Reinforcement Tensile Forces in Back-to-Back Retaining Walls

Back-to-back reinforced retaining walls are mostly used in approach embankments of bridges and flyovers. In the internal stability check for mechanically stabilized earth (MSE) walls, earth pressure theory is used to obtain the tensile forces in the reinforcement. However, tensile forces calculated from this method are found to be very conservative (by a factor of two) in comparison to the actual field measurements. The objective of this study is to examine the mobilization of reinforcement tensile forces at different levels within back-to-back MSE wall at working stress condition. Tensile forces in the reinforcements with reinforcement connected in the middle (i.e., reinforcement extending from one wall to the other) are also obtained. Parametric study is carried out with the stiffness of reinforcement varying from 500 to 50,000 kN/m and the ratio of spacing between two walls to wall height (W/H) varying from 1.4 to 2.0 to investigate their effect on tensile forces at every level of the reinforcement. Charts are also proposed showing the variation of the maximum tensile forces along the height of the wall.