Paula Wallis, Reporter

Alignment of twin 7.1km tunnels at 160-640m underground

Mired in a legal battle that left them idle more than a year, the TBMs will again roar to life on Vancouver’s Seymour Capilano water tunnel project.

Metro Vancouver awarded Frontier-Kemper/J.F Shea/Aecon the completion contract for the twin tunnels that are roughly 50% complete. The JV’s winning lump sum, fixed-price bid of $181 million is just $5 million less than its original 2004 bid for the entire project.

Back then the client anticipated the 7.1km twin tunnels would cost $200 million and take three years to build. That included the original $99.7 million contract with Bilfinger Berger for construction of the tunnels as well as the job’s design engineering, the tunnel lining and other associated costs. Overall costs are projected to double with the new contract to $400 million.

Robbins TBM in launch shaft

Inflation is partly to blame for the ballooning cost said Bill Morrell, spokesperson for Metro Vancouver, the regional utilities provider that includes the project’s client, the Greater Vancouver Water District (GVWD). “First of all, there’s a five or six year separation in time and of course escalating construction costs contributed to that,” said Morrell. “But at its root, this is what the industry said it would cost. This was a competitive process, and based on the best determination of the folks capable of completing the work, that’s what it is going to cost to finish this project.”

GVWD received a second bid from a JV of Dragados, SELI and Schiavoni but the bid price was withheld. Morrell said it was “not the policy of the GVWD’s purchasing department to release the value of bids contained in proposals.”

Rock instability in the crown (above) and in the walls

A further bid, from the McNally International, Obayashi Corporation, and local contractor Procon JV, was non-compliant. “We required all submissions include a target price and a fixed price and that particular bid only entered one price,” said Morrell. He didn’t say which.

Dave Rogstad, President & CEO of JV lead partner Frontier Kemper, confirmed that the JV will proceed using the original engineering and the two Robbins hardrock TBMs currently in place, but directed all questions concerning the specifics of the contract to the GVWD. These questions included if and how the JV might be planning to modify the TBMs to better handle the ground conditions. When pressed on the issue, engineers with the GVWD said in a written statement, “we cannot discuss the details of the contractor's proposed means and methods.”

Rogstad also confirmed that Frontier-Kemper’s tunneling team would come from the contractor’s challenging but successfully completed TBM drive on the region’s Ashlu Creek hydro project in the mountains north of Vancouver near Whistler. J.F. Shea’s TBM tunneling team is also available, having recently completed the grueling five-year Arrowhead water tunnels project in Southern California through exceptionally difficult ground conditions.

Bilfinger Berger is suing Metro Vancouver as well as the project engineer Hatch Mott MacDonald, and the landowner the District of North Vancouver, alleging “unlawful and wrongful” dismissal, among other claims, following termination of its contract by the client in May 2008. John Penner, Contracts Manager for Bilfinger Berger Canada, said the recent award supports the company’s claim that ground conditions were fundamentally different than as described in the GBR.

“We believe that the recent budget increase for the project by Metro Vancouver represents an acknowledgement that tunneling conditions are more adverse than those contained in the initial geotechnical baseline report, and reinforces Bilfinger Berger’s position, that enhanced tunneling equipment and procedures are required to safely complete the project,” said Penner.

Shaft bottom work area

According to Bilfinger Berger, tunneling in the current conditions could not be performed safely using an open-type TBM as specified by Metro Vancouver and that the steel ribs, rockbolts and welded wire mesh support elements, as specified in the contract, were “not sufficient, safe or viable in the changed conditions.”

Termination of Bilfinger Berger’s contract stems from the contractor’s concern for workers safety following injuries sustained by several workers due to unstable rock in the unlined tunnels. WorkSafeBC, the occupational health and safety executive of British Colombia, ordered the water district to conduct an investigation and submit recommendations for ensuring safe continuation of the works.

“We met all the requirements,” said Morrell. “We in fact took our refined tunnel support proposals to world experts to ensure that what we were doing was appropriate and we received nothing but positive comments. Certainly there was no reason in the mind of expert tunnellers, rock mechanics, and tunnel engineers that the project could proceed, and yet Bilfinger Berger declined to do so.” Bilfinger Berger says the client refused to pay for the new recommendations.

“Metro Vancouver never issued a contractual change order authorizing the additional tunnel support recommendations,” said Penner. “As a result we could not proceed with them. We also provided, as requested, the pricing and a schedule for incorporating various modifications to the specified TBMs but again, Metro Vancouver never issued a contractual change order to authorize the modifications.”

Section of the deep tunnel alignment

Penner also said the client failed to provide requested information verifying anticipated geological conditions for the balance of the tunnel drives.

The cost of the suggested changes was not disclosed, however, in a letter asking Metro Vancouver to review its decision to terminate the contract, three unions involved with the project said it was “still considerably below the bid of the next lowest tender,” referring to Frontier-Kemper’s original bid of $186 million.

With the overall cost of completing the project now at an anticipated $400 million, the utility has sued to recover these additional costs from Bilfinger Berger. In return, the German contractor is suing to recover its loses, including more than $38 million of equipment confiscated by Metro Vancouver, and more than $22 million in unpaid labor and materials supplied to the project prior to termination.

When the job came to a halt in January 2008, the two 3.8m-diameter TBMs were struggling to navigate the worst ground conditions of the five support classes identified in the GBR. Class V support includes “steel ribs (+ shotcrete)” in “extremely poor” rock, which is described as that with a Q rating of <0.1, an RMR of <25, and “full pattern bolts (+ shotcrete) using 2.5m long rock bolts as per the design specifications” in “very poor” rock, that with a 0.1>Q <1 rating and a 25 <RMR <45.

These are the ground conditions in which the new tunneling team will restart excavation at some 4.1km and 3.8km or about 55% into the 7.1km long drives. The greatest risk however may still be ahead, at the far end of the downhill drives, where the tunnels pass beneath a deep glacial valley in the bedrock that is infilled with waterbearing sediments.

The JV is mobilizing now and if all goes to plan the TBMs will resume their drives within the month (April 2009) and head towards a new anticipated completion date of late 2012 or early 2013.

References

Rebid reprieve for Seymour Capilano – TunnelTalk, Jan 2009
Vancouver’s twin tunnels contract terminated - TunnelTalk, May 2008
Final breakthrough for Arrowhead – TunnelTalk, August 2008
TBM drive done at Ashlu Creek - Tunneltalk, Apr 2009

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