ARCHES 



57 



Chord of Two-hinged Arch with Open Web. As in the case 

 of the three-hinged arch the moments M L and M R are 

 zero, and 



M? = _ //+ <. . . . (91) 



y y 



FIG. 376. WEB MEMBERS 



FIG. 37. 



The influence diagram for -^ is the frase diagram drawn 



o 



with CD equal -. This is indicated by heavy lines in 



Fig. 37a. The values of H for a unit load at each panel 

 point of the loaded chord are computed and laid off above 

 DB and the upper ends connected by straight lines. The 



