Papers by Author: Jing Yu Chen

Abstract: Generally the shear strength of saturated soils has been predicted by the Mohr-Coulomb theory. However, field data accumulated in the past have evidently shown that saturated conditions are actually never reached in arid and semi-arid regions. An analytical model is developed to predict shear strength of an unsaturated soil with respect with matric suction. The formulation takes into account the influence of the mean stress on soil water retention curves. The results of the model developed for predicting the shear strength are compared with available experimental results. The good agreement between the estimates and the experimental data indicates that the proposed equation is promising and reliable for estimating preliminary unsaturated shear strength parameters.

Abstract: The shear strength value of unsaturated loess is required in the design in geotechnical engineering in the North and the North West of China. In 2004, a new method, that is the fractal model theory, was proposed for determining the shear strength of unsaturated soil. Based upon the fractal model theory, the surface fractal dimension DS and the air entry value of two unsaturated loess samples are obtained from their soil-water characteristic curve (SWCC), the shear strength contribution due to matric suction of the two loess samples is determined, a new approach for determination of the shear strength of unsaturated loess with its SWCC is presented. By comparing results of this paper with those of the laboratory tests, the relationship between the SWCC and the shear strength of unsaturated loess is discussed and the validity of the fractal model theory for unsaturated loess is explained.