Predictive Equation for Estimating Lateral Deformation of GRS Abutments

The geosynthetic reinforced soil integrated bridge system (GRS-IBS), which consists of closely-spaced layers of geosynthetic reinforcement and compacted granular fill material, is a fast and cost-effective approach for bridge support that is increasingly being used. The in-service performance of this innovative bridge support system is largely evaluated through the deformations of the GRS abutments. This paper presents a predictive model for estimating the lateral deformation of GRS abutments under service loads. The parameters that are considered in the predictive model include abutment geometry (height, foundation width, facing batter), backfill friction angle, and reinforcement characteristics (stiffness, spacing, length), and applied static loads from 0 to 400 kPa. In order to develop this predictive equation, a comprehensive parametric study was conducted using a validated 3D finite difference numerical model. The results of the parametric study were used to derive the predictive equation using statistical analysis. The developed equation was validated using four case studies. Such a prediction model would be useful to practitioners in preliminary GRS abutment design.