Simulation of Chayu Mw8.6 ground motion based on kinematic source
In order to obtain the spatial distribution of the ground motion of the 1950 Chayu Mw8.6 earthquake,and to explore the influence of the source model on the simulated ground motion and the influence of the earthquake on the lower reaches of the Yarlung Zangbo River,the single-fault and double-fault kinematic hybrid source mod-els were established on the basis of previous studies.Considering the lithospheric velocity structure model UST-Clitho1.0 and the global crustal model Crust1.0,the underground one-dimensional velocity structures corresponding to the single-fault model site and the double-fault model site were constructed respectively.The spectral element method was used to study the ground motion synthesis in the target area of the 1950 Chayu Mw8.6 earthquake.By comparing the similarities and differences between the simulated acceleration time history and response spectrum of the four observation points in the target area and the previous research results,the applicability of the model con-structed in this paper is verified.The analysis results of ground motion characteristics in the study area show that:(1)the surface ground motion intensity is large.In the projection area of the fault zone,the maximum PGA,PGV,and PGD of the single and double fault models are 1050 cm/s2 and 1145 cm/s2,472 cm/s and 291 cm/s,and 107 cm and 652 cm,respectively.(2)The source model has a great influence on the simulated ground mo-tion.The maximum difference of PGA,PGV and PGD in the surface projection area of the single and double fault model is 95 cm/s2,181 cm/s and 545 cm,respectively.(3)The attenuation fitting effect of single-fault model ground motion with fault distance is better than that of double-fault model ground motion.Except that the PGD val-ue of EW component of double-fault model decays slower with the increase of fault distance than the other two com-ponents,the PGD of PGA,PGV and other components of single-fault model and double-fault model decays at the same speed with the increase of fault distance.The attenuation rate of ground motion in the hanging wall with the increase of fault distance is faster than that in the footwall.(4)The Chayu Mw8.6 earthquake produced strong ground motion and obvious permanent surface displacement at each engineering site.If the historical earthquake is repeated,the adverse effects of the earthquake will inevitably occur at each engineering site,and attention should be paid to preventing the occurrence of serious earthquake disasters.
Chayu earthquakespectral element methodsingle and double fault sourcesimulated ground mo-tionnear-fault effectattenuation effect
万方数据
维普
