Static and Dynamic Performance of Anchored Bored Pile Excavation Support Systems in Three Soil Groups: Eurocode 7-Based Design, Time-History Analysis and In Situ Inclinometer Validation

Anchored bored pile walls are widely used to control deformation in deep urban excavations, but their serviceability performance depends on soil stiffness, excavation depth, wall stiffness, anchor configuration, construction staging, groundwater conditions and seismic demand. This study compares three real excavation support projects in contrasting soil groups: soft to hard clay, hard to very hard clay, and dense to very dense gravel. The calculations follow a Eurocode 7-compatible Design Approach 2 framework. Static finite-element analyses, equivalent-static seismic analyses and scaled time-history analyses were compared with in situ inclinometer measurements. The seismic input included site-specific spectral parameters, horizontal acceleration coefficients, Rayleigh damping parameters and 11 scaled PEER ground-motion records. The key design insight is that increasing the number of anchor rows alone cannot compensate for low ground stiffness or limited wall stiffness; soil-structure interaction must be interpreted together with support configuration. The finite-element and measured maximum horizontal displacements were 79.97 and 75.80 mm for the sports hall excavation, 23.22 and 22.70 mm for the residential excavation, and 27.67 and 23.20 mm for the controlling square-project section. The study demonstrates the value of integrating Eurocode-based design checks, dynamic analysis and field monitoring for deep-excavation safety.