Presented by Lance Hummel
Survey of Irrigation Canals
Railway Surveys
Construction Surveys
Property Boundary Surveys
Pipeline Assembly
Survey of Roads
Bridges
Survey around Obstacles
The origin of the curve
It starts with the circle
Circle 360 o
Diameter (d) 180 o d
Radius (R) R
Central Angle / Delta
Center of Curve (cc) cc
Beginning (BC) and End (EC) BC EC
Arc / Length (L) L
Chord (CH) CH
The Basic Components BC EC CH L R cc
The Curve in Survey Applications
Where does the curve fit
Back and Forward Tangent 90 o
Point of Curvature and Tangency PC PT
Sub Tangent (T) T
Point of Intersection (PI) PI
Delta
Half Delta 90 o cc PI 2
Mid-Ordinate (M) M
External (E) E
Curve Components R cc BC, PCEC, PT CH L T PI E M
Degree of Curve (D) D 100’ or 30.48m
Examples of Formulas Tangent = R tan Chord = 2R sin Length = R 2 2