Optimal reinforcement arrangement for the stability of back-to-back MSE walls

As key characteristics of back-to-back MSE walls, the width to height ratio and reinforcement arrangement have important influences on the internal stability and failure modes. This paper presents a numerical study on the stability of back-to-back MSE walls with unconnected, connected, and separated reinforcements, to investigate the influence of reinforcement arrangements. Results indicate that the unconnected reinforcement arrangement is more effective in reducing facing displacements for narrower back-to-back MSE walls, while the connected reinforcement arrangement is more effective for wider back-to-back MSE walls. The unconnected reinforcement arrangement is suitable for relatively narrow back-to-back MSE walls to reduce the required reinforcement tensile strength. The width to height ratio has an important influence on the stability of back-to-back MSE walls with unconnected and separated reinforcements. However, the width to height ratio has a minor influence on the stability of back-to-back MSE walls with connected reinforcements. For the back-to-back MSE walls with unconnected reinforcements, the failure mode at small width to height ratios is reinforcement pullout failure, and transitions to external sliding as the width to height ratio increases. The failure modes are reinforcement connection failure and external sliding for back-to-back MSE walls with connected and separated reinforcements, respectively.