An Experimental Study on Creep Characteristics of Q2 Loess in the Guanzhong Area of China
Based on the triaxial creep test on Q2 loess in the Guanzhong area of China, the strain-time curve and the stress-strain curve of Q2 loess with different confining pressures and moisture contents are thus obtained. Analysis of the experimental curves shows: confining pressure and moisture content have a rather great impact on the creep characteristics of loess Q2 in the Guanzhong area. Specifically, the creep deformation amount and moisture content are positively correlated under the same confining pressure, while with the same moisture content it has a negative correlation with confining pressure. Through a further fitting analysis of experimental data on failure stress of creep and confining pressure plus water content, a positive linear correlation between failure stress of creep and confining pressure can be obtained, and there is a negative logarithm variation between failure stress of creep and moisture content. Based on the above analysis, by improving the nature and structure of parameters in the commonly-used five-element model (HKK), the seven-element nonlinear creep model able to describe the accelerated creep of Q2 loess can then be obtained, and furthermore, the fitting identification on the model by the use of the experimental data attributes eventually to the expected results.