强度折减法分析加筋土坡的稳定性探讨

Stability Analysis of Reinforced Soil Slope by Strength Reduction Method

采用强度折减法对高20m、边坡坡率1∶1、加筋层间距0.6m的土工格栅加筋土坡的稳定性进行了分析。根据强度折减法的特点、滑动面形状、以及计算出的稳定安全系数与Bishop法结果的比较,分析了强度折减法用于加筋土坡稳定性计算的合理性,阐述了上述加筋土坡稳定安全系数Fs与边坡土的粘聚力c和内摩擦角φ的关系。结果表明,Fs与边坡土的粘聚力c和内摩擦角φ分别近似呈线性增长的关系。当φ不变时,c越小,则提高c值带来的Fs增长率越高,特别是当φ≥30°时更加明显;而当c不变时,φ越小,则提高φ值带来的Fs增长率也越高。

The Strength Reduction Method（SRM for short）is employed to evaluate the stability of a geogrid-reinforced soil slope,which is 20 min height with a slope of 1∶1and a reinforcement spacing of 0.6m.The reasonability of SRM for analyzing a reinforced soil slope is presented based on SRM＇s principles,the shape of the sliding surface determined by SRM,and the comparison of Fs,the stability safety factors of the geogrid reinforced soil slope,given by SRM with those given by the Bishop method.The relationships between Fsand c（the soil＇s cohesion）or Fs andφ（the soil＇s internal friction）are discussed.It is found that Fsincreases approximately either with c or withφlinearly.Ifφis certain,the increasing rate of Fs with the increase of c will be greater when c is lower,especially while.Similarly,if c is certain,the increasing rate of Fs with the increase ofφwill also be greater whenφis lower.