Study of the major landslide at the community of Ropoto, Central Greece, mitigation and FBG early warning system design

This paper refers to the world known major landslide at the community of Ropoto, belonging to the Municipality of Trikala, in the Central part of Greece. The size of the landslide and the massive destruction of community’s infrastructure alarmed all the relevant public authorities, pushed by the community and the press, in order to find a fast and permanent solution to this longlasting geotechnical problem. Some of the community’s houses were partially affected, while others were totally destroyed and the time was ticking. The authors' intention was the complete determination of the geotechnical conditions of the entire community's area through a complete geotechnical field work, which wasn't conducted during the previous investigations (1976, 1979 and 1990). In addition, the proposition of immediate and long term remedial measures for the slope's stabilization, as well as the geostructure’s global behavior monitoring was of the author's highest priority. The geotechnical program included the drilling of four (4) 20 m deep sampling boreholes, along the axis of the landslide, in which piezometers and inclinometers were installed, the drilling of one (1) 111 m deep hydrogeological 0.25 m borehole, in order to immediately pump the excessive underground water. Based on the results from the geotechnical laboratory tests, a full scale landslide modeling, as well as a stability analysis of the slope was conducted, and remediation measures were calculated for immediate implementation. Finally, an advanced surveillance method using fiber optics (fiber Bragg grating) was further studied, in order to monitor the geostructure’s health, and to function as an early warning system.