Field test and semi-analytical simulation of unsaturated road subgrade in various water content subjected to a heavy duty truck

• DOI: 10.1016/j.soildyn.2021.106667
• Publication Date: 2021-03-25T11:07:48Z
• Authors: Zheng Lu; Chuxuan Tang; Yahui Duan; Ran Fang; Hailin Yao; Shuan Guo
• Keywords: Heavy duty

Abstract Field test is the most direct and essential way to evaluate subgrade dynamic responses, which is of great importance in designing and ensuring long-term subgrade performance. Many researchers have performed field tests considering the dynamic responses of subgrade. However, in the previous tests, the water content of the soil, which decides the mechanical properties of unsaturated soil, is rarely considered. In this paper, the dynamic responses of subgrade in different saturations are investigated by both field tests and analytical simulations. The vertical stress and acceleration tested in the field under different water contents, depths, truck speeds, and axle weights are presented. The result shows that as the water content in the subgrade rises, vertical stress variation is insignificant, while the amplitude of acceleration increases. According to the distribution of water content of the subgrade, a double-layer unsaturated soil model was proposed using the stiffness matrix method. The comparison between field test and simulation results shows that the agreement is good.