不排水桩复合地基固结解析解  

Analytical solution for consolidation of composite ground with impervious pile

作　　者：卢萌盟[1,2,3] 谢康和[3] 周国庆[1,2] 郭彪[3] 

机构地区：[1]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州221008 [2]中国矿业大学力学与建筑工程学院,江苏徐州221008 [3]浙江大学软弱土与环境土工教育部重点实验室,浙江杭州310058

出　　处：《岩土工程学报》2011年第4期574-579,共6页Chinese Journal of Geotechnical Engineering

基　　金：中国博士后科学基金项目(20100481183);国家自然科学基金项目(51009135);中国矿业大学青年科研基金项目(2009A008);深部岩土力学与地下工程国家重点实验室博士后基金项目(PD1003)

摘　　要：以轴对称固结模型为基础,得到了不排水桩复合地基固结问题的控制方程,从理论上证明了不排水桩复合地基土体内只会产生竖向渗流,而且桩体施工扰动造成的扰动区土体径向渗透系数变化对地基固结不产生影响。然后分别给出了外部荷载瞬时施加和单级施加两种情况下的地基固结解析解,最后对不排水桩复合地基的固结性状进行了分析。结果表明:不排水桩复合地基的固结速率大于天然地基而又小于散体材料桩复合地基的固结速率;随着井径比(影响区与桩体半径之比)的减小或桩-土压缩模量比的增大,地基固结速度加快;井径比对地基固结的影响存在一个最佳值,大于该值,地基固结速率没有明显变化;加载历时对地基的固结影响较大,加载历时越久,地基固结越慢。Based on the axisymmetric consolidation model,an equation governing the consolidation of composite ground with impervious piles is obtained.It is proved theoretically that only vertical flows will occur within the surrounding soil during the consolidation of ground reinforced by impervious piles.In addition,the variation of the horizontal permeability of soil due to the pile construction has no influence on the consolidation of ground.Analytical solutions are then derived for the consolidation of composite ground subjected to an instant loading and a ramp loading,respectively.The consolidation behavior of foundation reinforced by impervious piles is subsequently investigated.The results show that the consolidation rate of composite ground with impervious piles is greater than that of the natural ground,but is less than that of the composite ground with granular piles;and with the reduction of the radius ratio（radius ratio of the influence zone to the column） or the increase in the pile-soil compression modulus,the consolidation rate is accelerated.There is an optimal value for the influence of the radius ratio on the consolidation rate.When the radius ratio is larger than this optimum value,the consolidation rate of ground is almost not changed.The loading period has a greater influence on the consolidation rate.The longer the loading period is,the rapider the consolidation rate is.

关 键 词：固结 复合地基 不排水桩 瞬时加荷 单级加荷 

分 类 号：TU473[建筑科学—结构工程]