Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2025Re-evaluation of excavation class limits for underground excavations based on new data
Gurocak, Zulfu; Kaya, Ayberk; Kanik, Mustafa; Alemdag, Selcuk
Many researchers have proposed empirical excavatability classifications to easily and quickly assess rock masses. These classifications mostly apply to surface excavations, while those for underground excavations are limited. Updating the classifications proposed for underground excavations based on new data is important in terms of eliminating the deficiencies in this regard. This study determined the engineering properties (RMR, Q, GSI), rock material strengths, and in-situ excavation classes of 16 underground rock masses. The new data were compared with excavation classifications from various researchers and empirical classes. The study found that empirical classifications for surface conditions are not applicable for underground. Excavation is more challenging in underground conditions due to stress from overburden. While excavation classes align for good to very good rock masses in both conditions, there is no perfect match for medium, weak, and very weak rock masses for underground. The study suggests that for underground excavation classes (blasting, hammer&blasting, hammer, and digging), both RMR89 and Q values should be used together to differentiate between classes. When using GSI for classification, the Is(50) value of the rock material should also be considered. The σcm parameter is the most critical in evaluating rock mass excavatability.
- MakaleAçık Erişim2018Combination of discontinuity characteristics and GIS for regional assessment of natural rock slopes in a mountainous area (NE Turkey)
Bostanci, Hasan Tahsin; Alemdag, Selcuk; Gurocak, Zulfu; Gokceoglu, Candan
Geographical Information Systems (GIS) have a very large spectrum of users. As in many engineering applications, GIS are frequently used in geotechnical projects, especially in producing various thematic and zoning maps such as various susceptibility and hazard maps. Instability maps for large areas with similar characteristic can be produced in a practical way by evaluating the results obtained by the data collected from field and laboratory studies. In order to introduce a methodology for producing rock slope instability maps for a large area, discontinuity controlled slope failures in the Köse Granitoid Complex (NE Turkey) were selected. To determine the types of failure such as planar, wedge, and toppling, and possible instable slope orientations kinematic analyses were carried out in the limited areas. The relationships between orientations of natural slopes and discontinuities obtained from kinematic analyses were evaluated with GIS software. Finally, discontinuity controlled instability maps were produced for the study area. Resulting maps show that the most common type of failure is wedge type. Additionally, the distributions of unstable areas along road networks were determined. Various land use types such as agriculture, grassland, settlement, and forest were also classified in order to predict the possible effects of slope instabilities. The methodology introduced in this study indicates highly promising results for the assessment of rock slope instability in large areas.
- MakaleYalnız künye2015Assessment of the Rock Slopes by Kinematic and Limit Equilibrium Methods on the Bağlarbaşı-Tekke (Gümüşhane) Motorway
Özkirişçi Oktay, Ceren; Gurocak, Zulfu; Alemdag, Selcuk
Kinematic analysis method is one of the widely used methods to evaluate potential failures such as planar, wedge and toppling in rock slopes. In this method, orientations of slope and discontinuity with the friction angle of the discontinuities planes are used to analyze possible failure types. However, the reliability of the results obtained from kinematical analyses is not sufficient for optimum slope design. For this reason, it is necessary that the results of kinematical analyses should be controlled using limit equilibrium or numerical analyses. In this study, stability of rock slopes on the highway of Bağlarbaşı-Tekke (Gümüşhane) was investigated using kinematical and limit equilibrium analyses. The results of thekinematical analyses showed that there may be planar and wedge type instabilities for the rock slopes numbered 5, 6, and 7. The limit equilibrium analyses conducted for the types of plane and wedge show that the rock slopes numbered 5 and 6 are instable while number 7 is stable
- MakaleAçık Erişim2015A comparison of support systems obtained from the RMR89 and RMR14 by numerical analyses: Macka Tunnel project, NE Turkey
Kanik, Mustafa; Gurocak, Zulfu; Alemdag, Selcuk
The aim of this study is to highlight the importance of the numerical approach in realistic support design for tunneling. The Macka Tunnel, which is planned to be constructed between the Trabzon-Gumushane highways, located in the Northeastern Turkey, was selected for a field study. The lithology of the study area consists of Late Cretaceous-aged sedimentary rocks, known as the Catak and Esiroglu formations, and the Late Cretaceous-aged Kackar Rhyodacite. In order to determine the geotechnical properties of rock masses and intact rocks, field and laboratory studies were carried out.The rock masses were classified in terms of the Rock Mass Rating (RMR) using the versions of RMR89 and RMR14 and then the preliminary support systems for the tunnel were determined, accordingly. The support systems obtained from the RMR versions were analyzed using the finite element method (FEM). The maximum total displacement and the maximum thickness of plastic zone occurred around the Macka Tunnel after installation the support systems suggested by the RMR89 and RMR14 versions were compared to determine which the RMR version suggests more realistic support system. The results showed that the support systems obtained from the RMR14 version suggests more realistic support element for fair rock masses and great horizontal stress values.
