ABSTRACT: Stress and strain fields near the ground surface are strongly influenced by ground morphological conditions, so that sometimes, in the case of shallow tunnel design, numerical predictions of the induced subsidence are required to account for an initial stress which may not be simply geostatic. In this paper, this problem is studied with reference to a real tunnel excavated in a stiff clay deposit under the most intensively urbanized area of the city of Ancona (Italy). The results of the monitoring show that, displacements at the ground surface caused by tunnel excavation can be only explained if soil morphology is taken into account. In this particular problem, the morphological effect arise as a consequence of the sloping that characterize the ground surface at the beginning of the tunnel. A numerical, finite element model of the tunnel problem is presented to clarify such a behavior through parametric analysis.
Morphological effects on settlements induced by shallow tunneling / Segato, David; Scarpelli, Giuseppe. - (2006). (Intervento presentato al convegno International Conference on Numerical Methods in Geomechanics. Edited By Schweiger tenutosi a Graz, Austria nel 6-8 Settembre 2006).