KDOT Survey & Layout Verification 3 — Questions and Answers
Question 1: What is the purpose of a 'check shot' taken by the inspector during grade verification?
- To verify that the surveying instrument is properly calibrated by shooting a known elevation (Correct answer)
- To record the depth of the subgrade material
- To confirm the contractor's daily production volume
- To measure the distance between survey monuments
Correct answer: To verify that the surveying instrument is properly calibrated by shooting a known elevation
A check shot is taken on a known benchmark or control point to verify the instrument's setup elevation before recording grade data.
Question 2: On a KDOT grading plan, a cut section shows 'C=3.2'. What does this notation mean?
- The compaction factor is 3.2
- The cut depth at centerline is 3.2 feet (Correct answer)
- The curve radius is 3.2 stations
- The concrete thickness is 3.2 inches
Correct answer: The cut depth at centerline is 3.2 feet
On grading cross-sections, 'C=3.2' indicates a cut depth of 3.2 feet at the centerline of that station.
Question 3: A KDOT inspector is checking subgrade elevation after rough grading. The design elevation is 1,204.50 ft and the measured elevation is 1,204.62 ft. What does this indicate?
- The subgrade is 0.12 ft high and must be cut down before paving (Correct answer)
- The subgrade is 0.12 ft low and requires additional fill
- The reading is within tolerance and no action is needed
- The benchmark elevation has shifted and must be re-established
Correct answer: The subgrade is 0.12 ft high and must be cut down before paving
A measured elevation 0.12 ft above design means the subgrade is too high and must be cut to achieve the correct grade before paving operations begin.
Question 4: Which instrument is most appropriate for establishing precise vertical control during KDOT bridge deck paving operations?
- Handheld laser level
- Digital automatic level with invar rod (Correct answer)
- GPS rover with RTK correction
- Carpenter's level and tape measure
Correct answer: Digital automatic level with invar rod
A digital automatic level with an invar rod provides the highest vertical accuracy needed for bridge deck grade control, typically to ±0.001 ft.
Question 5: When reviewing a contractor's as-built survey for a KDOT drainage structure, the inspector finds the pipe invert is 0.15 feet lower than designed. What is the likely consequence?
- Improved drainage flow velocity
- Potential standing water upstream or inadequate outlet capacity (Correct answer)
- No functional impact if the pipe length is correct
- The difference triggers a change order credit to KDOT
Correct answer: Potential standing water upstream or inadequate outlet capacity
A pipe invert 0.15 feet lower than designed can cause standing water upstream if the outlet lacks sufficient cover or creates a hydraulic jump condition.
Question 6: A KDOT highway project uses a 'superelevation runoff' section. What does the inspector verify in this transition zone?
- That the pavement cross-slope transitions uniformly from normal crown to full superelevation (Correct answer)
- That the guardrail post spacing matches the superelevation rate
- That the shoulder width increases through the transition
- That drainage inlets are installed at the end of the runoff section
Correct answer: That the pavement cross-slope transitions uniformly from normal crown to full superelevation
The inspector verifies that the cross-slope transitions smoothly and uniformly through the superelevation runoff so there are no abrupt grade changes.
Question 7: On a KDOT plan sheet, contour lines that are closer together indicate what condition?
- Flat terrain with minimal slope
- Steeper terrain with greater slope gradient (Correct answer)
- A change in soil classification
- A proposed fill area
Correct answer: Steeper terrain with greater slope gradient
Closely spaced contour lines indicate steeper terrain because the same elevation change occurs over a shorter horizontal distance.
KDOT Survey & Layout Verification 3
What is the purpose of a 'check shot' taken by the inspector during grade verification?