桩周黏弹性土体固结分析  

Consolidation analysis of visco-elastic soil around a driven pile

作　　者：刘加才[1] 宰金珉[1] 梅国雄[1] 高鸿[1] 

机构地区：[1]南京工业大学土木工程学院,江苏南京210009

出　　处：《岩土工程学报》2009年第9期1361-1365,共5页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(50608038/E0806)

摘　　要：沉桩过程中桩周土体产生超静孔隙水压力,桩承载力的提高很大程度上依赖于超静孔隙水压力的消散。采用Merchant流变模型模拟土体黏弹性,考虑土体径、竖向耦合固结,研究沉桩后土体的再固结问题。假定沉桩后产生的超静孔压满足圆孔扩张理论,根据连续性条件,获得研究问题的控制方程。采用分离变量法、结合Laplace变换求得其级数解答。将该解答编制成应用程序,对一算例进行了分析。算例分析表明,深度在5.0m范围内土体的孔压消散受竖向固结影响较为明显;土体黏弹性减慢固结速度主要表现在中期接近后期阶段。Installation of a driven pile will generate excess pore pressures in the clay adjacent to the pile. Pile capacity mostly depends on the dissipation of the excess pore pressures. The reconsolidation of the clay around the pile is investigated, assuming that the Mechant model can be used to describe the visco-elastic features of the soil. The initial excess pore distribution away from the pile wall varies according to the cylindrical cavity expansion theory. The governing equation is derived under the continuity condition. The general solution is obtained by separating the variables and using the Laplace transform and the inverse transform. The corresponding solutions are introduced into a program and a case is analyzed using it. The results lead to the following conclusions： 1） The vertical consolidation has great influence on the soil whose depth is less than 5.0 m; and 2） The visco-elastic feature of the soil delay consolidation usually happens obviously at the middle to late stages.

关 键 词：桩 土体 黏弹性 固结 

分 类 号：TU433[建筑科学—岩土工程]