Performance of marginal fillers reinforced with geosynthetics under static loads

Geosynthetic reinforced soil retaining walls (GRS-RW) have been widely applied worldwide since the late 1960s and in our country since the 1980s. GRS-RW is preferred highly due to its economic features, rapid production, flexibility to tolerate large displacements and loads that may occur under static and dynamic loads, and aesthetic appearance. Generally, granular fills are used for that kind of walls due to the drainage properties of the soil. In this study, the performance of geosynthetic reinforced soil retaining walls with marginal fills under static loads was investigated as an alternative to granular fills by using the finite element software, Plaxis 2D. First, the results obtained from the well-instrumented full-scale reinforced soil wall test by Yang et al. 2012 was used for the validation. For that purpose, finite element analysis and analytical method results were compared with the structure adapted from the literature. As it is seen in the validation analysis, the experimental results of full-scale structures agree with the analysis results. After that, parametric study was performed on marginal fills. The parametric properties of the marginal fill are taken from the SPT tests obtained from the drilling studies at the determined location. Coating and reinforcement properties were adapted from the values used in the literature. According to the parametric study results of marginally filled walls, it was found that marginal fills to be safer than granule filled walls with increasing reinforcement hardness. Moreover, no shear stress was obtained in the finite element analysis for the marginal fill. This shows that there is no collapse under the static loads for the examined models. In addition, a cost analysis was carried out to determine the economically reasonable model by using the selected variables in the models. Based on the observations made, stiffer geogrids and marginal fills in geogrid reinforced soil walls have been found to be one of the viable options if drainage measures are provided.