North Carolina (NC) “H” Grading & Excavating Contractor
Practice Exam – 200 Questions with Answers & Rationales|
INSTANT PDF DOWNLOAD
1. A contractor is preparing a bid for a large commercial site that requires excavating 12,000
cubic yards (LCY) of common earth. The swell factor is 25%, and the contractor's truck fleet
has a heaped capacity of 18 LCY per truck with a cycle time of 20 minutes. How many 18-LCY
truckloads will be required to haul the material, assuming an operational efficiency of 50
minutes per hour?
A. 834 truckloads, because 12,000 CY × 1.25 = 15,000 LCY, and 15, = 833.33, rounded up to 834.
B. 667 truckloads, because 12,000 CY / 18 = 666.67, rounded up to 667, and the swell factor does not affect
truck count.
C. 900 truckloads, because 12,000 CY × 1.25 = 15,000 LCY, but you must add 20% for efficiency loss,
resulting in 18,000 LCY / 18 = 1000, but adjust to 900 for crew size.
D. 750 truckloads, because 12,000 CY × 1.25 = 15,000 LCY, but 15, = 833.33, and you subtract 10%
for moisture content to get 750.
Answer: A. 834 truckloads, because 12,000 CY × 1.25 = 15,000 LCY, and 15, = 833.33,
rounded up to 834.
2. During a mass grading operation, a contractor is required to cut 25,000 BCY and fill 30,000
BCY, but the fill material has a shrinkage factor of 90%. If the contractor borrows from a site
that has a bank density of 2,800 lb/BCY, what is the net volume of borrow (BCY) needed after
using 25,000 BCY of cut material?
A. 30,000 BCY, because the fill requirement remains constant regardless of shrinkage.
B. 8,333 BCY, because the cut provides 25,000 × 0.9 = 22,500 compacted CY, leaving 7,500 CY to be filled,
but then adjusted for bank density to get 8,333.
C. 5,000 BCY, because the cut fills 25,000 of the 30,000, leaving 5,000 to borrow.
D. 8,333 BCY, because the cut provides 25,000 × 0.9 = 22,500 compacted CY, leaving 7,500 compacted CY,
which is divided by the shrinkage factor to get 8,333 BCY.
Answer: D. 8,333 BCY, because the cut provides 25,000 × 0.9 = 22,500 compacted CY, leaving
7,500 compacted CY, which is divided by the shrinkage factor to get 8,333 BCY.
3. A site has a required compaction of 95% of standard Proctor maximum dry density. The soil
has an optimum moisture content of 14%, and the field density test shows a dry density of 108
lb/ft³ while the maximum dry density is 112 lb/ft³. What is the actual relative compaction, and
what action should the contractor take?
A. 96.4% compaction, and the lift is acceptable.
B. 96.4% compaction, but the lift fails because it is over 95%, so the contractor must add water and
recompact.
C. 96.4% compaction, and the lift passes, but the soil is too wet, so it must be aerated.
D. 96.4% compaction, and the lift passes, but the soil is too dry, so water should be added.
Answer: A. 96.4% compaction, and the lift is acceptable.
4. A contractor is excavating a trench in Type C soil with a depth of 12 feet. The trench will be
open for 48 hours, and there is no traffic surcharge. According to OSHA regulations, what is
the maximum allowable slope for the trench walls without shoring or shielding?
A. 1.5:1 (horizontal to vertical), because Type C soil requires the least steep slope.
, B. 1:1 (horizontal to vertical), because Type C soil can be sloped at 1:1 for depths up to 20 feet.
C. 0.75:1 (horizontal to vertical), which is typical for Type C soil in stable conditions.
D. 2:1 (horizontal to vertical), because Type C soil is cohesive and stable.
Answer: A. 1.5:1 (horizontal to vertical), because Type C soil requires the least steep slope.
5. During excavation, a contractor encounters an underground utility line that is not shown on
the plans. The line appears to be a high-pressure gas main. What is the contractor's first
responsibility under OSHA and general safety practices?
A. Immediately stop work in the area, notify the utility owner and the project owner, and have the line located
and marked before proceeding.
B. Continue excavation but cautiously avoid the line, documenting its location for future reference.
C. Proceed with excavation as planned but contact the utility company after the work is complete.
D. Backfill the trench and relocate to a different area, leaving the line undisturbed.
Answer: A. Immediately stop work in the area, notify the utility owner and the project owner,
and have the line located and marked before proceeding.
