Simple circular curves part 1

simple circular curve, necessity, types:reverse curve, compound curve, degree of curve, curve from offset from tangent

1. SIMPLE CIRCULAR CURVE

2. INTRODUCTON CURVES ARE GENERALLY USED ON HIGHWAY AND RAILWAYS WHERE IT IS NECESSARY TO CHANGE THE DIRECTION OF MOTION A CURVE MAY BE DIVIDED INTO 3 TYPES: SIMPLE COMPOUND REVERSE DEVIATION CURVE

3. 1) SIMPLE CURVE A SIMPLE CURVE IS THE ONE WHICH CONSIST OF A SINGLE ARC OF A CIRCLE. IT IS TANGENTIAL TO BOTH THE STRAIGHT LINE

4. 2) COMPOUND CURVE A Compound curve consists of two or more simple arcs of different radius that turn in the same direction and join at common tangent point There centre lies on the same side of curve

5. 3) REVERSE CURVE It is a curve made up of two arcs of equal or different radii bending in opposite side of a common tangent at their junction. Centre of curve lies on the opposite side of a common tangent. They are also called as ‘S’ curves Common tangent

6. 4) DEVIATION CURVE It is a combination of two reverse curves. It consists of three arcs or curves of different or equal radii. It is provide when it become essential to deviate from a given straight path to avoid obstacles.

7. Angle of Intersection Various parts of curve

8. Designation of Curve Degree of curve : or (30 m)

9. Relationship between degree and radian of curve (Chord length=30m)

10. Elements of simple curve 1) Angle of deflection ( )

11. Mid Ordinate

12. 1) Perpendicular offset from tangent

13. 2) Radial offset from tangent O1 O2