为研究武隆鸡尾山滑坡的滑动面节理参数(法向刚度JKN,切向刚度JKS,内摩擦角φ,黏聚力c)对变形特征影响的显著性,基于正交试验设计原理,运用大型3D离散元软件3DEC进行数值模拟试验,将监测点位移量作为试验指标,方差分析结果显示:(1)滑动面切向刚度JKS和内摩擦角φ对水平和竖向位移具有高度显著性影响,而滑动面法向刚度JKN和黏聚力c对滑体的位移影响有限;(2)滑动面节理力学参数对稳定性影响作用主次顺序为JKS〉φ〉JKN〉c(水平位移);JKS〉φ〉c〉JKN(竖向位移)。最后又以正交试验16个案例中最危险案例5为典型,调查了滑坡破坏过程中的位移变化特征:破坏初期,对于水平(EW方向)位移,滑体关键块体在前缘山体的阻挡下,主要向东侧悬崖方向滑动,关键块体的位移量远远大于后面的驱动块体;对于SN方向上的水平位移以及竖向位移,驱动块体的位移量远远大于关键块体。同时数值模拟结果也显示,前缘关键块体先于后部驱动块体发生整体破坏,率先滑向悬崖。模拟结果与实际情况一致。
In order to investigate the influence of mechanical parameters of sliding plane,normal stiffness JKN,shearing stiffness JKS,internal friction angle φ ,and cohesion c,on the rockslide stability,the numerical simulations were conducted based on the orthogonal design method and 3D discrete element software 3DEC,the displacements concerning a monitoring point located in the front of sliding block were chosen as indicator in the orthogonal experiment. The analysis of variance shows that:(1) JKS and φ of sliding plane have a significant effect on the displacement of monitoring point along all of X,Y,and Z direction,as for the c and JKN,it seems that they have a limited influence on the displacement.(2) According to the influence degree on the rockslide stability, the order for 4 mechanical parameters may be arranged by JKS〉φ〉JKN c(for horizonal displacement);JKS〉φ〉c〉JKN(for vertical displacement). The next research was focused on the most dangerous case among the 16 cases,in the initial stage of failure,for the horizontal displacement(EW),the key block mainly moves to the east cliff due to the support from the rock mass,the amount of displacement for key block is much larger than that for driving block. For the horizontal displacement(SN) and vertical displacement,the displacement for driving block is bigger than that for key block. It can been seen that the key block slides down to the cliff following by driving block,numerical simulation results make a good agreement with the real situation.