Research On The Consolidation Properties Of Saturated Remolded Clay Considering The Timeliness

The consolidation deformation of soil is always a function of stress level and time level,and the research on this topic has been the focus of geotechnical engineering all the time.Around this theme,this paper explores and studies the engineering properties and constitutive model of saturated remolded clay under K₀ state,by means of experiment and theory combined.Firstly,the paper summarizes the previous work,and studies the whole process of K₀ consolidation of saturated remolded clay by the means of laboratory tests.On this basis,rate-dependent empirical model and nonlinear rheological constitutive model are established to simulate and the describe the consolidation process.At the same time,the influence degree of the static earth pressure coefficient K₀ on the consolidation stress state is discussed,and the mathematical formula is established to quantitatively describe the effect of that.Finally,by means of statistical methods,the inference that the final deformation value of one-dimensional K₀ consolidation is unchanged and the adaptive shear stress q is the only influence factor are proved.In summary,the following major tasks are completed mainly in this paper:1?Experimental study on consolidation deformation of soil under K₀ condition.By using uniaxial unconfined continuous loading consolidation tests and triaxial K₀ consolidation tests of saturated remolded clay,the consolidation properties of saturated remolded clay under K₀ state and the rate-correlation reflected are investigated systematically.On the basis of a large number of experimental datas,the mechanism of K₀ consolidation is analyzed,drawing the conclusion that the relationship of stress-strain showed different response in the two stage of the experiment,to provide the basis for later subsection modeling from this.2?The influence of the timeliness of the static earth pressure coefficient K₀ on the consolidation state is discussed.Through analyzing the datas,it is found that there is a process value of K₀ larger than the final stable value,and it is of timeliness.A mathematical formula about the relationship of K₀-?_v-v is established,which is used to calculate the process value,and the solution of the maximum value of K₀ is further discussed.Meanwhile,the overall trend of the static earth pressure coefficient and loading rate are analyzed,and the u that reflects the approach degree of the value of K₀ and spherical stress state is defined,the mathematical formula about u and the loading rate is established with the help of u,so as to realize the quantitative description about timeliness of K₀ on the stress state.3?The inference that the final deformation value of saturated remolded clay under one-dimensional K₀ consolidation is unchanged is proved.The final deformation value of one-dimensional K₀ consolidation is ratiocinated through the relation between strain and time in constant loading consolidation period,and with the aid of the statistical method,that the final deformation of saturated remolded clay with the same initial conditions under certain stress level is unchanged is proved.4?The only relationship between the adaptive shear stress q and the strain is proved.By analyzing q-?_v curve under the action of the different loading rate,loading time,loading rate,stress path and stress history,it is found that q-?_v curve is continuous at different loading stages of tests,and all datas are concentrated in a smaller range of bandwidth,in addition,the variables introduced can not be normalized,and reflecte the unique relationship.With the help of statistical methods,it is proved that the adaptive shear stress q is the only factor for the deformation of the saturated remolded clay under conditions of one-dimensional consolidation.5?The rate-dependent models of time-explicit and time-implicit are established according to the loading and constant consolidation of this test.By analyzing the physical meaning of the parameters in the model,and comparing and analyzing all models with the measured datas,it is concluded that the ?_v-v-t rate-dependent model established by the adaptive shear stress q which is as an intermediate variable is the optimal empirical model,which is high accuracy and good applicability,and is the first model type of rate-dependent empirical model established in this paper.6?The apparent consolidation resistance is defined,and the time-implicit ?_v-?_v-??? rate-dependent empirical model is established by means of this value in the loading section.Based on the analysis of the data of the uniaxial unconfined continuous loading consolidation test,the apparent consolidation resistance is defined,and its effect of strain-rate is analyzed,and the time-implicit rate-dependent empirical model is established by means of it as an intermediate variable,and the physical meaning of the model parameters is discussed.7?Based on the unity of consolidation and rheology,the nonlinear rheological model of semi-empirical and semi-element is established by using the idea of strain separated.the part of linear viscoelastic and linear viscoplastic is described with element model,and the part of nonlinear viscoplastic is modified by the nonlinear power function empirical formula,and the parameters of the model are determined by using the method of parameter regression with the help of User-Defined Functions of Origin software.This model is compared with the rate-dependent empirical model established in this paper.The parameters of the two models are established to link by using Taylor series and polynomial regression,and the rationality and practicability are verified by each other.