改进的桩承式加筋路堤荷载传递效应计算方法

Improved calculation method for load-transfer effect of reinforced piled embankments

采用PFC2D建立了桩承式路堤离散元数值分析模型,通过接触力链对土拱形态及其演变规律进行了分析;基于极限平衡理论并引入荷载修正系数α对H&R土拱模型进行了改进,进而进行了筋材受力变形计算,并通过正交数值模型对α进行了反算确定.结果表明:临界状态下的拱高约为8/10倍桩净间距;α随路堤填筑高度与桩净间距比的增加呈线性增大,而随路堤填料摩擦系数的增加呈幂函数关系减小.最后,通过现有文献模型试验结果对所提计算方法的正确性进行了验证.

A discrete element method （DEM ） numerical model of piled embankment was established by PFC2D .Then ,the analyses of the features and evolution of soil arching were performed with the variation of contact force chains in the embankment .Afterward ,the H＆amp;R soil arching model was im‐proved based on the limit equilibrium theories with the introduction of a load‐correction coefficient α. Then ,the stress and deformation calculations of geosynthetic were performed by the improved H＆amp;R model .Meanwhile ,the load‐correction coefficient αwas obtained with a series of orthogonal DEM models by the inverse computation .T he results indicate that the critical arching height is about 8/10 of clear pile spacing ,and the load‐correction coefficient α increases linearly with the ratio of the em‐bankment height and pile clear spacing ,but decreases in the form of power function with the friction coefficient of embankment fill .Finally ,the presented method was verified with the experimental data of the publication .