Nonliner Finite Element Analysis On The Consolidation Of Saturated Soft Soil Foundation With Surcharge Preloading

As an economical and effective method in the consolidation of soil, surcharge preloading is being more and more widely used in capital construction, and its scope of application also relates to more and more saturated soft soil reinforcement. By now, there is a lot of successful practical experience in consolidation of saturated soft soil with surcharge preloading method, but the theory study still significantly lags the engineering practice at all times. At present, the designs of surcharge preloading are mainly depended on the experience and test.In this paper, the constitutive model of soil was discussed. Based on different yield criterion, the elastoplastic constitutive matrix and large deformation constitutive equation of soil were obtained for numerical analysis. In order to further promote the development of theory and applied research on surcharge preloading, based on comprehensive analysis of relevant information and research data of domestic and foreign saturated soft soil foundation reinforcement with surcharge preloading method, taking into account the solid-fluid interaction properties , material nonlinearity and geometric nonlinearity in consolidation of saturated soft soil with surcharge preloading, and using elastic-plastic model based on Biot consolidation theory, dynamic equilibrium equation on finite element was educed. Model was set up in the use of Abaqus to calculate the soil's settlement, displacement and pore water pressure of every moment in the surcharge preloading course. The data was disposed to photo by software of Excel to analyze the complex micro-mechanic behavior and macro-deformation characteristics of saturated soft soil foundation under multi-level loading. Through contrast between the calculated value and measured value, and then explore numerical simulation method of surcharge preloading and field test results to study the application of saturated soft soil dealing with the plastic drainage plate preloading method and the possibility of construction parameter. Such as: determine setting the depth of plastic drainage plate according to pore water pressure dissipation in the role of plastic drainage plate; determine the effective reinforcement depth of soil according to the vertical deformation along the depth direction; determine the scope of the reinforcement in accordance with horizontal displacement, will be proposed for the design of surcharge preloading and evaluation of reinforcement effect to provide a theory basis.