. The

earthquake design category shall be Type III.

8.3. Infill slab design Where track slabs are specified using 'top down' methods in which a concrete infill section is

provided to connect the track fixings to the base slab, the concrete infill shall be designed and


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detailed to ensure structural adequacy and durability to give a 100 year design life in

accordance with AS 5100.

Figure 1 illustrates a typical top down track slab arrangement showing infill slab.

Figure 1 – Typical 'top down' track slab arrangement showing infill slab

The reinforcement provided in the infill shall be designed to limit cracking due to early thermal

and shrinkage effects. Cracks shall not exceed 0.2 mm in width.

The infill slab shall be adequately tied down to the main track slab to ensure that de–bonding

does not occur due to dynamic effects or thermal or shrinkage effects. The maximum spacing of

the tie-down bars shall be 500 mm in any direction.

The minimum design thickness of the concrete infill for new construction shall be 250 mm.

8.4. Allowable movements The design of the track slab shall ensue that slab movement does not adversely affect the

integrity of other infrastructure such as track and signalling. Movements shall not result in the

track geometry being outside the limits as specified in ESC 210.

The design shall provide for construction, expansion and contraction joints as appropriate.

8.5. Drainage design requirements Provision shall be made for track slab surface drainage by efficiently directing water into the

track drainage system.

The design AEO shall note that an additional requirement of the drainage system in the vicinity

of a track slab is to consider the management of water at track slab foundation level to avoid

upward water pressure forces on the track slab across the life cycle.

The drainage of water which may flow upward from the sub-grade shall be facilitated by the

drainage system designed by the design AEO.

The track drainage system shall be designed as specified in T HR CI 12130 ST Track Drainage.

Baseplates and fastenings shall remain above water at all times.


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Ponding shall not occur on track slabs or in the void beneath any floating slab. The drainage

design shall ensure that depth of run–off water on track slabs does not interfere with signalling

and electrical equipment.

Additional drainage provisions shall be made to lower the ground water levels in rock

foundations with seepage forces. The presence of bedding planes within the influence zone of

the foundation pressure shall be taken into account.

8.6. Track and track slab interface Section 8.6.1 through to Section 8.6.3 explains the track and track slab interface requirements.

8.6.1. General interface requirements

The design of the track slab shall take into account the interaction with the track including

longitudinal effects, thermal effects, concrete shrinkage, traction and braking loads. The design

shall consider the effect on both the track and the track slab, including interaction of slab

expansion and rail expansion.

Rail fastenings shall be approved resilient fastenings in accordance with SPC 234 and

SPC 235.

Where epoxy grouts are used under the rail base plate, the minimum thickness of the pad shall

be 7.5 mm.

A minimum clearance of 60 mm under the rail shall be provided for maintenance purposes.

8.6.2. Turnouts Where turnouts are designed in the track slab, full base plate fixings shall be installed to allow

installation of the turnout. Cast-in fixings are prohibited at turnout locations in a track slab.

For turnouts in track slabs, the rail shall be continuous through the turnout location without the

use of mechanical joints.

8.6.3. Derailment containment devices The need for derailment containment devices shall be a risk based decision in accordance with

the requirements of the TfNSW Enterprise Risk Management Standard.

Where derailment containment devices are provided at a location, the design AEO shall ensure

that a train remains clear of the protected structure in the event of a derailment which is

successfully contained by the derailment containment device.

Derailment containment devices shall not be used as a means of providing further risk

mitigation for structures that comply with collision loads specified in ASA standards.


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Derailment containment device design

Guard rails shall be installed in accordance with the following requirements:

• Guard rail shall be new rail manufactured in accordance with AS 1085.1 or recycled rail

Category 1 (white rail) in accordance with ESC 220.

• Guard rail section shall be the same as the running rail or one section size less than the

running rail.

• Top of guard rail shall be no higher than the adjacent running rail and no more than 50 mm

below the running rail.

• Guard rail shall be plated and fastened on both sides at the same spacing as the running

rail fasteners. 'A' clips shall be used for fastening the guard rail.

• Guard rails shall extend parallel for a minimum 20 m on the approach to the area being

protected on the train approach side.

• Guard rails shall extend parallel for a minimum of three metres beyond the area being

protected on the train departure side.

• A tapered nose section ('vee'), minimum 3.6 m long, shall be installed on the train

approach side of the guard rail. The minimum vee length shall be in addition to the required

approach length specified above. The nose of the vee shall be bolted

• Where rail traffic is bi–directional, the guard rail shall extend 20 m beyond the area being

protected on both approach and departure sides

• Where rail traffic is bi–directional, the tapered nose section shall be installed on both sides

• The clearance between the gauge face of the running rail and adjacent face of guard rail

shall be 380 mm

• Block–out holes for guard rail fastenings in track slabs and concrete sleepers shall be

grouted with a high strength epoxy grout. A minimum compressive strength of 70 MPa shall

be achieved prior to loading

Interface between derailment containment device and signalling equipment

Suitable isolation arrangements shall be made, where required, in track circuited and electrified

areas.

The tapered nose section (‘vee’) shall be insulated with an approved component. Figure 2

shows a typical insulation configuration. This insulation requirement applies to new installations

and where refurbishment of the guard rails is undertaken.


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Figure 2 – Typical configuration of tapered nose section ('vee') showing insulation joints

Where guard rails exceed 50 m in length, additional insulation and bonding arrangements may

be required. Design drawings shall specify that insulation and bonding arrangements shall be in

accordance with the requirements of the Lead Signals and Control Systems Engineer, ASA. For

further information, refer to ESG 100.17.

