Browsing by Author "Varol, Oguen Ozan"

Now showing 1 - 2 of 2

A Comparative Study on Rockfall Block Motion Characteristics Using 3-D and 2-D Rockfall Simulations: a Case Study From Cappadocia (Mazı, Türkiye)
(Springer, 2025) Akin, Mutluhan; Dincer, Ismail; Orhan, Ahmet; Varol, Oguen Ozan
Within the scope of this research, rockfalls in Maz & imath; village of & Uuml;rg & uuml;p (T & uuml;rkiye) district were simulated on a digital surface model constructed using high resolution (2.9 cm) point cloud data retrieved from a real orthophoto mosaic gathered by an unmanned aerial vehicle in order to compare the results of 2-D and 3-D rockfall models. At the initial stage, 3-dimensional rockfall analyses were carried out using RocPro3D software and block dynamics such as trajectory, maximum runout distance, bounce height and total kinetic energy of the blocks were determined. Subsequently, a total of eight slope profiles were obtained from the point cloud data and 2-dimensional rockfall analyses were executed by means of RocFall 2-D software. Using a rockfall point source indicating the starting position of 2-D rockfall analysis, the rockfall analyses were repeated on 3-dimensional digital surface model and the block motion characteristics obtained from 2-D and 3-D analyses were compared. Eventually, it is revealed that block runout distances may differ in 3-D and 2-D rockfall analyses. Additionally, 3-D analyses reveal a significant advantage over 2-D analyses in terms of including topographic roughness, curves and obstacles in the model. On the other hand, one of the most significant variances between 2-D and 3-D rockfall analyses retrieved in this research is in the bounce height values. While the bounce height value in 2-D models may attain a maximum of 7 m, 3-D simulations point out that the detached blocks mostly roll over the slope with very low bouncing. When the simulation results are evaluated in terms of total kinetic energy, it is concluded that kinetic energy values are commonly higher in 2-D rockfall analyses than those of 3-D simulations. Conversely, block translational velocity values are typically comparable in both 2-D and 3-D rockfall models. Besides, considering the trajectories obtained via 3-D rockfall models for the study site, it is obvious that the settlement is under the risk of rockfall to a significant extent. Rockfall simulations highlight that the total kinetic energy values of the blocks are also quite high, which increase the destructive effect of rockfalls.
Investigation of the Effect of Surface Coating Resin Application on Salt Crystallization Resistance in Ignimbrites With Different Welding Degrees
(Springer Heidelberg, 2025) Varol, Oguen Ozan; Akin, Mutluhan; Dincer, Ismail
In this study, the salt crystallization resistance of ignimbrites obtained from Nev & scedil;ehir and Kayseri regions in untreated and water-repellent-treated conditions was determined. X-Ray Fluorescence Spectroscopy (XRF) and X-Ray Diffraction (XRD) analyses were conducted to determine the mineralogical-petrographic characteristics of the ignimbrites, Scanning Electron Microscopy (SEM) analyses were performed to identify changes in the internal structure of the samples before and after salt crystallization, and Brunauer-Emmett-Teller (BET) analyses were carried out to determine changes in pore structures. In the conducted study, both untreated and treated samples were tested for their physical and mechanical properties, including unit weight, uniaxial compressive strength, ultrasonic wave velocity, water adsorption by weight, porosity, Shore Leeb hardness, and point load strength. It was found that the welding degree of the ignimbrites had a significant impact on the effectiveness of the water repellent application. The most important conclusion drawn from this study is that determining the welding degrees of ignimbrites before surface protective coating processes is crucial because the welding degree directly affects the porosity, strength, and durability of the stone. Especially for ignimbrite samples used in historical and hospitality structures in regions such as Nev & scedil;ehir and, Kayseri understanding these properties helps to select the appropriate surface coating, enhancing the material resistance against decay processes.