应力波作用下锚喷支护巷道稳定性分析与失稳机理研究

The bolt-shotcrete support is used in more than 90% of roadway in China's state-owned large and medium coal mines. It is of great significance to keep the roadway unblocked and the surrounding rock stable for the safety production of coal mine. With the increase of coal mining depth, the ground temperature increases, the mine pressure appears and aggregates, the dynamic effect is obvious, and the roadway support becomes more difficult. The essence of dynamic disturbance, such as rock breaking and roof fracture, is the interaction of stress wave and roadway.This study is based on the geological mechanics evaluation and the calculation of the ground stress of the surrounding rock of the bolt-shotcrete support roadway, the physical and mechanical model of bolt-shotcrete roadway under the action of stress wave is established and its theoretical calculation is carried out. The finite difference software FLAC is used to simulate the dynamic effect of bolt-shotcrete roadway. The similar material simulation experiment of bolt-shotcrete roadway under the action of stress wave is carried out in the laboratory, and the failure law of roadway instability under the action of stress wave is analyzed. Based on BP artificial neural network, the stability analysis model of bolting roadway is established, and the failure mechanism of roadway under the action of stress wave is studied. It provides theoretical support for the selection of bolting design parameters and determination of supporting scheme, and guarantees for ensuring the safe mining of coal.

我国国有大中型煤矿90%以上的巷道采用锚喷支护，保持巷道畅通和围岩稳定对煤矿安全生产具有重要意义。随着煤炭开采深度增加，地温升高，矿山压力显现加聚，动力效应作用明显，巷道支护难度加大。掘进破岩、顶板断裂等动力扰动的本质是应力波与巷道相互作用。本项研究在锚喷支护巷道围岩地质力学评估及地应力计算的基础上，建立应力波作用下锚喷支护巷道物理力学模型并进行理论计算，应用有限差分软件FLAC完成锚喷支护巷道动力效应的数值模拟，在实验室进行应力波作用下锚喷支护巷道相似材料模拟，分析巷道在应力波作用下失稳破坏规律。建立基于BP人工神经网络的锚杆支护巷道稳定性分析模型，研究应力波作用下巷道失稳破坏机理，为锚杆支护设计参数选择和支护方案确定提供理论支撑，为确保煤炭安全开采提供保障。

随着煤炭开采深度增加，地温升高，矿山压力显现加聚，动力效应作用明显，巷道支护难度加大。掘进破岩、顶板断裂等动力扰动的本质是应力波与巷道相互作用。本项目通过研究应力波作用下锚杆（索）网支护巷道稳定性分析与失稳机理研究,揭示了应力波扰动作用下围岩变形及控制的原理。首先，考虑地应力、煤岩力学性质、淋水环境、特殊地质构造下的对巷道支护的影响。建立了厚煤层淋水巷道水-力耦合模型，利用FISH语言实现淋水对围岩力学性质的损伤，并揭示了高预应力“锚杆（索）+网双拱协同支护原理。针对开拓巷道过陷落柱提出熵权-模糊综合评价优化方法得到“锚（索）网+工钢棚”最优支护参数。然后，利用弹性波的函数展开法求解应力波(P波)绕巷道的散射，利用FLAC3D数值模拟软件分析了振动强度、振动频率和时间对围岩的影响。应力波扰动强度对围岩破坏影响敏感，应力波扰动时间对围岩变形影响敏感。扰动强度越大，频率越低，扰动时间越长对围岩变形破坏越严重。最后，课题组自主研发了动力扰动作用下的相似材料试验设备，并依托试验设备进行了动力荷载下巷道锚杆支护抗动力效果，并利用人工神经网络对巷道稳定性评价。通过对比动力扰动作用下支护巷道与未支护巷道，得到锚杆（索）+网支护巷道具有一定抗扰动作用，可通过加密锚杆提高抗扰动强度。