P-y curve models for laterally loaded lattice-shaped diaphragm wall as sea-crossing bridge foundations

Abstract

Lattice-shaped diaphragm walls (LSDWs) are novel foundation systems increasingly used in large-span, deep-water bridges for their exceptional rigidity, cost-efficiency, and adaptability to diverse geotechnical and marine environments. Despite their growing adoption, the lateral load-bearing behavior of LSDWs remains insufficiently studied. The p-y curve method is a widely used approach for analyzing the lateral behavior of deep foundations, relating lateral soil resistance to horizontal displacement. However, conventional p-y curve models, developed primarily for pile foundations, are not directly applicable to LSDWs due to differences in structural configuration and load transfer mechanisms. To address this gap, this study develops improved p-y curve models for single-chamber LSDWs, derived from comprehensive numerical simulations under horizontal static loads in cohesive and sandy soils. The models incorporate foundation dimension and depth effects, accurately predicting ultimate soil resistance and initial subgrade reaction modulus. Validation against published field tests and experimental data confirms their high accuracy in capturing lateral soil-structure interactions. These findings provide valuable guidance for optimizing the design and analysis of LSDW foundations in marine bridge construction.