- MakaleAçık Erişim2015Utilization of the limit equilibrium and finite element methods for the stability analysis of the slope debris: An example of the Kalebasi District (NE Turkey)
Alemdag, Selcuk; Kaya, Ayberk; Karadag, Mustafa; Gurocak, Zulfu; Bulut, Fikri
The stability of the slope debris in residential area of the Kalebasi District (Ozkurtun-Gumushane) was investigated using the Limit Equilibrium (LE) and Finite Element Shear-Strength Reduction (FE-SSR) methods. Along the survey lines, four trial pits were dug and fourteen boreholes having a total length of 345m were drilled. Also, seismic refraction studies were conducted along the five lines. According to the field studies, thickness of the slope debris covering the 98ha of the study area varies between 1 and 36m. To determine the physical and shear strength properties of the slope debris, undisturbed samples were taken from the trial pits. As a result of the laboratory tests, soil categories of the debris were found to be as Clayey Sand (SC), Silty Sand (SM) and Low Plasticity Clay (CL). The deformation-controlled shear box tests were carried out to determine the shear strength parameters of the slope debris. According to these tests it was found that the peak cohesion and peak friction angle varies between 2.63-16.35kN/m2 and 20-27°, respectively. Stability analyses were performed using the obtained data from field and laboratory investigations in the Slide v5.0 and Phase2 v6.0 software programs and results were compared. In LE stability analyses, the factor of safety (FOS) of survey lines were found to be as 1.44, 1.80, 1.96, and 1.72; however for the FE-SSR method they were determined as 1.39, 1.72, 1.59, and 1.58, respectively.
- MakaleAçık Erişim2015A simple regression based approach to estimate deformation modulus of rock masses
Alemdag, Selcuk; Gurocak, Zulfu; Gokceoglu, Candan
Rock mass characterization has a crucial importance in rock engineering applications including foundation design, slope design, support design and others. For these purposes, it is necessary to determine some input parameters for design, such as deformation modulus (Em), uniaxial compressive strength (σci) and Poisson ratio (υ). The Em is an important input parameter and the practical and economical way to determine this parameter is to apply a rock mass classification system and estimate using the rock mass properties. Data from four different sites were used in the study. The values of Em were calculated using the existing empirical equations based on the Rock Mass Rating (RMR89) system. Furthermore, pressuremeter tests were carried out to determine the Em in one of the sites. The relationship between the RMR89 and the Em was obtained via simple regression analysis using the Em calculated from empirical equations based on RMR89 system. Afterwards, performance of the equation obtained from regression analyses was examined and compared the predicted Em values with experimental values with respect to the R2 values using the data of fourth site. Overall R2 value was found to be as 0.75.
- MakaleAçık Erişim2012Assessment of permeability and injection depth at the Atasu dam site (Turkey) based on experimental and numerical analyses
Gurocak, Zulfu; Alemdag, Selcuk
This study was performed in order to evaluate the permeability of the basalts and pyroclastics and the maximum depth of grout injection at the Atasu dam site, Turkey, using the equations of Kiraly and Hoek and Bray based on values obtained from Lugeon tests. In order to evaluate maximum discharge values and depth of injection, seepage analyses were performed using the finite element technique for each 10 m up to 100 m. The results indicate that to establish an impermeable zone at the dam site, the depth of injection should be taken as 50 m for the left and right slopes and 40 m for the river bed.
- MakaleAçık Erişim2012New considerations for empirical estimation of tensile strength of rocks
Gurocak, Zulfu; Solanki, Pranshoo; Alemdag, Selcuk; Zaman, Musharraf M.
In this paper, a combined laboratory and modeling study was conducted to develop a database for predicting tensile strength of rocks. Six hundred eighty six rock samples from 24 different sites throughout eastern Turkey were collected and tested for the development of this database and evaluation of models. A total of 512 samples were used for developing the models and the remaining 174 samples were used as control dataset. The material parameters selected in the development of the models include tensile strength (σ t), point load index (Is (50)), Schmidt rebound number (N) and unit weight (γ). A total of four models, two regression models, namely, simple linear regression and multiple regression, and two feed forward-type artificial neural network (ANN) models, namely, radial basis function network (RBFN) and multi-layer perceptron network (MLPN) are developed. A commercial software, Statistica 8.0, is used to develop these models. The strengths and weaknesses of the developed models were assessed by comparing the predicted σ t values with the experimental values with respect to the R 2 values. Overall, the MLPN model was found to be the best model for the present development and evaluation datasets. As a result of these analyses, an equation was suggested based on ANN model to estimate the tensile strength of rocks.
