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The quality of bucket wheel excavators (BWEs) operations is largely influenced by the physical-mechanical (structure, mineralogical composition, plasticity, anisotropy, degree of fracturing etc.) and technological properties (compressive strength, tensile strength, shear strength, compaction, consolidation, cutting resistance etc.) of the rocks. If the excavated materials are relatively homogenous, without intercalations with excessive cutting resistance, it is not difficult to conduct the technological process. I...

One of the frequent problems that needs to be addressed when mining coal deposits is the presence in the working face of cohesive materials having high mechanical strength in relation to the average rock to be excavated. These are generally called пїЅhard formationsпїЅ or пїЅhard inclusionsпїЅ and are in the form of either continuous layers or boulders. This problem is of particular importance in Europe where lignite deposits are exploited in large opencast mines utilizing Bucket Wheel Excavators (BWEs) as the mai...

The performances of the excavation machines depend largely on the tool and overall machine characteristics and on the other hand on physical mechanical characteristics of the excavated rock. There were more theories based on analytical deductions to explain the main cutting parameters on the basis of basic physical mechanical properties of the excavated rock. In this paper we use a new methodology, based on reliable laboratory data, which make possible to obtain correlation and regression formulas in order to pred...