层状泥岩隧道锚围岩滑动破坏特性研究

为了研究层状泥岩隧道锚围岩滑动破坏的特性,通过隧道锚1∶10现场缩尺模型进行加载破坏试验,分析加载过程中模型锚系统的地表变形、深部岩体变形、地表破坏裂缝,得到了在加载破坏过程中围岩的荷载-变形曲线和破坏特征,并结合数值计算结果进行分析。研究结果表明:荷载加载到3.5P(P为设计荷载)后岩体开始进入破坏屈服阶段,出现在地表的裂缝形成倒U型破坏轮廓线,位于前锚面正上方的典型裂缝(a)贯穿整个裂缝群,从而推断出上滑移层位置,深部岩体在深度为7.67 m的位置发生较大错动,且错动的方向与锚体成约17°的夹角向前,可推断出下滑移层位置,且围岩的破坏模式是拉剪破坏,两滑移层面内围岩变形较明显且塑性破坏大部分位于这两条滑移面之间。

Damage Sliding Characteristics of Surrounding Rock in Bedded Mudstone Tunnel Anchorage

In order to study the characteristics of sliding layer of surrounding rock in bedded mudstone tunnel anchor, the load the destruction test on field tunnel anchor 1:10 model is carried out, to analysis the surface deformation, the deep rock mass deformation and the surface cracks in system of anchor model during the loading process, the curve of load-deformation and characteristic of destruction on surrounding rock during process of loading destruction, and comprehensive analysis unite numerical simulation of results of loading test is carried out. The research results show that the rock mass begins to enter the failure yielding stage. When the load is loaded to 3.5P (P is design-load), the surface cracks forming inverted u-shaped contour during the process of loading destruction, and the typical crack (a) which locate in right above of anchor front face, and throughout the whole cracks, so as to judge the upward sliding layer, the position of excessive deformation locate in depth of 7.67 m in deep rock, the direction of diastrophism with the anchor into 17° angle to go forward, so judging the downward sliding layer, and the failure mode of surrounding rock is tensile shear failure, Two the deformation of surrounding rock is obvious in slip plane, and most of the plastic failure is between the two slip planes.