Sunday, May 5, 2013

Bay Bridge Opening Could Be Postponed

The planned September 2013 opening of the new Bay Bridge connecting Oakland and San Francisco could be delayed by broken bolts and cracked welds threatening seismic stability of the structure, as well as political infighting and potential conflicts of interest involving a Legislative Analyst's Office panel of experts appointed to perform an engineering review of the structure's construction difficulties. The latest complication facing completion and opening of the new span is discovery of cracks in 20 welds in the bridge tower, each of which is 33 feet long and 4 inches thick. In a cost saving measure on the $6.4 billion construction contract,  these tower welds were completed using an inexpensive and faster welding technique known as electroslag welding. The cracked welds connect huge steel plates at the base of the 525 foot tall tower just above the water line. The seismic strength of the tower depends on the stability of these welds.

Back in 1977, the Federal highway Administration declared a moratorium on electroslag welding for bridge construction, and only lifted the ban in 2000, based on technical improvements and increased reliability using narrow gap electroslag welding techniques. the Bay Bridge electroslag welds are reported to be the longest ever performed using electroslag techniques. Engineering professors familiar with the Bay Bridge project attribute the cracked weods, as well as earlier failure of 32 broken bolts on the seismic equipment for the eastern pier of the Bay Bridge suspension span a couple months ago, on hydrogen contamination during the welding process from moisture at the construction site.

While the defective welds can be repaired, no one has yet estimated the cost or time involved in making the repairs and opening the bridge to traffic. Initial appraisal of the problem is expected to be released by CALTRANS on May 8. 

Meanwhile, an ongoing legislative investigation into the design and construction of foundations for the Bay Bridge is under attack for apparent financial conflicts of interest affecting five of the seven members of a Legislative Analyst's Office panel appointed to evaluate earthquake performance of  Bay Bridge foundations.  Panel Chairman and Georgia Tech engineering school chairman Reginald DeRoches has been paid by CALTRANS for work on a number of research projects, including one just being completed for which the agency paid $150,000.00. DeRoches also thanked CALTRANS chief engineer Brian Maroney for help with DeRoches' 1997 Berkely doctoral dissertation based on a project partly funded by the agency. 

Panel member Ahmad Itani, an engineering professor at University of Nevada, Reno, is a for,er employee of CALTRANS and a frequent recipient of CALTRANS research funding. His website lists CALTRANS as his most frequent grant benefactor. Itani has also worked in the past as an employee of Bay Bridge co-designer Parsons Brinkerhoff.

Panelist Sena Kumarasena started working on the panel while still employed full time by New York design and construction firm Ammann & Whitney, which did design work on the Bay Bridge suspension span. Kumaraena also worked for HNTB, one of the construction managers for the Bay Bridge, and for Kewit Corporation prime contractor for the Bay Bridge tower foundation. He was also a technical adviser fot design of the Bay Bridge.

University of Illinois professor Youssef Hashash has had one study funded by CALTRANS and has also worked for Bay Bridge co-designer Parsons Brinkerhoff. Stanford University professor Jack W. Baker has occasionally had research funded by CALTRANS. The only two panel members without any apparent financial connection to CALTRANS or its Bay Bridge contractors are  are University of Texas professor Robert B. Gilbert and Georgia Tech professor Roberto T. Leon.

Somehow, it seems odd that LAO could not find seven engineers across the globe qualified for panel membership who never took money from the Bay Bridge agency or any of the construction firms whose work is under review by the group.

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