Solutions Manual for Steel Design 6th Edition by Segui |
Answers to Problems | All 10 Chapters Covered
Chapter 1: Introduction
1. The primary purpose of a building code in structural engineering is to:
A) Minimize construction costs
B) Specify the exact materials to be used
C) Establish minimum safety requirements for structures
D) Provide aesthetic guidelines for architects
Answer: C) Establish minimum safety requirements for structures
Explanation: Building codes are legal documents that establish minimum requirements to safeguard life,
health, property, and public welfare. They ensure structures are designed and built to withstand
expected loads without failure.
2. Which of the following loads is classified as a live load?
A) Weight of the structural steel frame
B) Snow accumulation on the roof
C) Occupants and furniture
D) Wind pressure on walls
Answer: C) Occupants and furniture
Explanation: Live loads are those that can change in magnitude and position over time, such as people,
furniture, and movable equipment. Snow and wind are environmental loads, while dead loads are
permanent, such as the weight of the structure itself.
,3. Load and Resistance Factor Design (LRFD) is a design philosophy that:
A) Uses a single safety factor applied to the allowable stress
B) Applies load factors to service loads and resistance factors to nominal strengths
C) Neglects the probabilistic nature of loads and material properties
D) Only considers dead loads in the design process
Answer: B) Applies load factors to service loads and resistance factors to nominal strengths
Explanation: LRFD uses load factors (greater than 1) to account for uncertainties in loads and resistance
factors (less than 1) to account for uncertainties in material strengths. The design requirement is that
the factored load does not exceed the factored resistance.
4. In Allowable Strength Design (ASD), the safety factor (Ω) is applied to:
A) The service loads to increase them
B) The nominal strength to reduce it
C) Both loads and resistances simultaneously
D) Only live loads
Answer: B) The nominal strength to reduce it
Explanation: In ASD, the nominal strength is divided by a safety factor (Ω) to obtain an allowable
strength. The service loads are used directly, and the design requirement is that the service loads do not
exceed the allowable strength.
5. Which of the following is a standard wide-flange shape designation according to AISC?
A) C12×20.7
B) L4×4×1/2
C) W18×35
,D) HSS6×4×3/8
Answer: C) W18×35
Explanation: Wide-flange shapes are designated by the letter "W" followed by the nominal depth in
inches and the weight per foot in pounds (e.g., W18×35). C shapes are channels, L shapes are angles,
and HSS are hollow structural sections.
6. Structural steel is composed primarily of iron with a carbon content typically between:
A) 0.02% and 0.08%
B) 0.10% and 0.25%
C) 0.50% and 1.50%
D) 2.00% and 4.00%
Answer: B) 0.10% and 0.25%
Explanation: Structural steel typically contains between 0.10% and 0.25% carbon. This range provides a
good balance of strength, ductility, and weldability.
7. The minimum specified yield strength of A992 steel (commonly used for wide-flange shapes) is:
A) 36 ksi
B) 42 ksi
C) 50 ksi
D) 60 ksi
Answer: C) 50 ksi
, Explanation: A992 steel is the most common material for wide-flange shapes and has a minimum
specified yield strength (Fy) of 50 ksi and a minimum tensile strength (Fu) of 65 ksi.
8. Design specifications, such as those published by AISC, are essential because they:
A) Replace the need for building codes
B) Provide detailed procedures for designing steel structures
C) Only apply to bridge design
D) Are optional guidelines with no legal standing
Answer: B) Provide detailed procedures for designing steel structures
Explanation: Design specifications, such as the AISC Specification for Structural Steel Buildings, provide
detailed requirements for the design, fabrication, and erection of steel structures. They are typically
adopted by reference in building codes.
9. Which of the following is a dead load?
A) Wind pressure
B) Snow accumulation
C) Self-weight of a concrete slab
D) Occupant weight
Answer: C) Self-weight of a concrete slab
Explanation: Dead loads are permanent loads that include the weight of the structure itself, fixed
partitions, and permanently attached equipment. The self-weight of a concrete slab is a permanent load
that remains constant over time.
