Influence of width to height ratios on the dynamic response of back-to-back MSE walls

As a key parameter of the back-to-back mechanical stabilized earth (MSE) walls, the width to height ratio has an important influence on the dynamic response. This paper presents shaking table tests on two back-to-back MSE walls to investigate the influence of width to height ratio on the acceleration response and deformation modes. The two reduced-scale models had the same height of H = 1 m, but with different widths of W = 1.6 m and 1.1 m. The models were designed according to similitude relationships, and were constructed using modular facing blocks, biaxial geogrid and poorly graded sand. The test results demonstrate that the width to height ratio has a negligible influence on the acceleration response for small input motions. As the peak acceleration of input motion increases, the influence of the width to height ratio on the acceleration response becomes more pronounced, and the amplification effects of the wide back-to-back MSE walls are larger than those of the narrow back-to-back MSE walls. For small input motions, the predominant deformation modes of the two models are rotation. The deformation modes of back-to-back MSE walls with wide and narrow MSE walls are bulging and rotation for stronger input motions, respectively.