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Öğe The analysis of radial displacements occurring near the face of a circular opening in weak rock mass(Pergamon-Elsevier Science Ltd, 2010) Basarir, H.; Genis, M.; Ozarslan, A.The effect of opening size, rock properties and stress conditions on the radial displacements ahead and behind of the advancing face of a circular opening is one of the most important topics in civil and mining engineering. In this paper we develop a prediction system for radial displacements around the face of an opening by combining rock mass rating classification system, a three dimensional finite difference code and multiple regression modeling. Predictive equations and response surfaces for rock mass response are proposed. By using these equations and response surfaces, it is possible to assess radial displacements around the face and to construct the longitudinal deformation profile of a circular opening with different diameters excavated in weak rock mass under different stress conditions. The predictive equations were validated by means of statistical tests and analytical solution. Proposed response surfaces and equations can provide the basis of guiding the design and construction of underground openings. (C) 2010 Elsevier Ltd. All rights reserved.Öğe A fuzzy logic based rippability classification system(South African Inst Mining Metallurgy, 2007) Basarir, H.; Karpuz, C.; Tutluoglu, L.Due to the environmental constraints and the limitations on blasting, ripping as a ground loosening and breaking method has become more popular in both mining and civil engineering applications. Because of the technological advances in dozer manufacturing techniques, more powerful dozer types are available today. Thus, the ground, previously classified as non-rippable, has become rippable. As a consequence, a more applicable rippability classification system is needed which considers both equipment properties as well as rock properties in all applications. This paper is part of a complementary research work and presents the development of a previously published grading rippability classification system by the application of fuzzy set theory. The integrated rippability classification system considers the combined utilization of the rock and equipment properties, as well as expert opinion. Fuzzy set theory was chosen mainly because it deals well with uncertainty in the choice of variables. Although there are apparent sharp or discontinuous boundaries in existing classification systems, practically most of the factors involved in the ripping process are less well defined and boundaries are more blurred (or fuzzy) or uncertain in nature. Also by means of fuzzy logic it is possible to eliminate bias or subjectivity. The validity of the proposed system was checked by the comparison against existing classification systems and direct ripping production values obtained at studied sites. It is seen that by means of fuzzy logic, the uncertainties are reduced and biased usage of the final ratings that appear in alternative systems are efficiently dealt with.Öğe Numerical analysis of support performance and rock-support interaction considering different rock conditions(Uceat-Chamber Mining Engineers Turnkey, 2007) Basarir, H.This paper presents the results of performance analysis of support systems designed using the rock mass rating system (RMR), one of the most widely used rock mass classification systems, and the results of rock support interaction analysis based on numerical modelling. Five different rock mass conditions were assumed from very poor to very good by assessing different RMR values. Necessary support systems were determined based on the RMR system. By using a finite element program the performances of the proposed support systems were analysed and the stability of the opening were evaluated. Numerous model runs were conducted for estimating the deformations and stresses around an opening excavated in different rock mass conditions and different depths. Instead of a single ground reaction curve whole families of curves, representing variations in the rock mass quality of the assumed ground conditions and different depths, were obtained. By means of obtained ground reaction curves, engineers can justify the support performance and practical range of deformation expected to occur for their own conditions. However, these curves are produced for idealized rock mass properties, they should be reproduced by following the approach described in this paper for individual sites.Öğe Prediction of the performance of impact hammer by adaptive neuro-fuzzy inference system modelling(Pergamon-Elsevier Science Ltd, 2011) Kucuk, K.; Aksoy, C. O.; Basarir, H.; Onargan, T.; Genis, M.; Ozacar, V.Impact type excavators are widely used for excavations, performed in weak-laminated-foliated-anisotropic rocks. Therefore the prediction of the performance of impact hammer is very important in many mining and civil engineering projects. This paper describes the construction of adaptive neuro-fuzzy inference system model for predicting the performance of impact hammer type excavator by considering rock and excavating machine properties such as block punch strength index, geological strength index system and impact hammer power. Extensive field and laboratory studies were conducted in the tunnel construction route of the second stage of Izmir Metro Project, which excavated in laminated-foliated flysch rocks. The results of the constructed adaptive neuro-fuzzy inference system and traditional multiple regression models were compared. Although the prediction performance of traditional multiple regression model is high, it is seen that adaptive neuro-fuzzy inference model exhibits better prediction performance according to statistical performance indicators. By means of the developed model, the performance of impact type excavators can be predicted in terms of net excavation based on the selected rock and machine properties. (C) 2010 Elsevier Ltd. All rights reserved.Öğe Specific energy based rippability classification system for coal measure rock(Pergamon-Elsevier Science Ltd, 2008) Basarir, H.; Karpuz, C.; Tutluoglu, L.Specific energy is simply defined as the work done per unit volume of rock excavated. Specific energy is an important performance parameter as it relates cutting force to the amount of rock excavated. In this paper the development of a new rippability classification system for coal measure rock based on specific energy is presented. Extensive field and laboratory studies were conducted at six different lignite open pit mines and rock mechanics laboratory. Since both ground and machine properties are incorporated, the rippability classes of rocks and the approximate hourly ripper productions of different dozer types can be assessed by using the developed system. (C) 2008 ISTVS. Published by Elsevier Ltd. All rights reserved.
