Abstract A numerical time-dependent deformation model of rock by incorporating the stress corrosion model into a three-dimensional discrete element code was established to investigate time-dependent deformation and fracture evolution of surrounding rock around underground excavations with circular, inverted U-shaped and rectangular cross-sections. The mesoscale model input parameters were calibrated to replicate the mechanical behavior and failure patterns of the rock observed in laboratory. Numerical simulations on the time-independent and -dependent deformation and fracturing evolution of the rock around underground excavations with different shapes under hydrostatic stress were studied. The results show that the maximum time-independent displacements of circular, inverted U-shaped and rectangular openings are 11, 15, and 34 mm at left roof, right floor and left side, respectively. It shows that the surrounding rocks around the circular, inverted U-shaped openings are much more stable than that around the rectangular opening. The cracks within the surrounding rock around different shaped openings gradually increases as time goes by, and the tensile cracks are dominant. The progressive failure process of the circular openings under varying lateral pressures was further modeled. The results show the failure zone at the roof wall and floor wall becomes more evident with an increase in the lateral pressure coefficient.

中文翻译：

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地下基坑周围随时间变化的变形和断裂演化

摘要 将应力腐蚀模型纳入三维离散元代码，建立岩石时变变形数值模型，研究圆形、倒U形和矩形地下基坑围岩时变变形及断裂演化。交叉区域。校准中尺度模型输入参数以复制实验室观察到的岩石的力学行为和破坏模式。研究了不同形状地下基坑周围岩石在静水应力作用下的非时间和依赖变形和破裂演化的数值模拟。结果表明，圆形、倒U形和矩形开口的最大时间无关位移在左侧屋顶分别为11、15和34 mm，分别是右侧地板和左侧。表明圆形、倒U形洞口周围的围岩比矩形洞口周围的围岩稳定得多。不同形状洞口周围的围岩裂缝随着时间的推移逐渐增多，以张性裂缝为主。进一步模拟了在不同侧向压力下圆形开口的渐进破坏过程。结果表明，随着侧压系数的增加，顶墙和底板的破坏带越明显。不同形状洞口周围的围岩裂缝随着时间的推移逐渐增多，以张性裂缝为主。进一步模拟了在不同侧向压力下圆形开口的渐进破坏过程。结果表明，随着侧压系数的增加，顶墙和底板的破坏带越明显。不同形状洞口周围的围岩裂缝随着时间的推移逐渐增加，以张性裂缝为主。进一步模拟了在不同侧向压力下圆形开口的渐进破坏过程。结果表明，随着侧压系数的增加，顶墙和底板的破坏带越明显。