Macroscopic and microscopic test study on dynamic characteristics of undisturbed and remolded lacustrine soft clay
In order to compare the difference between the dynamic characteristics of undisturbed and remolded lacustrine soft clay near Hengshui Lake,this paper uses GZZ-50B resonance column instrument to carry out dynamic characteristics tests on the undisturbed and remolded lacustrine soft clay respectively,adopts Davidenkov constitutive model to fit the dynamic characteristics parameters obtained by the tests,and draws the relationship curves of G-γ,λ-γ and G/Gmax-γ,and the obtained dynamic characteristic statistical values were compared with the recommended values given by other scholars.The microstructure before and after the resonance column test is measured by SEM electron microscopy,and the change regularity of microstructure parameters is analyzed.The results show that when the consolidation confining pressure is the same,the G-γ curve of the undisturbed lacustrine soft clay is greater than that of the remolded soil,and the λ-γ curve of the undisturbed soil is always smaller than the remodeled soil.When the dynamic shear strain is large,the dynamic shear modulus G of the undisturbed soil drops sharply and approaches the remolded soil.The relative difference of the Gmax,the different of G/Gmax-γ and λ-γ fitting curve between the undisturbed and the remolded soil decreases with the increase of the consolidation confining pressure.By comparing with the research results of other scholars,it was found that sedimentary environment was not the determining factor of soil dynamic characteristics.The dynamic characteristics of soft clay in the same sedimentary environment but different regions would also be different.Through quantitative analysis of the microstructure parameters,it is found that with the increase of consolidation confining pressure,the average area and the average maximum diameter of the undisturbed soil particles and pores are decreased,but the difference is not obvious in the remolded soil,and the relative difference of the microstructure parameters is positively correlated with the relative difference of the maximum dynamic shear modulus Gmax.After the resonance column test,the large and medium particles and pores of the undisturbed lacustrine soft clay are transformed into small and micro particles and pores,the large sheet structure and aggregate structure are reduced,and the microstructure parameters of undisturbed soil are close to those of remolded soil,which explains the macroscopic soil dynamics characteristics from a microscopic perspective.
万方数据
维普
