Numerical-Simulation Method For Seismic Reliabilities Of Linear Structures

Large earthquakes attack frequently China and both 1976 Tangshan and 2008 Wenchuan earthquakes caused significant damage to lives and pro- perties. Structural earthquake responses and resistance capacities are uncertain due to the uncertainty of earthquake, site ground motion and structural parameters and anti-seismic performance research has been a big difficulty. It's needed to use the seismic reliability to judge structural anti-seismic performance and perform the anti-seismic design of structures in earthquake regions. The analysis of the structural seismic reliabilities, therefore, is of great practical and engineering significance.In this paper an analysis method is developed to provide an efficient procedure for the estimation of the seismic reliabilities of linear structures subjected to non-stationary earthquake loads with the uncertain spectral density. This method is derived by the following there steps. First, calculate structural response samplings by the deterministic finite element methods. Secondly, estimate the structural conditional seismic reliability with the deterministic spectral density of earthquake by the direct Monte Carlo simulation (MCS) or the importance sampling proposed by Au and Beck. Finally, calculate the structural unconditional seismic reliability by combining Gauss's numerical integration and simulations.The seismic reliabilities of a single-degree-of-freedom system and a three-span six-storey steel frame are analyzed by the present method. Numerical results demonstrate the effectiveness and accuracy are apparently high in the seismic reliability analysis of the linear structures subjected to non-stationary earthquake loads.