6. A trench is excavated to a depth of 15 feet in Type B soil, and a trench box is required. The
trench box has a maximum depth rating of 20 feet, but the soil is saturated due to recent heavy
rain. What should the contractor do according to OSHA?
A. Use the trench box as planned because the rating is sufficient, but monitor the trench for instability.
B. Reclassify the soil as Type C because of saturation, and use the trench box with a reduced capacity or
additional precautions.
C. Parallel the trench box to the trench walls, which is acceptable in all conditions.
D. Increase the depth of the trench box to extend above the trench depth to prevent cave-ins.
Answer: B. Reclassify the soil as Type C because of saturation, and use the trench box with a
reduced capacity or additional precautions.
7. A contractor is planning to work in a trench that is 8 feet deep. The soil is classified as Type
A, but there is a heavy vibration from nearby construction equipment. What does OSHA require
for the maximum allowable slope for the trench walls?
A. 1.5:1 (horizontal to vertical), because vibration reduces soil stability.
B. 0.75:1 (horizontal to vertical), because Type A soil can be steeply sloped, but only if vibration is not present.
C. 1:1 (horizontal to vertical), because vibration changes the classification to Type B.
D. 0.75:1 (horizontal to vertical), which is standard for Type A soil even with vibration.
Answer: C. 1:1 (horizontal to vertical), because vibration changes the classification to Type B.
8. A contractor is conducting a soil analysis for a cut slope that is 20 feet high in sandy soil.
The soil's angle of internal friction is 30 degrees, and the cohesive strength is negligible. Using
the simplified method, what is the maximum stable slope angle (from horizontal) without
reinforcement?
A. 45 degrees, because the angle of repose is 30 degrees, but a 1.5:1 slope is 33.7 degrees, so 45 is safe.
B. 30 degrees, because the angle of repose is the friction angle, and a slope steeper than 30 degrees would
be unstable.
C. 33.7 degrees, which corresponds to a 1.5:1 slope, but for sand, the slope should be flatter than the angle of
repose.
D. 60 degrees, because the soil can stand at a slope equal to the friction angle plus 30 degrees.
Answer: B. 30 degrees, because the angle of repose is the friction angle, and a slope steeper
than 30 degrees would be unstable.
Practice Exam – 200 Questions with Answers & Rationales|
INSTANT PDF DOWNLOAD
1. A contractor is preparing a bid for a large commercial site that requires excavating 12,000
cubic yards (LCY) of common earth. The swell factor is 25%, and the contractor's truck fleet
has a heaped capacity of 18 LCY per truck with a cycle time of 20 minutes. How many 18-LCY
truckloads will be required to haul the material, assuming an operational efficiency of 50
minutes per hour?
A. 834 truckloads, because 12,000 CY × 1.25 = 15,000 LCY, and 15, = 833.33, rounded up to 834.
B. 667 truckloads, because 12,000 CY / 18 = 666.67, rounded up to 667, and the swell factor does not affect
truck count.
C. 900 truckloads, because 12,000 CY × 1.25 = 15,000 LCY, but you must add 20% for efficiency loss,
resulting in 18,000 LCY / 18 = 1000, but adjust to 900 for crew size.
D. 750 truckloads, because 12,000 CY × 1.25 = 15,000 LCY, but 15, = 833.33, and you subtract 10%
for moisture content to get 750.
Answer: A. 834 truckloads, because 12,000 CY × 1.25 = 15,000 LCY, and 15, = 833.33,
rounded up to 834.
2. During a mass grading operation, a contractor is required to cut 25,000 BCY and fill 30,000
BCY, but the fill material has a shrinkage factor of 90%. If the contractor borrows from a site
that has a bank density of 2,800 lb/BCY, what is the net volume of borrow (BCY) needed after
using 25,000 BCY of cut material?
A. 30,000 BCY, because the fill requirement remains constant regardless of shrinkage.
B. 8,333 BCY, because the cut provides 25,000 × 0.9 = 22,500 compacted CY, leaving 7,500 CY to be filled,
but then adjusted for bank density to get 8,333.
C. 5,000 BCY, because the cut fills 25,000 of the 30,000, leaving 5,000 to borrow.
D. 8,333 BCY, because the cut provides 25,000 × 0.9 = 22,500 compacted CY, leaving 7,500 compacted CY,
which is divided by the shrinkage factor to get 8,333 BCY.
