The Rockfall Potential of the Southwestern Part of Kastamonu Castle (Turkey) Based on 2-D and 3-D Analyses

Abstract

Urbanization around steep rock slopes with jointed rock masses is mostly under the threat of rockfalls. Numerous catastrophic rockfall hazards have been reported throughout the world due to the downslope movement of detached rocks. It is quite critical to determine the rockfall potential of a location considering rockfall trajectories, run-out distances, bounce heights and the kinetic energies of falling rocks. Therefore, the determination of rockfall paths requires the use of rockfall simulations. In practice, 2-D and 3-D models are most commonly employed during rockfall event modeling. The rockfall trajectories are simulated on a slope profile with X and Y axis in 2-D models, whereas 3-D models encompass a real space with X, Y and Z axis to calculate the rockfall paths. In this study, the rockfall potential of the southwestern part of the Kastamonu Castle, which is situated on a steep sandstone hill, was evaluated on the basis of 2-D and 3-D rockfall analyses using RocFall v.4.0 and ROTOMAP software, respectively. The close vicinity of the Kastamonu Castle, especially the southwestern region, is surrounded by residential houses and these settlements were adversely affected by disastrous rockfalls in the past. Based on 2-D and 3-D simulations, two different preliminary rockfall hazard maps were prepared and rockfall high-risk areas were defined. Both the 2-D and 3-D analyses pointed out that the southwestern part of the castle is under the great danger of rockfalls of which the weight of falling blocks may reach up to 10 tons. Finally, it is concluded that the maximum fall-out distances in 3-D analyses are more remote than those of 2-D analyses in the study area. © Springer International Publishing Switzerland 2014.