两相饱和介质半无限空间位错位移场  

THE DISPLACEMENT FIELD OF DISLOCATION ON THE HALF-SPACE OF TWO-PHASE SATURATED MEDIUM

作　　者：丁伯阳[1] 樊良本[1] 孟凡丽[1] 丁翠红[1] 曹云中[2] 

机构地区：[1]浙江工业大学建筑工程学院,浙江工业大学减灾防护工程研究所,杭州310014 [2]浙江大学机械学院,杭州310027

出　　处：《地球物理学报》2003年第3期408-414,共7页Chinese Journal of Geophysics

基　　金：浙江省自然科学基金资助项目 ( 2 0 0 2- SO10 87) .

摘　　要：弹性位错理论是研究地震震源正演和反演的重要工具之一 .单相介质位错理论求得的地面变形场是稳定的、不变的 ,而实际地震后的地面变形场是变化的 .本文利用集中力作用下无限空间中两相饱和介质Green函数的柱函数表达式 ,通过弹性运动方程积分解的Helmholtz方程的Hansen矢量变换 ,再叠加自由表面影响场的方法求得两相饱和介质半无限空间位错位移场 .本文结果结合Nur的DD模式 ,在进水排水的假说下能解释地震后地面变形场的变化 .The elastic dislocation theory is an important part of seismology. Since the fracture of fault can be regarded as the displacement mutation in elastic medium, under given condition the displacement field can be studied with static elastic dislocation theory, and the change of elastic displacement field can be also deduced from the dislocation theory. The dislocation form proposed in this paper is based on the two-phase saturated medium. Because lots of dilatancy fissure appear in fault before earthquake, and then the water draw in it is saturated, the rock becomes two-phase saturated medium. It is on the grounds of DD model by Nur(1972), analogue hypothesis of Scholz(1973) etc. and interpretations of Whitcomb(1973) and Feng(1998) etc. to some symptoms before-earthquake process. Using Green function represented by Bassil function in two-phase saturated medium of action concentrated force and elasticity dynamic equation, with Hansen Vector transformation to Helmholtz equation, the authors obtain the displacement field of dislocation on the half-space of two-phase saturated medium. The dislocation displacement in half-space of single phase was studied by Stekette(1958) first. Later, Ben-Memahem and Singh(1964)(1981) studied it with Hansen Vector, and Chen(1974) generalized it to multi-layer elastic space with Haskell matrix. After dislocation of single phase the displacement is stable, but it changes in fact. Authors hope that the earth surface deformation is variable after earhquake, that will be explained according to the theory about dislocation on the half-space of two-phase saturated medium.

关 键 词：两相饱和介质 半无限空间 位错位移场 弹性运动方程 Hansen矢量变换 

分 类 号：P315.3[天文地球—地震学]