Empirical and analytical design of large openings at a proposed national underground science laboratory.
Zipf-K; Tesarik-D; Johnson-J
Proceedings of the 21st International Conference on Ground Control in Mining, August 6-8, 2002, Morgantown, West Virginia. Peng SS, Mark C, Khair AW, Heasley KA, eds., Morgantown, WV: West Virginia University, 2002 Aug; :318-327
The famous Homestake gold mine in Lead, South Dakota, closed recently after 125 years of operation. However, the mine may receive a new lease on life as a National Underground Science Laboratory (NUSL) supported by the National Science Foundation (NSF) and dedicated to high-energy physics experiments involving neutrinos. These experiments require the construction of many large underground chambers tens of meters wide at depths of over 2118 m. Construction of such large openings at such extreme depths has few precedents in civil-engineering-type construction. The Spokane Research Laboratory has a long history of ground control research at the Homestake Mine and has supported NSF and the physics community in their efforts to develop a NUSL at Homestake or other suitable location. This paper will summarize underground science and describe proposed underground science laboratories in the United States, in particular the proposed NUSL at Homestake. Next, the paper describes and empirical design approach using the Q system of rock mass classification for these large openings. An initial site investigation that produced three good case histories is described. The actual support system used at the three sites agrees well with support recommendations from current suport design charts, giving credibility to estimates of the classification parameters and Q. Feasibility of, and support requirements for, 25-, 50-, and 100-m spans are estimated in the anticipated rock mass. This analysis indicates that 25- and 50-m spans are probably feasible, but a stable 100-m span may be unachievable. The empirical predictions are then compared to detailed numerical analyses. The paper concludes with preliminary support recommendations and necessary site investigations needed to make a proposed NUSL a successful reality. These studies have been important input to NSF for their decisions on the technical feasibility of developing the proposed NUSL. If NUSL is developed, it could enable scientific experiments in areas beyond high-energy physics. The laboratory could also enable research in rock mechanics, ground water hydrology, mining engineering, mine safety and health, and ground control.
Laboratories; Underground-mining; Ground-control; Rock-mechanics; Analytical-models; Ground-stability; Safety-research; Safety-engineering; Occupational-health; Environmental-factors
Peng-SS; Mark-C; Khair-AW; Heasley-KA
Proceedings of the 21st International Conference on Ground Control in Mining, August 6-8, 2002, Morgantown, West Virginia