Question

A digital automatic level is used to profile a road centerline. The backsight reading is 3.57 ft on BM #1, which has an elevation of 210.50 ft. A foresight reading on Turning Point #1 (TP#1) is 4.52 ft. At the next setup, a backsight of 2.91 ft is read for TP#1 and an intermediate foresight for Sta. 0+00 is read as 5.67 ft. Determine the elevation of Sta. 0+00 in ft.

Answer 1

Answer:

209.55 ft

Explanation:

Given Data:

Benchmark:

Reduced Level or Elevation = 210.50

Height of Instrument = Reduced Level + Back sight Reading

Height of Instrument = 210.50 + 3.57 = 214.07 ft

Turning Point:

Back sight Reading = 2.91 ft

Fore Sight Reading = 4.52

Reduced Level or Elevation of Turning Point = Height of Instrument – fore sight Reading

Reduced Level or Elevation of Turning Point = 214.07 – 4.52 = 209.55 ft

Height of Instrument at Turning Point = Reduced Level + Back sight Reading

Height of Instrument at Turning Point = 209.55 + 2.91 = 212.46 ft

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