Application of the results of excavation response experiments at climax and the Colorado School of Mines to the development of an experiment for the underground research laboratory

Large-scale underground experiment programs to examine excavation response have been performed at the Climax facility in Nevada and at the Colorado School of Mines. These two programs provided fundamental information on the behavior of rock and the effects of excavation; on instrument performance and configuration; and on the relationship between test geometry and test behavior. This information is being considered in the development of a major excavation response experiment to be carried out in the Canadian Underground Research Laboratory. 11 refs., 3 figs

An evaluation of some innovative fragmentation systems for oil shale

This report describes a large-scale underground mining method, large-hole stoping, using some innovative fragmentation systems (buffer blasting, continuous loading/hauling, and mechanical miners for development). This study includes a literature review and an experimental study of one of the key design factors--buffer blasting. The purpose of the buffer-blasting experiments is to examine the swell that is necessary to achieve satisfactory fragmentation results. The study also includes a technical and economic evaluation of the new mining method compared with conventional room and pillar mining. The purpose of this study is to examine innovative methods that exist today and may provide a more efficient mining system than that currently used. Note that this is a conceptual study, and that the mining for the two mine designs were compared using a daily production rate of 75,000 tones per day. This amount was chosen because it is the maximum amount possible for a rubber-tired room and pillar operation with only a one-shaft complex

Rock fragmentation

Experts in rock mechanics, mining, excavation, drilling, tunneling and use of underground space met to discuss the relative merits of a wide variety of rock fragmentation schemes. Information is presented on novel rock fracturing techniques; tunneling using electron beams, thermocorer, electric spark drills, water jets, and diamond drills; and rock fracturing research needs for mining and underground construction. (LCL

Earthquake damage to underground facilities

In order to assess the seismic risk for an underground facility, a data base was established and analyzed to evaluate the potential for seismic disturbance. Substantial damage to underground facilities is usually the result of displacements primarily along pre-existing faults and fractures, or at the surface entrance to these facilities. Evidence of this comes from both earthquakes and large explosions. Therefore, the displacement due to earthquakes as a function of depth is important in the evaluation of the hazard to underground facilities. To evaluate potential displacements due to seismic effects of block motions along pre-existing or induced fractures, the displacement fields surrounding two types of faults were investigated. Analytical models were used to determine relative displacements of shafts and near-surface displacement of large rock masses. Numerical methods were used to determine the displacement fields associated with pure strike-slip and vertical normal faults. Results are presented as displacements for various fault lengths as a function of depth and distance. This provides input to determine potential displacements in terms of depth and distance for underground facilities, important for assessing potential sites and design parameters