Rock mass collapse mechanism of concealed karst cave beneath deep tunnel
Rock mass collapse mechanism of concealed karst cave beneath deep tunnel
复制标题
DOI：
10.1016/j.ijrmms.2016.11.017
复制
发表时间：
2017
影响因子：
7.2
通讯作者：
F. Huang;Lian-heng Zhao;Tonghua Ling;Xiao‐Li Yang
中科院分区：
文献类型：
--
作者：
F. Huang;Lian-heng Zhao;Tonghua Ling;Xiao‐Li Yang
在岩溶地区隧道施工中，特别是隧道与溶洞之间的岩柱很薄时，经常发生围岩局部坍塌。隧道施工中围岩的坍塌具有突发性，可能造成巨大的经济损失甚至生命损失。为了预测溶洞上隧道开挖岩体的崩塌，在上界定理的框架下，通过变分计算，导出了塌陷面的解析表达式。在解析解的基础上，绘制了塌陷面形状，研究了围岩参数对隧洞塌陷面的影响。根据塌陷面随巷道与洞室距离的变化规律，导出了防止岩柱塌陷区最小安全厚度的计算公式。为了评估本文提出的方法的有效性，我们将解析解与数值解进行了比较。对比结果表明，解析解与数值解吻合较好，表明本文所提出的解析方法是有效的。
Local collapse of the surrounding rock often occurs during tunnel construction in a karst area, particularly when the rock pillar between the tunnel and the karst cave is very thin. The collapse of the surrounding rock in tunnel construction is sudden and may lead to great economic loss or even loss of life. To predict the collapse of rock mass where a tunnel is excavated above a karst cave, an analytical expression of the collapse surface is derived from variational calculation in the framework of the upper bound theorem. Based on the analytical solution, the shape of the collapse surface is plotted to investigate the effects of rock parameters on the collapse surface of the rock mass where a karst cave exists beneath a tunnel. According to the changing law of the collapse surface varying with the distance between tunnel and cave, the computational formula of the minimum safety thickness for preventing the collapse of rock pillar is derived. To evaluate the validity of the proposed method in this paper, we compared the analytical solution with numerical solution. The comparison result indicates the analytical solution matches up with the numerical solution very well, which suggests that the analytical approach proposed in this paper is valid.