LANDSLIDE-PILE-TUNNEL INTERACTION BY 2D AND 3D FINITE ELEMENT MODELLING

Abstract eng:
This paper is focused on the interaction of a railway tunnel with a slow-moving landslide in clay soil. The tunnel, built as a reinforced concrete box structure protected by sheet-piled walls, crosses the accumulation of an earthflow situated at the eastern suburbs of Potenza city, in southern Italy. The landslide develops in the formation of Varicoloured Clays and, due to its very slow but continuous displacements, induces progressive damage to structures and infrastructures built on it. As for the tunnel, there are signs suggesting an evolution of its state of stress and deformation over the last 30 years. The study of the landslide-piletunnel interaction required sophisticated FEM analyses to adequately take into account all the involved elements and the real 3D nature of the problem. Analyses were carried out by FEM geotechnical and structural software. Some results selected from a comprehensive numerical study are hereby reported and discussed. A geotechnical software was used in its 2D and 3D versions to obtain the spatial distribution of earth pressure on the tunnel owing to soil movements. The interaction was confirmed to be strongly 3-dimensional, with more evident displacements and bending of the tunnel box concentrated at one end. As a matter of fact, the movements of the landslide seem to make the structure open in horizontal, like a fan. The structural analysis made by applying the above mentioned pressure values confirmed which are the most stressed sections of the tunnel, giving a useful information toward the provision of possible interventions aimed to lengthen the life span of the tunnel.

• Export as: BibTeX | MARC | MARCXML | DC | EndNote | NLM | RefWorks
• Add to your basket