Evaluation of Secondary Reinforcement Layers on Segmental MSE Wall Behavior Using 3D Finite Element Method: A Case Study

Mechanically Stabilized Earth Segmental Wall (MSESW) is a composite retaining structure consisting of cruciform panel facing, geosynthetic strips, and granular backfill which is extensively utilized in various infrastructure projects. MSESW's typical vertical spacing between primary reinforcement is 0.75 m, which is a notably significant distance that may result in the wall bulging. The implementation of the secondary reinforcement, GeoGrid, is positioned in the gaps between such spacings. This research focuses on how secondary reinforcement affects the behavior of the MSESW. MSESW behavior can be observed through the back analysis of the field monitoring data collected with a total station. 2D and 3D Finite Element Method, which generates the most realistic models, is used to perform the back analysis. The most practically ideal model is the gap between panels that are installed with bearing pads. Parametric studies are also conducted by varying the secondary and primary reinforcement properties, i.e., type, length, and ultimate tensile strength. Secondary reinforcement improves the MSESW's behavior significantly, in terms of wall deflections, tensile loads, and reinforcement deformations. The optimum length for applying secondary reinforcement is 0.5 of the primary reinforcement's length. Secondary reinforcement primarily enhances internal stability, i.e., rupture, pull-out, and connection failure, but not compound failure. For MSESW, Biaxial GeoGrid use is not advantageous. Applying tensile loads at the connection of facing and reinforcement is mandatory, as per many international standards, i.e., American Association of State Highway and Transportation Officials (AASHTO), Canadian Standards Association (CSA), Association Fran & ccedil;aise de Normalisation (AFNOR), and British Standards Institution (BSI).