| The
new Benicia-Martinez bridge will be the largest lightweight concrete
segmental bridge in California. It is about 2 km long carrying 6 traffic
lanes. This is the first new long-span bridge to be built in recent
years in California (since the building of the Vincent Thomas bridge
in early 1960s') which needs to be designed to the new generation
seismic design criteria. The new seismic design criteria include:
two performance levels: functional and safety levels involving both
response spectrum and 3 sets of multiple-support time histories analyses.
EMI was chosen
to be the lead geotechnical engineer in this project. Our role included
development of seismic design criteria, geologic and geotechnical
studies, soil-structure interaction analyses and foundation analyses.
The structure
is supported by a group of large diameter piles. Each pile has a
2.5 meter diameter steel pile to construct a 2.2 meter diameter
rock socket below the steel pile. One of the challenges is construction
of these large diameter piles about 60 meter long.
|
