抄録
This research was initiated after a couple of bridge piers failed due to an earthquake in Miyazaki. The main objective was to carryout an experimental evaluation of such failures. A Dywidag bridge pier model was constructed and tested. The results showed a strong nonlinear response and a softening of the hard spring under increased periodic loading. Analytical interpretations became necessary, because of the inability to evaluate the dynamic material properties experimentally, and a need for the explanation of the nonlinear failure phenomenon. The loss of ductility and reserve capacity with an increase in acceleration is verified by the experiment and the analytical model. This renders the pier inserviceable, though the structure did not collapse. The procedure used for system identification is equivalent linearization, but it is being carried forward to accomodate a nonlinear programming optimization model.
