含软弱夹层层状隧道围岩变形机理研究

堡镇隧道地质条件复杂,局部地段处于高应力区,围岩变形具有变形速度快、变形量大且破坏严重、持续时间长的特征.通过对堡镇隧道左线出口段围岩变形量测资料和掌子面地质素描的比较分析后发现,不论强度高、节理裂隙发育的砂质页岩,还是处于高地应力、强度低、围岩破碎的炭质页岩,掌子面有软弱夹层分布时,其变形破坏程度较相邻段同类围岩严重的多.因此,依据软弱夹层与掌子面围岩的典型组合情况,结合堡镇隧道所揭示的不同围岩室内三轴试验结果,建立了含软弱夹层围岩的力学模型,探讨了含软弱夹层围岩变形破坏的形成演化过程,揭示了高地应力条件下软弱夹层引起围岩变形失稳的机理.

Research on deformation mechanism about stratified tunnel surrounding rock mass containing weak intercalation

The geological conditions of Baozhen Tunnel are complex,such as high geostress,deep-buried,rich groundwater,very weak and cracked rock masses and bias pressure along the rock seam.During construction,intense deformation and serious failure happened very often.Monitoring data showed that deformation is rapid with long duration,at the same time the deformation presented asymmetric and uneven features.Comparing and analyzing with the monitoring data of surrounding rock and geologic sketch of the work face,the ...