Abstract
A landslide in a stiff clay formation, interrupting the excavation of a tunnel for a major railway in Sicily, is reported. Limit equilibrium and FEM undrained and drained analyses of the slope before tunnel excavation agree in showing that the slope was stable with a relatively high factor of safety and the critical slip surface is located well above the tunnel. The undrained stability of the tunnel checked both via FEM and via standard analytical solutions for face stability is also verified. The FEM analyses of the slope have been repeated considering the excavation of the tunnel in undrained and drained conditions. The advancement of the tunnel face is simulated in a plane strain analysis by the Panet method. In undrained conditions, the system keeps stable. In drained conditions with a stress release factor of 50 %, the slope is on the verge of failing with a very low safety factor, while with a stress release factor of 80 %, it fails following a complex mechanism that matches the observed failure surface. These findings are discussed and some conclusions attempted.
Similar content being viewed by others
References
Chandler RJ, Skempton AW (1974) The design of permanent cutting slopes in stiff fissured clays. Géotechnique, London, England 24(4):457–466
Christian JT, Whitman RV (1969) A one-dimensional model for progressive failure. Proceedings VII ICSMFE, Mexico. 2:541–545
Croce A, Jappelli R, Pellegrino A, Viggiani C (1969) Compressibility and strength of stiff intact clays. Proceedings VII Int Conf Soil Mech Found Eng, Mexico, I:81–90
Morgenstern NR, Price VE (1965) The analysis of the stability of general slip surfaces. Géotechnique, London, England 15(1):79–93
Panet M, Guenot A (1982). Analysis of convergence behind the face of a tunnel. Tunnelling 1982–The institution of mining and metallurgy, pp 197–204
Powrie W (2012) Groundwater profiles and effective stresses—chapter 15 In: Burland J, Chapman T, Skinner H, Brown M (eds). I.C.E. manual of geotechnical engineering I:163–166
Vermeer PA, Moller SC, Ruse N (2003) On the application of numerical analysis in tunnelling. Post proceeding 12th Asian regional conference on soil mechanics and Geotech Eng, Singapore, 2:1539–1549
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Maiorano, R.M.S., Russo, G. & Viggiani, C. A landslide in stiff, intact clay. Acta Geotech. 9, 817–829 (2014). https://doi.org/10.1007/s11440-013-0249-0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11440-013-0249-0