摘要
针对柔性桩承式加筋路堤,建立了路堤-网-桩-土相互协调共同工作的荷载传递模型,通过改进的路堤荷载传递模型和假定的柔性桩侧摩阻力分布模式分析了路堤土拱效应和桩土相互作用,根据平衡条件推导获得了新的可以考虑土拱效应、拉膜效应和桩土相互作用三者耦合条件下桩土应力比及桩土差异沉降计算公式。通过工程实例的分析计算,验证计算模型的合理性,并分析了各因素与桩土应力比的关系。结果表明:网上、下桩土应力比均随路堤填土内摩擦角的增加先增大后减小,随桩体压缩模量、路堤填土压缩模量的增加而增大,随桩间土压缩模量、桩间距的增加而减小,且网下桩土应力比大于网上桩土应力比;网上桩土应力比随土工格栅抗拉强度的增加而减小,网下桩土应力比随土工格栅抗拉强度的增加而增大,网上、下桩土应力比差随土工格栅抗拉强度、路堤填土重度和填土高度的增加而增大。桩土应力比和桩土差异沉降理论计算值与工程实例实测值对应较好。
For deformable pile-supported and geosynthetics-reinforced embankments,a load transfer model for common coordination working mechanism of embankment-net-pile-soil is established.Soil arching effect of the embankment and mutual coordination working mechanism of pile-soil are analyzed based on the modified load transfer model for embankments and the assumed distribution of skin friction on piles.According to the force equilibrium,a new formula for pile-soil stress ratios and the differential settlement between piles and soil is deduced under the coupling of soil arching effect,tensioned membrane effect and mutual coordination working mechanism of pile-soil.The model is verified through practical projects,and the relationships of the pile-soil stress ratios with correlative influence factors are analyzed.It is found that the pile-soil stress ratios will first increase and then decrease with the increase of angle of internal friction of fill,will increase with the increase of the pile modulus of compressibility and the fill modulus of compressibility,and will decrease with the increase of the soil modulus of compressibility between piles and the pile space.With the increase of the tensile strength of geo-grids,the pile-soil stress ratios on net will decrease,and those below net will increase.The latter is larger than the former,and the relative difference between them will increase with the increase of the tensile strength of geo-grids,the fill modulus of compressibility,the unit weight and the height of fill.The theoretical value of the pile-soil stress ratios and the differential settlement between piles and soil are close to the observed ones.
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2011年第5期705-713,共9页
Chinese Journal of Geotechnical Engineering
基金
重庆交通大学(桥梁)结构工程重点实验室开放基金项目(CQSLBF-Y11-2)
中国矿业大学深部岩土力学与地下工程国家重点实验室开放基金项目(SKLGDUEK1012)
泉州市科技计划项目(2010Z81)
华侨大学基本科研业务费专项基金资助(JB-ZR1123)
关键词
柔性桩承式加筋路堤
桩土应力比
土拱效应
拉膜效应
桩侧摩阻力
deformable pile-supported and geosynthetics-reinforced embankment
pile-soil stress ratio
soil arching effect
tensioned membrane effect
skin friction
