旧桩拔除对临界桩基承载力的影响分析  

作　　者：孔劲奇 毛一玫 刘菲 王琰 卫翔 

机构地区：[1]江苏省中成建设工程总公司,江苏南京210041

出　　处：《科技创新与应用》2021年第11期71-72,76,共3页Technology Innovation and Application

摘　　要：拔桩残留的桩孔在回填前由于桩孔孔壁侧压力解除,形成较大的自由面,地层压力向自由面发生径向应力释放,土性较差时可引起土体的较大扰动。针对旧桩拔除引起的工程环境效应问题,基于小孔扩张理论,分析了旧桩拔除引起的桩周土体强度变化及其对周边桩承载特性的影响。结果表明:旧桩拔除对周边环境的扰动影响范围约为6倍的桩径,并随着距孔壁距离的增大而快速减小。Due to the release of the lateral pressure of the removed pile,a large free surface is formed in the residual pile hole before backfilling.The formation pressure releases radial stress to the free surface,and the soil around the hole can be greatly disturbed when the soil property is poor.Aiming at the problem of engineering environmental effect caused by removal of old pile,based on the small hole expansion theory,the strength change of soil around the removed pile and its effect on the bearing capacity of adjacent pile were analyzed.The results show that the pile removal disturbance extent is about 6 times of the diameter of the removed pile;the disturbance decreases greatly with the distance.

关 键 词：旧桩拔出 小孔扩张 扰动分析 桩基承载力 

分 类 号：U455.4[建筑科学—桥梁与隧道工程]