Steel Design (IS 800) MCQ for GATE Civil Engineering
163 Questions5 Difficulty Levels20-25% in GATEFree Practice
Steel Design follows IS 800:2007 and carries 4-8 marks in GATE CE. The code uses the limit state method with partial safety factors γm0 = 1.10 (yielding) and γm1 = 1.25 (ultimate stress). Questions focus on tension member design (yielding of gross section, rupture of net section), compression member design (column buckling using Perry-Robertson curves), beam design (laterally supported and unsupported), and connection design (bolts and welds). Understanding section classification (Class 1-4) and its impact on moment capacity is crucial.
Difficulty Levels
L1 · Foundation · 54 Qs
L2 · Understanding · 25 Qs
L3 · Application · 40 Qs
L4 · Analysis · 23 Qs
L5 · GATE Ready · 4 Qs
Key Topics Covered
Tension members (Tdg, Tdn)
Column buckling (fcd, KL/r, buckling curves)
Laterally supported beams (Md)
Lateral torsional buckling
Bolt design (shear, bearing, kb)
Fillet weld design
Plastic analysis (shape factor, collapse load)
Key Formulas
Tdg = Ag·fy/γm0
fcd = χ·fy/γm0 (buckling)
Md = βb·Zp·fy/γm0 ≤ 1.2·Ze·fy/γm0
Vdsb = fub/(√3·γmb)·n·Anb
fw = fu/(√3·γmw·Mw)
GATE Exam Tip: Know the steel grades (E250 fy=250, E350 fy=350) and partial safety factors cold. Column buckling problems are the most common — practice computing KL/r, non-dimensional slenderness, and fcd from the buckling curve formula. For connections, the kb factor calculation for bearing capacity is frequently tested.
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Q1 · Level 1 · SE-STL-1020
When specifying a bolt for structural connections, the diameter of the hole is conventionally taken as:
Q2 · Level 1 · SE-STL-1094
For a standard 45-degree fillet weld, what is the ratio of the fillet leg length to the effective throat thickness?
Q3 · Level 1 · SE-STL-1013
Considering a riveted joint designed with the minimum pitch as stipulated by IS: 800, what is its typical efficiency in terms of load-carrying capacity?
Q4 · Level 2 · SE-STL-1012
For members designed to resist tension, what is the maximum allowable spacing for tack rivets when connecting back-to-back angle sections?
Q5 · Level 2 · SE-STL-1007
By ensuring adequate clearance from the edge of the plate, which of the following failure modes in a riveted connection can be prevented?
Q6 · Level 2 · SE-STL-1024
According to structural analysis principles, the external wind pressure acting on a roof is influenced by which factors?
Q7 · Level 3 · SE-STL-1005
For steel stacks, the maximum permissible spacing between rivets, expressed in terms of 't' (the thickness of the thinner plate being joined), is governed by which of the following limits?
Q8 · Level 3 · SE-STL-1095
Consider a roof with a 15-degree inclination where no access is intended for walking on the roof. What is the prescribed value for the imposed load per square meter?
Q9 · Level 3 · SE-STL-1060
For a compression member supporting both permanent and temporary loads, what is the maximum permissible slenderness ratio?
Q10 · Level 3 · SE-STL-1104
For a solid circular column with an external diameter 'D', what is considered its least lateral dimension for slenderness ratio calculations?
Q11 · Level 3 · SE-STL-1105
In welded connections for built-up members using batten plates, the extent of overlap between the batten plates and the main structural elements must exceed a certain multiple of the batten plate thickness (t). What is this minimum overlap?
Q12 · Level 4 · SE-STL-1032
Based on structural analysis, what is the relationship between the plastic section modulus and the elastic section modulus?
Q13 · Level 4 · SE-STL-1082
For rivets with countersunk heads that are subjected to tensile forces, what is the adjustment to their tensile value?
Q14 · Level 4 · SE-STL-0028
For a laterally unsupported rolled I-beam, the LTB imperfection factor αLT as per IS 800:2007 is:
Q15 · Level 4 · SE-STL-1056
Which type of riveted connection is designed to avoid bending stresses?
Q16 · Level 5 · SE-STL-0037
A simply supported ISMB 400 beam (Zp = 1095 cm³, Iy = 622 cm⁴, ry = 28.2 mm) in E250 steel spans 8 m with no intermediate lateral bracing. The beam carries a factored UDL of 25 kN/m. If λLT for this configuration is 1.35 and χLT = 0.42, determine:
(a) The factored bending moment
(b) The design bending capacity
(c) Whether the beam is adequate
Q17 · Level 5 · SE-STL-0039
A bracket connection uses 6 mm site fillet welds (γmw = 1.50) to connect a plate to a column flange in E250 steel. The weld group consists of two vertical welds, each 200 mm long, spaced 150 mm apart. A factored vertical load of 100 kN acts at an eccentricity of 200 mm from the weld group centroid. Determine the maximum resultant stress on the weld and check adequacy.
Q18 · Level 5 · SE-STL-0038
For the beam in SE-STL-0037 (ISMB 400, 8 m span), if intermediate lateral bracing is provided at mid-span (reducing LLT to 4 m), and the new λLT = 0.72 giving χLT = 0.88, what is the revised Md and is the beam now adequate?
Q19 · Level 5 · SE-STL-0040
A portal frame of E250 steel is to be analyzed using plastic analysis. The frame has a span of 10 m and column height of 4 m. The beam is ISMB 400 (Zp = 1095 cm³) and columns are ISMB 300 (Zp = 611 cm³). The plastic moment capacity of the beam is Mp,beam and column is Mp,col. For the frame to form a valid collapse mechanism under a uniformly distributed load on the beam:
(a) What is Mp,beam?
(b) What section classification is required for plastic analysis?
(c) If the collapse load factor λ = 16Mp/(wL²) for a beam mechanism, and the factored UDL is 30 kN/m, is the beam adequate?