$ 267 million seismic security contract approved for Transbay Tube


OAKLAND – The final Part of BART’s modernization work in the Transbay metro will cause headaches for commuters very early in the morning, but the goal – to ensure passengers are not trapped under the bay if a catastrophic 1,000 earthquake years is happening – is something the agency can not ignore.

Most of the work inside the tube has already been completed, and this final piece will add extra layers to minimize flood damage in the event of a massive earthquake.

BART’s board on Thursday approved the more than $ 267 million contract for Shimmick Construction and California Engineering Contractors Inc. to install steel interior liner inside the 3.6 mile concrete tube and for build a new water pumping system. This is the latest major contract in BART’s $ 1.3 billion seismic safety program, said Tom Horton, group director of the program.

Work on the tube will not actually begin until the summer of 2018, but during the construction period of more than two years, the BART would open at 5 a.m. instead of 4 a.m. on weekdays, a move in particular. heavy for low income people. and non-white passengers. The agency is considering various options – including express buses or a combination of trains and buses – to serve passengers while it completes the renovations. BART would also run single-track trains in the metro from 9:30 p.m. Sunday through Thursday, meaning trains would run every 24 minutes instead of every 20 minutes now.

The tube that passes under San Francisco Bay in West Oakland is seismic in the event of a 500-year earthquake, but would be vulnerable to flooding in the event of a catastrophic event, Horton said. The upgrades will not prevent the tube from flooding, but are designed to allow people enough time to escape.

“(The tube) is not going to collapse,” he said. “But what he will do is leak. And in a very big earthquake… there will be a lot of leaks. It will leak more than our pumps can handle.

The contract also includes options to add an additional $ 46.5 million to further consolidate the tube because, even with all upgrades, there is still a possibility that in a very extreme case the tube will be flooded. The board approved the base contract on Thursday, and if it finds more funding in the future, it could extend it.

According to BART, approximately 2,600 passengers board the system between 3:45 a.m. and 4:45 a.m. each day. The largest proportion, 450 of them, ride at Pittsburg-Bay Point station, followed by Dublin-Pleasanton station and El Cerrito del Norte station.

Of those morning commuters, 66% are minorities, up from 56% the rest of the day, and 37% are low-income (meaning they earn less than $ 50,000) per year, according to BART.

With service starting at 5 a.m., contractors will have access to the tube for six hours, up from five with the current opening time, said Paul Oversier, deputy general manager of operations at BART. Horton said staff planned to have subcontractors work five hours out of six days, which would allow BART to keep its 4 a.m. start time, but decided not to because it was more efficient for subcontractors and because BART also needs time to perform its own maintenance.

BART board director Rebecca Saltzman said she felt staff left the board with few options because asking contractors to work only five hours at night would require a relaunch the project.

“It’s a huge change and it’s a decision the board needs to make,” Saltzman said. “At this point, we have no choice. … And that puts us in a very difficult situation.

BART will present a recommended alternative to early morning train service in summer 2017, which may include an express bus or a combination of train and bus service.

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