剪胀角对土坡应力应变规律的影响

Influences of dilatancy angle on the stress-strain mechanism of soil slopes

为了更好地反映剪胀性对土体塑性应变、塑性区范围的影响规律,从剪胀角的变化入手,考查剪胀角对边坡位移(水平和竖直方向)、边坡塑性应变、塑性区范围等的影响.当剪胀角从0°到28°范围变化时,分析了一均质边坡的应力变形规律.计算结果表明,对于均质土坡,剪胀角对沉降和水平位移影响不大,对塑性应变和塑性区范围有明显的影响;相对而言,坡顶和坡脚的水平位移、塑性应变对剪胀角的变化较为敏感.

D-P criterion is used as the yield function in the ANSYS software. This criterion takes the intermediate principal stress σ2 and the hydrostatic pressure （or the average stress） σm into account for influences on the failure. Meanwhile, ANSYS can take dilatancy into account for influences upon the the plastic strain and plastic zone of soil through dilatancy angle ψ. Using the existing ANSYS with D-P criterion to analyze the influences of the dilatancy angle on the stress-strain mechanism of soil slope under the plane strain contion, Examples show that the dilatancy angle has a marked effect on the plastic strain and plastic zone of the slope, but the effects on the settlement Uy and the horizontal displacement Ux are not very significant. By comparison, the horizontal displacement and plastic strain of slope top and slope toe are more sensitive to the change of dilatancy angle ψ.