Finite element analysis of lateral earth pressure on sheet pile walls

Sheet pile walls providing lateral earth support are widely employed as excavation supporting systems for cutting slopes along the high-speed railway. In this study, a validated three-dimensional finite element (FE) model based on field measurements was used to explore lateral earth pressure distribution on sheet pile walls, aiming to provide guidelines and recommendations for design of the sheet pile walls. To this end, the influence of pile length, sheet's location, pile's stiffness, and soil properties on the pile performance were investigated. The results showed that the optimum pile length was about 14 m for the sheet pile walls at a China high-speed railway. The sheet's location could affect the formation of soil arching and the mechanism of earth pressure distribution. The moment of inertia of sheet pile walls was found to be effective in controlling pile displacement and earth pressure, compared to Young's modulus of the pile. Variations of soil parameters led to negligible changes in the earth pressure distribution. Furthermore, a proposed simplified straight-line form for earth pressure diagram based upon the FE analysis was developed. Compared with traditional earth pressure methods, the proposed diagram considers the sheet effect. Overall, the conducted study provided useful help toward the process of safer design and more economical sheet pile walls.