Stability analysis of embankments on soft ground reinforced with soil-cement columns using a finite element model

Abstract

The construction of roads and drainage canals in the soft soil regions of the Chao Phraya River basin frequently encounters challenges related to embankment stability and displacement due to the low strength and high compressibility of the soft clay layers. To mitigate these issues, embankments are often reinforced with ground improvement techniques such as the cement deep mixing method. Consequently, the stability analysis and design of reinforced embankments on soft clay are of paramount importance. This study conducts a stability analysis of embankments on soft ground reinforced with soil-cement columns using the finite element method. A case study is presented, focusing on a drainage canal construction project in Ayutthaya Province, with the objective of evaluating the stability of soft soil embankments by assessing factors of safety at various stages of construction. The analysis incorporates soil investigation data and laboratory test results from the project, employing the Mohr-Coulomb model to simulate soil behaviour under both construction and long-term usage conditions. Preliminary findings indicate that the inclusion of soil-cement columns significantly enhances the factor of safety during construction stages, with predicted embankment displacements closely aligning with field measurement data. Key factors affecting the analysis results include the choice of soil model, the parameters selected for soft clay and soil-cement columns, and the construction sequence.