Experimental Study On Dynamic Shear Modulus And Damping Ratio Of Hebei Loess

As a typical special soil,loess is widely distributed in our country,and it has obvious regional distribution characteristics.With the increase of construction projects and the deeper of the seismic study work,the research on the dynamic characteristics of the loess area has caused people's attention increasingly.Therefore,it is of great significance to contact dynamic test of loess in Hebei and get the dynamic characteristic parameters to analyze the change law of the different conditions.In this paper,the stress and strain data and damping ratio of different water content,dry density,confining pressure and frequency are obtained by using the three axis test of Hebei loess,and then the dynamic stress-strain relationship curve and the dynamic shear modulus and damping ratio versus strain curve are obtained to analyze the influence characteristic of the factors on the dynamic stress strain relation,dynamic shear modulus and damping ratio.The experimental results show that the water content,dry density and confining pressure have significant influence on the dynamic stress and strain relationship and dynamic shear modulus while the influence of frequency is not obvious;water content and dry density have significant influence on damping ratio while the influence of confining pressure and frequency is not obvious.According to the test results,the maximum dynamic shear modulus is obtained,and the influence of the factors is analyzed to obtain the calculation formula of the variables of water content,dry density and confining pressure by fitting.The formula for the variation of damping ratio with the dynamic shear strain is established,in which the parameters are related to the moisture content and dry density.Finally,the fitting formula of the maximum damping ratio with the water content and dry density is given.The results of this research can provide reference and basis for the seismic design and dynamic analysis of Engineering in Hebei loess area,and provide the data for the related research of loess,enriching loess dynamics research database.