Large gravitational collapse structure on a rocky coast (Kvarner, NE Adriatic Sea)

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Čedomir Benac
Sanja Dugonjić Jovančević
Dražen Navratil
Andrea Tadić
Lovro Maglić


The studied rock collapse structure is located on the Liburnian coast (Rijeka Bay, channel zone of the NE  Adriatic). The relief of the southern part of this coast, with a length of 6.5 km, is a large escarpment with very steep to vertical slopes reaching heights of 100 m above sea level, as a result of tectonic movements along the Kvarner fault zone. These events probably led to a sudden relaxation of the highly fractured rock mass. The progressive expansion occurred at locations where previously favourably oriented faults and fissures had formed a polygonal rock collapse resembling a rock-slide which is the focus of this study. Another aim of this study is to reconstruct and explain the complex morphological evolution of the studied landslide, from the pre-failure deformations, through the failure itself, to post-failure displacements, as well as possible future  instabilities. Recent techniques to survey the instability, location and to analyse the evolution of the rupture surface and its dimensions were combined (Unmanned Aerial Vehicle, Side Scan Sonar and Remotely Operated Vehicles). The estimated total volume of displaced rock mass is 950,000 m3. The lower part of the instability phenomenon was submerged during the Holocene sea level rise. Since then, a large part of the displaced rock  mass has been in a stable position, with sporadic rock falls. However, given unfavourable orientation and  discontinuity characteristics, as well as unfavourable environmental influences, possible instabilities might also  be expected in the future. 


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Article Details

Original Scientific Papers
Author Biographies

Čedomir Benac, University of Rijeka, Faculty of Civil Engineering, Rijeka, Croatia

Geotechnical Department

Andrea Tadić, University of Rijeka, Faculty of Civil Engineering, Rijeka, Croatia

Hydrotechnical Department


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