Design of Steel Structures (CE 415)- Assignment 6
Date: 3rd December, 2021
State any assumptions/recommendations clearly. Making suitable assumptions is part of
designer’s job.
Q.1.
(Marks:15)
Design the compound column consisting of rolled steel I section and cover plates for
factored axial load of 1200 kN. The length of the column is 4.5 m. Assume that the bottom
of the column is hinge and the top is rotation fixed, translation free and 𝑓𝑦 = 250 MPa.
Q.2.
Marks (10)
Calculate the compressive resistance of a leg of a transmission line tower consisting of
200 x 200 x 16 angle section of length 3.5 m. Assume that the conditions at both ends of
the z-z and y-y planes are such as to provide simple supports. Take the yield strength of
steel as 250 MPa and assume that the load is concentrically applied to the angle.
Q.3.
( Marks 15)
Design a double angle discontinuous strut to carry a factored load of 150 kN. The length
of the strut is 3.5 m between intersections. The two angles are placed back-to-back are tack
bolted. Adopt the configuration of two angles in star formation. Assume Fe410 grade steel
with 𝑓𝑦 = 250 MPa. Gusset plate is 10 mm thick. Discuss the spacing for tack
bolting/welding.
Q.4.
( Marks 20)
Design a laced column 11 m long to carry a factored axial load of 900 kN. The column is
restrained in position but not in direction at both ends. Provide single lacing system with
bolted connections. Adopt a configuration with two channels placed toe-to-toe.
( Marks 20)
Design a continuous beam to spans 4.9 m, 6 m and 4.9 m laterally restrained by a concrete
floor. Due to factored loads, the beam experiences a maximum bending moment and a
maximum shear force of 146.5 kNm and 292.5 kN, respectively at one of the supports.
Neglect the serviceability limit state. Check for web buckling and web crippling assuming
a stiff bearing length of 100 mm. Provide necessary recommendations, in case your trial
design does not meet the design checks.
Q.5.
Q.6.
( Marks 20)
Design a simply supported beam of span 5 m carrying a reinforced concrete floor capable
of providing lateral restraint to the top compression flange. The uniformly distributed load
is made of 25 kN/m imposed load and 15 kN/m live load. Assume Fe 410 grade steel and
the section is stiff against bearing.