ANALYTICAL SEISMIC ASSESSMENT OF HIGHWAY BRIDGES WITH SOIL-STRUCTURE INTERACTION

The paper describes a new approach and its practical implementation for the analysis of the inelastic dynamic response of bridges with soil-structure interaction using multiple analysis platforms. The development is presented through an application test bed; the Meloland Road Over-crossing (MRO) bridge. The structure was heavily instrumented and has been shaken several times by significant earthquakes, rendering it an ideal benchmark to test the accuracy of the new development. The approach embankments, abutments, and supporting pile groups are modeled as three-dimensional finite element idealizations in OpenSees with realistic soil material models. The bridge structure is modeled in Zeus-NL, the Mid-America Earthquake Center analysis platform. The mode shape and fundamental properties of the soil-structure system are compared with those determined from system identification of the bridge based on measured ground motion. Response history analysis is conducted by distributed computation of geotechnical and the structural model on four separate computers, representing four geographically distributed simulation sites. In addition to the earthquake assessment observations given in the paper, the results and comparisons indicate that the analysis of large interacting structure-foundation-soil systems using distributed computation is an extremely powerful tool that provides accurate results at considerable savings in computing effort. The presented framework is also suitable for hybrid-distributed NEES-like simulations