The drama that gripped the region for the entire spring and summer over those cracked steel bolts/rods in the new eastern span of the Bay Bridge has finally come to a quiet close. The temporary shims that were put in place in August, inside some critical seismic stabilizers east of the span's main tower, were removed yesterday after the permanent fix for the broken bolts was finally completed, as the Oakland Tribune reports.
As you may recall if you studied the details of this highly technical drama as it played out, some high-tension steel rods that played a critical role in the bridge's earthquake safety snapped during tightening back in March. It turned out that the contractor or some engineers involved had selected the wrong kind of steel for these bolts, and they had cracked due to "hydrogen embrittlement." But the actual details of how the mishap occurred, and why the bridge took so ridiculously long to complete, will now be the subject of a full investigatory hearing by the Senate Transportation and Housing Committee.
The permanent fix to the problem involved the installment of a steel "saddle" that wrapped and fixed the cracked bolts into place in the concrete pier. The fix cost a reported extra $25 million, up from an initial estimate of $10 million. The entire bridge project cost $6.4 billion.