Where epoxy grouts are used under the rail seat pad, the minimum thickness of the pad shall

be 7.5 mm.

Joints in guard rails

Joints in guard rails shall have at least two bolts on each side.

If standard fishplates are used, six bolts are required.

If modified fishplates are used, the four bolts shall all have the nuts on the inside. Fishplates

shall be modified by machining, not by oxy–acetylene cutting.

No joints, other than insulated joints, are permitted in the vee.

Automatic Train Protection interface

The Automatic Train Protection (ATP) project team shall be consulted for guidelines and

requirements on all projects where a guard rail arrangement is required to be installed on a

track slab. The final arrangement shall be approved by the Lead Civil Engineer, ASA.


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8.7. Noise and vibration Noise and vibration arising from track slabs is a highly complex issue. Section 8.7.1 through to

Section 8.7.3 describes the key noise and vibration concepts to be considered in the design of

track slabs.

8.7.1. Environmental noise and vibration

Noise and vibration from trains operating on track slabs at sensitive locations such as

residences shall comply with the Rail Infrastructure Noise Guideline (RING). Project specific

limits, for example, in Conditions of Approval shall also be complied with.

Where assessment and mitigation of ground–borne noise and vibration is required,

methodologies shall be consistent with those defined in ISO 14837–1 – Mechanical vibration –

Ground–borne noise and vibration arising from rail systems – Part 1: General guidance.

8.7.2. In–tunnel noise and in–train noise To reduce ground–borne noise, rails are often mounted on a floating track slab or with resilient

rail fasteners for conventional slab. This limits the amount of vibration from the wheel and rail

interface which enters the ground. This may result in increased operational air-borne noise

inside tunnels and trains.

When designing track slabs for tunnel or enclosed structure environments, consideration shall

be given to operational air–borne noise within the enclosed environment and the impact this will

have on the ability of rolling stock to comply with AS 7513 Railway Rolling Stock Interior

Environment (all parts).

8.7.3. Performance and maintenance considerations in design The design shall take into account flexural vibration and noise radiation.

Where floating track slabs are used to mitigate noise and vibration effects, they shall be of

proven design with demonstrated performance in operating environments similar to the TfNSW

heavy rail network.

Ground-borne noise and vibration is likely to have a significant bearing on the tunnel alignment

and track design. Operational and maintenance issues that may influence ground–borne noise

and vibration from tunnels shall be considered, including the following:

• track design features such as curves and crossovers, which increase the levels of

ground-borne vibration generated at source

• trackbed vibration isolation system shall be optimised for operation with the rolling stock

that is required to operate on the track


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• ongoing maintenance of rolling stock, particularly wheels

• ongoing maintenance of track, particularly the rail running surface

The selection and design of track slab support systems for ground–borne noise and vibration

control requires careful consideration of maintenance and performance aspects.

Particular consideration shall be given to the following:

• modes of vibration of floating slab elements which may lead to a significant increase in low

frequency radiated noise

• transitions between track sections with differing support stiffness characteristics

• wheel and rail interface issues such as corrugation development

• access and inspection and maintenance of resilient components

8.8. Transition section trackforms Transition section trackforms shall be provided in locations where two differing trackforms abut.

The transition section shall be designed to provide the following:

• a progressive change in track stiffness

• an easily maintained trackform transition, which may not be prone to differential settlement

• continuity of drainage between the track slab drainage and track drainage

• accurate matching of track alignment under all load conditions, in order to avoid stress

concentrations in components or uneven ride characteristics

• the nominated levels of vibration and regenerated noise attenuation

• a minimum number of transition sections

Where track slabs abut ballasted track, a transition slab shall be provided to achieve a

progressive change in track stiffness. The ballasted track on the transition slab shall be

designed and installed in accordance with TfNSW’s track engineering standards.

The minimum length of transition section trackform shall be 5 m.

Transition section trackforms shall be designed for the same loads as the track slab.


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9. Decommissioning or disposal Decommissioning is the final process of withdrawing an asset from active service on the

network.

Disposal is the process of removing an asset from the network. For example demolition of an

overbridge or track slab followed by removal and recycling.

The decommissioning or disposal of an asset is the final stage of the asset life cycle. Proper

planning of this part of the life cycle is an integral part of the strategic life cycle process.

The process to be undertaken for the disposal of a track slab shall be as follows:

• A report shall be produced to confirm that the asset is surplus to the requirements of the

rail network or it is life expired.

• The report shall identify the benefits including financial and costs arising from the proposed

decommissioning or disposal.

• The report shall confirm stakeholder engagement regarding the proposed action. Such

engagement shall include, but not be limited to heritage, council and environmental body

consultation.

• The means of decommissioning or disposal shall be a risk based decision carried out in

accordance with the TfNSW safety management system. Refer to 30-ST-164 TfNSW

Enterprise Risk Management Standard for requirements regarding the mitigation of risk

SFAIRP.

• The report shall include a decommissioning or disposal plan for implementation.

Following decommissioning or disposal, the asset database shall be updated to reflect network

changes.

95% of construction and demolition waste by weight of the decommissioned asset shall be

diverted from landfill.


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Documents

Technical Note – TN 008: 2019 · Track slab requirements shall be considered and implemented across the full life cycle of the asset including construction, operation, maintenance