New BART extension tracks to cross Hayward Fault


This is the frame of the new Warm Springs BART station, slated to open in just over two years. Nearby, the new BART tracks will cross the Hayward Fault.

Engineers will protect the rails from an earthquake by using recycled tires, shredded into small pieces. Called tire-derived aggregate, it will form the base for the rail bed. An 800-foot long section will be installed.

"It's proven in a number of capacities, but not in a heavy rail transit application," BART project manager Paul Medved said. "So this will be among the first of the applications for that, and we are taking measurements before and after to try to improve the understanding of its effectiveness application."

Nearby, the San Francisco Public Utilities Commission, which owns and operates the Hetch Hetchy water system, is also facing seismic risk. It's installing a new 72 inch pipeline that also crosses sections of the Hayward Fault.

To prevent ruptures, a new system of ball and slip joints is encased in a series of articulating concrete boxes. This will allow the new pipeline to move up to 6.5 feet during an earthquake. The pipeline can also compress up to nine feet from seismic ground movement.

Video provided by the San Francisco PUC shows the technology that's never been tried before on his scale. And it's important, considering the Hetch Hetchy system delivers water from the Sierra to 2.6 million customers in the Bay Area.

These two projects, plus road improvements tied into the BART extension, will help Fremont to develop hundreds of acres of new housing and new business developments.

"People want to work in area where they can potentially stay on mass transit like BART, and get to there, and we're going to build that area that allows people to live, work, shop, play in Fremont," said Fremont Mayor Bill Harrison.

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