区域地震状态的损伤张量分析  

Damage Tensor Analysis on Regional Seismic Status

作　　者：钟继茂[1] 程万正[2] 

机构地区：[1]中国地震局兰州地震研究所,兰州市东岗西路410号730000 [2]四川省地震局预报研究所,成都610041

出　　处：《中国地震》2005年第3期398-408,共11页Earthquake Research in China

基　　金：地震科学联合基金课题(105004);"十五"<强地震短期预测及救灾技术研究>项目(2004BA601B0102)

摘　　要：本文采用损伤力学的理论研究区域地震的状态问题。对地壳块体由地震破裂引起的宏观损伤状态,通过引入损伤度ω、损伤率ω、应变率ε来刻画。所研究地块内地震过程引起的平均应变速率等于发生在单位时间、单位体积内的所有地震的地震矩张量之和。为描述地壳块体微损伤的各向异性,引入裂纹密度表示的损伤张量形式。由震源坐标系表示的震源断层面换算到观测坐标系得到其外法向矢量,可求得研究地块以地震裂纹密度张量计算的宏观损伤度的变化。这为认识地下损伤状态或应力状态提供了新的分析方法。In this paper, we researched the regional seismic status by using theories of the Damage Mechanics. The macroscopic damage status of the earth crust block, which is caused by earthquake fracture, is described with several concepts—the damage degree, the damage rate and the strain rate. In earthquake process, average strain rate of the research block is equal to the sum of all seismic moment tensors of the earthquakes taking place in unit time and physical volume. To describe the anisotropy of microdamage of the crust block, we use the damage tensor that is expressed in the fissure density. By means of the transformation from the focal coordinate system to the observation system, we obtained the external normal vector of the focal fault plane expressed in its observation system, and obtained the macrodamage degree of the researched block, which is calculated in dyadic. This provides a new analysis method for recognizing the underground damage status and the stress status.

关 键 词：损伤张量 损伤度 地震状态 

分 类 号：P315[天文地球—地震学]