22 NOTES ON PLATE-GIRDER DESIGN 



For tin- |>r<i|H-r il<-}:ivr of strength (a) shouM <-i|iial (b). 



I /,' If h 



_._ or p __ (5> 



In order to show the application of (5) to determining 

 rivet pitch: Let Fig. 5a represent a portion of the girder 



FK;. 5a. 



used to illustrate the method of finding lengths of cover 

 plates in Art. 1. 



The shear at a- H>:;.:,IMI. at b = 153,000, and ate = 118,000. 



The value of a rivet in bearing = 24 ,000, and in shear 

 10 11-. per sq.in. 



The pitch for ;" rivets, at (a) = 



1 77X12X7876 



2.34 



provided the flange angles are designed to carry the 

 entire flange Mress at this point. If, however, as was 

 assumed in finding the length of the cover plates, the 

 portion of the web used as flange area is 2.81 sj.in.. then 



2.34X12.33 2.34X12.33 

 lllfl pltch " (12.33 -2.81)" U.te 



= 3.03". The pitch 



of J.34" would re(juire that two lines of rivets be used, 

 an good construction requires that the rivets !>< not closer 



