Design of a Strut-Free Retaining Wall System for Deep Excavation in Soft Clay Using an Elastic Structural System

Excavation systems are widely used around the world due to land scarcity and high property costs. The study aims to understand the impact of excavation system geometry on overall performance and, focuses on designing a strut-free excavation system for a depth of 30 meters. Key parameters include the optimal number and specifications of buttress walls, rib walls, cross walls, and diaphragm wall geometry. A comprehensive parametric study was conducted using the finite element software PLAXIS, involving over 1,950 simulation trials to evaluate maximum wall deflection and ground settlement. Furthermore, predictive equations for maximum wall deflection and ground settlement were developed using Multiple Linear Regression (MLR) and Multivariate Adaptive Regression Splines (MARS) techniques. The research also investigates diaphragm wall configurations to identify effective methods for reducing deformation following buttress wall displacement. The findings indicate that incorporating inclined diaphragm walls offers the most effective reduction in wall deflection and ground settlement, although this approach requires additional construction space.