大跨度矩形巷道围岩失稳破坏机制及数值模拟

巷道围岩的失稳破坏是资源开采阶段面临的重要问题。首先，对巷道围岩失稳机制进行了理论分析，探究巷道稳定性的主要因素，并基于ANSYS/LS-DYNA仿真平台对不同跨度巷道（4 、6 、8 、10 m）进行动静荷载耦合响应数值模拟分析。结果表明：当巷道埋深、底板梁厚度等因素一定时，巷道跨度是影响巷道围岩失稳的主要因素。巷道围岩在初始静应力场作用时，第一主应力随着跨度的增加呈现逐渐增大的趋势；跨度的增加（10 m）会使巷道围岩x和y方向的应力发生突增现象，均在巷道底板处有相对较大的拉应力。巷道跨度的增大，导致左右两帮的移近量有所增加；顶板下沉和底板隆起的程度显著增加，加剧巷道失稳破坏风险。在静动荷载耦合作用下，巷道围岩发生失稳破坏，破坏程度随跨度的增加而增加。

Failure Mechanism and Numerical Simulation of Surrounding Rock of Long-span Rectangular Roadway

The instability and failure of roadway surrounding rock is an important problem in the stage of resource exploitation. The instability mechanism of the surrounding rock of roadway was theoretically analyzed, the main factors of roadway stability were explored. Based on the ANSYS/LS-DYNA simulation platform, the dynamic and static load coupling responses of different span roadways (4 m, 6 m, 8 m and 10 m) were simulated and analyzed. The results show that when the buried depth of the roadway and the thickness of the floor beam are constant, the roadway span is the main controlling factor affecting the surrounding rock instability of the roadway. When the roadway surrounding rock is under the action of the initial static stress field, the first principal stress gradually increases with the increase of the span, and the increase of the span (10 m) will lead to a sudden increase in the stress in the x and y direction of the roadway surrounding rock. There is a relatively large tensile stress at the roadway floor. With the increase of roadway span, the proximity of the left and right sides increases, and the degree of roof subsidence and floor uplift increases significantly, which aggravates the risk of roadway instability and failure. Under the coupling action of static and dynamic load, the surrounding rock of roadway is unstable, and the degree of failure increases with the increase of span.