Numerical Analysis of Geosynthetic-Reinforced and Pile-Supported Earth Platforms over Soft Soil

TLDR

Geotechnical engineers designing over soft soils face bearing failure, settlement, lateral pressures, and instability, and geosynthetic‑reinforced and pile‑supported platforms offer an economical solution that improves load transfer and reduces settlements, especially for rapid construction or strict deformation requirements. A numerical study examined pile‑soil‑geosynthetic interactions by varying fill height, geosynthetic tensile stiffness, and pile elastic modulus. The simulations show that stress concentration ratio and maximum geosynthetic tension rise with fill height, geosynthetic stiffness, and pile modulus, with peak tension occurring near the pile edge.

Abstract

Geotechnical engineers face several challenges when designing structures over soft soils. These include potential bearing failure, intolerable settlement, large lateral pressures and movement, and global or local instability. Geosynthetic-reinforced and pile-supported earth platforms provide an economic and effective solution for embankments, retaining walls, and storage tanks, etc. constructed on soft soils; especially when rapid construction and/or strict deformation of the structure are required. The inclusion of geosynthetic(s) in the fill enhances the efficiency of load transfer, minimizes yielding of the soil above the pile head, and potentially reduces total and differential settlements. A numerical study has been conducted to investigate pile-soil-geosynthetic(s) interactions by considering three major influence factors: the height of the fill, the tensile stiffness of geosynthetic, and the elastic modulus of pile material. While current methods have not fully addressed important effects of the geosynthetic stiffness and pile modulus on the soil arching ratio, numerical results suggested that the stress concentration ratio and the maximum tension in geosynthetic increase with the height of the embankment fill, the tensile stiffness of geosynthetic, and the elastic modulus of the pile material. The distribution of tension force in the geosynthetic reinforcement indicated that the maximum tension occurs near the edge of the pile.