Tunnel segments like these were surplused when a contractor was replaced; they will be recycled.
Contractor Jay Dee Coluccio, or JDC, is almost finished with the final two miles of tunnel for the Brightwater Treatment System project. JDC expects to finish the tunnel about 16 months ahead of the original contractor’s estimated completion date and is doing the work for millions of dollars less.
Back in February 2010, King County Executive Dow Constantine declared an emergency to hire a new contractor and keep Brightwater tunnel mining on an acceptable schedule and within budget. That spring, the County hired JDC to complete construction of the remaining two miles of the four-mile BT-3 tunnel (which basically spans from Kenmore to Lake Forest Park). JDC is now preparing its tunnel boring machine to make the final connection between the two tunnel sections.
King County had contracted with Vinci, Parsons and Frontier-Kemper (VPFK) to build the BT-3 tunnel, but in mid-2009 the contractor’s machine broke down and required time-consuming repair. Executive Constantine determined that completing the tunnel with this machine would likely result in unacceptable and costly project delays. He made a decision to hire JDC, which had completed the adjoining four-mile BT-4 (Point Wells to Lake Forest Park) tunnel and already had its machine in place.
Since VPFK could not complete mining as originally contracted, King County is currently in litigation with VPFK to recover all of King County’s costs to complete the tunnel and the expenses due to the delay.
Because JDC’s machine was built to mine a 13-foot-diameter tunnel, new tunnel segment were manufactured. As a result of the change, the tunnel segments manufactured for VPFK’s machine (14.4-foot-diameter) were no longer needed.
The County investigated potential other uses for the segments, but no safe or appropriate alternative uses could be found. King County consulted with tunnel design engineers, contractors and machine manufacturers with worldwide experience. No one knew of any project where tunnel segments were successfully transferred from one project to another. The County also explored creative alternate uses, such as for play structures in parks, but the concrete contains steel fibers that could cause injuries if the segments were to become chipped or damaged. VPFK is recycling the segments for roadbed material.
JDC is scheduled to complete the tunnel connection work in September. VPFK remains under contract to complete other work in the BT-3 tunnel and North Kenmore Portal.
The treatment plant will begin operating this summer. The public is invited to a grand opening celebration of the Brightwater Treatment System project on September 24.
The Brightwater tunnel and outfall system is expected to begin transporting treated wastewater from the treatment plant to Puget Sound in August 2012.
The $1.8 billion Brightwater project is currently within 3.3 percent of its original baseline budget established in 2004, when accounting for 5 percent inflation.
According to the most recent cost trend report issued in January, the $964 million Brightwater conveyance tunnel is actually $141 million under the baseline budget established in 2004.
Posted on July 18, 2011 by cheathb
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