Canelles landslide: modelling rapid drawdown and fast potential sliding
A large landslide (40 × 106 m3) was reactivated on the left bank of Canelles reservoir, Spain. The instability was made evident after a considerable reduction of the reservoir level. The drawdown took place during the summer of 2006 after several years of high water levels. The drawdown velocity reached values between 0.5 and 1.2 m/day (registered at low elevations). The paper reports the geological and geotechnical investigations performed to define the movement. The geometry of the slip surface was established from the detailed analysis of the continuous cores recovered in deep borings and from limited information provided by inclinometers. Deep piezometric records provided also valuable information on the pore water pressure in the vicinity of the failure surface. These data allowed validating a flow–deformation coupled calculation model, which takes into account the changes in water level that occurred 4 years previous to the failure as well as the average rainfall. The analysis indicates that the most likely reason for the instability is the rapid drawdown that took place during the summer of 2006. The potential sudden acceleration of the slide is also analysed in the paper introducing coupled thermal hydraulic and mechanical effects that may develop at the basal shearing surface of the sliding mass. The results indicate that the slide velocity may reach values around 16 m/s when displacement reaches 250 m.
KeywordsLandslide Analysis Modelling Finite elements Stabilisation Rapid drawdown Fast sliding
This research work received partial support from the Safeland project funded by Commission of the European Communities (grant agreement 226479) and from the Big Risk (contract number BIA2008-06614) project funded by the Spanish Ministry of Science.
- Alonso EE (2005) Parámetros de Resistencia en cálculos de estabilidad. VI Simposio Nacional sobre Taludes y Laderas Inestables. Valencia, 21–24 June 2005. Alonso E, Corominas J, Jordà L, Romana M and Serón JB (eds.), 1131–1195Google Scholar
- DIT-UPC (2002) CODE_BRIGHT. A 3-D program for thermo-hydro-mechanical analysis in geological media. User’s guide. CIMNE, BarcelonaGoogle Scholar
- Hutchinson JN (1983) Methods of locating slip surfaces in landslides. Bull Assoc Eng Geol 20:235–252Google Scholar
- Martínez Peña B, Pocoví A (1988) El amortiguamiento frontal de la estructura de la cobertera surpirinaica y su relación con el anticlinal de Barbastro-Balaguer. Acta Geol Hisp 23:81–94Google Scholar
- Moya J (2004) Determination of the failure surface geometry in quick slides using balanced cross section techniques. Application to Aznalcóllar tailings dam failure. In: Hack R, Azzam R, Charlier R (eds) Engineering geology for infrastructure planning in Europe. Springer, Series Lecture Notes in Earth Sciences, no. 104, 414–421Google Scholar
- Pinyol NM, Alonso EE (2010b) Fast planar slides. A closed form thermo-hydro-mechanical solution. Int J Numer Anal Methods Geomech 34:27–52Google Scholar
- Pinyol NM, Alonso EE and Olivella S (2008) Rapid drawdown in slopes and embankments. Water Resources Research 44, W00D03, 22 pp. Special issues on: Hydrology and mechanical coupling in earth sciences and engineering: interdisciplinary perspectivesGoogle Scholar
- Vergés J (1993) Estudi geològic del vessant Sud del Pirineu Oriental I Central: Evolució en 3D. PhD Thesis. Universitat Politècnica de Catalunya, Barcelona, Spain. 203p (printed by the Institut Cartogràfic de Catalunya in 1999)Google Scholar