Synergistic Effects and Mechanical Properties of Adjacent Composite Pile-Sheet Wall in Embankment Widening Project

Abstract

To address the technical challenges caused by terrain constraints in existing embankment widening projects, the innovative "Adjacent Composite Pile-Sheet Wall (ACPSW)" supporting system is proposed. This structure forms a compo-site supporting system by adding parallel new pile-sheet walls among existing pile-sheet walls. Combined with the engineering practice of the Lanzhou Hub Project of the Zhongwei-Lanzhou Railway, the numerical simulation method is adopted to systematically study the horizontal displacement of piles, distribu-tion characteristics of soil pressure behind the wall, and the collaborative bear-ing mechanism between old and new piles of the ACPSW structure throughout the construction process. The research reveals that under the coupled action of new embankment filling and train operation loads, the old and new pile-sheet walls can achieve collaborative deformation, forming a load distribution ratio of 0.6:1 between old and new piles. The research results provide a design basis and engineering practice reference for new supporting structures in existing railway reconstruction and projects adjacent to existing railway lines.