Track & Signal Monday 1/02/2016

+ Be Inspired Awards winner London Underground Limited's work train heads out to carry out remedial work on thecity's Jubilee Line.

Tunnel team had nightly 2.5-hour working window:

Underground projectwins innovation award

TONY DUBOUDINEditor

[email protected]

The three finalists in the innovationin rail and transit section of theBentley Be Inspired Awards rep-

resented three totally different types ofproject.

One was a new tram line in Dallas,Texas, another was a remote rail assetmonitoring system and the third an un-derground tunnel remediation project.

Each used a variety of Bentley soft-ware to achieve its ends.

The standout project was the reme-dial work on 215m of London's Jubileeunderground line between the BakerStreet and Bond Street undergroundstations which presented some unique

problems, the major one being that thework had to be carried out while the linecontinued to operate normally, whichmeant there was access for only just 2.5hours a night.

For this £34 million ($72m) project,London Underground Ltd undertookthe safe replacement of the existing ex-panded concrete lining with a spheroi-dal graphite iron. London Undergroundinitiated this project with an ambitioustarget of 20 per cent cost reduction byimproving planning, design and assur-ance efficiencies.

The project was unique in that a Lon-don Underground tunnel had never be-fore remained operational while workof this nature and scale with all the as-sociated risks was being undertaken.Normally it would require the completeclosure of the affected tunnel section,or a series of long-term closures to com-

plete pre and post enabling works andthe tunnel relining process.

The project team in effect had to builda mobile, self-sufficient travelling work-site using a former London Undergroundtrain. The tunnel lining replacement wasa complex mechanised system using aSegment Handling Plant (SHP) mountedon the purpose-built work train which,together with the construction team, hadto be driven to the work site every night.

The SHP was used in the stage replace-ment of the existing degraded tunnellining, from the precast concrete systemto the more robust cast-iron segmentequivalents as used on much of the Lon-don Underground network.

Other challenges identified by theproject team included:• the drilling and sampling of the exist-ing expanded precast concrete (EPC)tunnel linings with test samples cores

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INFRASTRUCTURE

recovered from up to three metres within the surroundinggrounds soil. Together with groundwater pressure monitor-ing, advance geotechnical and mineralogical testing was un-dertaken on samples recovered to inform the design of reme-dial measures and to allow the project team to make predic-tions of the ground, groundwater and tunnel behaviour bothbefore and during remedial works;• production of an interpretative geotechnical ground modelthat explained the EPC tunnel segment movement behaviourthat would be used predictively during the remediation re-lining design process;• the depth of the tunnel section beneath ground level movedthe tunnel bore out of the stable London clay and into Lam-beth Group, which is highly variable, with sand beds and wa-ter within clay. This could increase the risk of water ingressand partial soil collapse and the need for grouting during there-lining process;• finally, the project was subject to high-profile scrutiny fromthe press, rail transit industry regulatory bodies, the Mayor ofLondon's office, the London Assembly's transport committee,the requirements of the Freedom of Information Act and therequirements of the Environmental Information Regulations(EIR).

Information technology was vital to the success of the proj-ect, with a need to communicate effectively with all the proj-ect stakeholders to achieve a safe and successful outcome, allof which had to be properly managed to ensure the smoothexecution of the project in a cost-effective manner.

The project team made extensive use of Bentley software in-cluding AECOsim Building Designer, Bentley Descartes, Bent-ley Pointools and Bentley Navigator, and ProjectWise enabledcollaboration and supported the creation of a geospatially ac-curate, fully co-ordinated 3D model. The 3D and 4D modelscontributed to stakeholder and decision-maker understand-ing, resulting in numerous return-on-investment savings. Lon-don Underground realised a 15pc reduction in safety planning,risk assessment and assurance costs.

"Bentley Systems' suite of tools helped London UndergroundLimited build a cohesive, collaborative design, assurance andconstruction delivery team, allowing us to leverage the collec-tive intelligence of the group. The software ensured we wereable to manage uncertainties inherent in today's complexinfrastructure projects and deliver with confidence," projectmanager Garry Pratt said.

As well as winning the Bentley Be Inspired award, the proj-ect also won the United Kingdom Institute of Engineers' TheGreatest Contribution to London award.

One of the runners-up was a project undertaken by Track Ac-cess Services Limited for Britain's Network Rail

In preparation for Network Rail's infrastructure improve-ments to the east-west Crossrail route between Paddingtonand Reading, a 40,000 ($850,500) survey of 60km of doubletrack was conducted using terrestrial laser scanning.

