地震导致地壳块体损伤的平板模型和加卸载响应比新定义

A plate model for the damage of a crustal block induced by earthquake and the new definition for the load/unload response ratio

地震孕育的实质是孕震区介质的损伤程度不断增加,最后导致突然失稳(破坏)。研究地块的损伤演化是研究地震孕育过程的科学方法。加卸载响应比(LURR)的提出正是基于这一基本思路,把地壳块体看作平板,断层看作平板中的裂纹,建立了地壳块体的平板模型。该模型可以用来研究地震形成的断层导致的地块损伤,损伤程度用刚度的减少来刻画。研究了地块在地震影响下弹性性质的变化及损伤,并把它们作为加载与卸载响应量,进一步得到新的LURR解析式,赋予LURR以新的、更为确切的物理意义。

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.