Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleYalnız künye2026Machine learning-based multi-class classification of rock mass permeability using integrated geotechnical and geophysical parameters
Sari, Mahmut; Alemdag, Selcuk; Melek, Mesut; Seren, Aysel
In engineering applications, machine learning (ML) provides a promising approach when direct characterization of subsurface properties is challenging, time-consuming, and costly. This study developed a multi-class ML framework for classifying rock mass permeability based on Lugeon values using 86 observations from drilling and geophysical investigations at the Kırklartepe dam site in Bayburt, Türkiye. Seven predictors were considered: depth, Rock Quality Designation (RQD), joint frequency, Schmidt hammer hardness, P-wave velocity, S-wave velocity, and electrical resistivity. The observations were assigned to four permeability classes: very low, low, moderate, and high. Six classifiers were evaluated: Polynomial Kernel Support Vector Machine (P-SVM), Linear Discriminant Analysis, k-Nearest Neighbors (k-NN), AdaBoostM2, Bagged Trees, and Radial Basis Function SVM. Sequential Forward Feature Selection and Leave-One-Out Cross-Validation were used for feature selection and model evaluation, respectively. Robustness was further assessed using bootstrap confidence intervals, class-imbalance treatments, feature-selection stability, and learning curves. Among the baseline models, P-SVM using all seven predictors achieved the highest accuracy (79.07%), with a macro-F1 of 0.774 and the lowest Golden Distance (GD = 0.4372). When balanced class-wise performance was prioritized, k-NN with in-fold SMOTE achieved the lowest overall GD (0.4126) and a macro-F1 of 0.777. S-wave velocity and electrical resistivity were the most influential predictors. Overall, the findings demonstrate that the proposed framework effectively integrates geotechnical and geophysical data for rock mass permeability classification, providing a robust, data-driven decision-support approach that supports subsurface characterization and complements conventional permeability assessment in engineering applications.
- MakaleAçık Erişim2022Determination of rock quality designation (RQD) in metamorphic rocks: a case study (Bayburt-Kırklartepe Dam)
Alemdag, Selcuk; Sari, Mahmut; Seren, Aysel
The role and importance of rock mass classification systems from past to present in engineering designs are indisputable. Therefore, the correct estimation of the parameters that make up these systems is essential in terms of reliability, time, and economy. One of the crucial parameters commonly used in rock mass classification is the rock quality designation (RQD). This study aimed to indirectly estimate the RQD value determined from the core samples obtained from the exploration drillings. In this context, P wave velocity (Vp) was obtained by seismic refraction tomography (SRT) from the geophysical measurements applied in the metamorphic rock mass, and the discontinuity frequency parameter was obtained from the line survey studies carried out on the rock mass. What determined RQD values with the help of simple regression analyzes and empirical equations with high estimation capacity using Vp and discontinuity frequency parameters were obtained without drilling in the rock mass. Accordingly, the performance indexes of the equations produced by different researchers and the equations produced in this study were evaluated in determining the RQD parameter. In the generated equations, the highest coefficient of determination value depending on joint frequency and Vp wave velocity with RQD was calculated as R2 = 0.89 and R2 = 0.82, respectively. When the produced equations are evaluated according to the performance indexes, it is seen that the empirical equations obtained by previous studies have the highest root mean square error (RMSE) and values account for (VAF) values compared to the other equations and have very high estimation capacities. Thanks to the equations with high estimation capacity, the RQD value was determined depending on the joint density and Vp speeds.
- MakaleYalnız künye2020Determination of geological structures by geophysical and geotechnical techniques in Kırklartepe Dam Site (Turkey)
Sari, Mahmut; Seren, Aysel; Alemdag, Selcuk
In foundation research of engineering structures, application of geophysics methods before drilling work allows not only more economical studies but also a more detailed determination of underground sections. Especially in pre-feasibility studies on long tunnel routes, dam sites and lake areas, it has a vital importance in terms of structural safety to determine possible underground buried fault lines, lithology changes, anticlinal-synclinal structures and underground openings. By considering these effective factors, the alluvium/bedrock border and the positions of potential buried faults in the dam site and lake area in the Kırklartepe area of the province of Bayburt in northeastern Turkey were determined by comparison with geophysical and geotechnical methods. First of all, the resistivity of the dam axis location and the change of the Vp wave velocity by depth were determined by comparing the results between geophysical methods of electrical resistivity tomography (ERT) and seismic refraction tomography (SRT), respectively. Afterwards, from the foundation boreholes opened in the dam axis location, joint frequency and the other parameters determined by observations were obtained. With these parameters, 2-dimensional zoning profiles of the dam axis location were formed, and the alluvium-bedrock border and the locations of the buried faults were determined. Two potential faults in the NW-SE direction relative to the location of the dam axis were clearly revealed in the zoning profiles obtained in the ERT and SRT measurements. Additionally, the presence of these faults was determined as a result of examining the separation and joint frequency parameters from the drilling core samples collected from the BH_3 and BH_5 boreholes opened in the investigated area based on changes in the vertical and horizontal directions. In addition to these, in the ERT study, two potential faults other than the determined two were also detected. It was seen in the zoning profiles that these faults corresponded to right under the BH_2 borehole and 60 m SW of the BH_6 drilling. Consequently, in the zoning studies conducted at the examined site, the change in the lithology at the dam axis by depth (alluvium-bedrock border), lateral correlations of boreholes and potential faults were determined. It was recommended for the selected dam axis location to be constructed at a more suitable place in the NW direction in terms of engineering. Furthermore, with this study, it was revealed once again that it is highly essential to use geophysical and geotechnical together in conceptualizing large engineering structure projects.
- BildiriAçık Erişim2016A Study on the Performance of GPR for Detection of Different Types of Buried Objects
Toksoz, Derya; Yilmaz, Isik; Seren, Aysel; Mataraci, Isil; Salame, C.; Aillerie, M.; Papageorgas, P.
The objective of this research is to evaluate the applicability of Ground Penetrating Radar (GPR) method to detect burried objects in the shallow depths using 250 MHz and 800 MHz center frequency antennas. For this purpose, different objects were burried in several places of a certain test site. GPR data were collected along six paralel profiles using 250 MHz and 800 MHz antennas which are compatible with RAMAC CU II system. The reflections profile data were processed using the computer program ReflexW. After the processing of data, the reflected /scattered reflections on the processed radargrams were examined and the radargrams were interpreted to determine the depths and positions of the objects from the surface. Also, the data obtained from 250 and 800 MHz antennas were compared and the differences between them in terms of resolution were discussed.
- BildiriYalnız künye2014Imaging of the deteriorations and concrete quality of the tunnels (Zigina, Torul) with ground penetrating radar
Saricicek, Isil; Seren, Aysel; Lambot, S.; Giannopoulos, A.; Pajewski, L.; Andre, F.; Slob, E.; Craeye, C.
Ground Penetrating Radar (GPR) that give high resolution image and no damage to the researched surface, holds an important place in the use of near surface shallow researches. In this study; it is aim to investigate the fracture-crack system, the stratigraphy and the deterioration of the walls of Zigana Tunnel which is located at the way Trabzon-Gümüşhane in order to evaluate the existence of risk area leaking water out and structure contents. Furthermore, in addition to Zigana tunnel, the concrete quality of the Torul tunnel which has built recently was investigated. During examinations, GPR data were collected along totally 20 profiles at the entrance of the both sides of tunnels by using 500 MHz and 800 MHz shielded antennas. After applying data processing stages to the collected data, 2D and 3D images were acquired and interpreted.