A geo-tagged 3D point cloud and synchronised HD video wascollected using a Topcon 1PS2 scanning rig. The data collect-ed will be used to support the design stages for the Crossrailproject. By 2019, the £14.8 billion ($31.5b) Crossrail will linkLondon's main employment centres, ease congestion and im-prove connections.

UK railways, like others around the world, experience con-siderable difficulty in mounting rail survey operations, assafety is of paramount importance and avoidance of servicedisruption is a close second.

Static scanning or contact scanning methods often require

O P U S RAIL

PROVIDING SOLUTIONSTHAT TRANSFORM OURTRANSPORT NETWORKS

PUBLIC TRANSPORT AND FREIGHT NETWORK PLANNING! RAIL SYSTEMS I PROJECT PLANNING i SYSTEMSENGINEERING! INFRASTRUCTURE AND STATION DESIGNI TECHNICAL STRATEGY I ENVIRONMENTAL PUNNINGI STRATEGIC ASSET MANAGEMENT i PROJECT ANDENGINEERING MANAGEMENT

Opus Rail - The specialist rail division of OpusInternational Consultantswww.opusrail.com.au

Paul Street+61 3 9911 [email protected]

Track + Signal January-March 2016 29




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+ A schematic view of the Jubilee Line work trains shows the extent of the project.

expensive track possession. In the caseof the section of rail surveyed by TrackAccess, this was virtually impossible asit serves mainlines services for the WestCountry and London Airport Heathrow.

The level of detail required limited thevalue of an aerial LIDAR survey becauseof visibility restrictions.

The project cameras and scannerswere mounted on a diesel locomotivewhich was then slotted into the existingtimetable, thus avoiding any disruptionto services. The project was complet-ed with a single run of the locomotivefrom Paddington to Reading and returnso the entire survey was completed inslightly more than two hours, with post-processing and data delivery completedwith 10 days.

Bentley ProjectWise and MicroStationwere used for project collaboration andpost-processing of the data, respective-ly. The ability of MicroStation to modelthe vast amounts of disparate 3D andimage data types was essential for in-formation post-processing. The surveymethod for this project was estimatedto be 75pc less expensive than typicalstatic laser scanning, the only other vi-able option.

"Major infrastructure programs need aquick and affordable - and safe - meth-od of surveying the 'as is' on the ground,especially after a major commission-ing. This survey met the criteria andprovided rapid information to our de-signers to progress with the latest 'asis' information possible," Rob Farrell,

engineering data manager for CrossrailONW, said in reference to the Track Ac-cess project.

The second runner-up project wasTexas's first modern tramway system,which runs over a historic 101-year-oldviaduct bridge over the Trinity Riverfloodplain in Dallas linking Union Sta-tion in downtown Dallas to the Oak Cliffcommunity.

The project received a $US26 million($35.7m) Transportation Investment

The bridge's structure required exten-sive rehabilitation because of its age andconsiderable concrete deterioration.

The project featured several innova-tions.

It is the first tram in the US to usewireless traction power. On the surfacestreets, the trams are powered by nor-mal overhead wires, but they operatewith an on-board energy storage systemas they cross the 1.6km bridge.

Rehabilitating the bridge comprised

+ LEFT: A tram crosses the 101-year-old viaduct bridge over the Trinity Riverfloodplain in Dallas, Texas, in the United States. RIGHT: A screen grab gives aninsight into the video asset survey undertaken by Track Access on part of theCrossrail project.

Generating Economic Recovery (TIGER)grant from the Federal Transit Author-ity, with the rest of the funding comingfrom the City of Dallas, the North Cen-tral Texas Council of Government andDallas Area Rapid Transit.

The single track bi-directional tramalignment required constructing in cast-in-place concrete trackslab along thehistoric Houston Street Bridge, whichis listed on the US Register of HistoricPlaces.

a substantial portion of the project'sscope. With no overhead catenary per-mitted on the bridge it would need toaccommodate the loading of a moderntram.

Bentley ProjectWise was used to con-nect 70 professionals across 18 offices,saving money and helping to managethe work schedule.

Other Bentley products used includedMicroStation, InRoads, GEOPAK, Des-cartes and Pointools. T+S




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Track & Signal Monday 1/02/2016