Simulation And Application Of Multi-point Ground Motions For Engineering Structures

As the development of domestic long-span structures, seismic responses of long-span structure affected by spatial variation effects cause the attention of many scholars all over the world, scholars have done a lot of research and obtained some theoretical achievements.However,there is still an amount of work needed to apply these results to engineering using.In this thesis which is based on on-hand researching results,four aspects including multi-point ground motion model parameters calibration, program interface design, reasonableness test and engineering application are researched and analyzed.The main research contents include:① This thesis presents two mature algorithms in spatially varying earthquake ground motion simulating fields. Coherence functions, power spectrum density functions, apparent wave velocity, local site effect, and non-stationary characteristics were analyzed in detail. The methods used for transformation of response spectrum into power spectrum were also analyzed in this thesis.Parameters in Clough-Penzien PSD function model are fitted based on response spectrum curve in seismic design of building code, which lays a foundation of canonical simulating.② A viewable multi-point ground motion simulator MGMS-I was programmed based on above theory. Users only need to input a few parameters to simulate the spatially varying earthquake ground motion which has taken wave passage effect, coherence effect, and local site effect into account.Two operation guide examples were also provided to exemplify how to use this program.③ Based on stochastic process theory, spectrum analysis theory, and time series similarity analysis theory, a comprehensive test and evaluating system was set up. Through these methods in this system, multi-point ground motion simulated in this thesis has been proved reasonable.④ In engineering fields, the multi-point input modes of seismic response time history analysis in long-span structure was discussed. As one of the typical representatives, a long-span continuous rigid frame bridge model was analyzed. In this model uniform excitation, wave passage effect, coherence effect,and site effect were considered.The numerical analysis results have been presented to demonstrate that spatially varying effects of earthquake cannot be ignored and should be fully evaluated in engineering application.Finally, this thesis summarizes the full content and discusses the deficiency and limitation of this study. Some recommendations for following research are provided at the end.