Cutting performance assessment of a medium weight roadheader at Çayırhan coal mine

Download
2005
Keleş, Serhat
In this thesis, in-situ instantaneous cutting rates of boom type, medium-weight milling type roadheaders (Mk-2B) at Çayırhan Coal Mine are determined by studying previous performance tests and carrying out additional underground cutting tests. Some rock properties such as uniaxial compressive strength, tensile strength, Cone Indenter hardness, Shore hardness, Schmidt hammer rebound hardness and laboratory cutting specific energies are determined by laboratory tests for the rock and coal types encountered in the drivage of roadways. The relations between the instantaneous cutting rates and the above rock characteristics and the laboratory cutting specific energies are established. The results show that instantaneous cutting rates can be best predicted using laboratory cutting specific energy which provides the highest correlation (R2 = 0.8411) as compared to other rock properties. The model developed for the medium-weight machine to predict instantaneous cutting rate is compared with those developed earlier for the light-weight and heavy-weight machines. It is determined that improvements in cutting performance with the medium-weight machines as compared to light-weight machines is achieved for the rocks requiring laboratory cutting specific energy greater than 5 MJ/m3.

Suggestions

Fatigue Precracking Time Estimates for Three-Point Bending Specimens
Ghasabi, A. Alipour; Motameni, A; Kadıoğlu, Fevzi Suat (Springer Science and Business Media LLC, 2019-10-01)
Specimens containing sharp cracks are needed in certain types of mechanical tests, first and foremost for fracture toughness measurement of materials. Their use, however, is not just limited to this type of test. Another category of experiments deals with characterizing nonlinear vibrations of beams containing breathing cracks. To produce cracked beam specimens, fatigue cracks can be grown ahead of sharp notches under controlled loading. ASTM E399 and ASTM E1820 standards provide guidance on such procedures...
Shape optimization with the biological growth method: A parameter study
Tekkaya, AE; Guneri, A (1996-01-01)
Studies the effect of parameters controlling the biological growth method by applying it to the classical optimization problem of a plate with a central hole under biaxial stress state. It has been found that the optimization character of the method depends strongly on the so-called reference stress. Depending on the magnitude of this parameter either a local or global optimum is approached. A global optimum corresponds to the minimum possible v. Mises stress along the hole boundary (and hence in the plate)...
Performance assessment of hydraulic and cable shovels
Karpuz, Celal; Muftuoğlu, Yadikar (1992-04-01)
In this paper, performance assessment studies for hydraulic and cable shovels carried out on a nationwide scale in the surface lignite mines of Turkish Coal Enterprises are explained. The work was involved manual stopwatch surveys of shovel dig cycle times, estimation of bucket filling and hourly excavation capacity of shovels. The accumulated data is compared with the literature values in order to be evaluated in terms of ease of digging. The observed bucket size ranges of hydraulic and cable shovels varie...
Renovation of a safety-inspection methodology for river bridges
Yanmaz, Ali Melih; Caner, Alp (American Society of Civil Engineers (ASCE), 2007-09-21)
River bridges and related infrastructural elements need to be monitored and inspected periodically for deterioration and loss of function due to aging, adverse hydraulic conditions, and chemical attacks. Necessary protective works and related actions should then be implemented to increase safety. Types of items to be inspected would be categorized as structural, geotechnical, hydraulic, and structural material conditions. Requirements for periodic inspections and the ways of handling these activities were d...
Geotechnical characterization and performance assessment of bentonite/sand mixtures for underground waste repository sealing
Akgün, Haluk (Elsevier BV, 2010-08-01)
The objective of this study is to assess the performance of a bentonite/sand mixture for the sealing of underground waste repositories through performing geotechnical laboratory tests such as compaction and flow tests. Swelling, mechanical and shear strength tests along with analyses of seal/rock mechanical interactions of an axially loaded seal in rock have been conducted to recommend an optimum compacted bentonite/sand mixture and a suitable bentonite/sand seal length-to-radius ratio (L/a) as a function o...
Citation Formats
S. Keleş, “Cutting performance assessment of a medium weight roadheader at Çayırhan coal mine,” M.S. - Master of Science, Middle East Technical University, 2005.