Three-dimensional Consolidation Analysis Based On Porosity Change Of Soft Soil

Since established Terzaghi one-dimensional consolidation theory,consolidation theory has acquired extremely abundant research achievements in more than 90 years.In these research achievements,most of them research consolidation characteristics of soil based on traditional consolidation theory.But these traditional consolidation theory are based on various assumptions,for example soil deformation is small strain,permeability coefficient remains constant in the process of consolidation,etc.But in practical engineering,soft soil doesn't meet small strain theory due to great settlement of soft soil,and permeability coefficient is change in the process of consolidation.So calculation results of the traditional consolidation theory can't truly reflect the actual consolidation of soft soil in practical engineering.Therefore,building consolidation theory which can truly reflect the real consolidation deformation of soft soil,and applying it to practical engineering is becoming an urgent and important work.Based on the large strain consolidation theory,this paper embarks from the change rule of porosity,carries out further research of three-dimensional consolidation and the computational analysis through the theoretical analysis and verification of laboratory consolidation test.The main content of this paper is as follows:(1)summarizing and analyzing consolidation theory and research results about soft soil at home and abroad.(2)Based on the rule of soft soil porosity change and large deformation-strain theory,combining pore water movement equation?seepage continuity equation with equilibrium equation,building three-dimensional nonlinear consolidation equation applying to seepage consolidation of soft soil.The three-dimensional equation can be reduced into one-dimensional and two-dimensional situations,meanwhile,equation satisfies deformation compatibility conditions.(3)Using finite difference method to construct the explicit difference scheme,and using MATLAB to programme and solve.meanwhile,using three-dimensional partial differential equation having exact solution to verify the accuracy of difference scheme.(4)Selecting remoulded soil in Pearl River Delta as the research object,conduct 1-D consolidation tests.Contrasting 1-D consolidation tests with one-dimensional WG consolidation equation to verify the applicability of one-dimensional WG consolidation equation.meanwhile,Contrasting one-dimensional WG consolidation equation with Terzaghi one-dimensional consolidation theory to prove that one-dimensional WG consolidation equation is more suitable than Terzaghi one-dimensional consolidation theory for one-dimensional consolidation.(5)Selecting remoulded soil in Pearl River Delta as the research object,conduct 3-D consolidation tests.Contrasting 3-D consolidation tests with three-dimensional WG consolidation equation to verify the applicability of three-dimensional WG consolidation equation.Meanwhile,Contrasting 3-D Terzaghi-Rendulic consolidation theory?3-D Biot consolidation theory with three-dimensional WG consolidation equation to prove that 3-D WG consolidation equation is more suitable than 3-D Terzaghi-Rendulic consolidation theory and 3-D Biot consolidation theory for three-dimensional consolidation.Meanwhile,...