硬岩开采诱发断层滑移的震源时空演化规律及孕灾机理

In deep hard rock mining, the dynamic disturbance induces fault slip due to stress field changes caused by excavation unloading. It results in concentrated release of huge energy stored at faults by tectonic stress, and consequently causes high-strength failure of far-field surrounding rock. The damage and disaster caused by fault slip are affected by many factors such as the magnitude, the focal mechanism and the wave velocity field, which lead to extremely complicated disaster-pregnant mechanism. It is urgent to study the nucleation process of fault slip and the temporal and spatial evolution of microseismic activities induced by fault slip. In this study, the dynamic response of faults and critical conditions of slip instability under the coupling of internal and external incentives will be explored from the perspective of stress tensor evolution through laboratory tests and numerical calculations. The time-frequency combined full waveform moment tensor inversion method will be used to interpret the focal mechanism of fault slip and its mechanical model from the perspective of seismic wave radiation. The internal relationship between the focal mechanism of fault slip and the spatial distribution characteristics of far-field vibration will be explored, and the disaster-pregnant mechanism of instability of far-field surrounding rock is to be revealed from the perspective of focal mechanism based on in site tests and analysis of microseismic monitoring data. Finally, the temporal and spatial evolution details of fault slip induced by excavation unloading and instability of far-field surrounding rock induced by fault slip will be clarified, providing theoretical basis for monitoring, early warning and controlling of deep rockmass disasters.

深部硬岩开采中，受开挖卸荷导致的应力场不断改变影响，动力扰动诱发断层滑移，致使构造应力在断层处存储的巨大能量集中释放，引发远场围岩高强度破坏，严重制约深部资源安全高效开采。断层滑移引起的破坏和灾害受震级、震源机制及波速场等多因素影响，导致其孕灾机理极为复杂，迫切需要研究深部开采诱发断层滑移的孕育过程及断层滑移诱发微震活动的时空演化规律。本研究通过室内试验和数值计算，从应力张量演化角度探明内外诱因耦合作用下断层的动态响应及滑移失稳临界条件；采用时频组合全波形矩张量反演方法，从地震波辐射模式角度解译断层滑移的震源机制及其动力学模型；通过现场试验及微震监测数据分析，探清断层滑移震源机制与其诱发的远场振动空间分布特征间的内在关系，从震源成核角度揭示断层滑移诱发远场围岩失稳的孕灾机理，最终阐明开挖卸荷诱发断层滑移及断层滑移诱发远场围岩失稳的时空演化过程，为深部岩体灾害的监测、预警和控制提供理论依据。

深部硬岩开采中，受开挖卸荷导致的应力场不断改变影响，动力扰动诱发断层滑移，致使构造应力在断层处存储的巨大能量集中释放，引发远场围岩高强度破坏，严重制约深部资源安全高效开采。断层滑移引起的破坏和灾害受震级、震源机制及波速场等多因素影响，导致其孕灾机理极为复杂，迫切需要研究深部开采诱发断层滑移的孕育过程及断层滑移诱发微震活动的时空演化规律。本研究通过室内试验和数值计算，从应力张量演化角度探明了内外诱因耦合作用下断层的动态响应及滑移失稳临界条件；采用时频组合全波形矩张量反演方法，从地震波辐射模式角度解译了断层滑移的震源机制及其动力学模型；通过现场试验及微震监测数据分析，探清了断层滑移震源机制与其诱发的远场振动空间分布特征间的内在关系，从震源成核角度揭示了断层滑移诱发远场围岩失稳的孕灾机理，最终阐明了开挖卸荷诱发断层滑移及断层滑移诱发远场围岩失稳的时空演化过程，为深部岩体灾害的监测、预警和控制提供理论依据。发表论文3篇，授权专利2项。