Effect of reinforcement arrangement on dynamic behaviour of back-to-back mechanically stabilised earth walls

Reduced-scale shaking table tests were performed on steel-strip back-to-back mechanically stabilised earth (MSE) wall models to evaluate the effect of the overlap length of the reinforcements (L-R) and the connection arrangement of the opposing walls on the distribution of tensile force along the reinforcements and the propagation mechanism of the shear bands. The reinforcement elements were fully instrumented and particle image velocimetry (PIV) was utilised to identify the shear zones in the body of the models. On the basis of the PIV results, the combination of a concave surface and an inclined plane was determined to be the failure surface in the models. It was concluded that connecting two opposing walls can prevent the formation of a failure wedge in a back-to-back MSE wall (BBMSEW). It was observed that the geometry of the failure surface in the BBMSEWs was not affected by a change in L-R, but depended on the connection arrangement of the walls. It was found that, although the use of overlapping reinforcement instead of the direct connection of two walls caused further development of shear bands, it could be a good solution in reducing the mobilised reinforcement forces in BBMSEWs.