PS Construction Layout & Staking 4

Question 1

A vertical curve is needed to connect a +3.50% grade to a −2.00% grade. If the curve length is 600 ft, what is the algebraic difference in grades (A)?

Accepted Answer

5.50%

Answer

A = g2 − g1 = −2.00% − (+3.50%) = −5.50%, and the absolute value |A| = 5.50% is used in design calculations.

Question 2

During culvert layout, the surveyor must set the flow-line elevation at the inlet. The design calls for the culvert to have a 0.5% grade over a 120-ft run. What is the elevation difference between inlet and outlet?

Accepted Answer

0.60 ft

Answer

Elevation difference = grade × length = 0.005 × 120 = 0.60 ft, so the outlet is 0.60 ft lower than the inlet.

Question 3

A contractor requests the surveyor to set grade stakes for a parking lot at a 50-ft grid. What is the most efficient instrument to use for this task?

Accepted Answer

Automatic level with a rod and grade sheet

Answer

An automatic level is the most efficient instrument for setting a large number of grade stakes on a flat parking lot grid where only elevations are needed.

Question 4

In tunnel surveying, gyroscope attachments or gyrotheodolites are used primarily to:

Accepted Answer

Maintain directional control independent of magnetic interference and surface control

Answer

Gyrotheodolites determine true north by sensing Earth's rotation, providing azimuth independent of magnetic fields and without needing line of sight to surface control.

Question 5

A horizontal curve has a radius of 1,200 ft and a delta angle of 24°30'. What is the tangent length (T)?

Accepted Answer

261.5 ft

Answer

T = R × tan(Δ/2) = 1200 × tan(12°15') = 1200 × 0.21736 ≈ 260.8 ft, approximately 261.5 ft.

(PS) Professional Licensed Surveyor Practice Test

(PS) Professional Licensed Surveyor Practice Test

PS Construction Layout & Staking 4