唐山地震孕育过程的数值分析

Numerical Simulation of Seismogenic Process of Tangshan Earthquake

将损伤力学应用于地震孕育过程的研究中 ,编制了耦合损伤的有限元程序。应用所编程序对 1 976年唐山大地震进行了模拟分析 ,得到了区域中应力、应变、应变能、损伤、唐山断层走滑速率以及地震时地面位移的时空演变规律。计算结果与实际地震吻合良好。应用计算结果结合实测有关资料对唐山地震的孕育过程进行了整体分析。分析认为唐山地震的孕育经过了稳定、失稳、稳定、最后失稳发生地震等阶段。其孕震过程不但与唐山菱形块体的形状、性质以及受力状态有关 ,而且与唐山地区地壳的结构和形变状态有关。

With the use of continuum damage mechanics and finite element method,the Tangshan earthquake occurred in 1976 is simulated.Fields of stress,strain and elastic energy in the seismogenic process are obtained.The slide speed,damage evolution process of Tangshan fault and the displacement field of the ground are also obtained.All of the computer results coincide well with the facts of Tangshan earthquake.Using the results and some site surveying data,the whole seismogenic process of Tangshan earthquake is analyzed.