Method for Cutting Off a Large Waterflow by Means of Cement-grouting while Sinking a Mine Shaft.

摘要

21,790. Gevers, J. Oct. 3. Excavating; hardening ground.-Relates to the cutting off of water-flow met with while sinking a shaft. The portion of the shaft passing through the water-bearing seams is lined with a tubbing 2. A ballast skeleton bed 1 is then spread over the bottom of the shaft. In the case of a large water-flow, a floor 4 is substituted for the ballast bed. On the ballast or floor a concrete plug is then formed, a pipe 7 passing to the bottom of the shaft containing a suction pipe for keeping the water-level below the concrete plug while this is setting. When the plug has set, the suction pipe is removed and the pipe 7 closed by a cover 8 provided with a valve which is left open until the cover is secured. Cement grout may then be forced through pipes or bore-holes to stop the water-bearing cracks so that excavation may be resumed.