Performance and geocell-soil interaction of sand subgrade reinforced with high-density polyethylene, polyester, and polymer-blend geocells: 3D numerical studies

Abstract

Geocells are widely used in geotechnical and road applications due to their excellent reinforcing properties. However, variations in materials, joint configurations, pocket shapes, and other factors have led to geocell development in a wide range of types. Given this, the present study compared three typical geocells, polymer-blend geocells (PBGs), high-density polyethylene geocells (HDPEGs), and polyester (PETGs) geocells, in terms of pressure-settlement responses and geocell-soil interactions. A numerical model was firstly validated based on a plate loading test, and subsequently extended to analyze the sand subgrade reinforced with three geocell types. The numerical simulations considered geocells with varying weld distances, heights, and pocket-opening shapes. Numerical results showed that the reinforced performance of PETGs (diamond shape) was less sensitive to changes in wall height compared to PBGs and HDPEGs (honeycomb shape). There was little difference in the capacity to reduce soil bed settlement among the three geocell types, unless significant deformation occurs and the soil enters the plastic state. Furthermore, based on the shape of the opening pockets, the three types of geocells were classified into honeycomb-shaped and diamond-shaped categories to investigate geocell-soil interactions. The results of coupling shear stress, confining stress, and normal deformations demonstrated that diamond shapes may generate unreasonable lateral confining resistance, which was the main factor causing the geocell-soil interaction variation between these geocells.