Answer: D. 8,333 BCY, because the cut provides 25,000 × 0.9 = 22,500 compacted CY, leaving
7,500 compacted CY, which is divided by the shrinkage factor to get 8,333 BCY.
3. A site has a required compaction of 95% of standard Proctor maximum dry density. The soil
has an optimum moisture content of 14%, and the field density test shows a dry density of 108
lb/ft³ while the maximum dry density is 112 lb/ft³. What is the actual relative compaction, and
what action should the contractor take?
A. 96.4% compaction, and the lift is acceptable.
B. 96.4% compaction, but the lift fails because it is over 95%, so the contractor must add water and
recompact.
C. 96.4% compaction, and the lift passes, but the soil is too wet, so it must be aerated.
D. 96.4% compaction, and the lift passes, but the soil is too dry, so water should be added.
Answer: A. 96.4% compaction, and the lift is acceptable.
4. A contractor is excavating a trench in Type C soil with a depth of 12 feet. The trench will be
open for 48 hours, and there is no traffic surcharge. According to OSHA regulations, what is
the maximum allowable slope for the trench walls without shoring or shielding?
A. 1.5:1 (horizontal to vertical), because Type C soil requires the least steep slope.
, B. 1:1 (horizontal to vertical), because Type C soil can be sloped at 1:1 for depths up to 20 feet.
C. 0.75:1 (horizontal to vertical), which is typical for Type C soil in stable conditions.
D. 2:1 (horizontal to vertical), because Type C soil is cohesive and stable.
Answer: A. 1.5:1 (horizontal to vertical), because Type C soil requires the least steep slope.
5. During excavation, a contractor encounters an underground utility line that is not shown on
the plans. The line appears to be a high-pressure gas main. What is the contractor's first
responsibility under OSHA and general safety practices?
A. Immediately stop work in the area, notify the utility owner and the project owner, and have the line located
and marked before proceeding.
B. Continue excavation but cautiously avoid the line, documenting its location for future reference.
C. Proceed with excavation as planned but contact the utility company after the work is complete.
D. Backfill the trench and relocate to a different area, leaving the line undisturbed.
Answer: A. Immediately stop work in the area, notify the utility owner and the project owner,
and have the line located and marked before proceeding.
6. A trench is excavated to a depth of 15 feet in Type B soil, and a trench box is required. The
trench box has a maximum depth rating of 20 feet, but the soil is saturated due to recent heavy
rain. What should the contractor do according to OSHA?
A. Use the trench box as planned because the rating is sufficient, but monitor the trench for instability.
B. Reclassify the soil as Type C because of saturation, and use the trench box with a reduced capacity or
additional precautions.
C. Parallel the trench box to the trench walls, which is acceptable in all conditions.
D. Increase the depth of the trench box to extend above the trench depth to prevent cave-ins.
Answer: B. Reclassify the soil as Type C because of saturation, and use the trench box with a
reduced capacity or additional precautions.
7. A contractor is planning to work in a trench that is 8 feet deep. The soil is classified as Type
A, but there is a heavy vibration from nearby construction equipment. What does OSHA require
for the maximum allowable slope for the trench walls?
A. 1.5:1 (horizontal to vertical), because vibration reduces soil stability.
B. 0.75:1 (horizontal to vertical), because Type A soil can be steeply sloped, but only if vibration is not present.
C. 1:1 (horizontal to vertical), because vibration changes the classification to Type B.
D. 0.75:1 (horizontal to vertical), which is standard for Type A soil even with vibration.
Answer: C. 1:1 (horizontal to vertical), because vibration changes the classification to Type B.
8. A contractor is conducting a soil analysis for a cut slope that is 20 feet high in sandy soil.
The soil's angle of internal friction is 30 degrees, and the cohesive strength is negligible. Using
the simplified method, what is the maximum stable slope angle (from horizontal) without
reinforcement?
A. 45 degrees, because the angle of repose is 30 degrees, but a 1.5:1 slope is 33.7 degrees, so 45 is safe.
B. 30 degrees, because the angle of repose is the friction angle, and a slope steeper than 30 degrees would
be unstable.
C. 33.7 degrees, which corresponds to a 1.5:1 slope, but for sand, the slope should be flatter than the angle of
repose.
D. 60 degrees, because the soil can stand at a slope equal to the friction angle plus 30 degrees.
Answer: B. 30 degrees, because the angle of repose is the friction angle, and a slope steeper
than 30 degrees would be unstable.
