红粘土地层闭口管桩上浮模型试验研究  

Model test research on close-end pipe pile floating in red clay geology

作　　者：王家全[1] 张昊[1] 刘垒雷 彭泰[1] 

机构地区：[1]广西科技大学土木建筑工程学院,广西柳州545006

出　　处：《广西大学学报（自然科学版）》2016年第2期324-331,共8页Journal of Guangxi University（Natural Science Edition）

基　　金：广西自然科学基金资助项目(2015GXNSFAA139270;2015GXNSFAA139257);广西科技大学博士基金项目(院科博1011);广西研究生教育创新计划项目(YCSZ2014200)

摘　　要：为研究红粘土上硬下软地层中管桩上浮问题,对3组不同桩径的闭口管桩进行室内沉桩模型试验,分析单桩、群桩上浮量的变化规律和红粘土地层管桩上浮的机理。结果表明:静压单桩的桩身上浮量主要由桩顶卸荷回弹变形引起,桩径越大则回弹变形越大,但单桩上浮量远小于群桩引起的上浮量。沉桩过程中,邻桩上浮量并不随桩的贯入深度的增加而均匀持续增长,管桩压入上部硬塑土层对邻桩上浮的影响大于压入下部可塑土层对邻桩上浮的影响。在红粘土软硬土层交界处一定范围内,桩上浮的增长趋势会出现短暂的休止情况。To study the floating of pipe pile in the stratum that is soft in upper part and hard in lower part,three groups of indoor pile-sinking model tests were carried out on close-end pipe piles of different diameters,and floating mechanism and values of single pile and pile group were analyzed.Results show that the flotation of static pressure pile is mainly caused by the springback deformation of unloading,and the larger the pile diameter is,the larger the springback deformation will be. But the floatation amount of single pile is far less than that of pile group. In the pile-sinking process,the floatation amount of adjacent pile does not increases uniformly with the increase of pile penetration depth,and the influence of pipe pile penetrating into the upper and harder layer of plastic soil on adjacent pile floatation is larger than that of pipe pile penetrating into the bottom layer of plastic soil.In a certain range near the junction of hard and soft soil in red clay,the floating growth would temporarily stop.

关 键 词：红粘土地层 管桩 桩上浮 模型试验 

分 类 号：TU473[建筑科学—结构工程]