Studies on the Responses of Multi-degrees of Freedom Systems Subjected to Random Excitation with Applications to the Tower and Pier Systems of Long Span Suspension Bridges

Abstract

In this paper the responses of multi-degrees of freedom systems with applications to the pier and tower systems of long span suspension bridges due to earthquake motions are studied by the stochastic process theory and the results are compared with the direct-integration. For the present system, foundation conditon coupled with the pier dimensions has significant effects on the structural dynamic characteristics. The response behaviors and then their evaluation become complex for some foundation ranges. Here, on the assumption that the normal mode analysis can be applied, the direct-effects of individual modes and their cross-effects to the dynamic response characteristics are investigated by simulating earthquake motions to a suitable form.