Evaluation of Rockfalls With 3-Dimensional Probabilistic Analyses and Empirical Methods: the Case of the Kayseri – Soğanlı Settlement

Abstract

This study evaluated the potential rockfall hazards in the Kayseri-Soğanlı settlement using the energy angle method and 3-dimensional probabilistic rockfall modeling. The high-resolution digital surface model (DSM) was obtained with the help of unmanned aerial vehicles (UAV) and high-resolution orthophoto. 3-dimensional probabilistic rockfall simulations were conducted on the DSM using the CONEFALL software, and rockfall zones were determined according to the energy line angle method. The dimensions of previously fallen rock blocks were determined using fieldwork and orthophoto generated by UAV. As a result of 3-dimensional probabilistic analyses, the maximum kinetic energy values of 15,000 kJ and bounce height of 15 m were determined during the movement of 3-meter rock blocks along the slope. When the energy line angle method was considered, it was found that the previously fallen blocks were mostly concentrated in the 40° energy line angle zone in the southern part of the slope. On the other hand, although the rolling lines obtained from probabilistic 3-dimensional rockfall analyses for 3 metre block size reach up to the maximum 30° energy line angle zone, these rolling lines end in the 40° energy line angle zone, especially in the southern part of the slope. Therefore, the empirical method, 3-dimensional probabilistic method, and the positions of measured blocks in the field show general consistency. © 2023, TMMOB Chamber of Geological Engineers. All rights reserved.