The Design and Construction of Dams: Including Masonry, Earth, Rock-Fill, Timber, and Steel the Principal Types of Movable Dams (Classic Reprint)

The great advantages to be derived from large storage reservoirs, built for regulating the flow of a river, for irrigation purposes, or for domestic water supply, have led within recent years to the construction of a large number of such works in various parts of the world. Where water having great depth is to be retained, it would be extremely hazardous to rely on earthen dams, as numerous failures of such works have been recorded, and walls of masonry are, therefore, employed. The successful completion of the Furens Dam (164 feet high) in 1866 was soon followed by that of many similar structures in France, A lgiers, and I taly. In the United States a concrete dam (170 feet high) is being built nearS an Francisco; theS odom Dam (70 feet high) has been commenced on theE ast Branch of the Croton River; and the Quaker Bridge Dam, which will surpass all existing dams in height, has been designed to form an immense storage reservoir for the city of New York. While the practical importance of the subject of masonry dams seems to be steadily growing, the engineer who may be entrusted with the design of such works will find the theoretical study of the best form of profile for a masonry dam very disheartening. How widely the types proposed by eminent engineers differ from each other is shown on Plate A, page 43. The theory of masonry dams is based upon a few simple principles and conditions; the mathematics, however, to which they give rise, when applied to the design of an economical profile, are rather appalling. Thus, if we follow the methods of the French engineers Sazilly and Delocre, we have to solve lengthy equations, some of them of the sixth degree. Moreover, there is always an uncertainty which equation is to be used, and the only way of determining this is by trial. If we wish to employ the method of Prof. Rankine, but change the data assumed by him, we
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