Shani Wallis, TunnelTalk
Revised project procurement and contract management strategies for the new LRT extension into East Los Angeles marks a new start for the LA County MTA. Shani Wallis met with senior managers of MTA in LA in June 2005 to investigate the differences between this and previous LA Metro projects and to report on current construction progress.
- Los Angeles County Metropolitan Transportation Authority (MTA) is one year into its five-year design-build program to complete the 6-mile light rail line into East LA and the mood all round is positive.
Fig 1. Plan of the new LA Metro extension and segmental lining joint design
- "The IPMO - integrated project management office - we have established is already delivering the single entity advantage we intended," said Dennis Mori, Project Director for the MTA. "An early indicator of the management benefits has been limited change orders in this initial 12-month start up period to a total of about $400,000 which - on a $600 million contract - is exceptional by any previous experience.
- "Much of the advantage arises from the one field office that houses the site staff of the main contractor and its tunnel excavation subcontractor, as well as our integrated construction management team and the project's design consultants," said Mori.
- "Immediate and co-operative communications between the parties has RFIs (requests for information) and design submittals on a two-week turn around keeping the contract on schedule. This project set-up is also instrumental in an excellent safety record to date with no lost lime accidents recorded since the start of construction."
- The Authority's integrated construction management team under MTA's Project Manager Eli Choueiry, and Senior Construction Manager Fred Smith, incorporates personnel from prime construction management support services (CMSS) consultant Cater Burgess Inc and its tunnel subconsultant KBR (Kellogg Brown & Root) with Jim Richards of KBH the team's Chief Resident Engineer and Tom Saczynski the Tunnel Resident Engineer.
- Eastside LRT Constructors, a JV of Washington Group, Obayashi Corporation and Shimmick Construction, is the principal design-build contractor for the 6-mile, 8-station LRT line and Traylor Bros/Frontier Kemper is its tunnel subcontractor. Consultant to the design-build contract is DMJM-Harris and the Steiny/Balfour Beatty JV is subcontracted to design and install the electrical and operating systems.
- Project consultant to MTA for the 100% design-bid-build underground section is Parsons Brinkerhoff Quade & Douglas. The underground section comprises two portals, excavation of the two underground stations and 2km (1.3 miles) of twin running tunnels.
- Jim MacDonald and Brett Robinson of Traylor Bros are appointed Project Manager and Project Engineer respectively for the metro tunneling subcontract, and Amanda Elioff is Site Tunnel Engineer for Parsons Brinckerhoff Quade & Douglas.
- Underground works
Traylor Bros/Frontier Kemper is responsible for excavating the two EPBM running tunnels and six cross passages, two of which are combined cross passages/sump structures. It will also cast the invert track-bed and the side walkways. Washington Group, as leader of the prime contractor, is excavating the two underground station boxes, building the two portal structures and will construct the permanent station box works as part of the line's overall design-build contract.
- "Awarding the two elements of the alignment as one, rather than separate, contracts is also delivering advantages," said Mori. Contractors were invited to bid the underground section and the surface alignment either separately or together and five bids of different combinations were received in December 2003. "Awarding both to the combined bid of $600.4 million from the Eastside LRT Constructors JV has already identified time savings and advantages in the coordination of overlapping activities."
- "Subcontracting is not a usual role for Traylor Bros as leader of the tunneling subcontract JV," said Eli Choueiry, MTA Project Manager, "but excavation of the first station box by the prime contractor is more than half completed and casting of the launch pad in the bottom of the box, ready for assembly and launch of the TBMs toward the end of 2005, is its main focus. The TBM launch pad in the Boyle Heights station box and the base slab in the Soto station, ready for pull-through of the EPBMs when they arrive, are being designed as part of the permanent works which is another combined contract award advantage."
- "Excavation of the underground section is the critical path of the entire project," said Mori. "It is important in these early stages that progress stays on schedule."
- In the meantime the design-build surface alignment works are in the design phase. This is expected to be complete by June 2006 and presented for review and approved for construction. Of the total $600.4 million, 9.6km (6-mile), 8-station contract, the 2.72km (2-mile), 2-station underground section from portal to portal accounts for about $330 million with the remainder covering the surface alignment and the M&E elements.
- From previous difficulties on earlier heavy rail sections of the LA Metro there is a palpable sense that the MTA administration is on probation with this current contract. Earlier difficulties included the notorious Hollywood Boulevard tunnel collapse and the acrimonious finger pointing in the aftermath that resulted in termination of that Segment 2 contract and dismissal of the contractor. Institutional changes within the MTA and improved project management by a different management group did bring execution of the Red Line Segment 3 with its running tunnels from Hollywood through the Santa Monica Mountains into the San Fernando Valley to completion on time and within budget. However there is a conscious effort by many of the same members of the MTA team to do even better on the East LA project.
