. Principles of irrigation engineering, arid lands, water supply, storage works, dams, canals, water rights and products. being 149 lb. per cubic foot. The wateris assumed to weigh lb. per cubic foot and the flowing mud57 1/2 lb. per cubic foot additional. The figure under discussion is a section of the Granite Reef Damon Salt River project, Arizona. It is provided with a tight concretecurtain wall 6 ft. wide under the upper face of the dam, and anothercurtain wall with wide holes to permit water to escape which may MASONRY DAMS 243 have penetrated beneath the dam. On the upper section th
. Principles of irrigation engineering, arid lands, water supply, storage works, dams, canals, water rights and products. being 149 lb. per cubic foot. The wateris assumed to weigh lb. per cubic foot and the flowing mud57 1/2 lb. per cubic foot additional. The figure under discussion is a section of the Granite Reef Damon Salt River project, Arizona. It is provided with a tight concretecurtain wall 6 ft. wide under the upper face of the dam, and anothercurtain wall with wide holes to permit water to escape which may MASONRY DAMS 243 have penetrated beneath the dam. On the upper section the areais estimated at 184 sq. ft. and the weight of a section i ft. thick isgiven as 27,416 lb. On this the horizontal liquid pressure is esti-mated at 24,750 lb., and vertical liquid pressure at 5,040 lb. The curved section is designed on the theory that the watershould be forced to move in parallel lines down along the dam and Assumed Hieb Water For ralllDElbodj with Initial Ilarl£.nliKlt7 12>g ft. iMr Me a^d ;t = y— 4u. CUpm obL) 6 = aai l!^l «H^5a JOsllmft —?—U-. Fig. 50.—Cross-section of overflow dam with graphic analysis of stresses,Granite Reef Dam, Salt River Project, Arizona. then be deflected to flow directly away from it. This theory isfollowed out very well so far as the behavior of the water on theface of the dam itself is concerned, but after the direction is changedto a point where it should leave the dam, there is usually a retarda-tion resulting in a standing wave which offers a number of curiousphenomena. The water, instead of continuing with graduallyreduced velocity down-stream, gathers in a mass on the apron of 244 PRINCIPLES OF IRRIGATION ENGINEERING the dam and sets up a churning or rotary motion which threatensto undercut the apron if near the lower edge. Because of the difficulties involved by the standing wave orwhirlpool at the lower toe of the overflow masonry dams, thistype of dam has been made in
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectirrigat, bookyear1913
