SCE Structural Engineering 2 — Questions and Answers
Question 1: In steel design, the term 'compact section' means that the section can:
- Develop full plastic moment capacity before local buckling (Correct answer)
- Carry only elastic moment without yielding
- Resist lateral-torsional buckling without bracing
- Withstand any load without deflection limits
Correct answer: Develop full plastic moment capacity before local buckling
A compact section has width-to-thickness ratios small enough to allow full plastic hinge formation before local buckling occurs.
Question 2: For a fixed-fixed beam with a central point load P and span L, what is the fixed-end moment at each support?
- PL/8 (Correct answer)
- PL/4
- PL/12
- PL/6
Correct answer: PL/8
For a fixed-fixed beam with a central point load, the fixed-end moment at each support = PL/8 by standard fixed-end moment tables.
Question 3: Which of the following increases the critical buckling load of a column?
- Reducing the effective length factor K (Correct answer)
- Increasing the column's unsupported length
- Using a material with lower modulus of elasticity
- Reducing the moment of inertia of the cross-section
Correct answer: Reducing the effective length factor K
Euler's buckling load Pcr = π²EI/(KL)²; reducing K (by adding fixed end conditions) increases Pcr.
Question 4: In reinforced concrete, the purpose of stirrups (shear links) in a beam is to:
- Resist diagonal tension (shear) and confine the concrete core (Correct answer)
- Prevent longitudinal bars from corroding
- Increase the flexural capacity of the section
- Reduce the beam's self-weight
Correct answer: Resist diagonal tension (shear) and confine the concrete core
Stirrups resist diagonal tensile stresses caused by shear and also provide confinement to the concrete, improving ductility.
Question 5: The degree of static indeterminacy of a propped cantilever (fixed at one end, pinned at other, single span) is:
- 1 (Correct answer)
- 2
- 3
- 0
Correct answer: 1
A propped cantilever has 4 reactions (3 at fixed end + 1 vertical at pin) but only 3 equilibrium equations, making it once statically indeterminate.
Question 6: What is the primary function of the neutral axis in a flexural member?
- It is the axis where bending stress is zero, separating tension and compression zones (Correct answer)
- It is the axis of maximum shear stress in the section
- It is the centroidal axis of the reinforcement
- It is the axis about which the section is symmetric
Correct answer: It is the axis where bending stress is zero, separating tension and compression zones
The neutral axis is where normal bending stress transitions from compression to tension (or vice versa), resulting in zero bending stress at that location.
Question 7: In the context of soil-structure interaction, a 'pile foundation' is preferred over a 'shallow foundation' when:
- The soil near the surface has insufficient bearing capacity to support the structural loads (Correct answer)
- The structure has very light loads that need minimal foundation depth
- The water table is well below the foundation level
- The structure is a single-storey building on dense gravel
Correct answer: The soil near the surface has insufficient bearing capacity to support the structural loads
Pile foundations transfer loads to deeper, stronger soil or rock when near-surface soils cannot provide adequate bearing capacity or settlement control.
SCE Structural Engineering 2
In steel design, the term 'compact section' means that the section can: