加筋土坡临界高度的极限分析

为了解布筋形式与布筋密度等因素对土坡加筋效果的影响,用上限法对加筋土坡的临界高度进行了极限分析。使用刚体旋转破坏机构,并假设筋材的失效模式为本身的拉伸破坏,研究了3种布筋形式(均匀布筋、上稀下密线性布筋及上密下稀线性布筋)对边坡临界高度及滑裂面形状与位置的影响。结果表明:在平均布筋密度相同的情况下,上稀下密线性布筋对应的临界高度最大,而上密下稀线性布筋对应的临界高度最小;对于3种布筋形式,边坡临界高度都随平均布筋密度增大而明显增大;不同的布筋形式对应的滑裂面的形状与相对位置有较大差别;对于均匀布筋土坡,上限解与试验结果及有限元解有较好的一致性。

Limit Analysis of Critical Heights of Reinforced Soil Slope

For studying the influence of reinforcement distribution modes and distribution density on reinforcement effects for soil slope,the upper-bound method of the limit analysis was employed to compute the critical heights of the reinforced soil slope.In the analysis,the rigid body rotational failure mechanism was adopted and the invalidation mode of the reinforcement was assumed to be its own tensile failure.Influence of 3 types of reinforcement distribution modes,ie uniform mode,downwardly-strong linear mode and upwardly-strong linear mode on critical height of reinforced soil slope,and shape and position of slip surface were considered.With the same average reinforcement density,the downwardly-strong mode gave the maximum critical height,and the upwardlystrong mode gave the minimum one.For the 3 types of reinforcement distribution modes,the critical heights all increased obviously with the increase of average reinforcement distribution density.However,for different reinforcement distribution modes,the shapes and relative locations of slippage crack surfaces had great difference.Results show that the critical heights got from upper-bound method are found to be in good agreement with the results of tests and FEM.