SURVEY AND GRADING SURVEY AND GRADING Surface

SURVEY AND GRADING

SURVEY AND GRADING Surface drainage • Especially from house • Toward drain inlet

SURVEY AND GRADING Design berms and slopes

INSTRUMENTS OF SURVEYING Tape measure • >100’ • Feet/inches or feet/tenths

INSTRUMENTS OF SURVEYING Builder’s level • Tripod mounted “scope” • Leveled so view is perfectly level in all directions

INSTRUMENTS OF SURVEYING Transit • A builder’s level that also measures angles

INSTRUMENTS OF SURVEYING Laser levels

INSTRUMENTS OF SURVEYING Spinning laser beam and sensor

INSTRUMENTS OF SURVEYING Surveryor’s rod, big “yard stick, ” to estimate spot elevation

INSTRUMENTS OF SURVEYING

SURVEY AND GRADING What is elevation? • Height above average sea level

SURVEY AND GRADING Benchmark • Permanent reference point • Manhole cover, curb, fire hydrant

SURVEY AND GRADING

SURVEY AND GRADING Contour lines • Connect points of similar elevation • The closer together contour lines, the steeper the slope • The farther apart, the “flatter” the slope

SURVEY AND GRADING Contour lines

SURVEY AND GRADING What’s elevation of X(a) and X(b)?

SURVEY AND GRADING

SURVEY AND GRADING Contour lines based on spot elevations

SPOT ELEVATIONS Backsite • Reading on benchmark (BM) • BM has a known elevation • Backsite + Benchmark Elevation = Height of Instrument • 6. 12’ + 100’ = 106. 12’

SPOT ELEVATIONS Foresites Readings at unknown elevations Height of Instrument – Foresite = Elevation • • • 106. 12’ – 3. 98’ = 102. 14’ 106. 12’ 102. 14’

SPOT ELEVATIONS Construction stake at spot elevation Mark stake to indicate grade change • • +0. 0 (increase ground level in inches) -0. 0 (decrease level) Let’s say a construction plan proposes Foresite A to be 101. 00’ +1. 14’ The existing elevation was determined to be 102. 14’. Existing elevation – Proposed elevation = Grade Change 102. 14’ – 101. 00’ = 1. 14’

GRADING Rough grading uses stakes with proposed changes marked

GRADING

LASER LEVELING • Tractor adjusts box leveler according to laser level

LASER LEVELING

DETERMING SLOPES (39) • (V÷H) X 100 = % OF SLOPE • Vertical (V) distance between 2 points • Horizontal (H) distance • V = 3. 14’ – 1. 21’ = 1. 93’ • H = 150’ • (1. 93’ ÷ 150’) x 100 = 1. 29%

CREATING A SLOPE (%) H X Desired Slope % = Change in Elevation 3. 6’ H = 120’ Slope % = 3% (or 0. 03) 120’ x 0. 03’ = 3. 6’ Slope needs to drop a total of 3. 6’ to be 3%