Earthworks Value Engineering on the Inland Rail

Earthworks ValueEngineering onthe Inland RailAustralia’s Largest Freight RailInfrastructure Project

M. Drechsler1, R. Kelly1, A. Newson1, S. Sawtell1 and Tim Neville21SMEC Australia Pty Ltd, Australia, 2Australian Rail Track Corporation, Australia

Earthworks Value Engineering on the Inland Rail

Australia’s Largest Freight Rail Infrastructure Project

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Contents

03Executive summary

04Introduction

06Motives for change

08Development framework

10New specifications

12Recent learnings

12Conclusion

12References

17Authors

18Appendix



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Inland Rail is a 1700km freight rail line between Melbourne and Brisbane, and the formation and bulk earthworks comprise approximately a third of the project’s capital cost. The previous earthworks specifications were not adequate in addressing the varying geotechnical conditions and technical challenges along the route – for example sourcing suitable construction materials, the range of different soil types along the route and the use of local materials.In partnership with ARTC, SMEC (part of the Inland Rail Technical Advisor SMEC-Arup Joint Venture) and a range of stakeholders developed and implemented a new Earthworks Materials Specification (ETC-08-03)[1], and Earthworks Construction Specification (ETC-08-04)[2]. The new specifications have achieved value engineering for the project’s earthworks by moving to performance-based specifications that are agile enough to allow for design optimisation along the route. The result is a significant time and capital cost saving over the life of the project and in addition has provided a legacy to ARTC beyond Inland Rail for projects and maintenance into the future.

Executive summary



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Introduction

Identified as a Priority Project by Infrastructure Australia, Inland Rail is a once in-a-generation project that will enhance supply chains and complete the backbone of the national freight network between Melbourne and Brisbane via regional Victoria, New South Wales and Queensland. Comprising 13 individual projects and spanning more than 1,700 km, it is the largest freight rail infrastructure project in Australia and one of the most significant infrastructure projects in the world.

The Australian Government selected the Australian Rail Track Corporation (ARTC) to deliver Inland Rail, in partnership with the private sector, and has committed $9.3 billion to its delivery.

262,000tonnes of steel

1700kmof freight rail line

24hrInland Rail will allow freight movements between Brisbane and Melbourne in less than 24 hours.

5Sydney Harbour Bridges equivalent steel to build



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The sheer scale of geotechnical elements on the Inland Rail, as indicated by initial volume estimates early in the program, demonstrate the importance of earthworks specifications: We identified an opportunity to use earthworks specifications and the Inland Rail program Basis of Design (BoD) criteria to introduce improved engineering inputs and controls, and step beyond the ‘business as usual’ mindset.

Through the BoD criteria and standards management governed by ARTC, along with early planning of geotechnical strategies and a cultivated value engineering approach to the program’s geotechnical works, a robust and ‘fit for purpose’ set of earthworks specifications were developed for the Inland Rail program with provision for use on all ARTC projects in the future.

+17 million cubic metres of cut and 16 million cubic metres of fill, with limited cut/fill balance.

+8 million tonnes of ballast, capping and road base materials from limited remote sources.

+400km

of highly reactive black soils and soft ground conditions.

25m

Cutting and embankment heights.

8km of tunnels, up to 250m belown the existing surface level.



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Early in the project delivery schedule, we recognised that the 13 separate project sections presented very diverse and challenging geotechnical conditions, and that the existing earthworks specifications did not provide the flexibility, consistency and quality accountability needed for a project of the scale and nature of Inland Rail.With formation and bulk earthworks comprising around a third of the capital cost of Inland Rail[3], performance-based earthworks specifications were identified as a key value engineering opportunity.

Motives for change

Tottenham

Albury

Illabo

Stockinbingal

Parkes

Narromine

Narrabri

North Star

NSW/QLD Border

Gowrie

Helidon

Calvert

Kagaru

Acacia Ridge

Bromelton



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Design Method

Key technical challenges in the earthworks required advanced geotechnical design solutions. For example, we were dealing with a range of different geology types including expansive soils, soft soils and deep colluvium comprising varying soil and rock types which may be unstable. Most of the existing formation and ballast materials would also be fouled, contaminated and have varying and non-durable soil parameters.Prescriptive rather than performance-based, the existing specifications inhibited the design methodologies and value engineering required to overcome these technical challenges.

