Van Nostrand's engineering magazine . &c. The usual error is made, in ascertain-ing the stresses in Fig. 4, in not findingthe excess of weight thrown on one col-umn of the pier, and the diminution ofweight on the other column caused bythe wind pressure on truss and have so fully explained the propermethod above, that only involves the the-ory of couples, that it is needless tc at-tempt to make the proof plainer. Gaudard gives the horizontal windpressure on pier from truss at 20 tons,acting at a height of feet above topof pier, and the corresponding windpressure on train as t
Van Nostrand's engineering magazine . &c. The usual error is made, in ascertain-ing the stresses in Fig. 4, in not findingthe excess of weight thrown on one col-umn of the pier, and the diminution ofweight on the other column caused bythe wind pressure on truss and have so fully explained the propermethod above, that only involves the the-ory of couples, that it is needless tc at-tempt to make the proof plainer. Gaudard gives the horizontal windpressure on pier from truss at 20 tons,acting at a height of feet above topof pier, and the corresponding windpressure on train as tons, feet above top of pier. As a conse-quence the excess vertical load borne bythe leeward column, is 340 TAN NOSTRANDS ENGINEERING MAGAZINE. + = 52 tons, and the same load must be subtractedfrom that due to weight of truss and trainborne by the windward column. Now column tons, and at the top ofwindward column tons, both actingdownwards. The total wind pressure, + 20= tons,. the weight of loaded roadway borne byeach column is tons, to which add6 tons for the weight carried at each up-per apex, giving tons. From thisadd and subtract 52 tons, giving the re-sultant vertical load at top of leeward is transferred now to the top of pier, act-ing along the top member, by the couplesupposed, so that with the other datathe stress diagram is quickly drawn. As a proof of the incorrectness ofGaudards analysis, he gives as the wind THE ELECTRICAL TRANSMISSION OF ENKKiIY. 341 pressure acting on train tons, ontruss 20 tons and on pier 20 tons, tons, whereas at the base of pier, hesupposes a horizontal reaction of , which therefore cannot balance thetotal horizontal wind force as it should. As the scale is too small to give thestress diagram for this Bouble viaductvery clearly, we append a figure, havingsome resemblance, with the stress dia-gram drawn for the forces assumed. For this pier, the weight s
Size: 1381px × 1809px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1870, booksubjectenginee, bookyear1879
