Enhancing the Bearing Capacity and Settlement Performance of Soft Clay Using Geocell Reinforcement: A 3D Numerical Parametric Study

Problematic soils pose a risk to structures due to excessive or uneven settlement, swelling, and limited bearing capacity. To address some of these issues, mechanical reinforcement using geosynthetic products such as geocells can be employed, given their ease and speed of implementation. The purpose of this study was to assess the impact of geocells on the behavior of soft clay soil in Port Said, Egypt, using a three-dimensional finite element model, namely, the PLAXIS 3D software. The results show that replacing the top 1.5 m of the soft clay with sand significantly reduced settlement. This improvement was further enhanced by the addition of geocells available in the local market, where settlement was additionally reduced by approximately 51% to 63%, along with an appreciable increase in the bearing capacity. The effect of geocell material parameters was also investigated, including cell height, pocket dimensions, embedment depth, and reinforcement width. The results indicate that the best performance among the tested cases was achieved with a cell height of 300 mm, pocket dimensions of 210 × 245 mm, an embedment depth of 0.1 B, and a reinforcement width of 2 B, where B represents the foundation width. Furthermore, using gravel as both the replacement material and the geocell infill further improved performance, particularly in the presence of groundwater, by reducing settlement and increasing bearing capacity. The results indicate that combining gravel replacement with geocell reinforcement represents the most effective solution for improving the stability of soft clay soils in the study area.