An Analysis of Floating Geogrid-Reinforced Pile-Supported Embankments Containing Deep Softened Soil

Abstract

Floating geogrid-reinforced piles provide economic solutions when constructing embankments over areas with soft soil. The combination of piles and geogrids allows for the transfer of stress between the piles and adjacent soil through soil arching and tensioned membrane effects. Furthermore, floating geogrid-reinforced pile foundations can also significantly reduce embankment settlement. However, it has been found that in many cases, the ends of the piles may not be anchored due to layers of thick softened soil. Therefore, reduced scale model tests and numerical simulations were conducted in the current study for the purpose of evaluating the performances of different types of end-bearing and floating piles. The effects of different parameters were considered, including embankment filling heights; pile spacing ratios; stiffness ratios between the piles and the adjacent subsoil; internal friction angles of the embankment fill; and the effects of the tensile stiffness of the geogrids on the bearing capacities of the embankments. The results showed that the absence of firmly supported layers could transfer loads and reduce settlement. The results of this study’s numerical simulations revealed that enlarging the pile-soil stiffness ratios or tensile stiffness, and improving the shear properties of embankment fill could successfully improve the performances of geogrid-reinforced pile-supported embankments. This study’s findings can potentially be used to guide future analyses of floating pile load transfer mechanisms and settlement patterns.