Abstract
Firstly, Ideal with Elastic Dislocation Theory in view of the problem of crustal deformation in order to know displacement fields around earthquake faults. “Elastic Dislocation Theory” is a general idea which has been introduced to seismology by J. A. Steketee and developed by M. A. Chinnery, T. Maruyama, L. Manshinha & D. E. Smylie et al., and it becomes clear that the crust on a scale of seismology can be treated as a homogeneous elastic medium but not on a scale of engineering geology.
Secondly, in order to apply this theory to the problem of engineering geology I make use of the principle of superposition and estimate the complicated displacement field for the plural fault system in which rock mass consists of some faults. But generally it is believed that there are some secondary displacements along the ready-made fault or joint when main fault moves. So crust and rock mass deformations associated with formation are calculated by Finite Element Method (F. E. M.). At the time when it is put into practice, urface displacement obtained by Elastic Dislocation Theory is regarded as that of a fault plane in F.E.M. model. Consequently, it may be proved that it is very significant especially in the field of engineering geology to estimate the displacements of geological discontinuous planes when main fault displaces.
