Segmental retaining wall: Comparison between predicted and observed slip surface

Abstract

Reinforced soil structures as geotechnical and environmental works solutions are greatly considered in Brazil. Nowadays, design analyses are commonly used specially for segmental retaining wall design (SRW). These methods are mostly conservative, presenting a considerable security margin, depending on the adopted safety factors. However, literature shows cases where the structure has not attained the predicted safety factor which resulted in failure. In order to verify the main factors that influence the design of a SRW structure, this work shows the back analysis of two reported cases histories where the reinforced structure came to failure. Internal and global stability analyses for these cases were performed with the use of MACS-TARS® 2000 program, according to Maccaferri (2004), which is based on limit equilibrium analyses. In these cases, it is possible to compare the predicted safety factor and the corresponding critical surface with the real observed slip surface. The analyses show values of safety factor close to the ones commented by the authors and the predicted critical surfaces were located at the same region observed in the field. However, the quality and reliability of analyses are directly related to the exact description of the existent conditions in the field and entrance parameters of each application. The case where this program is used, it is important to investigate different intervals to analyze the potential surfaces of rupture, as well as to choose the width of la-mellas that can influence the results of stability analysis.