Optimization of the design of geosynthetic reinforced pile supported embankments using a numerical model

Abstract

The Geosynthetic Reinforced Pile Supported Embankment (GRPE) technique is an efficient ground improvement technique, that can reduce settlements and construction time drastically and is suitable to improve larger thicknesses of soft subsoils. Different design methods have their own assumptions and limitations that depart from actual field conditions eventually leads to a conservative design. Finite Element Analysis (FEA) could closely simulate the actual field condition, but further research is necessary in the area. In this study parametric analyses were done related to the design with and without geosynthetic reinforcement using PLAXIS software based on FEA. The analysis was carried out according to BS 8006 and Collin’s Method with manual calculations and the results were compared to optimize the design methodologies. The results need further studies with actual settlement data comparison with the FEA results to verify the applicability to actual conditions when analysing with PLAXIS software. Further, it can be said that BS 8006 leads to conservative designs for multiple basal reinforced piled embankments, but when using single basal reinforcement layer with appropriate pile and pile cap size, the efficiency can be increased to optimize the design outputs. Furthermore, when designing based on the Collin’s method, it predicts the average stress values acting on reinforcement but needs to consider the stress distribution between the pile caps with suitable factoring when designing GRPE systems with multiple reinforcement layers.