Pullout capacity at the bamboo reinforcement-compacted earth interface

Compacted earth materials are still popularly used to construct wall structures in rural areas. To address the drawbacks of poor ductility and low shear resistance in compacted earth walls, bamboo, with excellent tensile properties, is introduced as a reinforcement material. Pullout tests on bamboo-reinforced compacted earth were conducted in this study, in which the effects of four parameters of normal stress, bamboo reinforcement form (without node, with node, and with curved anchor head), bamboo reinforcement width, and embedment length were investigated. Results demonstrated that the presence of chemical bonding force, frictional resistance, and end resistance at the interface between bamboo reinforcement and compacted earth could contribute to the mobilized pullout capacity. The parameter impact on pullout resistance can be ranked as follows: embedment length > bamboo reinforcement width > normal stress > bamboo reinforcement structure. Based on the Mohr strength theory, a model for estimating the ultimate tensile capacity of bamboo-reinforced compacted earth was derived. The pullout capacities obtained from theoretical calculations and experimental measurements differed from 0.73% to 14.60%, mostly failing below 10%. The proposed calculation model enabled the estimation of load-bearing capacity at the bamboo reinforcement-compacted earth interface, providing valuable guidance for wall design.