Physical meaning and prediction efficiency of the load/unload response ratio of rocks in strain-weakening phase before failure  

作　　者：许昭永 杨润海 王彬 赵晋明 王赟赟 梅世蓉 

机构地区：[1]Seismological Bureau of Yunnan Province, Kunming 650041, China [2]Center for Analysis and Prediction, China Seismological Bureau, Beijing 100036, China

出　　处：《Acta Seismologica Sinica(English Edition)》2002年第1期47-55,共9页

基　　金：Key project from China Seismological Bureau (9691309020301); State Natural Sciences Foundation of China (19732060).

摘　　要：Rock experiment results indicate that the load/unload response ratio (LURR) of rocks expressed via strain energy may have singular or negative value after the stress in the rock reaches its maximum before rock failure or when the rock goes into the strain-weakening phase. The universality of this phenomenon is discussed. Expressed via strain or strain energy and the travel time of P wave, the variation form of the reciprocal of LURR during the process of rock failure preparation is derived. The results show that after a sharp decrease the reciprocal of LURR reaches its minimum when the main fracture of the rock is about to appear. This feature can be taken as an indication that the rock main fracture is impending.Rock experiment results indicate that the load/unload response ratio (LURR) of rocks expressed via strain energy may have singular or negative value after the stress in the rock reaches its maximum before rock failure or when the rock goes into the strain-weakening phase. The universality of this phenomenon is discussed. Expressed via strain or strain energy and the travel time of P wave, the variation form of the reciprocal of LURR during the process of rock failure preparation is derived. The results show that after a sharp decrease the reciprocal of LURR reaches its minimum when the main fracture of the rock is about to appear. This feature can be taken as an indication that the rock main fracture is impending.

关 键 词：strain-weakening phase load/unload response ratio prediction efficiency 

分 类 号：P315.8[天文地球—地震学]