A predictive exercise on the behaviour of tunnels under seismic actions

A typical damage pattern due to the longitudinal and transversal components of ground motion is that of extension cracks along the tunnel lining. In the transverse section of a circular tunnel, for instance, the ground shaking induces ovalisation of the lining (Owen & Scholl, 1981). Hence, depending on the stress level of the lining under ‘static’ conditions, cracks may open where tensile stress increments arise during shaking (Fig.1).