Field monitoring analysis of damage of buildings due to large deformations caused by adjacent deep excavations

Deep excavation has an important impact on the deformation and safety of its adjacent buildings. However, very limited case histories on damage of adjacent buildings caused by a safely constructed deep excavation are available. Field monitoring is carried out during the construction of a 12 m-deep excavation for the foundation of a luxury complex building. The settlement deformations of 11 adjacent buildings caused by the deep excavation are analyzed. Also investigated are the settlement-related ground conditions, construction process of the deep excavation, lateral displacements of retaining structures, and foundation types of the adjacent buildings. It is shown that the ground conditions, namely a thick mucky silty clay containing silty sand, and dewatering are the underlying causes leading to damage of 6 buildings with settlements over 100 mm. An effective water-resisting curtain and dewatering measures are the key to control the influence of deep excavation on the adjacent buildings.