Behaviour of existing tunnel due to adjacent deep excavation-a review

Behaviour of existing tunnel gets hugely affected by nearby construction activities, especially from deep excavation, which causes changes in the ground stresses. Such change in stress will affect the serviceability of the existing tunnel by causing displacements, strains and bending moment. This paper reviews from the available global literature on the extent of impact caused by such adjacent deep excavations on tunnels under two broad conditions (1) tunnel located below deep excavation and (2) tunnel located adjacent/side of deep excavation. Under these two broad conditions two sub-conditions were also examined. Furthermore, an attempt to identify the influence of different parameter on the features of the existing tunnel was carried out. Influencing parameters were categorized under primary, secondary and tertiary classes. This paper provides a knowledge on the range of values that can be expected on certain features of tunnel due to adjacent deep excavation.