- "We approached this project from a completely different perspective," said Mori. "Rather than playing a design monitoring role as in the past, we took a more pro-active approach to the Eastside project. We engaged a Tunnel Advisory Panel comprising Dan Eisenstein and Geoff Martin, and a Tunnel Review Board that includes Ralph Peck, Torr Brekke and Gregg Korbin, all of which will be guiding us through the tunnel excavation process. We also decided to involve ourselves fully in the day to day administration of the contract through the IPMO."
- From being totally new to metro tunneling in the early days, explained Mori, the MTA is now a mature agency with a great deal of experience and more confidence in its ability to manage projects directly. "In the past, we engaged an engineering management consultant to design the construction elements and a separate construction management team. This created distinct 'silos' of project management with the MTA at the top of the chart in a less active role.
- Soft cost savings
A comparison of previous organization charts and the current integrated IPMO reveals a considerable reduction in consultant management posts, many of which duplicated or shadowed management counterparts in each management organization or silo. This change is exemplified by the difference in project soft costs. "Management and administrative costs for the Segment 3 North Hollywood Metro Red Line represented some 30% of its $1.3 billion budget," said Mori. "On the East LA LRT line they account for 16% of its $898 million budget. Both projects are approximately 6-miles long and the Segment 3 Red Line is heavy rail and constructed entirely underground but the soft cost reduction is substantial."
- A time comparison can also be made. The Red Line Segment 3 opened in 2000 after receiving its FTA full funding grant agreement in 1993 while the East LA Line is scheduled to open in 2009 following its full funding grant agreement in 2004. Part of the time difference can be attributed to the IPMO and to letting the surface works as a design-build contract.
- "This is the agency's first rail transit design-build contract and major benefits from this form of procurement are envisaged and already evident," said Mori. "The underground section was retained as a full design-bid-build project in order to maintain tighter control on the construction process. Our advisory panel and review board advised this and recommended the services of a Disputes Review Board, the members of which are being assembled."
- Much of the positive start to the project is also attributed to support from the local community. "The local residents and merchants are willing to accept much of the inconvenience created by construction in order for us to keep our long awaited promise to deliver the project," said Mori. The new Mayor of Los Angeles, Antonio Villaraigosa, is also supportive of the line into this densely populated largely Hispanic area of LA.
- Progress on site
Following the meeting, TunnelTalk made a visit to the field office to meet with the IPMO Chief Resident Engineer Jim Richards. The site tour took in a visit undergroud into the Boyle Heights station where excavation was progressing beneath temporary road decking.
- The LRT alignment follows the road corridors for the most part with the surface sections built between the lanes of widened streets. From a transition ramp at the west end, the underground section continues in 5.75m (18ft 6in) i.d. twin running tunnels into a center island platform in the underground stations. It emerges at the east portal at grade and onto a widened street.
Excavation of the Boyle Heights station box beneath temporary road decking
- Soldier piles and timber lagging support the station box excavation of the dewatered aluvial soils, gravel, silts and clay deposits using front-end loaders mucking into crane lifted skips. Temporary decking above the initial 150m (400ft) long x 12 to 20m wide Boyle Heights station box excavation was undertaken at the weekend under full street closure and was completed in five weeks. Several major service lines, including storm water drains, sewer pipelines, water mains, and telecommunication and power cables, were uncovered and are now suspended in braces under the temporary decking. Excavation of the Boyle Heights station and installation of the base slab for launch of the TBMs by the end of 2005 is presently the focus of attention.
- At the same time, Hayward Baker, as a subcontractor to Traylor Bros, is undertaking permeation grouting and the first phase of subsequent compensation grouting to protect sensitive structures. Grouting will also assist break in and out of the TBMs at the stations and at the east portal, as well as excavation of the cross passages. "The tunnel passes under two freeways, under a major regional water feeder, and under some private property to the east of Boyle Station," said Richards. "Easements to underpass these structures are already secured."
- Although dewatering of the alluvial deposits assists station box excavation, tunnel excavation is specified by the contract documents as a closed-face pressurized TBM operation using two new machines. To comply, Traylor/Frontier Kemper has procured two new 6.5m EPB machines from Herrenknecht AG. Final inspection of the machines at the factory in Germany took place in early July and both are scheduled to arrive on site in October.
Factory inspection of the two Herrenknecht EPBMs
- In preparation, Traylor, as tunnel JV leader, has started site mobilization at the Boyle Heights station job site. It has also relocated the annular grouting plant and EPB conditioning agent station from its recently completed NElS interceptor sewer project in LA to the metro job.
- As the TBMs progress they will erect a one pass precast concrete segmental lining comprising five segments and a key in each 1.5m (5ft) wide bolted and gasketed ring. Annular grout and conditioning agent will be pumped to the TBMs from the surface plants. Fabrication, supply and installation of the segmental liner is awarded to the Traylor/Shea/Ghazi casting yard in Palmdale to the northeast of LA.
- A particular feature of the new EPBMs is a much lengthened screw conveyor, designed and installed by Herrenknecht at Traylor's request. The screw conveyors are 200ft long and are driven by three sets of motors.
