Catastrophe analysis of deep tunnel above water-filled caves

Abstract

To explore the influence of karst cavity pressure on the failure mechanisms of rock layers above water-filled caves, novel blow-out and collapse mechanisms are put forward in this study. The proposed method uses the nonlinear optimization to obtain the failure profiles of surrounding layered rock with water-filled cave at the bottom of the tunnel. By referring to the functional catastrophe theory, stability analysis with different properties in different rock layers is implemented with considering the incorporation of seepage forces since the groundwater cannot be ignored in the catastrophe analysis of deep tunnel bottom. Also the parametric analysis is implemented to discuss the influences of different rock strength factors on the failure profiles. In order to offer a good guide of design for the excavation of deep tunnels above the water-filled caves, the proposed method is applied to design of the minimum effective height for rock layer. The results obtained by this work agree well with the existing published ones.

摘要

为了探讨岩溶洞穴压力对充水洞穴中隧道基岩围岩稳定性的影响, 本研究提出了新的岩层坍塌 和爆破机制。该方法利用非线性优化方法得到隧道底部与充水洞顶之间层状围岩的破坏面, 并对隧道 底部充水洞穴围岩破坏过程的预测进行了数值优化。因为地下水在岩层破坏中起着关键作用, 基于功 能突变理论, 本文提出的方法结合渗流力作用对层状围岩破坏模式进行了运动学分析。本文同时进行 参数研究以分析不同岩石参数对破坏形状的影响。该方法为充水洞穴上方的深埋隧道开挖提供良好的 设计指导, 可应用于岩层的最小安全厚度设计。这项工作获得的结果与现有的已发表的结果很好地吻 合。