Louisiana (LA) 2.1 Culverts & Drainage
Structures Contractor Practice Exam
2026 | 100 Questions & Answers with
Detailed Rationales | Complete Exam
Prep & Study Guide
1. What is the primary purpose of a culvert?
A. To support a building foundation
B. To convey water beneath a roadway or other obstruction
C. To store construction materials
D. To stabilize a vertical wall
Answer: To convey water beneath a roadway or other obstruction
Rationale: Culverts are drainage structures designed to allow water to pass
beneath roads, driveways, embankments, and similar obstructions.
2. Which factor is most important when determining the required size of a
culvert?
A. Color of the pipe
B. Expected water flow and site conditions
C. Type of construction vehicle
D. Pavement striping
Answer: Expected water flow and site conditions
,Rationale: Culvert sizing must account for anticipated runoff, drainage area,
hydraulic conditions, slope, inlet and outlet characteristics, and other site
factors.
3. What is the term for the amount of water flowing through a drainage
structure per unit of time?
A. Headwall
B. Discharge
C. Backfill
D. Invert
Answer: Discharge
Rationale: Discharge is the volume of water passing a particular point over a
specified period, commonly expressed in cubic feet per second.
4. What does the invert of a culvert refer to?
A. The top of the roadway
B. The lowest inside surface of the culvert
C. The outside edge of the embankment
D. The top of the headwall
Answer: The lowest inside surface of the culvert
Rationale: The invert is the lowest elevation or bottom inside surface of a pipe
or other drainage conduit.
5. What is a headwall?
A. A wall constructed at a culvert entrance or exit
B. A temporary traffic barrier
C. A retaining wall for a building
D. A concrete pavement joint
Answer: A wall constructed at a culvert entrance or exit
,Rationale: Headwalls are commonly installed at culvert ends to retain fill,
protect the opening, and improve the stability of the drainage structure.
6. What is the primary purpose of a wingwall at a culvert?
A. To increase pavement thickness
B. To guide water and retain embankment material
C. To provide electrical grounding
D. To support overhead signs
Answer: To guide water and retain embankment material
Rationale: Wingwalls extend from culvert ends and help retain earth while
directing water toward or away from the culvert opening.
7. Which material is commonly used for rigid culverts?
A. Reinforced concrete
B. Untreated cardboard
C. Wood chips
D. Asphalt shingles
Answer: Reinforced concrete
Rationale: Reinforced concrete is widely used for box and pipe culverts because
it provides strength, durability, and resistance to many site conditions.
8. What is a major advantage of corrugated metal pipe in drainage
construction?
A. It cannot corrode
B. It is relatively lightweight and easy to handle
C. It requires no bedding
D. It cannot deform
Answer: It is relatively lightweight and easy to handle
, Rationale: Corrugated metal pipe can be easier to transport and install than
heavier rigid drainage materials, although corrosion protection and installation
requirements must be considered.
9. Why is proper culvert bedding important?
A. It provides uniform support beneath the pipe
B. It eliminates the need for backfill
C. It increases water temperature
D. It replaces the roadway surface
Answer: It provides uniform support beneath the pipe
Rationale: Proper bedding distributes loads and supports the pipe continuously,
helping prevent settlement, deformation, and joint problems.
10.What can occur if a culvert is installed on inadequate or poorly prepared
bedding?
A. Improved drainage
B. Uneven settlement or structural damage
C. Increased pipe capacity
D. Automatic erosion protection
Answer: Uneven settlement or structural damage
Rationale: Poor bedding can create unsupported areas beneath the culvert,
resulting in differential settlement, cracking, joint failure, or deformation.
11.What is the primary purpose of backfilling around a culvert?
A. To provide support and restore the excavation
B. To prevent all water from entering the culvert
C. To increase the pipe diameter
D. To eliminate the need for compaction
Answer: To provide support and restore the excavation
Structures Contractor Practice Exam
2026 | 100 Questions & Answers with
Detailed Rationales | Complete Exam
Prep & Study Guide
1. What is the primary purpose of a culvert?
A. To support a building foundation
B. To convey water beneath a roadway or other obstruction
C. To store construction materials
D. To stabilize a vertical wall
Answer: To convey water beneath a roadway or other obstruction
Rationale: Culverts are drainage structures designed to allow water to pass
beneath roads, driveways, embankments, and similar obstructions.
2. Which factor is most important when determining the required size of a
culvert?
A. Color of the pipe
B. Expected water flow and site conditions
C. Type of construction vehicle
D. Pavement striping
Answer: Expected water flow and site conditions
,Rationale: Culvert sizing must account for anticipated runoff, drainage area,
hydraulic conditions, slope, inlet and outlet characteristics, and other site
factors.
3. What is the term for the amount of water flowing through a drainage
structure per unit of time?
A. Headwall
B. Discharge
C. Backfill
D. Invert
Answer: Discharge
Rationale: Discharge is the volume of water passing a particular point over a
specified period, commonly expressed in cubic feet per second.
4. What does the invert of a culvert refer to?
A. The top of the roadway
B. The lowest inside surface of the culvert
C. The outside edge of the embankment
D. The top of the headwall
Answer: The lowest inside surface of the culvert
Rationale: The invert is the lowest elevation or bottom inside surface of a pipe
or other drainage conduit.
5. What is a headwall?
A. A wall constructed at a culvert entrance or exit
B. A temporary traffic barrier
C. A retaining wall for a building
D. A concrete pavement joint
Answer: A wall constructed at a culvert entrance or exit
,Rationale: Headwalls are commonly installed at culvert ends to retain fill,
protect the opening, and improve the stability of the drainage structure.
6. What is the primary purpose of a wingwall at a culvert?
A. To increase pavement thickness
B. To guide water and retain embankment material
C. To provide electrical grounding
D. To support overhead signs
Answer: To guide water and retain embankment material
Rationale: Wingwalls extend from culvert ends and help retain earth while
directing water toward or away from the culvert opening.
7. Which material is commonly used for rigid culverts?
A. Reinforced concrete
B. Untreated cardboard
C. Wood chips
D. Asphalt shingles
Answer: Reinforced concrete
Rationale: Reinforced concrete is widely used for box and pipe culverts because
it provides strength, durability, and resistance to many site conditions.
8. What is a major advantage of corrugated metal pipe in drainage
construction?
A. It cannot corrode
B. It is relatively lightweight and easy to handle
C. It requires no bedding
D. It cannot deform
Answer: It is relatively lightweight and easy to handle
, Rationale: Corrugated metal pipe can be easier to transport and install than
heavier rigid drainage materials, although corrosion protection and installation
requirements must be considered.
9. Why is proper culvert bedding important?
A. It provides uniform support beneath the pipe
B. It eliminates the need for backfill
C. It increases water temperature
D. It replaces the roadway surface
Answer: It provides uniform support beneath the pipe
Rationale: Proper bedding distributes loads and supports the pipe continuously,
helping prevent settlement, deformation, and joint problems.
10.What can occur if a culvert is installed on inadequate or poorly prepared
bedding?
A. Improved drainage
B. Uneven settlement or structural damage
C. Increased pipe capacity
D. Automatic erosion protection
Answer: Uneven settlement or structural damage
Rationale: Poor bedding can create unsupported areas beneath the culvert,
resulting in differential settlement, cracking, joint failure, or deformation.
11.What is the primary purpose of backfilling around a culvert?
A. To provide support and restore the excavation
B. To prevent all water from entering the culvert
C. To increase the pipe diameter
D. To eliminate the need for compaction
Answer: To provide support and restore the excavation
