FACULTY OF ENGINEERING

Code No. 2205

B.E. 4/4 (Civil) I-Semester (Supplementary) Examination, May 2013 Subject : Structural Engineering Design and Detailing – II (Steel) Time : 3 Hours

Max. Marks: 75

Note: Answer all questions of Part - A and answer any three questions from Part-B. Use of IS 800-1984, Steel tables and bridge rules is permitted. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

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PART – A (25 Marks) How is the economical span of a bridge fixed? Write the importance of intermediate stiffeners in a plate girder. Write the loads that act on a gantry girder along the three orthogonal directions. Explain the concept of EUDL for the design of bridges. For what forces the connection between flange plate and flange angles designed? Draw a neat sketch of rocker cum roller bearing. Explain portal bracing and sway bracing in through types truss bridges. Write about racking force in railway bridges. Write the wind pressure to be considered on the bridge when the bridge is (a) loaded with train (b) with no train load Mention the types of web splices used in plate girders.

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PART – B (50 Marks) Design the c/s of a simply supported welded plate girder to carry a super imposed load of 50 kN/m over a span of 16 m. Also design the connection between web plate and flange plate. The Flange plate c/s is same throughout (no curtailment done). (15) OR Design a bearing stiffener at the end of a 15 m simply supported riveted plate girder carrying a superimposed load of 40 kN/m. The c/s of the web is 8mm x 1000 mm. Also design the connection of stiffener to the web plate. Draw a neat sketch with details. (15) The c/s of a gantry girder consists of ISMB 300 topped with ISMC 250. Check the adequacy of the section for the following data: Crane capacity =220 kN ; weight of crab=75 kN Weight of crane girder = 150 kN ; minimum approach of crane hook=1.2m Width of wheel base = 3.5m ; span of gantry girder = 8m Span of crane girder = 14m (15) OR Design a railway board type roller bearing for the following data: Vertical load due to DL+LL+impact = 1000 kN Vertical load due to wind = 180 kN Lateral load on the bearing due to wind = 80 kN Longitudinal load = 200 kN (15) A through type truss girder bridge on broad gauge main line has a span of 24m. Find the force in any one top chord member and one web member due to DL, LL and wind load (sway bracing and portal bracing effects needs not be considered). (20) OR The control section of a plates girder of a deck type plate girder bridge consists of a web plate of 12mm x 1800 mm, flange angles of 2 ISA 150x 150 x 15 mm both at top and bottom and flange plates of 500mm X 24 mm at top and bottom. Span of the bridge is 22m, check the adequacy of the section considering DL, Live load and wind load effects. Design top lateral bracing for the bridge. (20) *****