A $7.7 million contract to strengthen BART’s Transbay Tube at Oakland’s waterfront could be approved by the transit agency’s board of directors on Thursday.

BART has determined that its underwater tube needs seismic strengthening at Pier 34 on the Port of Oakland. To shore up the line, construction crews are scheduled to bolt 2.5-inch steel frames to a concrete wall of the tube.

Although BART’s engineers estimated that the seismic retrofit work would cost $14 million, California Engineering Contractors, a Pleasanton-based company, offered to carry out the job for $7.7 million. After reviewing the company’s history, BART’s staff has recommended approving that contract offer.

wreisman@sfexaminer.com