Pullout resistance of bearing reinforcement embedded in coarse-grained soils

Abstract

The bearing reinforcement was developed as a cost-effective earth reinforcement. It is composed of a longitudinal member and transverse members. The longitudinal member is made of a steel deformed bar and the transverse members are a set of equal angles. The present article studies the influence of soil properties (friction angle, grain size and gradation) and dimension and spacing of the transverse members on the pullout mechanism of the bearing reinforcement. The total pullout resistance is the sum of the pullout friction and the pullout bearing resistance. The tan δ/tan ϕ ratio, where δ is the friction angle between soils and the longitudinal member and ϕ is the internal friction angle of soil, is greater than unity because of the roughness and rigidity of the steel deformed bar. The bearing failure mechanism of a single transverse member is dependent upon the B/D50 value, where B is the leg length of the transverse member and D50 is the average grain size of the soil. The transverse member interference is dependent upon the ratio of spacing between transverse members and the leg length of transverse members, S/B. Based on a critical analysis of the test results, the pullout resistance equations of the bearing reinforcement with different dimensions and spacing between transverse members embedded in different coarse-grained soils are introduced and verified. These equations were developed based on a limit equilibrium analysis, which is a simple rational method for analyzing the internal stability of bearing reinforcement earth walls.