- From an invert bulkhead portal the inclined section of the screws extend through the ring build zone and over the top of the segment-handling area to discharge directly into the muck skips. "The design was developed as a result of our experience at NElS," said Mike Traylor. "We will be passing through the same type of ground, below the ground water table and through potentially high concentrations of hydrogen sulfide and methane gases. The long screw conveyor will carry the muck to a single point of discharge and to an area on the backup where we can install extra ventilation facilities to dissipate gases. On NEIS, discharge of material onto the transfer belt allowed release of gases to continue as muck traveled to the skip loading point. The congested area of discharge onto the belt made installation of extra venting equipment difficult and resulted in frequent activation of the gas monitors. These alarms required the heading to be evacuated and for the CalOSHA representatives to be called to inspect the tunnel before work could resume. Several days were lost on the NEIS project due to gas infiltration. The longer screw conveyors on the larger diameter LA Metro EPBMs will improve this situation. They will also provide increased capacity to control ground water pressures.
- The contract's GBR also predicts boulders in the largely gravel and hard clayey alluvial materials. The cutterheads of the two EPBMs are dressed with disc cutters only.
- The one pass segmental liner has a double gasket design and provision for the joints between the gaskets to be post grouted if necessary to ensure a watertight and gas sealed lining throughout the operating life of the tunnels.
- Once launched, towards the end of 2005, the TBMs are expected to take about nine months to complete each 1.3 mile (2km) drive achieving a program target of 50ft/day, working two 10h or three 8h shifts/day for five of six days a week. Within the main five-year project program, the tunnel subcontract's end date is July 2007.
Shani Wallis, TunnelTalk
- Final breakthrough of both TBMs on the LA Metro Gold Line Extension into East Los Angeles before the end of 2006 is confirmation that the reputation for metro tunneling in the city is restored. "We have turned that corner and moved well down the track with this project", said Eli Choueiry, Deputy Executive Officer and Project Manager for Metro (Metropolitan Transportation Authority). "Both TBMs have progressed the 2.6km (1.6 miles) of EPB excavation under city streets, under the bridge piers of the l-5 freeway, close to the foundations of buildings, beneath a main water supply line and other major buried services, without a trace of serious settlement; without stopping for anything outside routine tunneling operation. We are extremely pleased with the performance of the machine, with the tunnel management and crews of Traylor Bros as leader of the tunnel subcontractor JV, and with the effectiveness of the IPMO (integrated project management office), which had the KBR construction managers, the Parsons Brinckerhoff design team and the MTA project staff all located in one site office to provide immediate attention to any issues that might arise."
Los Angeles Mayor Antonio Villaralgosa and LA County Supervisor Zev Yaroslavsky, a fierce opponent of metro tunneling in LA after earlier troubles, join Metro CEO Roger Snoble and Caltrans District 7 Director Doug Failing at the breakthrough celebrations
- When considering the 1.6-mile underground section of the new 6-mile extension in the early 2000s, MTA knew it had a great deal of reputation damage to repair, in the tunneling industry, with the local media, with federal and local funding agencies, and among the general public. Successful on-time and within budget completion of the Metro Red Line Segment 3 into North Hollywood was eclipsed by problems experienced on the earlier Red Line Segments 1 and 2 which left the Authority severely battered and the future of underground mass transit in the city in disarray.
- The short reach of light rail tunnel on the East LA Gold Line was recognized as a probationary project. It was a case of "get this right and maybe heavy rail tunneling can be revived" after being refused any consideration in LA at the end of the early Red Line troubles. "Passed with flying colors" was the sentiment of officials at the final breakthrough ceremony for the first of the contract's two 6.5m diameter Herrenknecht EPBMs in November. Even the FTA representative had high praise of the MTA and the project as a whole. The FTA contributed about 50% ($490.7 million) of the total $898 million East LA Gold Line project and is now more favorably disposed towards funding further transit tunneling in LA including the heavy rail extension of the Red Line under Wilshire Boulevard, probably the next step for expanding the system.
- In citing major differences between the present and past, Choueiry included the advances in soft ground tunneling and their specification on the contract (continuous EPB operation at all times, a one-pass segmental lining, immediate annulus backfilling, soil conditioning, sophisticated geotechnical instrumentation, etc); provision of a GBR and a DRB binding for up to $1 million in the contract; and the significant advantage of "having a contractor that understood the importance of the project and paid attention to the details. We have no differing site condition claims and no disputes with the Traylor/Frontier-Kemper JV," said Choueiry. "Two issues have been heard by the DRB but neither of them concerned the tunnel or the tunnel sub-contractor. Both concerned the work by the prime contractor (the Washington Group/Obayashi Corporation/ Shimick Construction Eastside LRT Constructors JV), one a contract interpretation issue and the other concerning open cut work."
- Following breakthrough of the second machine in early December, Traylor/Frontier-Kemper will complete the last of six cross passages and cast the invert walkway concrete. "Tunneling was the highest risk, critical path element on the whole job," said Choueiry. "That is now behind us and with work on the rest of the at-grade alignment also progressing well, the new line is projected to open in about mid-2009, well ahead of the official December 2009 due date."
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