. The Americana; a universal reference library, comprising the arts and sciences, literature, history, biography, geography, commerce, etc., of the world. sses. Since thestresses in an arch having less than three hingesare statically indeterminate, stresses of consid-erable magnitude may be introduced into thetrusses if the workmanship be imperfect, thesupports not located with sufficient precision,and the arch closed without the proper meansand care. The Niagara and Clifton arch was firstclosed as a three-hinged arch and then trans-formed into a two-hinged arch by insertingthe final member un
. The Americana; a universal reference library, comprising the arts and sciences, literature, history, biography, geography, commerce, etc., of the world. sses. Since thestresses in an arch having less than three hingesare statically indeterminate, stresses of consid-erable magnitude may be introduced into thetrusses if the workmanship be imperfect, thesupports not located with sufficient precision,and the arch closed without the proper meansand care. The Niagara and Clifton arch was firstclosed as a three-hinged arch and then trans-formed into a two-hinged arch by insertingthe final member under the sum of the com-puted stress due to the weight of the truss,and that due to the difference between the tem-perature at which the closure was made andthat assumed as standard in the stress compu-tations. This stress was secured in the mem-ber by inserting it when the hydraulic jackwhich forced apart the adjacent ends of theshortened chords registered the required amountof pressure. The arch had been erected as apair of cantilevers from each side extending420 feet out beyond the supports, and when theclosure was made the two arms came together.
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectencyclo, bookyear1908
