Question 1

Which of the following is not considered to be a vertical load that is applied to a structure?

Accepted Answer

An earth load is not considered to be a vertical load applied to a structure. Generally, there are two types of loads: vertical and lateral. Vertical loads are also known as gravity loads. Lateral loads act horizontally on structures, and include wind, earthquake, and hydrostatic loads.

Question 2

From which of the following conditions do structural forces originate?
1. Point loads
2. Uniform loads
3. Compression
4. Non-uniformly distributed loads
5. Tension
6. Moments

Accepted Answer

Structural forces originate from the following conditions:
• Point loads
• Uniform loads
• Non-uniformly distributed loads
• Moments
Structural forces, or loads on a structure, result in stresses on the structural material. There are two types of material stress: compression and tension.

Question 3

Which of the following best describes the structural load-related term "racking"?

Accepted Answer

The term "racking" is best described as significant lateral displacement. Racking results from lateral forces acting against a structure. For example, hydrostatic pressure acting against a circular underground tunnel can cause severe racking that deforms the circular shape into an oval shape. Severe winds can cause a barn structure to lean to one side.

Question 4

Which of the following methods are used to evaluate load combinations?
1. Load and resistance factor design
2. Allowable strength design
3. Load triangulation theory

Accepted Answer

Both the load and resistance factor design and allowable strength design methods are used to evaluate load conditions. The American Society of Civil Engineers (ASCE) Standard 7-10 (May, 2010) provides design criteria for determining dead, live, dynamic and combination of loads for buildings and other structures using both of these methods. ASCE also provides guidance for determining loads on tall buildings and evaluating extreme loads (winds, snow and seismic).

Question 5

Which of the following terms is defined as the "permanent deflection of a structural member resulting from a normal working load"?

Accepted Answer

Creep is defined as the permanent deflection of a structural member that results from a normal working load. Fatigue can be defined as a condition of a fluctuating loading that can eventually cause a structural member to fail. Racking is defined as a severe lateral displacement that results from lateral loading.

Question 6

Which of the following forces may result in cracking of structure walls and floors?

Accepted Answer

Expansion and contraction may result in cracking of structure walls and floors. The expansion and contraction properties of building materials should be taken into account during design. For example, a specialized concrete design mix may be used to minimize shrinkage and expansion of a large concrete slab when expansion joints are not allowed in the design criteria.

Question 7

Which of the following is not a common loading condition that may result in a triangular load on a structure?

Accepted Answer

Seismic pressure due to earthquake aftershocks is not an example of a typical triangular loading condition. The other examples may result in a triangular loading on a structure, which can be represented by a single concentrated load that is applied in the same direction of the load at one-third the height above its base.

Question 8

Which of the following is the approximate total load at the bottom of a fully submerged 5-foot wall?

Accepted Answer

The approximate hydrostatic pressure at the bottom of a fully submerged 5-foot wall is 937.5 pounds/foot of wall.
Solution: Use the triangular loading method to determine hydrostatic pressure
Given, 1 cubic foot of water = 62.5 pounds
Pressure (load) at water surface = 0
Step 1: Hydrostatic pressure at base of wall (5' deep)
= 62.5 pounds/cubic foot (pcf) *5 feet = 375 pounds/square foot (psf)
Step 2: Total load = ½ bh
= ½ (5 feet)(375 psf) = 937.5 pounds/foot

Quiz 15: Struct Loading