均匀弹性分层介质模型中的同震位移、应变以及应力

地震发生时产生的同震位移、应变以及应力变化,特别是同震应力的变化,在地震触发等问题的研究中有着重要的意义.本文进一步发展了基于均匀弹性水平层状介质,利用广义反射透射系数矩阵和离散波数计算同震位移的方法,使之可以计算相应的应变、应力以及同震库仑应力变化.可适用于多种情况,接收点可以位于地表以及地表以下,震源类型可以是剪切位错源以及拉张位错源.通过与半无限介质的解析解相比较,结果一致,验证了方法的可靠性以及计算精度,可以用于计算地震之后库仑应力变化,为判断余震分布提供参考.在计算同震位移时,使用了梯形积分与Filon积分相结合的积分方式,即提高了同震位移计算的速度,又保证了计算精度,有利于反演问题研究.

The coseismic displacement, strain and stress in the layered elastic model

The coseismic displacement,strain and stress,especially the change of the coseismic stress,are significant in the earthquake triggering investigation.Based on the layered elastic model,we develop a method to calculate the coseismic dislocation by the generalized reflection-transmission coefficient matrix and discrete wavenumber method.We can use it to calculate the coseismic strain,stress,and the change of Coulomb stress.It can be applied in the general situation.The receiver can be located on the surface or underground.The earthquake source can be pure shear dislocation source or tensile source.For the half-space model,the result of our method coincides with the analytical solution,so the precision of our method is reliable.The method can be used to calculate the Coulomb stress after an earthquake,and the change of Coulomb stress can give a reference to estimate the distribution of the aftershocks.We combine the trapezoidal integration method with the Filon integration method to calculate the coseismic displacement.It improves the speed of the calculation and there is no accuracy loss.It is useful for the inversion research based on the coseismic displacement.