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Caltrans downplays latest Bay Bridge rod failure

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Caltrans downplays latest Bay Bridge rod failure.


It seems that there are two serious problem with these tests:

1. There is no detail given on wgat level of tension these anchor rods at
the base of the single tower were subjected toand with what speed? The
micro cracks in the rods are quite sensitive to strain rate as well as
amplitude of the force.
During major earthquakes these bolts can be subjected to ver large forces
near their ultimate strength with frequencies of a few cycles per second.

2. It seems that Caltrans ignores the fact that hydrogen embrittlement is a
long term problem and the cracks in these anchor rods that are hydrogen
embrittled and now are sitting in salt water will continue to grow due to
stress corrosion. If Caltrans does these pull tests next year most likely a
few more bolts will fracture. Even if no pull force is applied the anchor
rods will continue to fracture since they are under a pretensioning force
equal to 48% of their ultimate strength.
The  design life of this bridge is 150 years. Imagine how many rods will be
fractured in 50 years or 100 years?

The question is since this is a serious public safety problem how a
registered P.E. , Dr Brian Maroney , the Caltrans Chief Engineer for this
bridge officially tell public, press and bridge authorities that the bridge
is safe?
What do you think?
Best regards


 Abolhassan ASTANEH-ASL, Ph.D., P.E., Professor
2013 Minner Faculty Fellow in Engineering Ethics and Social/Professional
 Responsibility and
2013-14 U.S. Fulbright Senior Research Scholar
Department of Civil and Environmental Engineering
781 Davis Hall,  MC 1710
University of California,
Berkeley,  CA 94720-1710, USA
Phone; (510) 642-4528

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