花岗岩巴西劈裂试验的矩张量反演研究  

Moment tensor inversion of Brazilian splitting test on granite

作　　者：任义 高永涛[1] 吴顺川[1,2] 李栋栋 甘一雄 REN Yi;GAO Yong-tao;WU Shun-chuan;LI Dong-dong;GAN Yi-xiong(Key Laboratory of Ministry of Education for Efficient Mining and Safety of Metal Mine,University of Science and Technology Beijing,Beijing 100083,China;Faculty of Land Resource Engineering,Kunming University of Science and Technology,Kunming,Yunnan 650093,China;Emergency Science Research Academy,China Coal Research Institute,Beijing 100013,China)

机构地区：[1]北京科技大学金属矿山高效开采与安全教育部重点实验室,北京100083 [2]昆明理工大学国土资源工程学院,云南昆明650093 [3]煤炭科学研究总院应急科学研究院,北京100013

出　　处：《岩土力学》2022年第1期235-245,共11页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.51774020,No.51934003);云南省高校科技创新团队支持计划资助。

摘　　要：为了研究岩石张拉破坏的过程和机制,首先通过模拟计算,验证了加权反演法在进行巴西劈裂试验矩张量求解方面的优越性;其次基于花岗岩的巴西劈裂试验,进行声发射监测、事件定位及矩张量反演,并分析标准反演法和加权反演法对应矩张量结果的差别;使用聚类分析K均值算法对矩张量结果进行分簇研究。研究结果表明:模拟计算中加权反演法可以降低巴西劈裂试验矩张量反演误差;室内花岗岩巴西劈裂试验中,加权反演法较大程度地优化了声发射事件的剪切成分以及压/拉应力轴的分布,使得反演结果更加合理。针对加权反演结果,所有事件可分成3簇,同簇内事件的破裂类型、应力状态、破裂机制、辐射模式等均相近;不同簇中的事件在时空上交叉分布,试验后期在圆盘东-西方向上具有较为明显张拉特性的事件骤增,于圆盘中心附近聚集并占据主导,最终导致试样的宏观破裂。研究结果解释了花岗岩巴西劈裂试验的破裂过程和破裂机制,为岩石力学行为研究提供进一步指导。To study the process and mechanism of rock tensile failure,the advantage of weighted inversion method in solving moment tensor of Brazilian splitting test is first verified by simulation calculation.Acoustic emission monitoring,event location and moment tensor inversion are performed during the Brazilian splitting test on granite,and the difference of moment tensor results between standard inversion method and weighted inversion method is analyzed.Then the moment tensors inverted by the weighted inversion method are analyzed by the K-means clustering algorithm.The results show that the weighted inversion method can reduce the moment tensor inversion error of Brazilian splitting test.In the laboratory granite Brazilian splitting test,the weighted inversion method greatly optimizes the distribution of the double couple component and pressure/tension axis of the acoustic emission event,which makes the inversion result more reasonable.For the weighted inversion result,the events selected for moment tensor inversion can be divided into three clusters,and the source type,stress state,focal mechanism,radiation pattern of events in the same cluster are similar.There is no significant difference in the occurrence time and position of events in different clusters,but in the later stage of the test,events with obvious tension characteristics in the east-west direction increase sharply and gather near the center of the disc and then dominate the whole rupture,which eventually leads to the split of the specimen.The results reasonably explain the failure process and mechanism of the Brazilian splitting test on granite,and can provide further guidance for the study of rock mechanical behavior.

关 键 词：矩张量反演 巴西劈裂 加权最小二乘 聚类分析 震源机制 

分 类 号：TU452[建筑科学—岩土工程]