Engineering and Construction Surveying
Core concepts
Construction surveying requires stationing, cut-and-fill, grade, slope, horizontal and vertical curves, earthwork volumes, control, and as-built verification. Know how to convert between percent grade, slope ratio, and vertical change; know the elements of horizontal curves and vertical curves; and know how to set offsets, batter boards, and grade stakes. Understand that construction layout depends on reliable horizontal and vertical control, and that as-built surveys document actual conditions rather than design intent.
Traps
A common trap is reversing cut and fill. Cut equals existing ground minus design elevation; fill equals design minus existing. Another trap is using slope distance where horizontal distance is required, or ignoring a station equation. In earthwork, do not confuse bank, loose, and compacted volumes. In curve problems, watch whether the degree of curve is defined by arc or chord.
Worked example
Existing ground at a stake is 104.25 ft and design elevation is 102.00 ft. Cut = 104.25 - 102.00 = 2.25 ft. If design were 105.00 ft, the same point would require 0.75 ft of fill. For grade, an elevation change of 2.50 ft over 500 ft is 2.50/500 = 0.005, or 0.5 percent. Rule of thumb: cut is existing minus design, and fill is design minus existing.