摘要
工程岩体震源机制研究是岩体破坏灾害监测预警研究和应用的基础。针对一次特大爆破诱发的采空区上覆岩体产生特大破坏案例的前兆微震定位数据,采用矩张量理论对前兆微震源定位事件进行震源机制解反演,计算监测所得微震定位事件的矩张量并进行分解,获得纯双力偶成分MDC分量;采用Feigner和Young矩张量破裂判据计算得到破坏类型判别参数R值,对前兆微震事件的岩体破裂类型进行判断,同时根据矩张量分量计算震源体积不变部分参数T和体积变化部分参数k,据此绘制并研究哈德森震源类型T-k图。分析表明,前兆微震源的破裂类型主要为剪切破坏;进一步根据矩张量分解所得纯双力偶成分MDC分量,解得岩体震源处的断层参数。将震源机制解分析得到的前兆微震事件剪切破裂类型与现场山体宏观剪滑破坏相对比,其结果是基本一致的。研究表明,基于微震矩张量理论对前兆震源机制解的分析,可较为准确地判断中尺度工程岩体破裂类型,该研究可作为进一步的中尺度工程岩体破裂机制研究以及岩体工程灾害预警研究参考。
The seismogenic mechanisms of engineering rock mass are the basis for both research and application of monitoring and early warning of rock failure.In this paper,based on the locating data of the precursory microseismic sources from a project case of a large-scale failure of the overlying rock mass over the mining goaf induced by a large blast,a back analysis of the seismogenic mechanisms was carried out by applying the moment tensor method to the precursory microseismic location events,and the pure double-couple components MDC were obtained by calculating and decomposing the moment tensor of the monitored microseismic localization events.The value of the discriminant parameter R,was calculated by the Feigner and Young moment tensor fracture criterion and used to determine failure types of the rock mass with the precursory microseismic events.The volume parameters of unchangeable part T and changeable part k were calculated according to the moment tensor components,and the T-k chart of Hudson source type was plotted.It is shown that the main failure type of the precursory sources is shear failure.Furthermore,the fault parameters of the locating sources were calculated according to the pure double-couple components MDC.The shear failure type of the precursory microseismic events analyzed by the focal mechanism solution basically matches with that of the on-site macroscopic shear-slip failure of the large landslide over the mining goaf.The research results show that the precursory focal mechanism solution based on microseismic moment tensor theory can more accurately determine the failure type of meso-scale engineering rock mass.The results of this study can be the reference to further research on the failure mechanisms of rock mass as well as early warning of engineering rock mass disasters.
作者
李庶林
林恺帆
周梦婧
张建霖
洪勇
胡静云
彭府华
LI Shulin;LIN Kaifan;ZHOU Mengjing;ZHANG Jianlin;HONG Yong;HU Jingyun;PENG Fuhua(School of Architecture and Civil Engineering,Xiamen University,Xiamen,Fujian361005,China;Changsha Institute of MiningResearch Co.Ltd.,Changsha,Hunan410012,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2019年第10期2000-2009,共10页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(51674218)
国家重点研发计划项目(2016YFC0600702)~~
关键词
采矿工程
微震监测
震源机制
矩张量解
岩体破裂类型
mining engineering
microseismic monitoring
source mechanism
moment tensor solution
fracture type of rock mass
