Mahmut Yavuz

In this paper, the stability analysis and preliminary support design for the Trepça main shaft deepening are addressed, thereby enabling the opening of new horizons (i.e., mining levels). Field investigations and rock mass classification systems (e.g., RMR, RMQR) indicate that the breccia, schist, and limestone rock masses along the shaft excavation exhibit stability problems, necessitating an optimal supporting structure. Using the finite element numerical method, the performance of the support systems recommended by the empirical methods was successfully evaluated. The numerical analyses and results showed that the empirical methods are not always valid and fail to investigate the performance of the supporting deep structures for weak and very weak rock masses. In this study, a series of numerical analyses was performed to evaluate different possible support scenarios. Accordingly, for three main different geological lithologies (e.g., breccia, schist, limestone), an optimal support system is proposed, with a concrete lining thickness ranging from 30 to 50 cm with concrete class C25 and C30. Consequently, satisfactory results were obtained and analysed with respect to total displacements and the thickness of the plastic zone.

Węgiel jest niezbędnym źródłem energii do wytwarzania energii elektrycznej i innych zastosowań przemysłowych. Kraje wykorzystujące to źródło energii jako zasób krajowy i naturalny powinny rozważyć swoją politykę wydobycia węgla. Jest to trudne zadanie dla osób odpowiedzialnych za rozwój i planowanie inwestycji, gdyż na politykę wydobycia węgla wpływają czynniki ekonomiczne, polityczne, społeczne, narodowe i środowiskowe. Ponadto, wiele czynników cząstkowych, które można pogrupować w ramach tych czynników, ma ogromny wpływ na podejmowanie decyzji dotyczących polityki wydobycia węgla. Czynniki te i podczynniki nie są od siebie niezależne, ale również pozostają ze sobą w relacjach. W artykule zaproponowano wielokryterialny model podejmowania decyzji umożliwiający wybór najlepszej polityki wydobycia węgla w Turcji przy użyciu metody Analytical Network Process (ANP), w której uwzględniane są wszystkie te efektywne czynniki i ich relacje. Turcja stoi w obliczu problemów z dostawami energii, ponieważ zapotrzebowanie na nią wzrosło w wyniku szybkiego rozwoju gospodarczego, rosnącej liczby ludności i rosnącej industrializacji. Turcja jest w dużym stopniu uzależnione od importowanych źródeł energii, takich jak ropa naftowa, gaz i węgiel kamienny, ponieważ naturalne zasoby energetyczne kraju ograniczają się do węgla brunatnego i kamiennego. W tym zakresie Turcja musi opracować politykę wydobycia węgla zgodnie ze swoimi warunkami. Głównym celem tego badania jest zbadanie najwłaściwszej polityki węglowej Turcji poprzez przyjęcie różnych perspektyw i ocenę tej kwestii jako problemu decyzyjnego. Po badaniach modelowych z wykorzystaniem ANP stwierdzono, że znacznie większa produkcja węgla powinna zostać zapewniona poprzez nowe inwestycje w sektorze wydobycia węgla w Turcji. Metodę ANP uznano za przydatną i praktyczną technikę decydowania o problemach polityki górniczej.