- MakaleYalnız künye2011Farklı ayrışma derecesine sahip kaya kütlelerinin kazılabilirlik özellikleri: Gümüşhane Granitoyidi örneği, Gümüşhane, KD Türkiye
Dağ, Serhat; Kaya, Ayberk; Gurocak, Zulfu; Alemdag, Selcuk
Kayaların kazılabilirlik özelliklerini belirlemek amacıyla yapılacak çalışmalar kazı maliyeti açısından mühendislik projelerinin uygulanabilirliğine katkı sağlamaktadır. Bu çalışmada, Gümüşhane ve yakın yöresinde yüzeylenen Erken Karbonifer yaşlı Gümüşhane Granitoyidi’nin kazılabilirlik özellikleri incelenmiştir. İlk olarak, dört faklı alan seçilmiş ve bu alanlardaki kaya kütleleri ISRM tanımlama kriterleri esas alınarak ayrışma derecelerine göre gruplandırılmıştır. Bu çalışmalar sonucunda 1, 2 ve 3 numaralı alanlardaki kaya kütlelerinin orta derecede ayrışmış, 4 numaralı alandaki kaya kütlesinin ise ileri derecede ayrışmış kaya sınıfında olduğu tespit edilmiştir. İkinci aşamada, eklemlerin mühendislik özellikleri ve kaya malzemesinin jeomekanik özellikleri belirlenmiştir. Sonraki aşamada ise kaya kütlelerinin RMR89, Q ve GSI değerleri belirlenmiş ve kazılabilirlik açısından sınıflandırılmıştır. Yapılan sınıflamalara göre, orta derecede ayrışmış kaya kütleleri “sökülebilir”, ileri derecede ayrışmış kaya kütlesi ise “kazılabilir” özelliktedir. İnceleme alanlarında yapılan kazı çalışmalarında orta derecede ayrışmış kaya kütlelerinin hidrolik kırıcı kullanılarak söküldüğü, ileri derecede ayrışmış kaya kütlelerinin ise kepçe kullanılarak kazıldığı tespit edilmiştir. Son aşamada ise bulunan sonuçlar ile uygulanan kazı yöntemleri karşılaştırılmıştır. Bu sonuçlara göre, Tsiambaos ve Saroglou (2009) tarafından önerilen kazı yöntemleri, yerinde yapılan kazı çalışmaları ile tamamen örtüşmektedir.
- MakaleYalnız künye2008Elazığ çevresindeki kayaçların beton agregası olarak kullanılabilirliği
Gurocak, Zulfu; Alemdag, Selcuk
Bu çalışmada, Elazığ çevresinde yüzeyleyen kayaçların beton agregası olarak kullanılabilirliğinin belirlenmesi amaçlanmıştır. Bu amaç doğrultusunda, Keban Uetamorfitleri, Elazığ Magmatitleri, Harami Formasyonu, Maden Karmaşığı, Kırkgeçit Formasyonu ve Karabakır Formasyonu' ndan farklı noktalardan kaya örnekleri alınmış, kaya ve agrega örneklerinde deneysel çalışmalar yapılmıştır. Petrografik ve kimyasal özellikleri belirlemek için, kimyasal analizler ve ince kesitlerde petrografik çalışmalar yapılmıştır. Ayrıca, kaya örneklerinin birim hacim ağırlık, ağırlıkça ve hacimce su emme, porozite, doluluk oranı, serbest basınç dayanımı belirlenmiştir. Çeneli kırıcı yardımıyla standart boyutta agrega örnekleri hazırlanmış, bu agregaların alkali agrega reaktivitesi, magnezyum sülfat çözeltisinde don kaybı, özgül ağırlık, su emme, yıkanabilir madde içeriği ve Los Angeles aşınma dayanımı belirlenmiştir. Deney sonuçları TSE standartlarındaki sınır değerler ile karşılaştırılmıştır. Keban Metamorfitleri, Elazığ Magmatitleri ve Kırkgeçit Formasyonu' nun düşük Los Angeles aşınma direncine ve özgül ağırlığa sahip olması nedeniyle, bu kayaçların beton agregası olarak kullanılması uygun değildir. Maden Karmaşığı ve Karabakır Formasyonu'na ait bazaltların tüm fiziko-mekanik özellikleri beton agregası olarak kullanılabilme açısından uygundur ve bu kay açlar beton agregası olarak kullanılabilirler.