1993-03-30_HYDROLOGY - M1977378 - Laserfiche WebLink

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Tunnel (beyond the Daylight Corner at approximately 2700 feet from the outside end of track) has intercepted 1350 gpm of ground water. Of this 1350 gpm, 90 percent can be accounted for from the intersection of five major fracture zones (the Washington vein, the Sunnyside vein, the Brenneman vein, a fracture zone at the 0700 runaround, and a fracture zone located 3020 to 3220 feet from the end of track (see section 4.2.1). Figure 6 is a schematic diagram showing the manner in which fracture permeability changes with depth. A dramatic demonstration of the localized nature of the fracture permeability in the deeper parts of the mine occurred when the American Tunnel first intercepted the Washington vein. During the late 1950's workings above the American Tunnel were flooded to approximately 50 feet below F Level according to Mr. Bob Ward, mine superintendent of the Sunnyside Mine at that time. This resulted in approximately 830 feet of hydraulic head over the American Tunnel. Diamond drilling was used to intercept the Washington vein from the face of the American Tunnel. When the vein was intersected the sustained water pressure and volume were so great that the full 150 feet of drill string was pushed back out of the hole into a twisted "spaghetti" of steel. A day later flow out of the 2-inch diameter hole was under enough pressure to shoot out approximately 20 feet from the drill hole. The estimated flow of water was approximately 580 gpm (see Appendix A). The nearest old workings on the Washington vein were located on I Level, approximately 350 feet higher than the American Tunnel. This indicates a very high permeability along the vein. ` All footages along the American Tunnel are referenced to track repair footages as marked on the tunnel wall. The track repair footages have a zero point just outside of the portal. sanjuan\sunny\110361\oct91.Rpt 15 HHl Simon HYDRO=HEWHCH