基于应力判据的隧道岩爆预测评估研究

Prediction and Evaluation of Rock Burst in Tunnel Based on Stress Criterion

近年来我国深埋隧道数量快速增长,深埋隧道通常处于高地应力场的硬岩环境中,开挖过程中岩爆灾害极易发生,给隧道工程建设带来的损失不可估量。因此,对于高地应力硬岩隧道的岩爆预测及防治研究极为重要。本文以蔓耗—金平线高速公路草果山隧道为工程背景,展开针对高地应力硬岩隧道岩爆预测研究。建立草果山隧道区域三维模型,根据现场地应力测试结果,得到区域初始地应力场回归方程,最终通过数值模拟手段反演分析得到草果山隧道工程区域初始地应力场分布。以草果山隧道初始地应力场反演分析结果为基础,通过数值分析和理论计算的手段,获取了隧道全长范围内各区段断面洞壁应力特征,结合室内三轴试验得到的岩体物理力学参数得到了在不同的岩爆判据下草果山隧道区域范围的岩爆预测结果,考虑多方面因素,得到最终预测结果。

In recent years,the number of deep-buried tunnels in our country has increased rapidly.Deep-buried tunnels are usually located in the hard rock environment with a high ground stress field.Rock burst disasters are prone to occur,and the losses to the tunnel construction are immeasurable.Therefore,it is extremely important for rock burst prediction and prevention research in high-ground stress hard rock tunnels.In this paper,the Caoguoshan Tunnel on the Manhao-Jinping Highway is taken as the engineering background to carry out the optimization research on the rock burst prediction and rock burst prevention and treatment measures for high ground stress hard rock tunnels.A three-dimensional model of the Caoguoshan tunnel area was established.Based on the in-situ stress measurement results,the regression equation of the initial ground stress field in the area was obtained.Finally,the initial ground stress field distribution of the Caoguoshan tunnel project area was obtained by inverse analysis through numerical simulation.On the basis of the inversion analysis results of the Caoguoshan tunnel’s initial in-situ stress field,by means of numerical analysis and theoretical calculation,the stress characteristics of the section wall of each section in the full length of the tunnel are obtained.Combined with the physical and mechanical parameters of the rock mass obtained by the triaxial compression test,the rock burst prediction results of the Caoguoshan tunnel area under different rock burst criteria are obtained,and the final prediction results are obtained by considering various factors.