摘要
Earthquake is a kind of complex natural phenomena and its physical essence is that the seismogenic fault undergoes the shear rupture accompanying rapid energy release.The essence of the earthquake preparation is the increase in the extent of the damage of the seismogenic zone until a sudden instability occurring in the medium.To study the evolution of the seismogenic zone’s damage is an effective scientific method to research the earthquake preparation.According to this idea,the Load/Unload Response Ratio(LURR)theory was put forward.In this paper,a block of crust is simplified as a plate,and the fault caused by earthquake is seen as a crack in the plate.The damage caused by earthquakes could be measured by the reduction of the crustal block’s rigidity.We study the change of elastic modulus and the damage of the crustal block,and use them as new responses of load and unload.Further more,we derive new analytical formulas of the LURR,which give the LURR a new and more precise physical meaning.