Reinforced steep vegetated slope 60 m height for landslide stabilization in Lona-Lases (Trento-Italy)
In the mountain area near Trento there is a very intensive quarry activity for the extraction of porphyry (very hard stone) used in many building applications (pavements, walking paths etc). Mount Gorsa side above Lases lake, located in Slavinac (Trento-Italy), after quarry activity has been interested by an impressive landslide movement hanging over both the provincial road S.P. “Fersina-Avisio” and the same lake with serious risk for the near built-up area and inhabitants. Following the exceptional meteoric events of November 2000 that caused a temporary acceleration of slope movements, the Public Disaster Prevention Department of the Province of Trento assigned to Prof. G. Barla (Polytechnic University of Torino) and Prof. A. Cancelli (University of Milano) a technical advice to study the landslide process, in order to define the guideline for final executive design of landslide stabilization and to analyse possible sceneries consequent to an increasing acceleration of landslide movement with particular reference to the evaluation of the wave effect produced by collapsing of instable rock portions into under lake.
The executed project shows a very complex geotechnical problem in landslide stabilization, and the reinforced steep slope with geosynthetics proved to be in this specific situation the best solution from the technical and environmental point of view. The possibility to have a vegetated face immediately after construction reduced the visual impact of such an imposing structure from the surrounding inhabited and tourist area. The reinforced steep slope has been completed in September 2005 and the automatic monitoring system installed is constantly measuring the behaviour of the structure and the versant. The concept to build a strengthened slope with multiple purposes as containment of active pressure of back soil, to re-profile the versant and to contribute to general slope stability resulted very interesting and effective. Some of these ideas might be used in future for similar projects.