Use of new technologies for tracking excavation progress

With new development, and increasingly more redevelopment, within urban areas, there is a clear need to efficiently and safely develop underground space. A major concern when placing deep excavations in urban environments is the impact of construction-related ground movements on adjacent buildings and utilities. In practice, when designers are faced with an excavation where ground movements are a critical issue, they can estimate movements using semi-empirical methods or results of numerical modeling. It is common to include a monitoring program during construction to record the ground movements and, in some cases, adjacent building movements. Ideally, these observations would be used to control the construction process and update predictions of movements. This paper describes novel developments in the user of laser scanning and digital photogrammetry for developing an accurate record of construction activities. These new technologies are illustrated using excavations in the Chicago area. Copyright ASCE 2006.