. Design of a steel railroad bridge . 508 2 angles, 6x6x7/8x2-6x31- 772 angles, 6x6x7/8x2-6x31- 77 1 plate, 10 1/4x5/8x1x13- IS 2 plates, 19 l/2xl/2x2-6x32- 8 06 Plates, 17x5/8x2-6x36- 9 0 Since there are 2 shoe bearings on each truss the an cuntis 2x1187- 2374 pounds Minor details: Pin plates 1500 Tie plates and lacing 2500 Connections, splices and etc. 2400 6400 pounds Flo<?-~ system: 6 stringers at 5000 30000 3 1/2 floor beams at 4600 16100 46100 pounds The total weight of one truss is 126550 M The total weight of the superstructure is therefore 8x126550 1012400 pounds, 4. DESIGN OP PIER
. Design of a steel railroad bridge . 508 2 angles, 6x6x7/8x2-6x31- 772 angles, 6x6x7/8x2-6x31- 77 1 plate, 10 1/4x5/8x1x13- IS 2 plates, 19 l/2xl/2x2-6x32- 8 06 Plates, 17x5/8x2-6x36- 9 0 Since there are 2 shoe bearings on each truss the an cuntis 2x1187- 2374 pounds Minor details: Pin plates 1500 Tie plates and lacing 2500 Connections, splices and etc. 2400 6400 pounds Flo<?-~ system: 6 stringers at 5000 30000 3 1/2 floor beams at 4600 16100 46100 pounds The total weight of one truss is 126550 M The total weight of the superstructure is therefore 8x126550 1012400 pounds, 4. DESIGN OP PIERS AND ABUTMENTS. Since the design of one of the piers was briefly outlinedabove under the head of the s election of design, it will notbe farther regarded. Owing to the lack of actual data thedesign of all the other piers will be the same. The designof one of the abutments will be considered next. The heightof the abutment will be assumed to be 15 feet. A sketchof it is given below and the abutment is computed in thefollowing The filling behind the wall consist of sand. The weightof a cubic foot of sand was assumed to be 100 pounds, andthe angle of repose of the material to be 50 degrees. Ifp be the unit intensity of the vertical pressiare of theearth and g the horizontal thrust, then for equilibriitm theformula will be^- = Jz^%?& =1/5 Considering the section of the wall to be one foot in lengththe average horizontal pressure is ? -100x5/3x2= 15CC/6pounds and the total pressure applied at 1/3 of theheightfrom the base is found to be 1500x15/6= 3750 pounds. By takingmoments about the base the overturning moment due to thispressure is 3750x5= 18750 foct-lbs or 225000 inch-pounds. Thetop and bottom dimensions of the section are also given in thesketch. The centre of gravity of section will be found next,by taking moments about BG and the equation becomes 7 0X5* 5XJ5++205(), and hence X= feet, the distanceof the center of gravity of the section fro
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Keywords: ., bo, bookcentury1900, bookdecade1900, bookiddesignofsteelrai00caha