Maden yataklarının kaynak ve rezervleri ile kalitesinin belirlenmesi için, maden yatağı hakkında yeterli bilgilerin elde edilmesi gerekmektedir. Bundan dolayı, kaynak ve rezervler bu bilgilerin nitelik ve niceliklerinin yeterliliği ölçüsünde belirlenmekte ve sınıflandırılmaktadır. Bir maden sahasında yapılan arama ve ilgili değerlendirme çalışmaları sonucunda yatağın hacmi ve tonajının yanı sıra fiziksel, jeokimyasal, jeolojik, mineralojik ve yapısal özellikleri de belirlenmektedir. Bu çalışmalar yardımıyla yatakta gerçekleştirilen proje faaliyetinin teknolojik, ekonomik, hukuki, çevresel ve sosyal boyutlarını ortaya çıkarmak için yapılan tüm çalışmaların bileşimi, o yatağın kaynağının/rezervinin belirlenmesine esas teşkil etmektedir. Madencilik, doğası gereği büyük riskler taşıyan, yatırım maliyetlerinin yüksek olduğu ve yatırımın geri dönüşünün uzun zaman aldığı bir sektördür. Öte yandan madencilik sektöründe getiri oldukça yüksektir. Arama faaliyetleri sonucunda keşfedilen madenin miktar ve kalitesinin tahmin edilmesindeki zorluklar, risklerin ana nedenidir. Bu risklerin azaltılması için arama dönemi ve sonrasında bilimsel, teknolojik ve çok disiplinli çalışmalar büyük önem taşımakta olup, uluslararası standartlara uygun numune analizlerinin akredite laboratuvarlarda yapılması ve yetkin kişiler tarafından raporlanması gerekmektedir. Bu sayede çalışmalar açık, şeffaf ve güvenilir olacak, mühendisler, yatırımcılar, finans kuruluşları gibi konu ile ilgili kişilerin fikir birliğine varması sağlanacaktır. Bu çalışmada, Ankara ili Beypazarı ilçesi sınırları içerisinde yer alan Çayırhan B linyit sahasının UMREK (Ulusal Maden Kaynak Rezerv Raporlama Komisyonu) Kodu’na göre rezerv miktarının kestirimi amaçlanmıştır. Rezerv kestirim çalışması, sahada daha önce MTA ve Palaris firması tarafından yapılan kaynak kestirim raporu doğrultusundaki çalışmanın devamı niteliğindedir.

The assessment of the stope stability is of great importance in the underground mine design process. The instability of stopes leads to serious economic and safety problems in mining operations. This paper aims to assist in the prediction of stope stability by making use of machine learning algorithms. For this purpose, a hybrid grid search-based Artificial Neural Network method is proposed. In the experiments, a total of 215 stope cases which have been collected from six underground mining operations located across Australia are used to prove the validity of the proposed method. Then, the performance of the proposed method is compared with k-nearest neighbour (kNN), naive Bayes (NB), support vector machine (SVM), decision tree (DT) and the stability graph method. Furthermore, several performance measures, such as accuracy, precision, specificity, recall, f-measure, and g-mean are considered during the performance comparison of the methods. The accuracy values are obtained as 91.63%, 81.86%, 77.21%, 76.74%, 73.95%, and 69.77% with the proposed hybrid grid search-based ANN method, SVM, DT, NB, kNN, and the stability graph method, respectively. The empirical results from the experiments indicated that the proposed hybrid approach outperformed the other aforementioned methods, which confirms that the proposed method is a useful tool to predict stope stability.

In this study, Fuzzy TOPSIS method was performed for the selection of open pit truck and the optimal solution of the problem was investigated. Data from Turkish Coal Enterprises was used in the application of the method. This paper explains the Fuzzy TOPSIS approaches with group decision-making application in an open pit coal mine in Turkey. An algorithm of the multi-person multi-criteria decision making with fuzzy set approach was applied an equipment selection problem. It was found that Fuzzy TOPSIS with a group decision making is a method that may help decision-makers in solving different decision-making problems in mining.

Underground mining method selection (UMMS) is one of the most important decisions in mining engineering. Choosing a suitable underground mining method to carry out extraction from a mineral deposit is very important for all stage of mining operations. In practice, UMMS is one of the multiple attribute decision-making (MADM) problems and mining engineers have some difficulties in making the right decision in the multiple criteria environment. In this paper, the following two similar MADM methods are described: analytic hierarchy process and fuzzy multiple attribute decision-making are applied to select the optimal underground mining method for lignite mine located in Istanbul. At the end of decision-making process, sensitivity analysis process is applied for each method.