Question

A parabolic vertical curve is being designed to join a road of grade +5 % with a road of grade -3 %. The length of the vertical curve is 400 m measured along the horizontal. The vertical point of curvature VPC is located on the road of grade +5 %. The difference in height between VPC and vertical point of intersection (VPI) (in m, round of to the nearest integer) is

• A. 10

Answer 1

The correct option is A 10

$n_1=0.05$

$n_2=-0.03$

$L=400m$

The difference in the height between VPC and VPI,
$y=n_1\times \frac{L}{2}$

$=0.05\times \frac{400}{2}$

$=10m$