What is the elevation of the point of vertical tangency for an equal-tangent sag vertical curve with the following given information?
G
1
= -4%, G
2
= +2%, L= 400ft, PVCSta = 100+00, PVCElev = 100.00 ft

Question

Quizplus · Accepted Answer

the elevation of the point of vertical tangency for an equal-tangent sag vertical curve is 96 ft. Solution Use the general parabolic formula for a vertical curve. y = ax 2 + bx + c Where a = (G 2 - G 1 )/2 = (0.02 -(-0.04))/2(400) = 0.00008 x = curve length = L = 400 ft b = G 1 = 0.04 c = PVC elevation = 100 ft y = 0.00008 (400) 2 + (-0.04)(400) + 100 = 12 - 16 + 100 = 96 ft.

What Is the Elevation of the Point of Vertical Tangency