Lateral equilibrium optimisation in deep excavations: the role of passive earth reinforcement

Abstract

This study introduces the Passive Earth Reinforcement for Lateral Equilibrium Optimisation (PERLEO) methodology, a novel approach to enhancing stability in deep excavations. Aimed at addressing limitations in existing geotechnical practices, especially in reducing deformations and bending moments in retaining structures, PERLEO utilises soil–cement blocks as passive reinforcement. Employing comprehensive numerical analysis through PLAXIS 2D software, the research advances traditional methods with sophisticated computational modelling. This study thoroughly evaluates the effect of soil–cement blocks’ geometrical configurations on the lateral displacement and bending moments of retaining walls. Key findings indicate that optimal dimensions of these blocks significantly mitigate wall deflection and bending moments, thereby enhancing the stability and the overall integrity of deep excavation projects. Additionally, this research introduces design charts, providing tools for engineers to determine the estimates for maximum lateral displacement and maximum bending moment, based on the specific dimensions of soil–cement block configurations and the depths of excavation and embedment. This methodology not only contributes to improved safety and efficiency in deep excavation works but also offers a more economical approach by reducing potential financial and temporal hazards associated with structural failures in complex geotechnical projects.

Keywords

• Passive earth reinforcement
• lateral equilibrium optimization
• soil–cement mixture block
• deep excavation
• design charts