One-Dimensional Consolidation Of Soft Soils Under Complicated Drainage Boundary Conditions

Since one dimensional consolidation theory has been proposed by Terzaghi in 1924,it is one of the important subjects in the field of geotechnical engineering.In order to make the consolidation theory be closer with the practical engineering conditions,many scholars at home and abroad have made a lot of research work which focused primarily on modifying the one-dimensional consolidation theory.From the development of engineering construction and existent research achievements,however,there are some limitations,and most previous studies considered the boundaries of the soft soil consolidation as pervious and impervious boundaries,so it needs to study and modify current consolidation theory further.Based on previous studies,this thesis focuses on the complex drainage boundary conditions under complex consolidation condition in soft soil for theoretical work.The main works of this paper are as follows.(1)The analytical solution of one dimensional consolidation theory with unsteady pore pressure boundary under time-dependent loading is derived.According to the numerical examples,the excess pore pressure is analyzed by MATHEMATICA mathematical calculation software under different boundary permeability,and drainage velocity at the boundary.The results are compared with the existing nonlinear consolidation theory.(2)The analysis of sensitivity has been considered to be one main method in the solution to identification of multiple parameters in geotechnical engineering.Based on the previous chapter,the sensitivity of parameters of the excess pore pressure and drainage velocity at the boundary is analyzed for further research.(3)The analytical solution of one dimensional consolidation theory by considering seepage force under time-dependent loading is derived,and the consolidation degree under both upward and downward seepage.The distribution of the seepage stress during soil consolidation is also analyzed by MATHEMATICA mathematical calculation software under different boundary permeability.(4)The Merchant model is a widely used rheological constitutive model in geotechnical engineering.Based on Merchant model and introducing continuous drainage boundary conditions,the method of variable separation is used to achieve the analytical solution of one dimensional consolidation of viscoelastic soils.According to numerical examples,some relevant characters of soft soil consolidation are found.In this thesis,the derived analytical solution can better reflect the actual soil characters conditions in soil.These can provided theoretical basis for reasonable prediction of consolidation settlement.