Study On Consolidation Characteristics Of Soft Clay In Dongting Lake Area

The data of soft soil in Dongting Lake area were collected.The physical and mechanical parameters of soil samples were obtained from the basic soil test.Through regression analysis,the relationship between physical and mechanical parameters and water content was obtained.Through the research,the soft soil in Dongting Lake area has the characteristics of high moisture content and low strength,the soil particles are relatively fine with soft mud.In this paper,the GDS advanced consolidation system is described in detail.The working principle,structure,operation mode and advantages and disadvantages of the system are introduced.The step loading consolidation test on Dongting Lake soft soil were carried out using GDS advanced consolidation system.According to the different drainage methods,the vertical drainage consolidation test and the radial drainage consolidation test were carried out.The void ratio,compressibility coefficient,compression modulus and consolidation coefficient of the samples under different drainage conditions were analyzed.According to the test results,the consolidation deformation characteristics of soil samples under different control conditions are analyzed.In this paper,a systematic study on the continuous loading consolidation test is carried out,and the CRS and CRL consolidation tests are carried out for the soft soil in Dongting Lake area,The results are compared with those of the continuous loading consolidation test.The consolidation characteristics of soil samples under different loading modes and drainage modes are compared and analyzed.It was found that the soil samples showed the same mechanical properties when the effective stress in soil samples is same although in different consolidation conditions.The nonlinear seepage model and nonlinear compression model of soft soil are analyzed.Based on the experimental results,the parameters of the nonlinear compression model and the nonlinear seepage model of the soft soil in Dongting Lake area are obtained.Considering the nonlinear variation of compression coefficient and permeability coefficient in the consolidation process,a one-dimensional nonlinear consolidation model of saturated soft soil is established,the analytical solution of the equation is obtained and the results are compared and analyzed.