软岩隧道在超前支护作用下的力学性能分析

Analysis of Mechanical Properties of Soft Rock Tunnel With Advance Support

以某高速铁路隧道为例,研究了在破碎岩层和强风化岩层软岩条件下不同超前支护方案的力学性能;通过CAE软件有限元分析法,分析了常规支护条件(无超前支护)、单纯深孔注浆条件、单纯锚索加强支护条件、深孔注浆联合锚索加强支护条件等4个支护方案的软岩超前支护力学性能。通过分析发现,只有使用深孔注浆联合锚索加强支护的超前支护方式,可以确保隧道顶板、两帮、底板的长期蠕变位移量小于200 mm的设计容忍极限。因此认为,经地面进行浅埋隧道软岩条件的深孔注浆配合锚索加强支护的超前支护方案,可以适应该项目的支护需求,而且在更复杂条件下,还可以通过加大注浆范围和加大锚索密度的方式,加强该联合支护方案,以期获得更有效的支护效果。

Taking a high-speed railway tunnel as an example,the meclianical properties of different advanced sup-port schemes under the conditions of broken rock and strongly weathered rock are studied;Four support schemes,under conventional support condition(without advance support),simple deep hole grouting condition,simple anchor cable reinforcement condition and deep hole grouting combined with anchor cable reinforcement condition,are analyzed by CAE finite element analysis method.The advanced support method of deep hole grouting combined with anchor cable is.only found to ensure the long-term creep displacement of tunnel roof,two sides and floor are less than 200 mm.Therefore,this support scheme can meet the support requirements of the project.Under more complex conditions,the combined support scheme can be strengthened by increasing the grouting range and anchor cable density so as to obtain more effective support effect.