Building Subsidence Associated with Cut-and-Cover Excavations in Alluvial Soils

Abstract

Assessment of building settlements associated with each stage of strutted deep excavations has become an essential step in most of the projects. Reliable prediction for the settlement comes by addressing all factors controlling its development in a mathematical representation. Among these factors are the subsurface soil condition, the foundation type and depth of the neighboring buildings, the stages of excavation, and the overall stiffness of the retaining system. This paper presents a case history in Egypt in which the settlements of existing structures surrounding a deep excavation retained by strutted diaphragm walls were monitored and the measured values were back analyzed. The analysis showed that building settlements during the different stages of deep excavations are substantially influenced by the foundation depth of the proximate buildings and their relation to the depth of excavation at any construction stage.