THE DISPLACEMENT FIELD OF DISLOCATION ON THE HALF-SPACE OF TWO-PHASE SATURATED MEDIUM
两相饱和介质半无限空间位错位移场

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.