Design Of Steel Structures

Step 1: Identify the purpose of different IS codes.
Different Indian Standard (IS) codes are published for different materials and design purposes.
Step 2: Analyze the given options.
(A) IS 456: This code is used for plain and reinforced concrete structures, not steel.
(B) IS 256: This code is related to timber construction.
(C) IS 800: Correct — IS 800 is the code of practice for general construction in steel.
(D) IS 100: Not related to structural steel design.
Step 3: Conclusion.
Therefore, the IS code used for general construction of steel is IS 800.

Step 1: Purpose of vertical stiffeners.
Vertical stiffeners in plate girders are provided to prevent buckling of the web due to shear forces.
Step 2: Code-based spacing rule.
Design recommendations specify that the spacing of vertical stiffeners should be limited relative to the depth of the web (distance between flange angles).
Step 3: Standard spacing criterion.
As per standard design practice, the maximum spacing of vertical stiffeners should not exceed:

Step 4: Conclusion.
Therefore, the correct answer is (B) .