Seismic response analysis of tiered back-to-back mechanically stabilized earth(MSE) walls subjected to different earthquake loadings

Abstract

As a newly developed embankment type, back-to-back mechanically stabilized earth(MSE) walls have been increasingly used for the construction of roads and embankments in recent years due to their great earthquake-resistant performance, and a large number of these walls are built in tiered configurations to meet the needs of construction. However, the available literature on the seismic response of tiered back-to-back MSE walls is very limited, and existing design guidelines do not provide a clear earthquake-resistant design approach for these walls. Based on previous analysis, a finite-element procedure was used to simulate the seismic response of two-tiered back-to-back MSE walls under earthquake loading. In this study, the backfill soil was simulated using the hardening soil model with small-strain stiffness (HSS model), and the block-block, and soil-block interactions under earthquake loading were considered. To gain insight into the seismic behavior of reinforced soil structures, 18 ground motion records at class I sites around the world were scaled to a peak acceleration of 0.4g and employed as the excitation motions, which had very different frequency characteristics and earthquake intensities. The results showed that an appropriate tier offset decreased the residual deformations and effectively increased the seismic stability of the walls; the deformation mode for two-tiered back-to-back MSE walls subject to seismic loading was mainly influenced by the frequency characteristics of the input ground motion as well as the fundamental frequency of these walls, and the change in the distribution of structure mass and stiffness due to the change in tier offset modified the structural vibration mode to a certain extent. It was also found that there existed good correlations between the maximum reinforcement load and the Arias intensity(IAinput), the duration Td, the tier off-set C, the predominant frequency fi of the input ground motion, and the natural resonant frequency check spelling of the wall, which identified the influence of these factors on the earthquake-resistant performance of back-to-back MSE walls from one side. The research results can provide reference for practical engineering design.

Keywords

• tiered back-to-back mechanically stabilized earth(mse) walls
• earthquake-resistant performance
• finite element analysis
• tier offset
• reinforcement load
• seismic response