. Theory of structures and strength of materials. ses the second driver is at a panel point. dead vjQxght includes the weight of the ironwork andflooring. The panel loads may be easily calculated, eitheranalytically or graphically. For example, let A, B, C, D hefour consecutive panel points, and let the third driver be at B. Panel load at y^ 198 , /108+ 52\ ^ „ = 75oo:;|g + i200ol^—^^—j = 11823, say 11,900 lbs. Panel load at B 90 /i8o-l-236-H2884-232\ , . /i4i4-77\ = 49387, say 49,500 load at C /56+28i\ , ^ /i87+2ii+284i+22oi\ ii8| = 38445, say 38,700 lbs. LIVE LOAD. 643 Or, gra
. Theory of structures and strength of materials. ses the second driver is at a panel point. dead vjQxght includes the weight of the ironwork andflooring. The panel loads may be easily calculated, eitheranalytically or graphically. For example, let A, B, C, D hefour consecutive panel points, and let the third driver be at B. Panel load at y^ 198 , /108+ 52\ ^ „ = 75oo:;|g + i200ol^—^^—j = 11823, say 11,900 lbs. Panel load at B 90 /i8o-l-236-H2884-232\ , . /i4i4-77\ = 49387, say 49,500 load at C /56+28i\ , ^ /i87+2ii+284i+22oi\ ii8| = 38445, say 38,700 lbs. LIVE LOAD. 643 Or, graphically, upon the vertical through B (Fig. 412) takeBM to represent 7500 lbs., and join AM. Let the verticalthrough a^ meet AM in b,, and the horizontal through AJllin c^. Then aj?^ represents the portion of 7500 lbs. borne atB, and b^c^ the portion borne at A. Also, take BN to represent 12,000 lbs. ; join AN, CN. Letthe verticals through a^, a^, a, meet AN, CN in b^,b^, b,, and the horizontal through N in c^, c^, c^. Then ^. aJb^ aj).. Fig. 412. represent the portions of each 12,000 lbs. borne at i5, whileb^c„, b^c^ represent the portions borne at A, and b^c^ the portionborne at C. Finally, take BO to represent 10,625 lbs., and join CO. Letthe verticals through a^, a^ meet CO in b^, b^, and the horizon-tal through O c^, c^. Then ap^, ajj^ are the portions of each10,625 lbs. borne at B, while b^c^, b^c^ are the portions borne atC. Thus the total weight at B = a J), + aj}^ 4- ajj^ + BN -\- ajb, + ajb^ -}- ajj,. It is open to grave question whether the extremely nicecalculations required by the assumption of arbitrary weightcalculations are not unnecessary except for floor systems. Theconstantly increasing locomotive and car weights and thevariety in type of locomotive would seem to render such cal-culations, based as they are upon one particular distribution ofload, of no effect. On the other hand, if it is assumed that the standard liveload consists of a uniform loa
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Keywords: ., bookcentury1800, bookdecade1890, bookpublishernewyo, bookyear1896
