Type of horizontal curves

 

Horizontal curves :-

There are four type of horizontal curves

      (a)    Simple Curves

      (b)   Compound Curves

      (c)    Reverse Curves

      (d)   Transition Curves

 

       (a)    Simple curve : A circular curve consisting of a single arc of uniform radius connecting two      tangents is called simple curve.

SIMPLE CURVE

This curve is expressed in terms of degree of curve, which is the angle in degrees subtended at the center by a chord of 30 meters length. This type of curve is suitable for large radius and for slow moving vehicles.

      (b)   Compound curve : A circular curve consisting of two or more simple curves of different radii, which turn in the same direction is called a compound curve.

COMPOUND CURVE

     (c)    Reverse curve : A circular curve consisting of two simple curves of same or different raddi and having their center in opposite direction is called a reverse curve. This is also called serpentine curve.

      

REVERSE CURVE

      (d)   Transition curve : The curve having its radius varying gradually from infinity at the tangent point to a designed radius of the circular curve or vice versa is known transition curve. This is also known as spiral or easemate curve.