摘要
结合某软岩深埋隧道工程实例,采用水压致裂法获取了开挖期间的地应力场特征,对开挖期的大变形破坏情况进行了预测。基于实测的围岩应力沿隧道径向的分布特征,分析了软岩隧道开挖期地应力场的变化调整规律;并进一步结合相关研究成果,指出了测试期间隧道围岩所处的应力状态,揭示了隧道围岩发生大变形和先期支护结构挤压破坏等宏观现象的机理,并提出了预防大变形破坏的施工与支护措施。测试资料与研究结果可为类似高地应力软岩隧道工程的开挖、支护及稳定性分析提供重要参考。
Combining specific deep-buried soft rock tunnel project, geotectonic stress is measured by using the hydraulic cracking method within the boreholes. The distribution characteristics of stress and features of stress concentration zone of surrounding rock are analyzed based on the measurements. The changes of rock stress before and after excavation of tunnels and its effects on deformation and failure of surrounding rocks are analyzed. Based on the experimental results and related mechanics theory, it is pointed out that the stress state of surrounding soft rock is near its ultimate strength, which results in large creep deformation and support construction damage. At last, the paper presents several supporting measures for high geotectonic stress soft rock tunnel construction to prevent large deformation damage, which lent a clue for a new type of tunnel support.
出处
《公路》
北大核心
2016年第1期228-234,共7页
Highway
关键词
软岩
高应力
大变形
水压致裂
应力释放
soft rock
high geotectonic stress
large deformation
hydraulic cracking
stress release
