桩承式灰土路堤基底荷载效应分析  

Analysis on Load Action Effect of Subgrade in Pile Supported Lime-soil Embankment

作　　者：张浩[1] 石名磊[1] 张瑞坤[1] 

机构地区：[1]东南大学,江苏南京210096

出　　处：《公路交通科技》2011年第6期25-31,共7页Journal of Highway and Transportation Research and Development

基　　金：建设部研究开发项目(2008-K2-12)

摘　　要：针对桩承式路堤结构的作用特点,基于Marston土压力理论,通过考虑填料粘聚力的柱面剪应力转移模型,对桩承灰土路堤基底荷载效应进行了研究;并结合Winkler地基模型提出了基底变形协调的荷载作用效应值迭代求解的方法。通过算例,对计算模型中剪应力修正系数β、填料粘聚力c、基底桩土刚度等因素进行了分析。结果表明：随着β、c的增大,桩间应力折减比S降低,桩顶应力集中明显,工程计算中不应忽略两者的影响;桩帽尺寸效应（b/s,mc）对基底桩、土刚度影响显著,计算中需对基底桩、土刚度系数进行修正;桩间应力折减比S随b/s呈先减小后增大的趋势,且当桩帽置换率mc约为25%~35%时,路堤土拱效应更为显著。According to the characteristics of embankment supported by piles,based on Marston soil pressure theory,the load action effect of basement in pile supported lime-soil embankment was studied with cylindrical shear stress transfer model,considered the cohesion force of filling.With the deformation compatibility condition and the hypothesis of Winkler foundation model,an iteration algorithm for basement load was obtained.In addition,a calculation example was given to analyze the influence from correction coefficient of shear stress（β）,cohesion of filling（c） and stiffness of pile and soil.It is found that（1） the stress reduction ratio（S） significantly decreases and pile top stress significantly concentrates with the increase of the correction coefficient of shear stress（β） and the cohesion of filling（c）,therefore,the impact of these two parameters should not be ignored in engineering calculation;（2） the stiffness of pile-soil are significantly affected by the sizes of pile cap（b/s,mc）,so the stiffness coefficient of pile-soil should be modified in capped pile supported lime-soil embankment;（3） the stress reduction ratio（S） shows a trend of decreases and then increases with b/s,and embankment soil arching is more significant when cap replacement rate（mc） is about 25%~35%.

关 键 词：道路工程 土拱效应 应力折减比 灰土路基 疏桩 

分 类 号：U416.1[交通运输工程—道路与铁道工程]