微地震荷载作用下含断层破碎带边坡的稳定性分析  

Stability Analysis of Slope with Fault Fracture Zone Under Micro-seismic Load

作　　者：陈刚 刘钢一 CHEN Gang;LIU Gangyi(Hubei Provincial Geological Environment General Station,Wuhan 430030,China)

机构地区：[1]湖北省地质环境总站,武汉430030

出　　处：《华南地震》2024年第1期133-148,共16页South China Journal of Seismology

摘　　要：次数多、震级小的微地震作用对岩质边坡稳定性的影响是地质灾害防治中必须面对的问题,而断层破碎带又具有特殊的物理力学性质,直接影响着边坡的动力稳定。因此,研究微地震荷载作用下含断层破碎带的顺层岩质边坡的动力响应规律及稳定性具有重要意义。以某含断层破碎带的顺层岩质边坡为研究对象,开展振动台模型试验和离散元数值模拟,对微地震作用下边坡的动力响应规律,变形破坏特征和动力失稳特征进行了研究。研究结果表明:该边坡在微地震作用下的动力响应具有高程放大效应和趋表效应;GPA放大系数随振幅的增大而减小,随频率的增大而增大,同时高程越高,PGA放大系数随幅值和频率变化的幅度越大;微地震强度越大,边坡发生失稳破坏对应的微地震次数越少;边坡的稳定性系数随着微地震强度和微地震次数的增加逐渐减小;不同振动次数下,边坡稳定性系数与微地震强度之间符合线性衰减的关系;当微地震次数为4500次时,微地震强度对于边坡稳定性的影响最大。The influence of frequently-occurring small-magnitude micro-seismic action on the stability of rock slope cannot be ignored in the prevention and control of geological disasters.Moreover,the fault fracture zone characterized by special physical and mechanical properties directly affects the dynamic stability of the slope.Therefore,it is of great significance to study the dynamic response law and stability of bedding rock slope with fault fracture zone under micro-seismic load.Taking a bedding rock slope with fault fracture zone as the research object,shaking table model test and discrete element numerical simulation were carried out to explore the dynamic response law,deformation and failure characteristics and dynamic instability characteristics of the slope under micro-seismic action.The results show that the dynamic response of the slope under micro-seismic action exhibits elevation amplification effect and surface effect.The amplification coefficient of ground peak acceleration(GPA)decreases with the increase of amplitude and increases with the frequency.Meanwhile,the higher the elevation,the greater the amplitude of PGA amplification coefficient with amplitude and frequency.The greater the intensity of the micro-seismic,the less the number of micro-seismic corresponding to the failure of the slope;the stability coefficient of the slope gradually decreases with the increase of micro-seismic intensity and micro-seismic times.Under different vibration times,the relationship between slope stability coefficient and micro-seismic intensity follows linear attenuation.When the number of micro-seismic events reaches 4500,the micro-seismic intensity has the greatest influence on the slope stability.

关 键 词：振动台模型试验 断层破碎带 动力响应规律 离散元数值模拟 边坡稳定性分析 

分 类 号：P642[天文地球—工程地质学]