BART Braces for Future Earthquakes; 30-Year-Old Transit System to Pursue $1.1 Billion Systemwide Retrofit Project.

Business Editors/Transportation Writers

OAKLAND, Calif.--(BUSINESS WIRE)--June 3, 2002

BART today announced the findings of a year and one-half study aimed at helping the transit system prepare for a major earthquake. The study recommends that BART adopt an aggressive systemwide retrofit program to strengthen elevated structures, the Transbay Tube, stations and equipment. The cost of the new systemwide retrofit program is estimated at $1.1 billion.

BART's original design, state-of-the-art when the system opened in 1972, withstood the 1989 Loma Prieta earthquake. However, recent U.S. Geological Survey statistics indicate that there is a 70 percent probability that a major earthquake could hit the Bay Area before the year 2030 and system improvements must be made, BART officials said.

"BART approach has been to better understand the potential risks to the system from a major earthquake, and then make the necessary improvements," said BART General Manager, Thomas Margro. "Prudent investment in preparation for a major seismic events will help to ensure the continued operation and safety of the system."

Since the Loma Prieta earthquake BART has conducted eight seismic studies and five retrofitting projects as part of its seismic retrofit program. The new Seismic Vulnerability Study, prepared by Bechtel/HNTB, is the most comprehensive evaluation of BART facilities since the system was originally constructed. The study recommends that the transbay tube be given priority.

"At the time of its design and construction, the transbay tube was an engineering marvel," said BART Chief Engineer, Jim Dunn. "In many ways it still is. But new engineering assessments indicate strengthening the tube is needed."

The study recommends that the tube be strengthened primarily because of what is known today about the liquefaction of certain soils. While the study concludes that the consequences of liquefaction of the tube are uncertain, a worst case combination of events could cause excessive movement of the seismic joints and structural stress along the tube itself that could cause significant damage.

"We studied the worst case scenario so that we could design a solution that is conservative and corrective," said Dunn.

In addition to the transbay tube, the study identifies vulnerabilities in aerial structures, including 24 miles of railways and 15 stations, administrative buildings and parking structures, and the Berkeley Hills tunnel, which crosses the Hayward fault.

As part of the study, several alternatives, representing varying degrees of retrofitting, were considered. The study recommends that the transit district adopt the $1.1 billion systemwide retrofit program that will take more than 10 years to complete. BART management is aggressively pursuing funding from a combination of federal, state and local sources.

"BART is the backbone of the Bay Area's transportation network and, as demonstrated in 1989 when the Bay Bridge failed, BART's ability to maintain service after a major earthquake is essential to avoid gridlock and keep the region's economy on the move," Margro said.

BART's Board of Directors is expected to hear a presentation of the Seismic Vulnerability Study on Thursday. Copies of the study are available upon request.