Question

3. A 300 ft vertical curve connects a-2.3% approach grade and a +1.6% departure grade. The PVI is at 45+65 with elevation 369.22'. The curve is designed for 35 mi/hr speed limit. Calculate stations and elevations for PVC and PVT A 4% grade meets a failing grade of-25%. Station at P1 is at 60+00 and elevation is 95 feet. The length between PVC and PVT is 1400 feet. Find the elevation of the curve at station 58+00 4.

Answer 1

3) L = 300 ft = 3 stations

G1 = -2.3 %

G2 = +1.6%

Station at PVI = 45+65

Elevation at PVI = 369.22'

Station at PVC = (45+65) - L/2 = (45+65) - (1+50) = 44+15

Elevation at PVC = Elevation of PVI - G1 * L/2 = 369.22 - (-0.023) * 150 = 372.67 ft

Station at PVT = (45+65) + L/2 =  (45+65) + (1+50) = 47+15

Elevation at PVT = Elevation of PVI - G1 * L/2 = 369.22 + (0.016) * 150 = 371.62 ft