Influence of facing conditions on the dynamic response of back-to-back MSE walls

Abstract

This paper presents an experimental study of shaking table tests on two back-to-back mechanical stabilized earth (MSE) walls with full-height rigid facing and modular block facing, respectively, to investigate the influence of facing conditions on the dynamic response. The reduced-scale MSE wall models were designed according to the similitude relationships considering model geometry, reinforcement stiffness, and input motions. The back-to-back MSE wall models were constructed using poorly graded backfill soil and geogrid reinforcement, and then were excited using a series of sinusoidal input motions with increasing acceleration. The threshold acceleration where acceleration amplification factors suddenly increase significantly for the back-to-back MSE walls with modular block facing is smaller than that for the full-height rigid facing walls. The full-height rigid facing walls have smaller facing displacements than those for the modular block facing walls under the same motions and can resist stronger earthquakes in terms of facing displacements. For the back-to-back MSE walls with full-height rigid facing, incremental reinforcement tensile strains increase significantly with increasing input acceleration, while the reinforcement strains of the modular block walls are similar under different input motions for the conditions investigated.