Experimental Study On Dynamic Properties Of Saturated Soilt In Zhengzhou Area

Silt is a special soil which is made up of sand particle,silt particle and clay particle.The property of the silty soil is mainly characteristics of silt.The engineering properties is between sand engineering and clay engineering which is a great difference between sand and clay for small permeability coefficient,low plasticity,capillary growth,capillary water rise,poor water stability and frozen sensitive.Silt will be caking when it is wet and dust in the dry and produce plastic deformation under load.When the pore water pressure accumulates to a certain extent,soil particles will produce suspension phenomenon and liquefaction phenomenon,causing great losses to people's life and production,such as plastic deformation and liquefaction of the silt subgrate under traffic load,slope stability under dynamic load,liquefaction and collapse and severe deformation of silt foundation and slope under earthquake or explosion or pulse force or pressure waves and so on.It is of practical significance to study the development law of silt under cyclic load.According to the Zhengzhou Huiji district underground silt,this paper studies dynamic strength characteristics,development law,pore water pressure and dynamic deformation characteristics of the saturated silt under cyclic load pressure under undrained.The specific contents are as follows:(1)Under the condition of equal consolidation,in this paper,we study the confining pressure on the dynamic shear strength and failure vibration time curve,confining pressure on the dynamic shear strength and failure vibration time normalization.The development rules of shear strength of soil under different acting forces are defined,and the development stages of shear strength of soil under different failure criteria are known.(2)On the basis of previous studies,the relationship between pore water pressure and the change of vibration was analyzed,and the development process and law of the vibration pore water pressure of Zhengzhou re-saturated silt were defined.Through the analysis of different types of dynamic pore water pressure development model,the development law of dynamic pore water pressure of saturated silt and the difference between dynamic pore water pressure of saturated were analyzed.By selecting different dynamic pore pressure development model and using the test data fitting analysis,the exponential and power function,polynomial type pore water pressure development model of silt dynamic pore water were compared,so as to clarify the dynamic pore water pressure development model in the form of the silt,and to establish a regression equation for the development law of pore water pressure.By fitting,the model parameters were determined,and the influnce of the model parameters on the curve of the development of pore water pressure was determined.(3)The research different failure criterion,different confining pressure under the dynamic shear strain,dynamic shear modulus and damping ratio of the relationship,dynamic shear strain on dynamic shear modulus and damping ratio of the law of development and confining pressure on the dynamic shear modulus and damping ratio of the influence,the maximum dynamic shear modulus on the dynamic shear modulus normalized degree,dynamic stress on the dynamic shear strain and damping ratio influence the relationship were cleared.(4)Through fitting analysis dynamic shear strain and dynamic shear modulus curves,dynamic shear modulus ratio and damping ratio curve,a description can be found out to better describe the relationship between the two expression with the H-D model,Davidenkov model,Chen Guoxing expression.