Prof Erik Eberhardt, University of British Columbia, Dr Christian Zangerl, of alps GmbH, Centre for Natual Hazard Management, and Prof Simon Low, Swiss Federal Institute of Technology, discuss asymmetrical subsidence associated with deep hard rock tunnels
A prime concern in any shallow tunnelling project is the impact that the excavation process may have on the surface environment. In most cases, the immediate concern involves differential settlements caused by ground /volume loss leading to damage to sensitive surface structured. In water-bearing ground, tunnel drainage may also lead to differential displacements due to time-dependent consolidation and subsidence. Reported cases almost exclusively involve shallow tunnels excavated in soft, unconsolidated soils.
