Responses of a masonry façade to multi-propped deep excavation-induced ground deformations: 3D numerical parametric study

Abstract

Basement excavation inevitably causes stress changes in the ground leading to soil movements which may affect the serviceability of adjacent structures specially in case of masonry building. Because soil stiffness degrades with induced stress release during excavation, it is vital to investigate the masonry façade responses to an adjacent excavation. This paper presents three-dimensional numerical parametric study to investigate damaging effects on an existing brick masonry façade due to an adjacent basement excavation. The orientation of the façade is perpendicular to the basement. An advanced hypoplastic (sand) model with small-strain stiffness is adopted. The model parameters are calibrated against centrifuge test results in sand reported in literature. Effects of excavation depths, wall locations with respect to excavation, sand density and applied loads on the wall are examined. The computed results revealed that differential settlement (with maximum settlement closest to the excavation) was induced in the wall due to excavation-induced stress relief. Consequently, cracks were developed in the façade during excavation. By increasing the relative density from 30% to 90%, the excavation-induced footing settlement decreases by up to 72%. The different loads applied on the top of the façade have significant effects on the responses of the wall due to excavation.