桩承式加筋路堤荷载分担计算改进模型

Modified load sharing calculation model of geosynthetic-reinforced and pile-supported embankments

  • 摘要: 基于桩间的土拱效应与加筋效应开展融合分析,建立了桩承式加筋路堤荷载分担计算的改进Hewlett模型。首先,根据土拱是否处于塑性状态,结合桩-土竖向受力平衡条件,分别求解球形拱和平面拱控制方程,并对路堤荷载进行初分配。然后,假定加筋带上覆荷载为更符合实际工况的倒三角形分布,并使用文克勒地基模型考虑加筋带影响范围内的桩间土反力,无需预设土工加筋挠度形式,即可构建并求解土工加筋受力平衡控制微分方程,进而由加筋效应对路堤荷载进行再分配。综合工程实例验证与讨论,并通过多模型对比分析,表明改进模型能够合理预测荷载分担与土工加筋受力结果。参数分析表明,改进模型能够合理预测几何、材料参数变化对桩承式加筋路堤荷载分担的影响。

     

    Abstract: Based on the combined analysis of soil arching effect and reinforcement effect between piles, an improved Hewlett model for load sharing calculation of geosynthetic-reinforced and pile-supported embankments (GRPSE) is established. Firstly, the governing equations of spherical arch and plane arch are solved respectively, according to whether the soil arch is in a plastic state and combined with the vertical force balance condition of pile-soil, then the load sharing of embankment filling is initially determined. Secondly, the differential equation for controlling the stress balance of the geosynthetic reinforcement can be built and solved without presetting the deflection form, the overlying load of the reinforcement belt is assumed to be an inverted triangle distribution in line with the actual working conditions, and the Winkler foundation model is applied to consider the soil reaction between piles within the influence range of one reinforcement belt. Thereafter, the embankment loading can be redistributed according to the calculated reinforcement effect. It proves that the improved model can reasonably predict the load sharing and the stress results of reinforcement according to the verification and discussion of case studies and the comparative analysis of several models. Parameter analysis shows that the improved model can reasonably predict the influence of geometric and material parameters on load sharing of GRPSE.

     

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