Stoppings: Technology developments and mine safety engineering evaluations

摘要

Advances in materials technology have resulted in newer products for the construction of stoppings used in USA underground coal mines. Some of the newer materials were developed for the construction industry and were consequently introduced into the mining industry. Ventilation control devices such as stoppings, overcasts and undercasts have traditionally been constructed of concrete block or metal panels. Efforts to reduce material and labor costs in the construction of stoppings and other ventilation controls have led to the introduction and use of "nontraditional" materials. The "nontraditional" or newer materials may consist of lightweight blocks composed of various cement-type compounds or panels composed of gypsum or other mineral-type compounds, and plastic membrane and steel fabricated designs. Reduced labor and material costs may be derived from such materials, while required safety properties are maintained. An MSHA engineering evaluation program was developed to assess the suitability of such newer products in terms of the safety standards for fire endurance and flexural strength as specified in USA Title 30, Code of Federal Regulations, Part 75.333. The engineering evaluation program is described and a short description of the fire endurance and flexural strength tests is presented. A discussion of the newer materials evaluated is included.