A parametric study of embankment supported by geosynthetic reinforced load transfer platform and timber piles tip on sand

Abstract

This paper presents the results of finite element parametric study on the performance of pile-supported embankment system built over soft soil utilizing geosynthetic-reinforced load transfer platform (GLTP), where timber piles tipped on sand. The studied parameters included thickness of top soft layer, lateral extent of GLTP, embankment height (H), pile spacing, GLTP configuration, and different soil profiles. Three performance criteria were considered: maximum geosynthetic tensile strain, settlement, and slope stability. The results show that extending GLTP to 1.5H for low embankment load and full extent of 2.0H for medium and high embankment loads satisfies slope stability. The required number of geosynthetic layers varies from 3 layers for low and intermediate embankment loads to 7 layers for high embankment load with large pile spacing. Increasing the thickness of top soft layer results in increasing the strains along geosynthetics. However, increasing the number of geosynthetic layers and thickness of GLTP results in lower strains along geosynthetics but have little effect on settlement. Increasing 2 geosynthetic layers results in 15–20 % reduction in geosynthetic strains, but <2 % reduction in settlement. Meanwhile, increasing GLTP thickness by 50 % results in 10 % reduction in settlement, and 20–25 % reduction in geosynthetic strains.