单排桩工况下软弱地基刚性桩支承路堤稳定性计算  

Stability of rigid pile supporting embankment on soft groundunder single-row pile conditions

作　　者：聂文峰[1] 李光慧[1] 豆红强[2] 李能[1] 孙希望[1] NIE Wenfeng;LI Guanghui;DOU Hongqiang;LI Neng;SUN Xiwang(Kunming Survey,Design and Research Institute Co.,Ltd.,of CREEC,Kunming 650200,China;School of Zijin Geology and Mining,Fuzhou University,Fuzhou 350108,China)

机构地区：[1]中铁二院昆明勘察设计研究院有限责任公司,云南昆明650200 [2]福州大学紫金地质与矿业学院,福建福州350108

出　　处：《自然灾害学报》2023年第6期197-207,共11页Journal of Natural Disasters

基　　金：国家自然科学基金项目(42007235)。

摘　　要：刚性桩支承路堤的稳定性评价是近年来研究的热点和难点问题。从刚性桩桩间软弱土是否发生绕流滑动破坏的角度出发,基于Ito T塑性变形理论率先推导了路堤荷载下单排刚性桩桩身被动荷载的分布模式;以极限分析的上限定理为框架,基于单排桩支承路堤旋转破坏机构的内外功能平衡关系构建了以安全系数为目标函数的约束方程,提出了软弱地基单排刚性桩支承路堤的稳定性计算方法,并借助数值模拟验证了该方法的合理性。计算结果表明:当路堤潜在滑裂面经过单排桩时,单排桩加固位置由路堤坡趾向路堤中心移动,其安全系数总体上呈现出先增大后减小的趋势;单排桩的最大加固比受路堤堆载高度影响不大,但随着软弱地基抗剪强度的降低而增大,亦随着路堤坡率的降低而降低;单排桩的最优加固位置则受路堤堆载高度、路堤坡率以及地基内摩擦角等的影响显著,受地基土黏聚力的影响较小。研究结果为刚性桩支承路堤的稳定性计算提供了一种新的思路和理论支撑。The stability evaluation of the embankment supported by rigid pile composite foundation is a hot and difficult problem in recent years.Based on the plastic deformation theory of Ito T and the soil arching effect,from the perspective of whether the soft soil between the rigid piles will cause sliding failure,the passive load distribution mode of a single row of rigid piles under the embankment load is deduced.Take the upper bound theorem of limit analysis as the framework,based on the internal and external functional balance relationship of the single-row pile-reinforced embankment rotating failure mechanism,a constraint equation with the safety factor as the objective function is constructed.Numerical simulation verifies the rationality of the method.The calculation results show that when the potential failure surface of the embankment passes through the single-row pile,the location of the single-row pile reinforcement moves from the toe of the embankment slope to the center of the embankment,and its safety factor generally shows a trend of first increasing and then decreasing.The maximum reinforcement ratio of a single row of piles is not affected by the height of the embankment.However,it increases with the decrease of the shear strength of soft foundation,and decreases with the decrease of the embankment slope rate.The optimal reinforcement position of a single row of piles is affected significantly by the embankment stacking height,the embankment slope rate,and the friction angle of the foundation,but less affected by the cohesion of the foundation soil.The research results provide a new idea and theoretical support for the stability calculation of rigid pile-supported embankments.

关 键 词：路基工程 软弱地基 上限定理 被动桩 稳定性 

分 类 号：TU443[建筑科学—岩土工程]