太岳山深埋长隧道地应力场研究及其应用

Research and application of in-situ stress field in deep-buried long tunnel passing through Taiyue Mountain

山西省黎城至霍州高速公路的太岳山隧道属于典型的深埋长隧道,采用水压致裂方法对工程区ZK6勘探钻孔进行了地应力测试。测试数据表明:工程区原岩应力主要为水平构造应力,总体应力场特征呈典型的构造应力场类型,隧道围岩属高应力水平。基于实测结果,分析了水平主应力随埋藏深度的变化规律,并论述了侧压系数、侧压比与埋藏深度的关系。通过对初始应力场进行有限元数值模拟可得,实测值与回归值吻合较好,模拟结果也良好反映了该区地应力分布规律。在应力分析的基础上,探讨了地应力场与隧道轴线布置方向的关系、隧道开挖形状的选取和岩爆预测等工程应用问题。

Taiyue Mountain tunnel, a section from Licheng to Huozhou highway Shanxi Province, is a typical deep-buried long tunnel. We measured the in-situ stress at ZK6 borehole by hydraulic fracturing method. The data show that the original rock stress level in this engineering area is mainly horizontal tectonic stress, and the general stress field characteristic is typical tectonic;the surrounding rock is at high stress level. Based on the measured data, we analyzed the horizontal stresses variation with burial depth and discussed the relationship of lateral pressure coefficient, lateral pressure ratio and buried depth. By the fi-nite element numerical simulation of the initial stress field, it is discovered that the measured values are in good agreement with the regression values and the numerical simulation results also well reflect the stress distribution in the area. According to the in-situ stress analysis, we investigate the relationship between the stress field and the tunnel axial layout, and the excavated shape of tunnel and rock burst prediction.