群锚对岩质边坡稳定性影响的数值模拟研究

Numerical Test on Investigation of Multi Anchorage Effect on Rock Slope Stability

针对李家峡双滑面岩质边坡,利用有限差分软件对预应力群锚加固岩质边坡稳定性进行数值模拟研究.从预应力对岩体应力状态的改善,锚索预应力随计算时步的变化情况,锚索锚力以及锚索失效对其他锚索以及边坡稳定性影响3个方面阐述了群锚作用机理.数值模拟结果表明:在多根预应力锚索作用下,单根锚索压应力集中区相互叠加后形成一个完整的压缩带,群锚效应抑制了边坡体的大变形,可使边坡整体性加强;由一级坡第一排锚索的预应力值变化规律可知锚索张拉会对相邻锚索预应力有一定影响;锚索锚力改变,对相邻锚索的影响较小,同时对增强锚固力作用不大;部分锚索失效,会引起锚索承担的荷载在群锚中发生转移,从而导致边坡稳定性降低.

As Lijiaxia dual-sliding rock slope regarded,with FLAC3D utilized,we carried out numerical analysis against the stability of rock slope reinforced by multi anchor cables.For one thing,the stress state of rock improved by prestress is presented,for another,the influence to the other cables and the slope by change of force of one cable or inactivation of one cable is set forth,so as to clarify mechanism of action of multi cables.And the results show： while concentration zone of compression stress of each anchor cable is formatted,afterwards they will be superimposed to be a complete one,moreover,which will strengthen the overall stability and restrain the bigger deformation of the slope.Meanwhile,it shows if we change the force,it exerts little impact on the around cables and effect on the enhancement of the slope.However,with some cables inactivated,the rest cables will redistribute the responded load,and thus the stability will be forced to be reduced.