摘要
在传统的复合地基固结理论中,等应变条件和桩土流量连续的假设之间存在着不一致的地方。为此,抛弃了桩土界面上水流量相等的假设,考虑了桩体径向渗流引起的桩体固结和变形,同时考虑了桩体施工扰动而造成的扰动区土体水平渗透系数抛物线分布的特点,给出了此类固结问题的控制方程和解答以及复合地基固结度的表达式,并对复合地基固结度的解进行了讨论,可以看出无论井径比(影响区半径和桩体半径之比)趋于1或无穷大,本文固结解均能退化到Terzaghi天然地基一维固结的解答。最后对本文的解和以往的解做了比较,结果表明:本文解给出的地基固结度比考虑扰动区土体水平渗透系数为直线变化或者保持不变的解给出的固结度更大;随着井径比的减小,本文解和以往的解得到的固结度差值变大。
In the traditional consolidation theories for assumption and the assumption of flow continuity at composite foundation, there is an inconsistency between the equal strain the column-soil interface. To remedy this inconsistency, the radial flow within the column instead of the equal flow assumption at the column-soil interface is considered to account for the consolidation and deformation of the column. In addition, the parabolic distribution of the horizontal permeability of soil in the disturbed zone due to the influence of the column construction is considered too. The governing equations for this type of consolidation problem are derived and the solutions to the governing equations are obtained. Then the solution of the average degree of consolidation is obtained and discussed. It can be seen that whenever the radius ratio （radius ratio of the influence zone to the column） approaches 1 or oo, the present solution for composite foundation all can be reduced to the solution of Terzaghi＇s one-dimensional consolidation for natual foundation. Finally, a comparison between the present solution and some previous solutions is made. The results show that the rate of consolidation calculated by the present solution is rapider than that by the solutions which assume the horizontal permeability of soil in the disturbed zone is linearly changed or kept constant as a reduced value. The difference between the average degree calculated by the present solution and that by the previous solutions increases with the reduction in the radius ratio.
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2009年第7期1069-1074,共6页
Chinese Journal of Geotechnical Engineering
基金
国家自然科学基金项目(50679074)
关键词
固结
复合地基
桩体固结
水平渗透系数
抛物线分布
consolidation
composite foundation
column consolidation
horizontal permeability
parabolic distribution
