Construction Surveying and Land Development
Construction Surveying and Land Development
The PS exam tests stakeout, grades, earthwork, and subdivision layout. Expect cut/fill, slope staking, horizontal and vertical curves, and plan-reading questions.
Stakeout and grades
Construction stakeout transfers plan geometry to the field: horizontal and vertical control, offsets, grade stakes, and slope stakes. Cut is a downward excavation; fill is an upward embankment. A grade stake marked "C 2.5" means cut 2.5 ft to grade. Always tie elevations to the project datum, not an assumed benchmark.
Earthwork
Average end area method: V = (A1 + A2)/2 × L. Volumes are in cubic feet; divide by 27 to convert to cubic yards. Prismoidal correction improves accuracy for varying sections.
Subdivision and land development
Layout must satisfy zoning setbacks, right-of-way widths, easements, drainage, and accessibility. Check that lot areas and frontages meet ordinance minimums. Retracement of a subdivision should hold original monumented lot corners.
Worked example
A roadway cut has end areas 120 ft² and 180 ft² over a 100-ft station interval. Average area = (120 + 180)/2 = 150 ft². Volume = 150 × 100 = 15,000 ft³. Convert: 15,000 ÷ 27 = 555.6 yd³. If the material swells 20%, haul volume = 555.6 × 1.20 = 666.7 yd³.
Traps
- Forgetting to divide by 27 for cubic yards.
- Reversing cut and fill signs.
- Using plan elevations that are not tied to the datum.
- Ignoring swell/shrink in earthwork quantities.
- Assuming setback is measured from the property line rather than the right-of-way when the ordinance specifies.