开挖扰动下高应力岩体的能量演化与应力重分布规律研究

为揭示深部灾害发生机理，探讨各因素对开挖扰动效应的影响机制，利用离散元PFC软件建立不同原岩应力状态及不同开挖断面下的开挖模型。通过显式计算得到不同情形下高应力岩体在开挖扰动中的动能释放曲线，并以曲线峰值及最终稳定值，分别作为评判开挖扰动程度及开挖系统稳定性的能量指标，利用该组指标分析表明在原岩应力接近静水压力状态、采用圆形断面开挖时扰动效应最小；通过进一步分析，得到不同开挖断面及不同原岩应力状态下高应力岩体应力重分布的一般规律，并以开挖卸载的角度重视应力重分布这一过程，最终揭示了原岩应力状态及开挖断面几何形态对应力重分布的影响机制。

Energy evolution and stress redistribution of high-stress rock mass under excavation distribution

In order to reveal the mechanism of the occurrence of deep engineering catastrophe and the influence of various factors on excavation perturbing effect,the models with different original stress states and different excavation sections are established by using the distinct element numerical simulation software PFC.Through explicit calculation,the kinetic release curves of high-stress rock mass under various circumstances are gained,and the peak and final stable values of the obtained curves are regarded as energy indices,which are used for representing the disturbance intensity and the stability degree of the excavation system respectively.The analysis based on these indices shows that the excavation with a circular cross section will induce the minimum disturbance effect under a nearly hydrostatic pressure stress state.The stress redistribution characteristics of high original stress rock mass excavated by different sections are also studied.Through the inspection of stress redistribution course which is regarded as an unloading process,the influence mechanisms of the original rock mass stress state and the geometry of excavation section on the stress redistribution are revealed ultimately.