Answers to Problems | All 10 Chapters Covered
Chapter 1: Introduction
1. The primary purpose of a building code in structural engineering is to:
A) Minimize construction costs
B) Specify the exact materials to be used
C) Establish minimum safety requirements for structures
D) Provide aesthetic guidelines for architects
Answer: C) Establish minimum safety requirements for structures
Explanation: Building codes are legal documents that establish minimum requirements to safeguard life,
health, property, and public welfare. They ensure structures are designed and built to withstand
expected loads without failure.
2. Which of the following loads is classified as a live load?
A) Weight of the structural steel frame
B) Snow accumulation on the roof
C) Occupants and furniture
D) Wind pressure on walls
Answer: C) Occupants and furniture
Explanation: Live loads are those that can change in magnitude and position over time, such as people,
furniture, and movable equipment. Snow and wind are environmental loads, while dead loads are
permanent, such as the weight of the structure itself.
,3. Load and Resistance Factor Design (LRFD) is a design philosophy that:
A) Uses a single safety factor applied to the allowable stress
B) Applies load factors to service loads and resistance factors to nominal strengths
C) Neglects the probabilistic nature of loads and material properties
D) Only considers dead loads in the design process
Answer: B) Applies load factors to service loads and resistance factors to nominal strengths
Explanation: LRFD uses load factors (greater than 1) to account for uncertainties in loads and resistance
factors (less than 1) to account for uncertainties in material strengths. The design requirement is that
the factored load does not exceed the factored resistance.
4. In Allowable Strength Design (ASD), the safety factor (Ω) is applied to:
A) The service loads to increase them
B) The nominal strength to reduce it
C) Both loads and resistances simultaneously
D) Only live loads
Answer: B) The nominal strength to reduce it
Explanation: In ASD, the nominal strength is divided by a safety factor (Ω) to obtain an allowable
strength. The service loads are used directly, and the design requirement is that the service loads do not
exceed the allowable strength.
5. Which of the following is a standard wide-flange shape designation according to AISC?
A) C12×20.7
B) L4×4×1/2
C) W18×35
,D) HSS6×4×3/8
Answer: C) W18×35
Explanation: Wide-flange shapes are designated by the letter "W" followed by the nominal depth in
inches and the weight per foot in pounds (e.g., W18×35). C shapes are channels, L shapes are angles,
and HSS are hollow structural sections.
6. Structural steel is composed primarily of iron with a carbon content typically between:
A) 0.02% and 0.08%
B) 0.10% and 0.25%
C) 0.50% and 1.50%
D) 2.00% and 4.00%
Answer: B) 0.10% and 0.25%
Explanation: Structural steel typically contains between 0.10% and 0.25% carbon. This range provides a
good balance of strength, ductility, and weldability.
7. The minimum specified yield strength of A992 steel (commonly used for wide-flange shapes) is:
A) 36 ksi
B) 42 ksi
C) 50 ksi
D) 60 ksi
Answer: C) 50 ksi
, Explanation: A992 steel is the most common material for wide-flange shapes and has a minimum
specified yield strength (Fy) of 50 ksi and a minimum tensile strength (Fu) of 65 ksi.
8. Design specifications, such as those published by AISC, are essential because they:
A) Replace the need for building codes
B) Provide detailed procedures for designing steel structures
C) Only apply to bridge design
D) Are optional guidelines with no legal standing
Answer: B) Provide detailed procedures for designing steel structures
Explanation: Design specifications, such as the AISC Specification for Structural Steel Buildings, provide
detailed requirements for the design, fabrication, and erection of steel structures. They are typically
adopted by reference in building codes.
9. Which of the following is a dead load?
A) Wind pressure
B) Snow accumulation
C) Self-weight of a concrete slab
D) Occupant weight
Answer: C) Self-weight of a concrete slab
Explanation: Dead loads are permanent loads that include the weight of the structure itself, fixed
partitions, and permanently attached equipment. The self-weight of a concrete slab is a permanent load
that remains constant over time.
