Experimental Study And Numerical Simulation Of Mechanical Properties Of Solidified Silt Soil Under Dynamic

The disposal and resource utilization of dredged silt soil is one of the current hot research topics in environmental geotechnical soil,which is of great significance to environmental governance and resource protection.The composition of the river dredged silt soil is complex and diverse,and the engineering properties are poor.It is often used at home and abroad to solidify the resources to utilize it.However,the mechanical properties of the solidified silt soil are obviously different,which is difficult to achieve widespread promotion.In order to ascertain the mechanical properties of solidified silt soil under cyclic loading and freeze-thaw cycles,this paper uses cement,lime and fly ash to improve the mechanical properties of the silt soil.Conduct research on migration and strength characteristics and deformation and stability of solidified soil embankments.The main work and conclusions of this article are as follows:?1?The basic physical and mechanical indexes of dredged silt soil are measured by indoor geotechnical test,and the moisture content of dredged silt soil is reduced to the specified value by the preloading method.The cement content was determined to be 6%,the lime content was 9%,and the fly ash content was 5%,10%,15%,and 20%,respectively,so as to jointly solidify the sludge.?2?The GDS dynamic triaxial apparatus was used to measure the strength and deformation characteristics of solidified silt under different curing agent dosages and consolidated confining pressures.The research results show that the dynamic stress-dynamic strain curve of solidified silt soil is strain hardening type.Under the action of cyclic load,the soil particles are squeezed and move to a more stable position.The failure form of the soil body is compression failure.The higher the amount,the greater the breaking strength.The initial dynamic elastic modulus of the solidified silt soil increases with the increase of the curing agent content and the surrounding pressure.?3?Perform freeze-thaw cycle tests on solidified silt soil to study the moisture migration and strength characteristics of the solidified soil under different freeze-thaw cycles,and analyze the failure strength,stress-strain relationship,and shear strength indicators of the solidified soil under different amounts of curing agent.Affected by the number of freeze-thaw cycles.The results show that:under the action of freeze-thaw cycles,the moisture in the solidified silt soil migrates,causing the internal moisture to migrate to the frozen front,and the higher the amount of the curing agent,the smaller the amount of water change;the damage strength and viscosity of the solidified silt soil The cohesion decreases with the number of freeze-thaw cycles,but the change gradually decreases.?4?Flac^3D was used to analyze the settlement and lateral displacement of the embankment during the construction process and the deformation law of the solidified silt subgrade after different freeze-thaw cycles.The simulation results show that the settlement and lateral displacement of the solidified dredged silt filled roadbed after filling are small,which meets the quality engineering requirements.Freezing and thawing will affect the deterioration of the roadbed.The vertical settlement of the roadbed increases first and then decreases with the increase of the number of freeze-thaw cycles.Finally,the deformation of the roadbed gradually stabilizes,which basically agrees with the test results.