Generalized pullout predictive equations of bearing reinforcement for cohesive-frictional soils at various water contents and fines contents

Bearing reinforcement, which is composed of a longitudinal member (steel deformed bar) and transverse (bearing) members (a set of equal angle steel), has been established as an effective earth reinforcement material. The usage of locally available soils as backfill material is particularly cost effective for construction sites where there is a lack of available quality friction (coarse-grained) materials. The pullout resistance of the bearing reinforcement comprises both friction and bearing components. In this research study, the test results of residual red clay and previously published test results were analyzed to develop generalized equations for predicting pullout resistance of bearing reinforcement when embedded in compacted cohesive-friction soils, with various water contents and fines contents. The pullout friction resistance can be calculated by utilizing the soil-reinforcement interaction factor,  , which reduced linearly with fines content (F). The bearing pullout resistance is controlled in the failure plane (  ) during the pullout of a single transverse member and. The water content to optimum water content ratio, w/wOWC and F are found to be dominant factors controlling both w/wOWC and IF. The reduced from  2 to  3 with the increase in w/wOWC and F. Equations for predicting  , in terms of the fines content and water content, were proposed in this paper. In addition, generalized pullout resistance equations in terms of normal stress, shear strength parameters, fines content and water content were also developed. The developed equations are innovative and useful for the internal stability analysis of bearing reinforcement earth walls during and post-construction