研究目的: 随着我国路网的不断延伸,其建设区域逐渐趋向于构造发育、艰险复杂山区。伴随着强烈的构造运动,该类建设区域孕育着复杂的地应力状态。深埋工程岩体不可避免会出现岩爆和大变形现象。需要充分依托实测地应力数据,并对其进行数值模拟分析,由点及面获得工程环境的三维地应力状态。之后根据此类地区的前期建设工程对岩爆和大变形的揭示情况,对比分析勘察设计阶段数据,并提出合理有效的岩爆和软岩大变形的分析判定建议。
研究结论: (1)伴随着极其复杂的应力状态,深埋隧道工程在硬岩条件下极易发生岩爆,在破碎软弱围岩条件下极易发生软岩大变形;(2)基于代表性的地应力测试结果,采用数值模拟的方法对场地的地应力场进行反演分析是全面分析场地地应力特征的一种有效可行的方法;(3)基于有限的地应力测试数据,依托该区域的地质勘察资料,结合地形地貌及地层岩性和相关构造,以有限元方法为基础,构建数值模型,最终获取了隧址区的三维地应力数据,经过模拟数据与实测数据的对比分析,验证了数据吻合度较高,同时揭示了隧址区的地应力发育特征;(4)岩爆及大变形的分析研判需结合实际工程实施后的经验数据进行适当修正,通过对比分析施工阶段实际揭示与勘察设计阶段的预测结果的差异,提出了更接近工程经验的分析判定标准以供后续类似项目勘察设计参考,以期合理控制工程风险和工程投资。

Research purposes: With the continuous extension of China's road network, its construction area gradually tends to be structurally developed, difficult and complex mountainous areas. With the strong tectonic movement, this kind of construction area is pregnant with complex in-situ stress state. Rock burst and large deformation are inevitable in deep buried engineering rock mass. It is necessary to fully rely on the measured in-situ stress data and carry out numerical simulation analysis to obtain the three-dimensional in-situ stress state of the engineering environment from point to surface. After that, according to the early construction projects in such areas, the data of rock burst and large deformation are revealed, and the data of survey and design stage and construction stage are compared and analyzed. Finally, reasonable and effective suggestions for the analysis and determination of rock burst and large deformation of soft rock are put forward.
Research conclusions: (1)With the extremely complex stress state, the deep buried tunnel project is easy to produce rock burst under the condition of hard rock, and it is easy to produce large deformation under the condition of broken soft rock.(2)Based on the representative in-situ stress test results, the inversion analysis of the in-situ stress field of the site by numerical simulation is an effective and feasible method to comprehensively analyze the in-situ stress characteristics of the site.(3)Based on the limited in-situ stress test data, relying on the geological survey data of the region, combined with the topography, lithology and related structures, the numerical model is constructed based on the finite element method, and the three-dimensional in-situ stress data of the tunnel site area is finally obtained. Through the comparative analysis of the simulated data and the measured data, it is verified that the data are in good agreement. At the same time, the characteristics of ground stress in the tunnel site are revealed.(4)The analysis and judgment of rock burst and large deformation need to be appropriately corrected based on the empirical data after the completion of the actual project. By comparing and analyzing the differences between the actual results of the construction stage and the predicted results of the survey and design stage, the analysis and judgment criteria closer to the engineering experience are proposed. These criteria can be used as reference for the investigation and design of similar projects in the future, so as to reasonably control the engineering risk and investment.