Topic 10: Horizontal Curves

Question 0

Rate of Curvature is designated either by:

Answer 0

1. radius of the curve (R)

2. Degree of curve (D)

Question 1

Horizontal Curves

Answer 1

-Are used in Route surveying to connect two straight tangent sections (for example, centerline of a highway with curves).
-horizontal curves are either:
Simple curves, compound curves, broken-back curve, reverse curve.

Question 2

Degree of curve can be defined by either:

Answer 2

1. Arc definition

2. Chord definition

Question 3

Point of Intersection (PI)

Answer 3

The point of intersection marks the point where the back and forward tangents intersect. The surveyor indicates it as one of the stations on the preliminary traverse.

Question 4

Intersecting Angle (I)

Answer 4

The deflection angle at PI. The surveyor either computes it’s value from the preliminary traverse station angles or measures it in the field.

Question 5

Radius (R)

Answer 5

Radius of the circle of which the curve is an arc.

Question 6

Point of curvature (PC)

Answer 6

The point where the circular curve begins. The back tangent is the tangent to the curve at this point.

Question 7

Point if tangency (PT)

Answer 7

The end of the curve. The forward tangent to the curve at this point.

Question 8

Length of curve (L)

Answer 8

Is the distance from PC to PT, along the curve.

Question 9

Curves are normally laid in the field by means of one of these methods:

Answer 9

Deflection angles
Tangent offsets
Coordinates
Middle ordinates
Ordinates from long chord