岩石损伤对地下核爆炸震源特性影响研究

本文在考虑动态力源扰动的情况下，对岩石损伤对地震波辐射的影响及其震源表示进行了理论推导，证明了当有动态力源存在时，Ben-Zion和Ampuero于2009年给出的结果只是岩石非弹性响应对震源及相应地震波场的贡献，而非其全部.在此基础上，应用相关结果对岩石损伤破坏对地下核爆炸震源成分的影响进行了分析，给出了地下核爆炸情况下补偿线性偶极子源和构造应力释放与岩石损伤破坏之间的关系.结果表明，地下核爆炸补偿线性偶极子源主要来自于地表反射拉伸波和空腔回弹冲击波等造成的爆心上方锥形区域中的岩石破坏，而构造应力释放则主要来自于整个岩石破坏区内的构造应力松弛. 

Effects of rock damage on seismic source characteristics of underground nuclear explosions

In this paper we readdress the effects of rock damage on seismic radiation and its source representation taking account of the existence of dynamic force disturbances in the source. We proved that, when dynamic force distur-bances exist, the result given by Ben-Zion and Ampuero in 2009 is not for the whole seismic wave field but for the contribution by the nonelasticity. Furthermore, based on the theoretical formulations obtained in this paper, we analyzed effects of rock damage upon source characterizations of underground nuclear explosions and relationships between rock damages and their non-isotropic secondary sources including the compensated linear vector dipole (CLVD) and tectonic stress release. The results show that, the CLVD of an underground explosion mainly comes from rock damages within a cone area above the explosion itself which is induced by surface reflected tensional shock waves and cavity rebound, while the tectonic stress release may be caused by stress relaxation within whole damaged area of the explosion.