Three-Dimensional Numerical Analysis of Performance of a Geosynthetic-Reinforced Soil Pier
Geosynthetic reinforced soil (GRS) consisting of closely spaced geosynthetic layers has been increasingly used to support bridges due to its rapid construction, low construction cost, and effectiveness in eliminating bump at the end of the bridges. GRS performance tests (also referred to as GRS mini-pier tests) were used to evaluate load-deformation behavior of a frictionally connected GRS mass to support a vertical load. Numerical analysis is an alternative approach to study the behavior of the GRS mass if the numerical model is well calibrated and/or validated. In this study, a three-dimensional numerical model was developed using FLAC3D, a finite difference method-based program. The Mohr-Coulomb model was used to describe the behavior of backfill soil. Geosynthetic reinforcement was modeled as a linearly elastic material using “geogrid” structural elements. Different interfaces were considered in the numerical model to simulate the interaction between different components. The numerical model was calibrated and verified against the measured load-deformation curve and the lateral displacement profile along the height of the GRS pier. This paper also presents the calculated lateral earth pressure profile behind facing blocks along the height of the GRS pier. Comparisons show that the numerical model was able to reasonably capture the behavior of the GRS pier in the experimental test.
KeywordsDeformation Geosynthetic Numerical analysis Pier Stress
This paper was completed while the first author visited the University of Kansas, USA as a visiting scholar, which was supported by the China Scholarship Council (No. 201506260117). Dr. Barry R. Christopher provided some guidance in the numerical analysis. The authors would like to appreciate the financial support and technical help.
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