加筋桩承式路堤的三维土拱效应分析与试验验证

为真实反映加筋桩承式路堤的土拱效应,采用三维球形土拱假设,建立了一种路堤荷载和均布荷载共同作用下的土拱效应分析方法。基于Hewlett土拱分析方法推导了无加筋体时路堤荷载和均布荷载作用下的桩土荷载分担表达式;对于加筋桩承式路堤,依据桩帽顶部加筋体沉降的特征,将加筋桩承式路堤分为2个部分,采用不同的沉降假设分别建立其竖向平衡方程,求得桩帽顶面和桩间土表面对加筋体的支撑力;通过离心模型试验和现场实测结果进行对比验证,采用参数分析法对影响土拱效应的主要因素进行等级评价。结果表明：加筋体抗拉强度对桩土应力比以及加筋体拉力均具有很高的影响等级,研究结果能够为分区域铺设加筋体提供理论依据。

Analysis of Three-dimensional Soil Arching Effect of Pile-supported Embankment with Geosynthetics and Its Test Verification

In order to truly reflect soil arching effect of pile-supported embankment with geosynthetics,based on a three-dimensional assumption of global soil arching,an analytical approach was presented to explore the soil arching effect of the pile-supported embankment with geosynthetics under the embankment load and uniform load.The pile-soil share-loading expression of pile-supported embankment without geosynthetics under the embankment load and uniform load was derived based on Hewlett arching analysis method.According to character of geosynthetics settlement at top of pile cap,the pile-supported embankment with geosynthetics was divided into two parts,their vertical balance equations were built through different settlement assumptions respectively,the support forces of pile cap elevation and soil surface to geosynthetics were calculated.The results from the centrifuge model tests and site tests were compared and parameter analysis method was used to evaluate the main influence factors on soil arching effect.The results show that geosynthetics tension strength has great influence on pile-soil stress ratio and geosynthetics tension and research outcomes provide the theoretical basis for the sub-regional installation of the geosynthetics.