Grade Compensation Problems and Solution
Here one mathematical example is taken for, how to determine grade compensation when gradient, and radius of curve is given.
Gradient on a highway is 1 in 15. Radius of curve is 160 m. After grade compensation the grade to be provided should not be less than 4%. What is grade compensation?
Gradient, N = 1/15 = (1/15)⨯100 = 6.67 %.
Grade compensation = (30+R)/R = (30+160)/160 = 1.1875%
or, 75/R = 75/160 = 0.47%
Use minimum i.e., 0.47%.
After grade compensation the gradient to be provided on the road is 6.67 -0.47 = 6.2 %(Which is more than 4%, hence OK)
So, Grade compensation = 0.47%.