UPTU B. Tech.
(SEM. VIII) EXAMINATION, 2006-07
STEEL STRUCTURES – II
Q1.Attempt any two of the following :
(a) Sketch an industrial building and show the following components in it clearly; Purlins, Sag rods, Wind bracings, Principal rafters, Eaves gutter.
(b)A purlin of 5m span is provided in the roof of an industrial building. Following loads are acting on it per panel :
Dead Load : + 4 kN, Live Load: + 7.5 kN,
Wind Load : -13.27 kN.
Calculate the worst load per panel for which it is to be designed and desiusing the IS code method of design. Illustrate with neat sketch
(c )A diagonal member in a roof truss is 2.5 m long and is connected by welding to the gusset plates at the ends. It is subjected to tensile load of 150 kN and a compressive load 75 kN. Design the member using unequal angle sections and illustrate by neat sketches the various details.
Q2.Attempt any two of the following: 10×2=20
(a) A industrial column is made up of two ISMC 300 sections placed back to back at a spacing of 250 mm c/c connected by suitable lacings.
The base provided is a slab base 800 x 650 mm size and 40 mm thick. The column is subjected to an axial load of 600 kN and a bending moment of 200 kNm about the major axis. Calculate and sketch the pressure distribution below the base. Also sketch the column details.
(b) A gantry girder is provided in an industrial building for an EOT crane having a wheel base of 3.5 m. The building has columns spaced at 10 mc/c. Assuming the maximum static wheel load as 130 kN, calculate the maximum bending moment for which the gantry girder should be designed, and suggest a suitable section for the gantry girder. Checking for stresses need not be done.
(c) Sketch an industrial frame in plan and elevation and show how wind bracings are provided at the roof and at the sides of the industrial frame.
Q3.Attempt any one of the following:
(a) A steel stack 15 m in diameter and 20 m high is made up of steel plates of size 2.5 x 1 m. The stack is used to store water with a free board 0.3 m. Design the stack using fillet welds. Sketch all details neatly and calculate the number of plates that would be required to make the stack.
(b) A welded plate girder is simply supported at the ends and carries a uniformly distributed load of 90 kN/m over a span of 21 m. Design a preliminary section of the plate girder using 10 mm thick plates and check by moment of inertia method.
Q4. Attempt any one of the following : 20×1=20
(a) A welded plate girder is made up of plates 8 mm thick, depth of the web plate being 1700 mm. It has three plates 500 mm wide on each flange. If the girder has a reaction of 800 kN at the ends, design a bearing stiffener and its connection with the web. Sketch all details.
(b) A welded plate girder is simply supported at the ends and carries a uniformly distributed load of 100 kN/m over a span of 20 m. The section of the plate girder consists of three plates of size 550 x 10 mm each, on each flange and web of size 1800 x 6 mm. Design suitable intermediate vertical stiffners for the girder. Sketch all details.
Q5.Attempt any one of the following:
(a) Show by a sketch how light gauge steel sections can be stiffened and explain the advantages of stiffening. Also explain the cold forming mechanism with the help of a sketch.
(b) A riveted plate girder is provided for a steel bridge having an effective span of 24 m. If the load on the girder produces a bending moment of 6000 kNm, design the section fo the girder using 12 mm thick plates. Assume permissible stresses are limited to 138 MPa.