Estimating for Cable-Stayed Bridge by Modified DASPA Procedure

The cable-stayed bridge belongs to a typical multi-degree-of-freedom system which has complicated vibration characteristic. The seismic performance of the cable-stayed bridge cannot be estimated by classic pushover analysis methods because of the great effects of higher modes on it. The principal objective of this investigation is to propose a displacement-and-adaptive-spectra-based pushover analysis procedure (DASPA) which is based on inelastic displacement response spectra. The contributions of higher modes to response and the redistribution of inertia forces because of structural yielding and the associated changes in the vibration properties of the structure are considered in the procedure. According to the special bridge type for cable-stayed bridge, the post-yield displacement pattern is modified to approach practice (MDASPA). The seismic performance determined by DASPA and MDASPA is compared with nonlinear RHA procedure. The results indicate that the MASPA procedure provides more superior accuracy in estimating seismic performance for structures compared with DASPA procedure.