THE PSEUDO STATIC/DYNAMIC RESPONSE COMPONENTS OF LARGE STRUCTURES UNDER NON-UNIFORM SEISMIC EXCITATIONS

摘要

During earthquakes,the spatial variability of strong ground motions should be taken into account for extended structures.In order to evaluate the importance of the effects of non-uniform ground motions on structures,based on a long-span structure,the seismic response is analyzed.With improved large mass method and displacement method respectively,the total response and pseudo static components of the inner forces of structures under seismic excitations are obtained directly,and then the dynamic components can be separated by subtracting pseudo static components from total components.This technique for pseudo static/dynamic components presented in the paper can yield results that are identical to those of theoretical method.With this technique,the dynamic response analysis of a large structure subjected to non-uniform seismic excitations has been performed,and the pseudo static/dynamic components of inner forces are separated.It reveals that the pseudo static components depend on relative displacements between the pier foundations.The seismic responses of structure members can be magnified or decreased irregularly by the resonance or counteraction of the pseudo static components and dynamic components.So,the complexity of the structural seismic response under multi-support excitations derives from the idiographic course of the two kinds of responses mentioned above.