Pullout resistance mechanism of bearing reinforcement embedded in coarse-grained soils: Laboratory and field investigations

Abstract

Abstract The bearing reinforcement system has been invented as a cost-effective earth reinforcement and comprises a longitudinal member and a set of transverse members. This research was undertaken to determine the pullout resistance mechanism of bearing reinforcement embedded in coarse-grained soils. The effect of water content and gradation on the pullout mechanism of the bearing reinforcement was also investigated. The pullout resistance is the sum of pullout friction contributions from the longitudinal member, Pf,max and bearing resistance contributions from the transverse members, Pbn. The interface angle between the longitudinal member and backfill ( δ ) is dependent upon the water content and gradation. The δ / ϕ is a constant and can be taken as 1.51, where ϕ is the friction angle. Generalized Pbn predictive equations in terms of transverse member interference factor (F), inherent failure angle ( β ) and interlocking were verified based on laboratory pullout testing data. The field investigation on the bearing reinforcement earth (BRE) wall indicated that the measured Pbn of bearing reinforcement is higher than the predicted one as field reinforcements are subjected to transverse displacement and oblique pullout due to the deformation of backfill. From the critical analysis of laboratory and field investigations, proposed methods for predicting the pullout resistance of bearing reinforcement and for estimating final lateral movement of the BRE wall on the hard stratum are presented, which are useful for BRE wall design.