Strong Ground Motion Simulation In Haicheng Ms7.3 Earthquake

In recent decades,the study of seismic strong ground motion has been developed a lot,and how to simulate the seismic wave propagation process in 3D complex media fast and accurately is one of the key problems.The finite difference method has become a mainstream algorithm for numerical simulation of strong ground motion because of its easy realization and high computational efficiency.Due to the important influence of topography on strong ground motion,this paper will use the curve mesh finite difference method to simulate.A Ms7.3 earthquake occurred at Haicheng city,Liaoning province,February 4,1975.The decastating earthquake occurred in Liaodong Peninsula,where is relatively densely populated and concentrated distribution of modern industrial.Despite the success of the forecast,it is still a huge loss to the national economy.After the earthquake,the National Seismological Bureau and the Liaoning Provincial Earthquake Office jointly composed of the team to investigate the seismic intensity,ground phenomena,earthquake damage and other detailed research.The investigation got a lot of valuable information which.provide a basis for further study of the Haicheng earthquake.The results show that there is still the possibility of moderate strong earthquakes in the end of the Haicheng River buried fault which caused the Haicheng earthquake in the future.So it is very important to carry out near-fault strong ground motion simulation in Haicheng area.In the paper,earthquake source model and a transmission medium model are established and the corresponding parameters are given with the accordance to the results from related previous study.Then we simulate the seismic wave propagation of Haicheng earthquake with 3D curved grids finite-difference method,and calculate the distribution of seismic intensity for the modeling region.The simulation results shows:(1)Seismic wave propagation is influenced by source,media and topography,and reveals near-fault concentration effect of peak ground velocity,rupture directivity effect,and basin effect.(2)Seismic intensity map is well consistent with real intensity map.The results from our simulation and analysis suggest that the source and transmitting medium parameters of Haicheng earthquake in our model are suitable.