基于非线性渗流的大变形固结有限元分析  

Finite element analysis of large-strain consolidation with nonlinear flow

作　　者：李刚[1,2] 张金利[2,3] 杨庆[2,3] 蒋明镜[4] 

机构地区：[1]西京学院土木工程学院,西安710123 [2]大连理工大学建设工程学部土木工程学院岩土工程研究所,大连116024 [3]大连理工大学海岸和近海工程国家重点实验室,大连116024 [4]同济大学地下建筑与工程系,上海200092

出　　处：《哈尔滨工程大学学报》2017年第8期1231-1237,共7页Journal of Harbin Engineering University

基　　金：国家自然科学基金项目(41572252)

摘　　要：为了研究土体在非线性渗流下的固结效应,基于大变形固结理论,考虑非线性渗流(耦合非Darcy渗流与变渗透系数)作用,建立了二维固结控制方程与有限元方程。采用自编程序对某一黏性土体的固结过程进行了计算。通过大量变动参数的计算与分析,探讨了非Darcy渗流与渗透系数随固结变化的影响。计算结果表明:与Darcy渗流相比,非Darcy渗流下的沉降小,超孔压消散缓慢,具有延迟效应。其中,非Darcy渗流试验常数m影响较大,线性渗流起始水力梯度iL影响较小。渗透系数变化对固结的影响与非Darcy渗流相似,压缩指数与渗透系数指数比值αc的影响较大。在非Darcy渗流与渗透系数随固结变化的耦合作用下,沉降显著减小,超孔压消散趋于缓慢,延迟效应更为明显。To study consolidation behaviors under non-Darcy flow, finite element equations and governing equations of plane consolidation were deduced with nonlinear flow （coupled non-Darcy flow with variable permeability coefficient） based on large-strain consolidation theory. The consolidation process of clays was studied by using a program that was developed based on finite element equations. The influence of non-Darcy flow and variable permeability coefficient on consolidation was analyzed by changing the parameters. Calculation results indicate that compared with the circumstances that consider Darcy flow, the settlement is smaller and the dissipation of excess pore water pressures is slower when non-Darcy flow is considered. The influence of parameter m （test constant of non-Darcy flow） on consolidation is greater than iL（ initial hydraulic gradient of linear flow） . The influence of permeability co-efficient is similar to that of non-Darcy flow, and the influence of αc（ratio between compression index and permea-bility coefficient index） is remarkable. The settlement decreased obviously when considering non-Darcy flow and variable permeability coefficient. The dissipation of excess pore water pressure becomes slow, and the delay effects are more evident.

关 键 词：大变形 非DARCY渗流 变渗透系数 有限元分析 超孔压 固结 沉降 压缩指数 

分 类 号：TU43[建筑科学—岩土工程]