基于土拱效应的桩网结构路基稳定性可靠度分析

基于路基土拱效应的应力集中现象,并考虑荷载及土体参数的变异性,建立了桩网结构路基稳定性的可靠度计算模型,给出了可靠度分析的计算方法及流程。以某一典型高速公路桩网结构路基进行稳定性分析为例,分别利用安全系数法和可靠度方法设计了该桩网结构路基加固桩长度,并基于荷载及土体参数变异性,对可靠度指标进行了敏感性分析,结果表明:荷载及土体参数的变异性对桩网结构路基的稳定性影响显著,利用可靠度方法来计算桩网结构路基加固桩长度的设计更为安全和合理;需要特别注意第二层土的极限侧阻力及路基面附加荷载变异性的影响,而路基填料内摩擦角及加固桩极限端阻力可当作常量来处理。

Reliability analysis of stability evaluation of pile-supported embankment based on soil arching effect

Based on the phenomenon of stress concentration induced by the soil arching effect and the variability of loads and soil parameters, a model for reliability analysis of stability evaluation of the pile-supported embankment was built, and the reliability index calculation method and flow chart were presented in this paper. Taking a typical pile-supported embankment of a highway as an example for stability analysis, the reinforced pile length for the embankment was designed with the safety factor method and reliability index method, respectively, and sensitivity analysis of the reliability index was conducted based on the variability of loads and soil parameters. The results show that the variability of loads and soil parameters has a large influence on the stability of the pile-supported embankment, and it is more reliable and reasonable to use the reliability index method to design the reinforced pile length. The results also indicate that the limit lateral resistance of the second-layer soil and the variability of additional loads on the embankment surface should be given close attention, and the internal friction angle of embankment filling and the ultimate resistance of the reinforced pile can be treated as constants.