Assessment Of Spatial Variability Of Unsaturated Clay In Hefei

The soil has a remarkable variability and the spatial variability analysis of the soil parameters is the theoretical basis of reliability design of geotechnical engineering.Therefor,this paper studied the unsaturated clay in Hefei to accurately estimate the spatial variability from three aspects,such as basic soil parameters,deformation parameters and hydraulic parameters.In aspact of soil water characters,based on the finite element numerical analysis software,setting up the numerical model of osmotic technique and filter paper method to analyze movement of water during the test,obtaining the equilibrium time of osmotic technique and filter paper method.And take into account the influence of the hydraulic parameters of soil,the initial gravity moisture content,initial dry density and the size of soil sample on equilibrium time.Meanwhile,the osmotic technique and filter paper method were tested to confirm the reliability of numerical simulation results.In aspact of spatial variability,22 kinds of undisturbed soil samples were subjected to laboratory measurements to determine basic soil parameters,deformation parameters and hydraulic parameters.The mean,standard deviation,coefficient of variation and distribution type of soil parameters were obtained using traditional statistical analysis while horizontal and vertical correlation distance were calculated by 5 kinds of calculation method based on random field theory,and the usability of different calculation methods was evaluated.Besides,this paper discussed the Impact of different soil parameters on correlation distance.The results show that the correlation distance which calculated by different soil parameters is consistent.