Finite Element Analysis On Drainage Consolidation Of Saturated Soft Soil Foundation Coupled Temperature Field

With the emergence of engineering problems such as thermal consolidation of soft soil foundation, geothermal development, nuclear waste disposal and design for directly buried heating pipeline, thermal consolidation problems of soil has become an important topic in the field of geotechnical engineering.In this paper, the experimental and theoretical results of thermal consolidation are summarized, and the basic principle of thermal consolidation is expounded, and on this basis, the numerical simulation of thermal consolidation is carried out.Firstly, this paper introduces the basic theory of thermodynamics and the effect of temperature on the engineering properties of saturated soil.Among this, the temperature will significantly reduce the viscosity coefficient of saturated soil pore water, resulting in the variation of permeability coefficient in the consolidation process, which should not be ignored. On the basis of this, combining traditional consolidation theory and percolation theory, the governing equation of coupling temperature consolidation is described.Then, the additional pore pressure generated by the heating of the one-dimensional saturated soil is solved.Relying on multi-physics coupling analysis software COMSOL Multiphysics, the numerical calculation of one dimensional foundation and sand well foundation consolidation is carried out.This numerical calculation includes three conditions:non-coupling temperature (NT),coupling temperature not to consider the effect of temperature on viscosity coefficient of pore water (CT), coupling temperature considering the effect of temperature on the viscosity coefficient of pore water (CTV). Through the comparison of stress and strain, temperature conduction, the dissipation of pore pressure and the degree of consolidation to analyze the basic law of thermal consolidation.Finally, the sand-well foundation is converted to sand-wall ground. A numerical simulation about synthesized drainage concretion method of preliminary press by accumulated Load and by temperature load is carried out in COMSOL Multiphysics platform.The numerical results of the coupling temperature are compared with the results of the non-coupling temperature.By comparing the settlement rate and the dissipation rule of excess pore water pressure, it is proved that thermal consolidation in soft soil reinforcement is of engineering application value.