Load and Settlement Analysis of Flexible-pile Supported Embankment Based on Double Equal Settlement Plane

DOI：

 作者 单位 赵明华，张承富，刘长捷 （湖南大学 岩土工程研究所，湖南 长沙 410082）

为了建立能充分考虑桩承式路堤各组成部分之间协调变形特性的理论方法，基于柔性桩-桩承式路堤的变形机理，提出了路堤-桩-土协调变形的双等沉面荷载传递模型. 首先，该模型基于路堤中的等沉面以及桩承式路堤的变形特点，在桩底以下一定深度处，引入一个与路堤中相似的等沉面. 其次，考虑到现有土柱模型的不足，引入能考虑内外土柱间相对位移对摩擦因数的影响的土柱模型. 介于上、下等沉面之间的路堤、桩、土，通过彼此的协调变形影响等沉面处的应力，从而影响路堤的总体沉降和桩土应力比. 最后，将本文计算结果和复合模量法计算结果与实测结果进行对比，结果表明：与实测值相比，复合模量法计算沉降值的相对误差为19.4%，本文计算沉降值的相对误差为9.6%，本文计算的桩土应力比相对误差为9.91%，证明了本文理论方法是合理的.

In order to develop a theoretical model that can fully consider the coordinated deformation characteristics between the components of pile-supported embankments, a double equal settlement plane model for embankment-pile-soil coordinated deformation is proposed based on the deformation mechanism of the pile-supported embankments with the flexible pile. Firstly, the model introduces an equal settlement plane at a certain depth below the pile-toe base on the deformation characteristics of the pile-supported embankment and the equal settlement plane in the embankment. Secondly, considering the deficiencies of the existing soil-column model, a new soil-column model that can consider the influence of the relative displacement on the coefficient of friction between the inner and outer soil columns is proposed. The stresses at equal settlement plane are affected by the coordinated deformation between the embankment, pile and soil, thus affecting the overall settlement of the embankment and the pile-soil stress ratio. Finally, the calculation results of the proposed method and the composite modulus method are compared with the measured values. The results demonstrate that the calculation errors of the settlement are 9.6% and 19.4%, respectively. The relative error of the pile-soil stress ratio calculated by the proposed model is 9.91%, which verifies the rationality of the proposed model.