坚固体孕震模式前兆场演化的数值模拟

本文针对华北地区的构造、应力场特征及介质特性，建立了华北地区具有代表性的坚固体孕震模型，对具有前兆观测意义的地表垂直位移场和近地表平均正应力场进行了模拟计算，并通过与均匀分层模型结果的,是出了地表垂直位移和近地表平均正应力的分布及其动态时空发展过程。结果表明，坚固体和下地壳隐伏断层的存在均可形成地表位移场和近地表应力场的异常。该异常随外荷载的增大呈加速增强趋势，因而具有很重要的前兆意义。

NUMERICAL STUDY ON EVOLUTION OF PRECURSORY FIELD THROUGH SEISMOGENIC MODEL WITH STURDY BODY

According to the characteristics of geological structure, stress field and media in North China. a typical seismogeic model with sturdy they for North China region was established in this paper Through computing the vertical displacement field on the surface and the average normal stress field in crust near the surface from the model, and comparing these fields with these from the layered homogeneous model, 'we obtained the dynamic distribution and evolution of the vertical displacement and average normal stress fields. The results show that the sturdy body and the buried fault in the lower crust can cause the abnormal variances of defacement and stress on or near the surface, and the variances increase speedily with the outer loading increase. This is of significance for precursory observation.