基于硬脆性岩体剥落性状的初始地应力场评估

处于高地应力环境的硬岩工程,由于开挖扰动导致围岩应力环境变化,进而发生脆性剥落破坏。线性工程沿洞线地应力场分布受到各种因素的影响,判别沿线地应力分布规律对于施工安全和衬砌支护设计具有重要意义。在介绍初始地应力分布统计规律的基础上,对地下洞室轴线与初始地应力场排布不同组合情况下,围岩二次应力场及偏应力分布规律进行了模拟研究。基于硬脆性岩石破坏准则,推导了考虑硬脆性围岩破坏宏观表征的洞轴平面初始应力场求解公式,对所推导的公式进行了工程验证,结果比较吻合。研究结果可为深埋硬岩隧道工程初始地应力场量值判别及工程支护设计提供一定的借鉴和参考。

Evaluation of in-situ stress based on spalling behavior of hard rock mass

Due to change of stress in rock mass during excavation, brittle failure will happen in hard rock engineering with high in-situ stress, such as spalling, rock burst, etc., and the in-situ stress along tunnel axis with linear underground engineering is influenced by various factors. It is important to determine the distribution of in-situ stress for safe construction and lining support design. Based on the introduction of statistical distribution of in-situ stress, stress redistribution and deviatoric stress law of the surrounding rock are simulated under different combinations of tunnels and directions of the principal stress. Based on the failure criterion for brittle rock, a formula for solving the in-situ stress of plane perpendicular to tunnel axis is deduced considering the characteristics of failure of hard rock brittle. The formula is verified by practical engineering with high coherency. The results provide references for the determination of in-situ stress of underground engineering and the design of engineering support.