MSE walls design in seismic regions

Reinforced soil walls perform relatively well under seismic action due to their flexibility. The current design practices consider the seismic action either by an analytical approach (Mononobe-Okabe formula) or by a pseudostatic analysis (geotechnical software). In both cases the seismic action is considered as a constant force acting in the horizontal direction outwards of the MSE wall. A vertical seismic force component may be added, which is generally a fraction of the horizontal one. Besides the simplified approaches, the seismic load can be considered in a more complex way by using accelerograms in FEM software. This method requires seismic records of the region as well as detailed geotechnical parameters for the foundation and backfill. The above mentioned dynamic approaches are discussed in the article along with their advantages and limitations. Some seismic recommendations from design codes are also included. Lastly, it is explained why the choice of the dynamic analysis method depends on the complexity of the situation.