Equal-tangent crest vertical curve: grade elevations and the high point
A 600 ft crest curve joining a +3.20 percent grade to a −2.40 percent grade is reduced to a grade sheet at full stations, with the high point located and the K value reported.
Apply· about 22 minutes by hand· 5 steps
Given
An equal-tangent parabolic vertical curve on a highway profile.
Grade in g₁ = +3.20 percent; grade out g₂ = −2.40 percent.
Curve length L = 600.00 ft, measured horizontally.
PVI at station 34+50.00, elevation 852.40 ft.
Grade elevations are wanted at every full station, plus the BVC, EVC and the high point.
Elevations to 0.01 ft; stations in 100 ft US customary form.
Required
Stations and elevations of the BVC and the EVC.
The algebraic grade change, the rate of change of grade, the K value and the external offset.
Station and elevation of the high point.
A grade sheet at full stations.
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