动力扰动遇高应力硐室衍射引起的围岩能量聚集与迁移规律

In the process of deep mining and engineering construction, the stress wave caused by mining and other dynamic disturbance will occur diffraction when it incident through the underground cavity or other discontinuous structure, wave diffraction lead the stress wave interact with the surround rock, forming the dynamic stress concentration, causing the failure of surrounding rock and the instability of the underground structure. Due to the complexity of the initial stress and diversity of the dynamic disturbance, leading the energy distribution law of the surrounding rock and rock failure mechanism are not clear. This project uses coupled test platform to realize the rock failure process caused by the coupled loading, and obtains the quantitative contribution of the initial energy storage and dynamic disturbance energy to the rock failure. The mathematical model of dynamic loading through the underground cavity with high initial stress is established, considering the initial stress and initial stress concentration distribution on the influence of wave propagation, the dynamic stress distribution law of underground cavity surrounding rock are solve by wave function method, the quantitative characterization methods of dynamic energy accumulation and migration around underground surrounding rock is obtained. Considering the influence of lithology and initial stress, the processes of dynamic loading through different high initial stress cavity are simulated. The change law of underground surrounding region energy are obtained, which provides a theoretical support to reveal the failure mechanism and security protection for underground cavity.

深部资源开采与工程建设中，采掘等动力扰动产生的应力波在围岩中传播遇到硐室等几何不连续空间结构时会发生衍射，使得应力波与硐室围岩相互作用，形成动态应力集中，诱发围岩破坏和结构失稳。由于硐室围岩复杂的初始应力环境和动力扰动的多样性，导致这一过程的围岩区域能量分布规律不清，岩石破裂机理尚不明确。本项目利用动静组合试验平台实现这一力学作用过程引起的岩石破坏，获得围压初始储能和动力扰动能量对岩石破坏的定量贡献。建立动力扰动遇高应力硐室衍射的数学模型，考虑初始应力和初始应力集中分布对波传播的影响，利用波函数法求解稳态和瞬态入射作用下硐室围岩周边的动态应力集中因子，获得硐室围岩能量动态聚集与迁移的量化表征方法。构建深部三维数值模型，考虑岩性和初始应力的影响，模拟动力扰动入射不同初始应力硐室的过程，获得围岩区域能量的变化规律，为揭示深部硐室围岩的破坏机理和安全防护提供理论支撑。

开采作业等动力扰动会引起硐室围岩出现应力集中，从而诱发围岩破坏和结构失稳。随着矿山开采逐渐走向深部，原岩初始应力越来越大，硐室或巷道周边的应力集中程度越来越突出，成为不可忽略的因素，严重制约了深部资源开采和深部工程建设。基于此，项目提出采掘等动力扰动产生的应力波入射穿过硐室的力学作用机制为应力波遇到硐室衍射引起的动态应力集中和硐室围岩静态初始应力集中的组合。.主要研究内容、重要结果以及关键数据为：（1）利用动静组合加载实验平台和DIC技术，通过设置不同的轴向初始应力和冲击加载强度，获得了不同工程扰动和围岩初始应力环境下孔洞周边的动静组合应力集中情况与围岩破坏特征。（2）设计了考虑压缩应力波在自由面反射成拉伸应力波的实验，利用霍普金森杆装置对含孔洞长杆形试样进行动态冲击，观察不同轴比、不同倾角下的椭圆孔洞周边岩石的破坏现象，获得了单一孔洞和双孔岩杆受动力扰动作用发生破坏的规律。（3）构建了应力波在深埋硐室和浅埋硐室中衍射的控制方程，获得了稳态和瞬态入射作用下硐室围岩周边的动态应力集中因子和硐室围岩能量动态聚集与迁移的量化表征方法。（4）利用LS-DYNA数值软件，建立了深部三维数值模型，考虑岩性和初始应力的影响，模拟了不同初始应力情况下动力扰动穿过深部圆形硐室和椭圆形硐室的衍射过程，获得围岩区域应力与能量的变化规律。.科学意义：该项目综合考虑了初始应力和动力扰动对硐室的组合作用，研究和揭示了动力扰动遇高应力硐室衍射引起的围岩能量迁移规律和破裂机理，研究成果一方面可为深部工程开挖设计和解释深部一些特殊现象的基本理论依据；另一方面也可为研究深部硐室围岩的诱导破裂和安全防护提供理论依据，具有重要的理论意义和实际工程应用价值。