Experimental Study of Loess Structural Strength and Resistance Coefficient

Abstract

The paper proposes a calculation method of soil particles framework structural strength, and provides a new parameter, defined as resistance coefficient, which can quantitatively describe the relationship between active stress and passive stress on soil particles framework. The research of the impact of water content, binding materials content and dry density on structural strength and resistance coefficient is conducted under confined compression test with undisturbed and man-made cement structural loess from Yangling. The research shows that structural strength of loess particles framework increases with the increasing of deformation, and with the same deformation, the structural strength of loess particles framework increases with the increasing of water content ; loess particles framework is sensitive to the weakening role of water. The resistance coefficient is smaller and more instability with the increasing of deformation under high water content conditions. The binding material has significant effect on structural strength and resistance coefficient. Moderate cement mixed with loess particles framework cannot only improve the structural strength but also decrease the sensitivity of loess particles framework to the weakening role of water. By controlling the binding material content, water content and dry density, the structural strength and resistance coefficient of man-made cement structural loess will be the same as the undisturbed loess. Increasing dry density can make the structural strength of loess particles framework higher, but the value and the stability of resistance coefficient of loess particles framework structure with high dry density is lower than that in the initial dry density.