or, -\ n TE-GIRDEB DESIGN 



end and HI the span length. Thb criterion enables any 

 group of loads to le placed n. pmducc a maximum moment. 

 The crilerion will somet hm> l>. d l>y more than 



position of the live load, p-nerally that position which 

 ha- the heaviest load at the point under consideration 

 and in addition the greater load on the structure i> the 

 one jiivini: maximum nnmieiit. The moment for all p< 

 tions of load which sati>lie- the criterion must be com- 

 puted for a certain determination of the maximum. 



For a deck structure the point of maximum bending 

 moment occurs at or near the center, generally a little 

 distance away from the center, the location of this point 

 of maximum moment being different for different systems 

 of loading. To aid in determining the position of tin- 

 loading for absolute maximum it should be remembered 

 that: 



(a) The maximum moment must occur where the shear 

 passes through zero; 



(6) For a system of concentrated loads the shear must 

 pass through zero at one of the loads; 



(c) The amount of load on either segment, into which 

 the point of maximum moment divides the span, 

 is to the total load on the span as the length 

 of the segment is to the span length. 



These requirements for practical cases fix the point of 

 maximum bending moment under one of the two win < !- 

 adjacent to the resultant of the system. The criterion for 

 the exact position of the loading to produce maximum 

 bending moment follows: 



