Analysis On Seismic Responses And Ultimate Bearing Capacity Of Structure Of The West Tianjin Railway Station

The influence of spatial variation of seismic ground motion can’t be neglected for long span space structure. It is a task resolved necessarily how to calculate the response of earthquake correctly. Focusing on this topic, multi-support excitations considering traveling-wave effect and the partial coherence effect was simulated, and the time history analysis method was established to conduct multi-support earthquake excitations for long span space structure. The incremental dynamic analysis method was introduced into the ultimate bearing capacity analysis of long span roof structure. Base on all of these studies, the seismic response and ultimate bearing capacity of the West Tianjin Railway Station were numerically simulated under the multi-support excitation.The specific research work included the following aspects:(1) The simulation of the multi-support excitations considering traveling-wave effect and the partial coherence effect. The appropriate coherence function model and power spectrum model were selected. And based on the harmonic superstition method, a program was developed to simulate multi-support excitations. Then the correctness of the program was verified by the baseline calibration of acceleration time history and frequency domain transform.(2) The establishment of time history analysis method to conduct multi-support earthquake excitation. The multi-support earthquake excitation equation motion of long span space structure based on large mass method was derived. Then the time history analysis method to conduct multi-support earthquake excitation was established. Then the effectiveness of this method was verified.(3) The seismic responses analysis of the West Tianjin Railway Station. Based on finite element software ANSYS, the three-dimensional model of the West Tianjin Railway Station was established. Then it was analyzed in uniform excitation, traveling-wave excitation and multi-support excitation under several chosen velocities.(4) The ultimate bearing capacity analysis of West Tianjin Railway Station. The incremental dynamic method was introduced into the ultimate bearing capacity analysis of the large span roof structure station house. Then the appropriate indicators were established, and the principles to determine the damage load and the ultimate bearing power were given.The results show that the multi-support excitations can be well simulated by the program developed in this text. The time history analysis using large mass method to conduct multi-support earthquake excitation has high accuracy. For West Tianjin Railway station, the internal force of is affected by the traveling-wave effect and the partial coherence effect, and the influence degree depends on the traveling-wave velocity selected. For the bars of different locations, this influence is also different. The damage mode of West Tianjin Railway Station is strength failure with the plastic developing to a certain degree. The ultimate bearing capacity of the structure changes because of the influence of the traveling-wave effect and the partial coherence effect.