TUTORIALS
Some useful guidelines on super elevation design for road
Recognize full super elevation is in fact the super elevation at the apex point of horizontal curve. Apex point is the middle or midpoint of a curve along its length or parameter.
The value of full super elevation.
The subsequent formula can be utilized for the approach.
e = h = Bv2/gR
B in the formula is the breadth of railway line or road
V is vehicle speed
g is acceleration = 9.8 m/s2
R = circular curve radius
Compute super elevation for a circular road with radius 300 meters and it’s 8 meter wide. Consider 50 km/hour as vehicle speed and consider centrifugal ratio equal to 1/10.
Full super elevation = h = Bv2/gR
V = 50 km/hour x 1000/60 x 60
V = 50 km/hour x 1000/3600
V = 13.89 m/sec
h = 8 x (13.89)2/9.8 x 300
h = 1543.456/943 = 0.5244 meters = 52.5 cm
Centrifugal ratio = 1/10
As a result, super elevation limit = SE limit = 1/10 x B = 1/10 x 8 = 0.8 m = 80 cm
The computed value is in limit. As a result, that’s okay. 52.5 cm could be provided like the full super elevation on the same road.
Watch the following video to learn the complete process.
Lecturer: SL Khan
