

CONTINUOUS TRUSSES 



51 



the fields of loading in this span which produce moments 

 of opposite character. 



The position of wheel loads producing the maximum 

 moment is best found by trial. 



For loads in the third span 



4+6n 



and 



, m> =0, 



r . . . . (83) 



4+6n 



Remembering that li=l$=l and dividing through by s, 

 M, _2fc3-3fc 3 2 +^ (84) 



The influence diagram corresponding to this expression 

 is shown by the shaded area BKM, Fig. 34. 



The position of wheel loads producing the maximum 

 moment is found by trial. This position when found will 

 remain constant for all centers of moments in the first 

 span. 



VALUES OF ^^ 



NUMBER OF PANELS IN SPAN. 



