File:An experimental investigation of a highway bridge (1912) (14584214239).jpg

Identifier: experimentalinve00myer (find matches)
Title: An experimental investigation of a highway bridge
Year: 1912 (1910s)
Authors: Myers, Howard Dimick Warren, George Edward
Subjects: Bridges Concrete bridges Reinforced concrete construction Theses
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Contributing Library: University of Illinois Urbana-Champaign
Digitizing Sponsor: University of Illinois Urbana-Champaign

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n each bar of the member. Thedeflectometer was attached to the post U2L2. All the instru-ments were connected in series with a battery of dry cells.By means of a switch the circuit was closed, thus startingthe recording mechanism of all the instruments simultaneously.The switch was held closed during the passage of the load,t.hen opened, stopping the instruments while the conditionswere being recorded by the operators. Two series of testswere- made with loads of somewhat different weights as shownin the tables in Art. 5. Art. 3. Description of Bridge.The bridge spans the Salt Fork drainage ditch at thenorthwest end of Crystal Lake Park. It is a pin-connected,pony Pratt truss, having a cantilever sidewalk outside theeast truss. The floors of both roadway and sidewalk are solidslabs of concrete with no expansion joints. The end panelsare fourteen feet long and the intermediate panels are thirteenfeet six inches as shown in Plate I. The roadway is eighteenfeet wide in the clear. PLATE I.
Text Appearing After Image:
The upper chord of the truss carrying the sidewalkis composed of two channels and a cover plate, laced under-neath. The other truss is laced on both top and bottom. All tests were made on the truss on the side of thebridge opposite the sidewalk, as it was impossible to at-tach the instruments to all the members of the other truss Art. *k Loadings.The truss without sidewalk was designed to carry alive and also a dead load of 1000 pounds per linear foot.The live load for the first series of tests was a teamweighing 3200 pounds, and wagon and load weighing 6200pounds, distributed as shown in Pig. 1. >0 o 6-6 41 8~0 ItOO 6-6 o o Q. Pig. 1 Fig. 2. The loading for the second series was of the same nature,the team weighing 2,500 pounds and the wagon and load weigh-ing ^,250 pounds, distributed as shown In Fig. 2. Art ,5. Computed and Observed Stresses.The theoretical stresses were computed by the usual methods from the loadings shown in Fig. 1 and Fig. 2. The actual stress S was determine

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