We also recognised that in moving to a performance-based specification, we could develop the necessary framework to challenge current design practice to move from semi-empirical approaches to methodologies that incorporate the mechanical properties of soils and rocks. This would optimize the design of rail formations and align design processes to those seen in road earthworks applications and overseas practices.who understand local context and industry expectations.

Construction and deliveryAnother issue was that the existing specifications did not define many quality or current construction methodologies. The level of detail provided was generally sufficient for small projects and maintenance works but insufficient for major projects under the Inland Rail program, which required detailed specifications to reduce contractual disputes and claims around latent conditions and variations, manage financial risk and ensure the desired construction quality is achieved. A new set of ‘live’ specifications could be carried through both the design and construction phases.

Meeting service offeringThrough their interpretation and quality controls, earthworks specifications could target the cost and performance objectives necessary to meet the service offering of the Inland Rail. The new specifications were developed to meet or exceed industry best practice.

Motives for change



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Development framework

Stakeholder engagementParticularly when a project has both brownfield and greenfield works, it’s easy to underestimate just how heavily earthworks specifications are interrelated to many project elements, influencing outcomes far beyond just those of a geotechnical nature.

A diverse group of stakeholders aired a complex mix of often competing interests through debate, disagreement and consultation. Nearly 2000 formal comments were captured and closed out along with further advice, experiences and knowledge incorporated through technical workshops, risk workshops and internal discussions between subject matter experts.

A stakeholder engagement process was completed progressively over the development of the specifications and included representation from the following areas of expertise:

‒ Geotechnical, geology and pavements,

‒ construction,

‒ deliver,

‒ environment,

‒ risk management

‒ asset management,

‒ standards and specification process,

‒ quality-control,

‒ legal,

‒ OH&S,

‒ operations,

‒ corridor maintenance.

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Development frameworkEarthworks Value Engineering on the Inland Rail


Managing risk Technical input & approvals

Risk assessment is crucial to developing a specification.With the agreement of all key stakeholders, the ‘So Far As Is Reasonably Practicable’ method of assessment was undertaken on key changes and new material. A risk management framework and risk criteria were developed specifically for the program.

A diverse range of subject matter experts and ARTC specialists provided technical input, leveraging their extensive rail and road experience throughout Australia to capture the latest construction methods, laboratory testing, industry and academia design best practices in the revised specifications. In addition to internal approvals from ARTC, the two new specifications were also approved by the Office of the National Rail Safety Regulator.The new ARTC specifications are live documents with the first construction project between Parkes and Narromine (P2N) in progress. Lessons learnt from project implementation of the specifications are being incorporated into future revisions of ETC-08-03 and ETC-08-04.

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New specificationsEarthworks Value Engineering on the Inland Rail


Earthworks materials Earthworks construction

The new ARTC Specification ETC-08-03 provides Inland Rail an overarching specification to replace the ETM-08-01[4] specification.ETC-08-03 provides a ‘deemed to comply’ set of parameters. Crucially, it also allows changes to these parameters on a site by site basis, supported by engineering calculations and materials testing, and subject to approval by ARTC, in order to maximize the use of site won materials. The specification also enables users to adopt innovative earthworks solutions currently not used in rail construction practice, providing they can be shown to achieve the required design performance. The aim is to reduce the cost of construction while achieving performance requirements.

A full list of key additions in the new specification is provided in Appendix A. ⟶

The new earthworks construction specification, ARTC Specification ETC-08-04, provides Inland Rail an overarching specification to replace the ETC-08-01[5] specification.ARTC Specification ETC-08-04 has been expanded far beyond previous ARTC specifications. It includes new elements such as zoned embankments, foundation treatments for embankments and cuttings, stabilisation, blasting, spoil, stockpiles and borrow sites that are likely to be required across the program. It also allows method compaction, which aims to increase productivity and manage construction risk while achieving performance requirements.

A full list of key additions in the new specification is provided inAppendix B. ⟶

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New specifications

We also had a particular focus on ensuring consistency between the two separate earthworks specifications. While each has a unique purpose and intent, both are required to provide a shared understanding on project outcomes through clear and unambiguous content. Both documents link to a higher-level Program Quality Plan that manages compliance to the specifications.

