【摘要】 本文用平面应变理论,结合按地壳深度增加的地温计算公式,计出自地面以下约10公里内的地壳为弹性层,10—20公里深度为弹塑性层,20公里以下至地壳底部为粘弹性层。由于地应力在弹塑性层内可以达到岩石的屈服强度,大于其他两层的地应力,故这一层即为线源地震经常发生的地层。具体数字例子是以唐山地区为例。更多还原

【Abstract】 In this paper, combined with the formula of terrestrial temperature as a function of depth we use a plane strain method to calculate the thermal stress of the crust. For instance in Tangshan area, we obtained that the stratum with depth=10 km is elastic. It is elastic-perfectly plastic from 10 to 20 km, and visco-elastic from 20 km down to the bottom of the crust. As the terrestrial stress can reach the yielding stress of rock in the elastic-perfectly plastic stratum, becoming the maximum terrestrial stress among the three, so shallow earthquakes are often related with this mostly stressed part (elasto-plastic) of the crust.更多还原