Surface Water Supply Of The United States 1930 Part 12 North Pacific Slope Drainage Basins B Snake River Basin Nathan C Grover Chief Hydraulic Engineer Gc Baldwin Lynn Grandall Gl Parker Cg Paulsen Ab Purton And Gh Canfield District Engineers Us Geological Survey Water Supply Paper 708

Author : John F. Abel
Publisher :
ISBN 13 :
Total Pages : 56 pages
Book Rating : 4.:/5 (319 download)

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Download or read book Ice Tunnel Closure Phenomena written by John F. Abel and published by . This book was released on 1961 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mechanics of closure, exhibited by ice tunnels, can be understood by considering the ice as a viscous solid. The viscous solid will flow, when subjected to a force, at a rate dependent on the magnitude of the force, the area of relief open for flow, and the apparent viscosity of the viscous solid. In the case of the ice tunnels, the force inducing the flow is the weight of the overburden; the area of relief open for flow is the tunnel opening; and apparent viscosity is the resistance to flow exhibited by the ice. The closure of a rectangular opening made in ice was measured. Maximum closure occurs at the center of unsupported roof, wall, or floor spans. The vertical closure rate decreases negligibly approximately 2% from the center of a room to approximately 6 ft from the wall. From the point about 6 ft from the wall to the wall, the closure rate decreases about 30%. Approximately 30% of vertical closure at the center of the span is due to flexure of the floor and roof. The remaining 70% is due to shortening of the wall height; the major portion of this wall closure occurs at the bottom of the wall. Over 80% of closure due to flexure of the floor and roof results from flexure of the floor. (Author).