Abstract:
The relationship between work and energy increment of thrust fault system with quasistatic deformation can be decomposed into two parts, i.e. the relationship between work and energy increment of volume strain energy and that of deviation stress energy,which was analyzed by using method of catastrophe theory. The research indicates that the characteristics displayed by fold catastrophe model can appropriately describe the earthquake generation condition, the evolvement process of main shock of thrust fault earthquake and some important earthquake effects as well. The bigger the surrounding press of surrounding rock is, the bigger the maximum principal stress is. The smaller the incidences of the potential thrust fault surface are, the smaller the rate between the tangential stiffness of surrounding rock and the slope is, which is at inflexion point on the softened zone of fault shearing strength curve. Thus when earthquake occurrs, the larger the elastic energy releasing amount of surrounding rock is, i.e. the larger the intensity of earthquake is. The larger the half distance of fault dislocation is.The larger the displacement amplitude of surrounding rock end face is. Fracturing, expanding of the fault rock body and releasing of volume strain energy of surrounding rock while earthquake occurrs enhance the foregoing earthquake effects together.