| In recent years,one belt,one road strategy has been applied to the development of the Western China.The demand for construction land in the Loess Plateau is increasing.The high fill works in the upper Loess Plateau are also increasing.Especially considering the influence of the water environment,the post construction settlement of the high fill foundation is a particular concern of the engineering field.Based on the summary of the research status of post construction settlement of high fill foundation under the influence of water environment,combined with the indoor SWCC,shear strength,uniaxial creep test,and the finite element software Geo-Studio,this paper analyzes the post construction settlement law.The main work is as follows:(1)Taking Q3 loess as the research object,the matric suction and its related permeability coefficient of undisturbed loess and remolded loess under different states were obtained by filter paper test,and the relevant parameters were obtained by VG model fitting,which provided parameter input for numerical simulation.In order to analyze the relationship between shear strength and matric suction,the matric suction and its related permeability coefficient of undisturbed loess and remolded loess under different moisture content were obtained by shear strength test The cohesion and internal friction angle of undisturbed loess and remolded loess under different compactness are analyzed,and the physical and mechanical properties of unsaturated Q3 loess are further analyzed.(2)Based on the uniaxial creep tests of undisturbed Q3 loess and compacted remolded Q3 loess,the strain time curves of Q3 loess under different moisture content,compaction degree and axial load are established.Finally,the fitting relationship between Q3 loess and creep strain under different moisture content,compaction degree and axial load is obtained,which provides reference(2)Based on the uniaxial creep tests of undisturbed Q3 loess and compacted remolded Q3 loess,the strain time curves of Q3 loess under different moisture content,compaction degree and axial load are established.Finally,the fitting relationship between Q3 loess and creep strain under different moisture content,compaction degree and axial load is obtained,which provides reference for numerical simulation of post construction settlement It can be used as a reference for related formulas.In order to further analyze the creep mechanism of loess,combined with burgers and M-B element model,the curve relationship between its parameters and compactness,moisture content and axial load is analyzed,and the advantages and disadvantages of each model are compared,and the element model combination suitable for the uniaxial creep test of loess is obtained.(3)Through the uniaxial creep tests,the model formulas of undisturbed Q3 loess and compacted remolded Q3 loess under different compactness under stable creep strain,moisture content and axial load are obtained,which can provide reference for numerical simulation of post construction wetting creep settlement(4)Firstly,the disaster of post construction settlement of loess high fill foundation induced by rainfall infiltration and groundwater level rise is analyzed.In order to solve the problem of poor prediction of post construction wetting creep of high fill foundation under the influence of rainfall infiltration and groundwater level rise,the relevant parameters and the model formula of creep strain,moisture content and load in stable stage are obtained through laboratory test analysis,Combined with the numerical software Geo-Studio,a model is established to analyze the variation law of humidifying water field and the law of post construction humidifying creep settlement under different compactness of fill,different rainfall conditions(light rain,moderate rain,heavy rain,rainstorm)of high fill foundation and different elevation of groundwater level(3m,5m,7m,10m,15m,20m,30m)Finally,the relationship between rainfall and water level rise provides the basis for the future related engineering problems. |
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