The influences of the dilatancy character on the potential sliding surface of soil slopes

The analysises of rock and soil slopes often adopt two extreme methods:overstating the material dilatancy character or ignoring the material dilatancy character, which do not agree with the engineering. The dilatancy character has influences on potential sliding surface of slope.In ANSYS software, this influences were considered through the variety of dilatancy angle. The potential sliding surface was simulated in plane strain condition with ANSYS in this article. The results show that the dilatancyangle has obvious influences on the potential sliding surface. The plastic zone has a trend on running through from the top to the bottom of the slope with the reducation of dilatancyangle. So the associated flow rules should be used to analyze the compacted sandy soil and over-consolidated clay with finite element method(FEM), because they have obvious shear dilatation during the shearing process;But for the loose earth(underconsolidation soil), the associated flow rules should be used because of its shear contraction; As for normal consolidated soil,the dilatancy angle should be reduced, it is suggested that the value of dilatancy angle taken as one third to one second of internal friction angle.