基于非Darcy渗流的饱和黏土一维固结理论  

ONE-DIMENSIONAL CONSOLIDATION THEORY OF SATURATED CLAY BASED ON NON-DARCY FLOW

作　　者：刘忠玉[1] 孙丽云[2] 乐金朝[2] 马崇武[3] 

机构地区：[1]郑州大学土木工程学院,河南郑州450001 [2]郑州大学水利与环境学院,河南郑州450001 [3]东莞理工学院建筑工程系,广东东莞523808

出　　处：《岩石力学与工程学报》2009年第5期973-979,共7页Chinese Journal of Rock Mechanics and Engineering

基　　金：河南高速公路发展有限责任公司科技项目(2007GF009);东莞市科技计划资助项目(2006-117)

摘　　要：按Terzaghi饱和黏土一维固结理论得到的固结度理论值有时与实际值之间存在较大的误差,其原因之一是忽略了某些饱和黏土中孔隙水的渗流对Darcy定律的偏离。引入可以同时考虑低速渗流曲线段和较高速渗流直线段的非Darcy渗流方程,重新推导饱和黏土一维固结方程,并采用有限体积法对该方程进行数值求解。与Terzaghi饱和黏土一维固结理论解析解的对比,证明该方法的有效性。在此基础上,探讨非Darcy渗流参数对固结过程的影响。计算结果表明,非Darcy渗流延缓了饱和黏土中孔隙水压力的消散速度,故使得地基的固结速度比Terzaghi一维固结理论值要慢。同时,除固结系数外,综合直线渗流起始水力梯度i1、土层厚度H、地面荷载p0等3个参数的指标I1也是表征饱和黏土渗透固结特性的一个重要指标。最后,讨论Terzaghi一维固结理论的适用范围。There sometimes exits notable difference between the solution of one-dimensional consolidation of saturated clay layers based on Terzaghi＇s theory and the field settlement observations, which can be in a certain extent ascribed to that the flow of pore water in these soil layers may not obey Darcy＇s law. In order to improve the precision of consolidation computation, Terzaghi＇s one-dimensional consolidation theory is modified based on the non-Darcy flow described by the power function for the lower velocity of flow and the linear function for higher velocity of flow, and the numerical analysis is performed using the finite volume method. In order to verify its validity, the numerical solution by the present method for the case that the flow of pore water obeys Darcy＇s law is compared with the analytical solution based on Terzaghi＇s one-dimensional consolidation theory. Then the effects of the parameters of non-Darcy flow on the consolidation process are investigated. The numerical results indicate that the non-Darcy flow delays the dissipation of pore water pressure in saturated clay layers： thereby the consolidation velocity of these soil layers is smaller than the solution based on Terzaghi＇s theory. Besides the coefficient of consolidation, a new parameter Ii composed of the threshold hydraulic gradient i1, the thickness of soil layer H and the vertical uniform load P0 is introduced to characterize the consolidation of these soil layers. Finally, the applicability of Terzaghi＇s one-dimensional consolidation theory is discussed.

关 键 词：土力学 固结理论 饱和黏土 有限体积法 非DARCY渗流 沉降 固结度 

分 类 号：TU431[建筑科学—岩土工程]