A Modern Approach in Analyzing and Designing of Rockfall Protection Measures: The City of Omiš Rockfall Protection Case Study

Rockfalls are the most frequent and dangerous type of landslides, generating high economic and social damages in zones built in different types of rock mass. The high danger of rockfall occurrence mainly lies in high speed of the falling rock mass that is very difficult for any fast response in the protection of human lives, settlements and infrastructure. The main part of Adriatic coast of Croatia is built in the limestone rock mass and numerous cities and traffic infrastructure were built in a narrow coastal belt, just below steep slopes of limestone massifs [1]. Numerous cities (e.g. Rijeka, Omiš, Makarska, Dubrovnik) and small settlements, as well as hundreds of kilometres of roads, are exposed to rockfall threats and their consequences expressed in human lives and economic damage. Because of the nature of a rockfall occurrence, where relatively small rockfall volume can cause extremely high damages, there were numerous projects in rockfall protection along the Croatian part of Adriatic coast last years. One of the most comprehensive and by its volume the most important project in Croatia was the City of Omiš rockfall protection project conducted from 2006 to 2018 [2]. After the numerous rockfall occurrences that hit the City during its known history, the modern rockfall protection constructions and new technologies in rockfall analyses and protection designing enabled the development of the efficient rockfall protection systems. In this paper, we will describe the methods of field and remote sensing investigation of rock slopes, identification of rockfall sources, modelling and simulation of rockfall propagation, as well as the selection of protection measures and their positioning at the slopes above the central part of the City of Omiš. The carried out measures and estimation of their efficiency in reduction of rockfall hazard and risk in the central part of the City of Omiš will be described.