Elements of ETC-08-04 have been drawn from the following specifications:

‒ ARTC ETC-08-01

‒ RISSB AS7638:2013[6]

‒ Aurizon EM.S.1305[7]

‒ RMS R44[8]

‒ TMR MRTS04[9]

‒ Standards for Highways Series 600[10]



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Learnings Parkes to Narromine (P2N) rail upgrade

The first Inland Rail project to complete detailed design and start construction was Parkes to Narromine, or P2N.The P2N project is a Design and Construct Only upgrade of the existing line between Parkes and Narromine, consisting of approximately 108 km of single line standard gauge track to 30 tonne axle load (30TAL) capacity. The terrain is gently undulating and crosses several broad floodplains, with no major cuttings to provide sources of locally won earthworks materials. More than 100 culvert structures were required for cross drainage.

< Parkes to Narromine timelapse video

https://www.youtube.com/watch?v=vsn5ihd1_U0&feature=emb_title



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Design improvements

The design team found challenging ground conditions typically comprising of low height embankments constructed of ballast, overlying deep profiles of fouled ballast and ash placed on reactive clay fills, possibly sourced from the cess[11].Amendments were therefore made to ETC-08-03 general fill and structural fill material minimum requirements and an option for lime stabilisation of materials was also presented.

We were able to achieve the following benefits:

‒ Re-use of all existing ballast, ash and clay materials on site, generating over 300,000 tonnes of general fill material;

‒ improvement of marginally compliant cut, subgrade and general fill materials using lime stabilisation;

‒ no importation of general fill materials was required;

‒ reduced excavation depths.

Construction improvements

During the early stages of construction, the contractor worked collaboratively with ARTC and the designer to develop Inland Rail-approved, projectspecific implementation plans for lime stabilisation and alternative compliance testing methodologies.The P2N project trialed Light Weight Deflectometer (LWD) testing against standard earthworks compliance testing[12]. The results showed benefits including real time availability of results, good correlation of design input parameters, and reduced laboratory testing effort with reduced time for earthworks lot acceptance. These outcomes can help save significant time and capital cost over the duration of the Inland Rail delivery program.

Learnings Parkes to Narromine (P2N) rail upgrade



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Conclusion

The development and implementation of project specifications is a major undertaking, facilitated only at major project scales rarely seen in the Australian rail industry. Representative of current industry best practice, these two new, performance-based specifications delivered value engineering for the program’s earthworks, while also supporting the the Inland Rail service offering.The Inland Rail project is a once-in-a-generation project and both individually and collectively the earthwork specifications ETC-08-03 and ETC-08-04 will play a key role in its delivery and provide significant value through design and construction. These two performance-based specifications are representative of current industry best practice and provide a legacy to the rail operator and maintainer for use beyond the Inland Rail project. Published and available to the public both ETC-08-03 and ETC-08-04 present opportunities for advancement in engineering and design of railway earthworks throughout Australia.



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References

1. Australian Rail Track Corporation, 2017. Earthworks Materials Specification. ETC-08-03.

2. Australian Rail Track Corporation, 2017. Earthworks Construction Specification. ETC-08-04.

3. Drechsler, M., and Kelly, R., 2019. Delivering improved earthworks performance and sustainability outcomes for Inland Rail. Rail Track Technology and Geotechnical Engineering Research Showcase 2019, University of Wollongong, New South Wales, 18 December 2019.

4. Australian Rail Track Corporation, 2010, Earthworks, Formation and Capping Material. ETM-08-01.

5. Australian Rail Track Corporation, 2006. Earthworks for New Tracks and Formation Widening. ETC-08-01.

6. Rail Industry Safety and Standards Board, 2013. AS 7638:2013 Railway Earthworks.

7. Aurizon, 2013. Civil Engineering Standard Specification Part 6 – Earthworks, EM.S.1305.

8. Roads and Maritime Services, 2013. Earthworks, R44, Edition 5.

9. Department of Transport and Main Roads, 2010. General Earthworks, MRTS04.

10. Standards for Highways website http://www.standardsforhighways.co.uk/ha/standards.htm. Manual of Contract Documents for Highway Works, Volume 1, The Specification for Highway Works, Series 600 Earthworks.

