LOW TRUSS HIGHWAY BRIDGES. 



123 



Weephole with perforated* 



' 



15-Ton Engine. 



ri 



i/ 6 concrete slab, botbm I" below tops ofjoiscs 

 ' -- .Wp'*^* 5 * 



-j ReinForcement\! ran ^' \Bot. same. Staqqer with top 

 \Lonq. f'sq. between adjacent joists. 



HalF5ection. 

 fj "bolts withjvund heads, about /8c.coc. 



Section through End Floorbearm 

 (' 



Cast Iron5hoe-Fixed End. 



5j& jliePb. StressSheetsOeneralDetails 



5TANDARD70'xl6'LOWTRU555PAH 

 Concrete Floor onSkeelJoists 



IOWA HIGHWAY COMMISSION 



FIG. 17. Low TRUSS SPAN WITH STRINGERS. 



Depth and Panel Length of Low Trusses. The depths and number of panels in Iowa High- 

 ly Commission low truss bridges with joists are as follows: 35 ft. and 40 ft. span, 3 panels, 6 ft. 

 ep; 45 ft. and 50 ft. spans, 3 panels, 6$ ft. deep; 60 ft. and 65 ft. span, 4 panels, 7 ft. deep; 70 ft. 

 !n, 5 panels, 7 ft. deep; 80 ft. and 85 ft. span, 5 panels, 8 ft. deep. For low truss bridges without 

 rists, 35 ft. span, 4 panels, 6 ft. deep; 40 ft. span, 5 panels, 6 ft. deep; 45 ft. span, 5 panels, 6J ft. 

 ep; 50 ft. and 55 ft. span, 6 panels, 6J ft. deep; 60 ft. span, 7 panels, 7 ft. deep; 65 ft. and 70 ft. 

 span, 8 panels, 7 ft. deep; 75 ft. span, 9 panels, 7J ft. deep; 80 ft. span, 10 panels, 8 ft. deep; 85 ft. 

 span, 10 panels, 8J ft. deep; 90 ft. span, 10 panels, 9 ft. deep; 95 ft. span, 10 panels, 9$ ft. deep; 

 100 ft. span, 10 panels, 10 ft. deep. 



