连续渗透边界下非饱和土竖井地基固结解析解  

Analytical solution to consolidation of unsaturated soil by vertical drains with continuous permeable boundary

作　　者：秦爱芳[1] 江良华 许薇芳 梅国雄[2] QIN Ai-fang;JIANG Liang-hua;XU Wei-fang;MEI Guo-xiong(Department of Civil Engineering,Shanghai University,Shanghai 200072,China;School of Transportation Engineering,Nanjing Tech University,Nanjing,Jiangsu 210029,China)

机构地区：[1]上海大学土木工程系,上海200072 [2]南京工业大学交通学院,江苏南京210029

出　　处：《岩土力学》2021年第5期1345-1354,共10页Rock and Soil Mechanics

基　　金：国家自然科学基金面上项目(No.42072292,No.41372279)。

摘　　要：基于非饱和土轴对称固结理论和等应变假设,引入连续渗透边界条件,采用边界条件齐次化、本征函数法,推导得到瞬时均布荷载下非饱和土竖井地基三维固结解析解。通过与双面完全渗透边界条件下已有解析解进行对比,验证了所得解析解的正确性。对所得解进行算例分析发现:通过设置合理上、下界面参数,所得解可用于模拟实际上、下边界透水透气任意分布的情况,弥补了目前无法考虑上、下边界渗透性介于渗透与不渗透之间或不对称分布的不足;在井径比及井深适当的前提下,当径、竖向渗透系数比大于2时,竖向渗流对于超孔隙压力消散的影响较小;当考虑竖向渗流时,上述影响随着上、下边界渗透性能的增强而愈加明显。In this paper,based on the axisymmetric consolidation theory of unsaturated soil and equal-strain assumption,an analytical solution using the homogenization of boundary conditions and eigenfunction method is proposed to three-dimensional consolidation of unsaturated soil enhanced by vertical drains under instantaneous loading,in which the continuous permeable boundary conditions are properly introduced.Then,the proposed solution is verified by the special cases of double drainage boundary conditions.Finally,the solution is analyzed using examples and the results show that the proposed solution can be used to simulate the arbitrary distribution of permeability of the top and bottom boundary by setting reasonable interface parameters,which makes up for the problem that the permeability of the top and bottom boundary is between pervious and impervious condition or follows an asymmetric distribution.In addition,with a proper ratio of influence radius to drainage well radius and appropriate depth of vertical drain,the influence of vertical flows on the dissipation of excess pore pressures is small when the ratio of radial to vertical permeability coefficient is greater than two.Last but not the least,the above influence of excess pore pressures is more obvious with the enhancement of the permeability of the top and bottom boundary considering the vertical flows.

关 键 词：非饱和土 解析解 连续渗透边界 三维固结 竖井 

分 类 号：TU431[建筑科学—岩土工程]