The influence of groundwater on tunnel engineering is very complicated. Due to the complexity of water flow water pressure transfer and uncertain defects in the stratum, all of which are key factors with regard to the design of tunnel engineering. Therefore, the variation of surrounding rock during excavation and the deformation and failure of soft surrounding rock under different seepage paths of underground water after excavation systematically. Experimental results showed that the stress change of surrounding rock caused by tunnel excavation can be divided into 3 stages: stress redistribution, stress adjustment, and stress rebalancing. In the process of water pressure loading, water flow rate is closely related to the experimental phenomenon. The between stable loading water pressure pore water pressure of the tunnel surrounding rock and the distance from the measuring point to the edge of the tunnel obey the exponential function of the decreasing growth gradient. With the increase of loading pressure, the pore water pressure and stress at the top of the tunnel increase, and the coupling of stress field and seepage field on both sides of surrounding rock more and more intense. The failure process of the tunnel can be divided into 6 stages according to the damage degree. The final failure pattern of the surrounding rock of the tunnel is mainly determined by the disturbed area of excavation. The arched failure area and the collapse-through failure area are composed of three regions. The surrounding rock is characterized by a dynamic pressure arch in the process of seepage failure, but it is more prone to collapse failure at low water pressure. The results of this study are the progressive failure mechanism of tunnel under different groundwater seepage paths and would be of great significance to the prevention of long-range disasters.

中文翻译：

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不同地下水渗流路径下隧道围岩破坏机理的试验研究

地下水对隧道工程的影响非常复杂。由于水流量的复杂性和地层中不确定的缺陷，所有这些都是隧道工程设计的关键因素。因此，系统地研究了开挖后地下水在不同渗流路径下的开挖过程中围岩的变化以及软性围岩的变形和破坏。实验结果表明，隧道开挖引起的围岩应力变化可分为应力再分布，应力调整和应力再平衡三个阶段。在水压加载过程中，水的流量与实验现象密切相关。隧道围岩的稳定加载水压力孔隙水压力与从测量点到隧道边缘的距离之间服从递减的增长梯度的指数函数。随着加载压力的增加，隧道顶部的孔隙水压力和应力增加，围岩两侧的应力场与渗流场的耦合越来越强烈。隧道的破坏过程可根据破坏程度分为六个阶段。隧道围岩的最终破坏模式主要由开挖扰动面积决定。拱形破坏区域和贯通破坏区域由三个区域组成。围岩的特征是在渗流破坏过程中具有动态压力拱，但是在低水压下更容易崩溃。研究结果是不同地下水渗流路径下隧道的渐进破坏机理，对预防远距离灾害具有重要意义。