This is a SGER project to collect and to study the perishable earthquake and structural response/damage data due to the October 17, 1989 Loma Prieta earthquake. Perishable site soil data by in-situ borehole/geophone experiments and dynamic property data of reinforced concrete members by laboratory tests of field samples will be collected, and evaluated. Soil damping, shear modules, and nonlinear soil stress-strain relationship will be determined. Using the basic data of soil and concrete, a dynamic analysis of the double deck bridge structures will be carried out. The California Department of Transportation will provide design blue prints and soil log charts of the bridge-sites to assist the study. The effort will lead to better understanding the effect of local soil to the structural response and improved understanding of failure causes of the bridge structures of the I-880 viaduct.
