Novel Technologies for Tracking Construction Progress of Deep Excavations

Underground space is an increasingly important component of urban infrastructure in cities throughout the world. Tunnels and deep open cut excavations are often developed in an already heavily built environment. The construction of these excavations has to be accomplished economically while minimizing adverse impact on adjacent structures. New analysis techniques are being developed to enhance the engineers' ability to predict these impacts. These techniques are also able to integrate measured performance during construction to improve predictions of performance due to later excavation activities. Robust application of these techniques requires accurate information on construction staging. This paper presents two new techniques, 3-D laser scanning and digital photogrammetry, which provides accurate record of progress of excavation activities. The accurate excavation data can be integrated with model simulation of excavation activities. These techniques can be used from significant standoff distances thus reducing the interference of personnel with earth moving activities.