11. Blanchet, V., Tun, Y.W., Yang, L., and Lo, E., 2019. Application of Li and Selig railway formation design method to expansive soil. 13th Australia New Zealand Conference on Geomechanics 2019, Perth, Australia.

12. Doe, A. and Blanchet, V., 2020. Design of rail formation and subgrade – matching testing to design parameters, submitted CORE2020 paper.

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Snowy Mountains Engineering Corporation Australian Rail Track Corporation

SMEC is a global engineering, management and development consultancy with over 5,500 employees in 35+ countries delivering technical excellence and specialist solutions to our clients, partners and communities.A joint venture of SMEC and Arup (SAJV) is providing Technical and Engineering Advisory services to the Australian Rail Track Corporation (ARTC) for the Inland Rail Project.

Australian Rail Track Corporation (ARTC) is one of Australia’s largest freight rail network owners with 20 years of experience in operating, maintaining and building rail infrastructure. Across five states, the ARTC manages and maintains an 8,500km rail network.



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Team

Richard Kelly Chief Technical Principal & General Manager Technical Excellence, SMEC

Mark Drechsler Technical Principal, Engineering Geologist, SMEC

Andrew Newson Senior Project Manager, Rail, Queensland, SMEC

Sam Sawtell Team Leader - Pavements, Queensland, SMEC

Tim Neville Senior Geotechnical Engineer, ARTC

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Key additions provided in the new earthworks materials specification, ETC-08-03

Minimum requirements provided for materials including capping, structural fill, general earth fill, select fill, bedding sand, rockfill, rock protection, drainage blanket and other drainage materials that are consistent ‘across borders’ and jurisdictions;

An amendment to the capping grading to be consistent with granular road base gradings in order to maximise quarry sources;

The addition of minimum 5 x 10-7 m/s permeability criteria for the capping. The purpose of this is to ensure the capping sheds moisture away from the underlying structural and general fill materials;

Modification of surcharge pressures for CBR testing from 4.5 kg to 9 kg for structural and general fill materials. The purpose of this is to apply surcharges reflecting overburden pressures;

Consistent test methods and conditions in accordance with latest Australian Standards;

Additional durability and performance testing methods prescribed for engineered materials based on industry best practice;

Homogeneous and zoned embankments using various general fill types to facilitate the use of locally won

reactive clays and lower strength materials in the lower zone of high embankments, whilst the upper zone will be comprised of more durable and less reactive general fill materials;

Both identification and classification of unsuitable materials;

Classification of geotextiles through strength and filtration criteria;

Classification of uniaxial, biaxial and multiaxial geogrids through grid structure and application criteria;

Defining that geotextiles/geogrids shall not be placed closer than 400 mm below the Formation Level, with the possible exception at stations, turnouts, and other track not likely to be subject to rail bound formation renewal;

Provision for opportunity of utilising locally won material as stabilised material in the track formation where supported by appropriate research, trials and supporting engineering documentation. These clauses are aimed at utilisation of black soils in particular as well as any other suitable low soaked-CBR material;

Variations to testing frequencies for consistent materials and alternative testing methodologies;

Provision of variations to compliant material criteria and formation geometry to provide opportunities for flexibility around conformance testing to achieve design criteria;

Where surplus earthworks materials are proposed to be reused, the provision of environmental compliance requirements in an Earthworks Materials Management Framework;

Quality of earthworks materials improved by consistent definitions, test method conditions and reporting requirements linked to a comprehensive Project Quality Plan.

Appendix A

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Key additions provided in the new earthworks construction specification. ETC-08-04.

Comprehensive definition of terms;

Definition of suitable and unsuitable materials;

Foundation treatments aligning with current industry practice;

Compaction requirements for both compacted layer method and method compaction;

Hold and Witness Points for the purpose of administrating the contract and ensuring adherence to the specification during critical earthwork activities;

Facilitation of quality control during short possessions while not impeding construction expediency;

Applications of geotextiles for filtration and separation and requirements for various applications;

Construction requirements for stabilisation including development of a project specific specification for stabilised material;

General conditions relating to private property, construction water, protection of earthworks and structures, permanent erosion and scour protection, non-rippable materials, benching in cuttings, scour protection for embankments and proof rolling.

Appendix B