ABSTRACT
The earthquake response analysis of rock mass is generally performed as elastic body. However, rock masses are essentially discontinuous, which have a lot of joint, fissure and others. The mechanical behavior of rock mass is strongly controlled by the mechanical property and geometrical conditions of discontinuities such as orientation, dip angle, spacing, number of set. The dynamic response analysis of the equivalent continuous rock with discontinuities which are depended on confining stress and have strong nonlinearity, have not been practicable due to use the direct integration. But we could be thought that the constitutive equations of joint are improved from the results of dynamiccyclic direct shear test and the technique of calculation ability has been developed rapidly, therefore dynamic analysis becomes now a practicable stage. We describe the results of two cases of earthquake response analytical results by the Multiple Yield Model (hereafter, it is abbreviated as MYM) (Sasaki et al. 1994).
