Study On Deformation Characteristics And Engineering Applications Of Loess Considering Time Effect

With the acceleration and development of western China,the relevant characteristics of loess deformation are of great significance to the project.At present,there are few studies on the time effect of loess deformation Based on this,this paper takes Xi'an loess as the research object to study the time effect of loess deformation under partial stress.By triaxial test of remolded loess,The characteristics of different confining pressure,moisture content and dry density on the loess deformation with time were studied.The results show that under partial stress axial strain-time curve of loess shows a linear deformation stage,nonlinear deformation stage and stable deformation stage.In the case of low confining pressure and large partial stress,the time required for the loess deformation to reach the stable stage is longer;In the case of low confining pressure and low partial stress,the time required for the loess deformation to reach the stabilization stage is shorter.And in the high confining pressure,regardless of the partial stress is large or small,loess deformation in a very short period of time to achieve stability.When the water content is high,the axial strain in the loess under different partial stress is higher than that in the low water content.When the partial stress is low,the axial strain of the loess is in the stable deformation stage,and the axial strain of the loess is in the unstable deformation stage with the increase of the partial stress.The time effect of analyzing the stress-strain relationship of loess can be obtained It is also shows that the stress-response time curve of loess has obvious nonlinearity,with the increase of time,the curve family is getting closer to the strain axis.the stress-strain-time curve of loess under different confining pressure,water content and dry density has some differences at different time nodes.The Singh-Mitchell model and the Mesri model and the hyperbolic model were used to fit the experimental data,the results show that the loess specimen in this area can be used to simulate the loess deformation law when the hyperbolic model is fitted,and this model has the advantages of easy access to parameters,good fitting degree and so on.Using GeoStudio analysis software,to establish the function of the deformation modulus of the soil with time under the hyperbolic model of the experiment.And compared with the experimental data analysis.The results shows that:under the effect of partial stress,the vertical strain of the foundation pit has obvious time effect,and temporal effect curve of stress strain.the hypergraph model can be used to fit the test data,which verifies the rationality and correctness of the model.