非饱和土渗透系数试验与模型预测及验证  

Permeability coefficient test and model prediction and verification of unsaturated soil

作　　者：刘小文[1] 罗海林 陈嘉帅 LIU Xiaowen;LUO Hailin;CHEN Jiashuai(School of Civil Engineering and Architecture,Nanchang University,Nanchang 330031,China)

机构地区：[1]南昌大学建筑工程学院,江西南昌330031

出　　处：《南昌大学学报（工科版）》2021年第1期1-10,共10页Journal of Nanchang University(Engineering & Technology)

基　　金：国家自然科学基金资助项目(51268046);江西省自然科学基金资助项目(20151BAB203037)。

摘　　要：为探究不同方法的适用性,通过压力板仪对江西某地区红土进行土-水特征曲线试验,结合动态多步溢出法、一维土柱试验的湿润锋前进法、CCG模型预测和VGM模型预测4种方法,获得土体在不同压实度下渗透系数与饱和度的关系。利用有限元软件Geo-Studio对一维土柱试验进行仿真分析,将采用VG模型拟合的土-水特征曲线及4种不同方法计算得到的渗透系数函数作为边界条件,得到了相应条件下的浸润锋时程曲线。分析模拟与试验结果发现CCG模型预测的非饱和土渗透系数与动态多步溢出法计算的结果较为接近且略小于实际渗流情况。由于湿润锋前进法土柱试样较大,其渗透系数较动态多步溢出法大10倍左右,且最接近于土柱试验实际渗流情况。In order to explore the applicability of different methods,a pressure plate instrument was used to test the soil-water characteristic curve of the red soil in a certain area of Jiangxi,combining the dynamic multi-step spillover method,wetting front advancing method of one-dimensional soil column test,CCG model prediction and VGM model prediction four commonly used methods,the relationship between permeability coefficient and saturation of soil under different compaction degrees was obtained.The finite element software Geo-Studio was used to simulate and analyze the one-dimensional soil column test.Taking the soil-water characteristic curve fitted by the VG model and the permeability coefficient function calculated by four different methods as boundary conditions,the time history curve of the infiltration front under the corresponding conditions was obtained.Analysis of simulation and test results found that the permeability coefficient of unsaturated soil predicted by the CCG model was close to the result calculated by the dynamic multi-step overflow method and slightly smaller than the actual seepage.Due to the large soil column sample of the wet peak advancing method,its permeability coefficient was about 10 times larger than that of the dynamic multi-step overflow method,and it was closest to the actual seepage condition of the soil column test.

关 键 词：一维土柱试验 渗透系数 湿润锋前进法 多步溢出法 土-水特征曲线 

分 类 号：TU443[建筑科学—岩土工程]