Stability and Serviceability Assessment of Reinforced Earth Retaining Structures: A State-of-the-Art and Way Forward

This paper reviews the previous studies on mechanically stabilized earth (MSE) wall, soil nail (SN) wall, and hybrid earth retaining structures (HERS) to provide a critical appraisal and state-of-the-art review followed by way forward regarding recommendations on the analysis, design, and practice. The first part of the paper deals with the brief review of the deterministic and reliability analyses of the MSE and SN walls. The second part presents the review of the literature related to the HERS, which consists of MSE over SN wall and shored MSE and narrow MSE walls. Even though the HERS are alternative to the MSE and SN walls and are especially effective in hilly terrains, they are not yet that popular owing to the lack of well-established design guidelines and construction procedures. A limited number of studies have been available in the literature on the HERS from the deterministic and probabilistic perspectives and are not available in the main-stream publications. Due to uncertainties of the material parameters of the soil and geo-synthetics, realistic and accurate prediction of the behavior of the reinforced earth retaining structures is very necessary and accordingly the studies reported on reliability studies are reviewed and presented. In the current design practice, the HERS are conservatively designed using guidelines developed for the MSE and SN walls. Therefore, there is a need to develop comprehensive analysis and design procedures for the safe and economical design of HERS.