Empirical evaluation of support of excavation wall performance across soil types

This study synthesizes over 1500 case histories of Support of Excavation (SOE) wall systems, creating one of the most comprehensive empirical datasets to date on wall displacements and ground settlements. Field-observed deformation data are compiled across a wide range of wall types, support systems, and geological conditions, providing a unified resource for evaluating SOE performance. Maximum horizontal wall deflections (δh,max) and vertical ground settlements (δv,max) are normalized by excavation depth (He), enabling cross-project comparisons and performance benchmarking. Deformation trends are statistically analysed across four generalized soil categories, fine-grained, coarse-grained, mixed soil, and soft soils over rock, revealing distinct behaviour patterns. Practical design benchmarks are proposed, with the majority of δh,max/He and δv,max/He values falling below 2% and 1%, respectively. These findings provide empirical guidance for preliminary design and risk assessment in geotechnical practice, while offering benchmarks for validating numerical models, particularly where site-specific data are limited.