Bridges and culverts for highway traffic, flat slab and girder type ... . ere heavy road rollers, up to twenty tons, and electric cars of a maxi-mum weight of forty tons must be provided for. Uniformly distributedload, 125 pounds per square foot. Class No. 3—City highway specification, designed for heavy con-sent rated loads and large interurban cars. This classification shouldbe adopted for all city work; the weight of the maximum car has beentaken as sixty tons. Uniformly distributed load, 150 pounds persquare foot. LOAD DIAGRAMS. The following diagrams represent the loadings adopted in the
Bridges and culverts for highway traffic, flat slab and girder type ... . ere heavy road rollers, up to twenty tons, and electric cars of a maxi-mum weight of forty tons must be provided for. Uniformly distributedload, 125 pounds per square foot. Class No. 3—City highway specification, designed for heavy con-sent rated loads and large interurban cars. This classification shouldbe adopted for all city work; the weight of the maximum car has beentaken as sixty tons. Uniformly distributed load, 150 pounds persquare foot. LOAD DIAGRAMS. The following diagrams represent the loadings adopted in the aboveclassifications and used in the design of the culverts and bridges shownin this bulletin: Q- X -47-0- -34-0- GhQ -8-6- _Q Fig. 1. Standard Car, Class No. 2—40 tons on eight - S6-0 - *3 -8 6—•. 9,9 T=f jo-o- m 00 toni on BigM wheels. , to .1 steam roller will be taken as indicatedtfo total load being assumed on thi J c P £ J ,^-rr- T 1 1 » ? . . nil . thaii riall) aidistribute Earth Fill divert oi ! <U ft] DEAD LOAD. luding the S+c/. Fig. 4. The trapezoid abed represents the amount of fill considered as sup-ported by the culvert; assuming the weight of the fill to be ioo poundsper cubic foot we ma\ write 12 s+d\Dt=lOOd( =Sod{2s + d) where Df=load on 12 length of culvert due to fill. Df will be con-sidered as a uniformly distributed load across the culvert. To obtain the total dead load add the weight of a 12 strip of culverttop, also the weight of paving or track system. LIVE LOADS. A uniform 1\ distributed load shall be considered as causing thespecified pressure per square f t on the bridge regardless of depth offill. iinmum fill of twelve inches is required on all bridges. \\ heel or road roller concentrations shall be considered as actingii a line whose length equals the out to out tread of the wheels. Loads on car tracks shall be considered as uniformly distributed overa width of roadway equal to the length of the ties and in the directionof
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectconcrete, bookyear190
