Experimental Study on Mechanical Properties of Reinforced Soil Interface under Dry-Wet Cycle

Abstract

The reinforced soil-retaining wall has been widely used in coastal projects, and the dry-wet cycles influence the mechanical properties of the reinforced soil interface. This study conducts macro-micro tests and selects four different water content samples of reinforced soil with five types of overburden pressure conditions and three sets of dry-wet cycles, with a total of 60 working conditions. The pull-out test was used to study the mechanical properties of the reinforced soil interface. The scanning electron microscope was used to observe the microscopic characterization of the particles under different working conditions. Through the analysis of the experimental results, we can draw the conclusion as follows. (1) The friction coefficient of the reinforced soil interface decreases with the increase of the number of dry and wet cycles. (2) The apparent cohesion of soil-reinforcement interface decreases with the increase of the number of dry-wet cycles. After 30 dry-wet cycles, the apparent cohesion of the soil-reinforcement interface with water content of 14% is the maximum 5.91 kPa. The variation law of cohesion derived from microstructure analysis conforms to the laws and conclusions obtained by the experiment. (3) The shear stress of the reinforced soil is linearly related to the normal stress, which is in accordance with Coulomb’s law.