fundamentals of engineering supplied-reference handbook - Ventech!

HORIZONTAL CURVE FORMULAS
D = Degree of Curve, Arc Definition
P.C. = Point of Curve (also called B.C.)
P.T. = Point of Tangent (also called E.C.)
P.I. = Point of Intersection
I = Intersection Angle (also called ∆)
Angle between two tangents
L = Length of Curve,
from P.C. to P.T.
T = Tangent Distance
E = External Distance
R = Radius
L.C. = Length of Long Chord
M = Length of Middle Ordinate
c = Length of Sub-Chord
d = Angle of Sub-Chord
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R =
D
L.C.
R =
2 sin /2
( I )
L.C.
T = Rtan ( I/2
) =
2 cos /2
π I
L = RI = 100
180 D
[ 1 − cos(
I/ ) ]
M = R 2
R
= cos ( I/ 2)
E + R
R − M
= cos I/ 2
R
c = 2R sin( d/ 2)
( )
⎡ 1 ⎤
E = R ⎢ −1⎥
⎣ cos( I/2)
⎦
( I )
Deflection angle per 100 feet of arc length equals
D
2
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LATITUDES AND DEPARTURES
CIVIL ENGINEERING (continued)
+ Latitude
- Departure + Departure
- Latitude