Experimental Investigation on Mechanical Behavior of a Hexagonal-Wire-Reinforced Granular Soil

Abstract

The use of hexagonal wire reinforcements to mechanically stabilize the earth works is a recent technique in reinforced soil construction. However, few studies have investigated the mechanical behavior of this kind of reinforced granular soil through large-scale triaxial tests. In this paper, a series of large-scale laboratory unconsolidated undrained triaxial tests were performed on specimens of hexagonal wire reinforced red-sandstone granular soil, and the results were compared to the unreinforced samples to evaluate how the number of hexagonal wire reinforcing layers, water content and degree of compaction affect the measured strength and deformation characteristics of red-sandstone granular soil. The behaviors of hexagonal wire reinforced red-sandstone granular soil were discussed in terms of stress–strain relationship, peak stress strength characteristics, critical strength properties, reinforcement strength ratio coefficient and reinforced mechanism analysis. The failure shapes and the two reinforcement–soil interaction mechanisms of the specimens were revealed. The experimental results show that hexagonal wire mesh reinforcement has an obvious improvement in both strength and deformation of red-sandstone coarse-grained soil, especially under lower confining pressure. In addition, the hexagonal wire mesh reinforcements give an apparent cohesion force to the soil, whereas displaying only a slight increase in the frictional angle. The vertical separation of 20 cm between the reinforcing layers is suitable, and it is suggested that the water content of the red-sandstone granular soil fillings should not exceed the optimum water content and the compaction should not be less than 90%.