Study On Subgrade Stability And Mechanisms Of Deformation Of Slope Soft Foundation

With the development of highway engineering and the increase of high-grade highways,more highways have been constructed in the slope soft foundation in mountainous areaswhere the geographic and geomorphic conditions are special and complicated. There areengineering diseases such as slip and differential deformation in subgrade of slope softfoundation, which often result in the damage of pavement structure, the pavement crack andthe decrease of riding comfort. In order to guarantee the stability of subgrede, the structuralintegrity and the good service level of the pavement, it is necessary to strengthen the study onsubgrade of slope soft foundation.Combining with the highway engineering construction in mountainous areas, this papersummarizes the main types of subgrade disease, proposes the condition types of the subgradeof slope soft foundation，builds numerical models，analyzes the stability and the settlementdeformation characteristics of the subgrade by using the method of finite element strengthreduction and the finite element settlement consolidation theory.View the structure layer geometry parameters of the foundation and subgrade, soilmechanics parameters, groundwater and rainfall condition as the main factors which influencethe stability of subgrade. Use the method of ABAQUS finite element strength reduction toanalyze the situation that various factors have influence on the stability by which thesensitivity of the various factors will be obtained. Regression analysis method has been usedto analyze the calculation results of stability by which stability formula of the variouscondition types of the subgrade has been established.Regard the structure layer geometry parameters of the foundation and subgrade, soilmechanics parameters as the main factors which influence the deformation characteristics ofsubgrade. Use the finite element settlement consolidation theory to analyze the situation thatvarious factors have influence on deformation characteristics by which the settlementdeformation characteristics of the subgrade will be obtained.The stability and deformation characteristics of subgrade change with various specificfactors, according to the corresponding analysis results, the subgrade design and treatmentprinciple of the slope wet soft foundation will been put forward.