Rock engineering for underground coal mining. A practical guide for supervisors at all levels, mine planners and students / Разработка горных пород для подземной добычи угля. Практическое руководство для руководителей всех уровней, проектировщиков шахт

It is necessary for those using this book to have some fundamental understanding of the basics of rock engineering. In this chapter, the basics will be explained in a simplified manner while the formal scientific treatment can be found in Appendix A. Some mathematics have to be used, but the more complex equations will be avoided. Another important element of the chapter is to define some of the terms that are used in the rest of the book. To avoid confusion later, it is necessary to provide this material first. There will be very few unfamiliar terms. The most obvious challenge will be to avoid confusing common terms used in the scientific context with different meanings in daily use.  The contents of the chapter have been carefully selected to include only those aspects that are important for understanding the material in the rest of the book. It should therefore not be seen as a comprehensive guide to fundamental rock mechanics. Entire books have been devoted to that subject. The interested reader is referred to the bibliography at the end of Appendix A.
The equations that are supplied in this chapter are mostly of a generic nature, which means that they can be used with any system of units. However, in the light of the practical intent of the material, units that are commonly used in South African coal mining are supplied with the equations. It is important to note that in doing this, the user has to be careful in supplying input to the equations that are of the same order of magnitude as the end unit. For instance, if Mega-units are used, all the input also has to be supplied in Megaunits. <...>