A Design Chart for the Analysis of the Maximum Strain of Reinforcement in GRPEs Considering the Arching and Stress History of the Subsoil

Abstract

Geogrid-reinforced piled embankments (GRPEs) provide an economical and effective way to construct highways and railways on soft soil foundations. This paper proposed a new design method for GRPEs. The method was based on the soil arching and tensioned-membrane effects, the bearing capacity of the subsoil was considered as well. The originality of the proposed method lies in considering the stress history of the subsoil, and different over-consolidation ratios (OCRs) were used in calculating the settlement of subsoil. This design method, initially, established the vertical equilibrium of the unit body between the pile caps immediately above the subsoil. After that, the design charts were produced by solving the overall equilibrium equation from which engineers can intuitively obtain the maximum strain of reinforcement, and the tensile force can be used in the ultimate limit state analyses. The design method was then validated by three case studies, which showed good reliability with the maximum error being less than 18%. Parameter study results indicated that the maximum strain of reinforcement for the under-consolidated soil was 80–120% larger than that for normally consolidated soil and more than four times greater than that for over-consolidated soil.