FUNDAMENTAL SURVEYING Horizontal and Vertical Curves

Question 1

According to the arc definition, the degree of curve (Da) is the central angle subtended by an arc of what length?

Accepted Answer

100 feet

Answer

The arc definition states that the degree of curve is the central angle subtended by a 100-foot arc, which is the standard used in US highway surveying.

Question 2

Which formula correctly expresses the tangent length (T) of a simple circular horizontal curve?

Accepted Answer

T = R × tan(Δ/2)

Answer

The tangent length T = R × tan(Δ/2) is derived from the right triangle formed by the radius, the PI, and the PC.

Question 3

The external distance (E) of a horizontal curve is the distance from:

Accepted Answer

The PI to the midpoint of the arc

Answer

The external distance E is the distance from the PI (Point of Intersection) to the midpoint of the curve, calculated as E = R × (1/cos(Δ/2) − 1).

Question 4

For a horizontal curve with R = 500 ft and intersection angle Δ = 60°, what is the arc length?

Accepted Answer

523.6 feet

Answer

Arc length L = πRΔ/180 = π × 500 × 60/180 = 523.6 feet.

Question 5

The Point of Curvature (PC) in a horizontal curve alignment is defined as:

Accepted Answer

The point where the straight tangent ends and the circular curve begins

Answer

The PC (Point of Curvature) marks where the back tangent ends and the circular curve begins; the alignment sequence is PI → PC → curve → PT.

FUNDAMENTAL SURVEYING Practice Test

FUNDAMENTAL SURVEYING Practice Test

FUNDAMENTAL SURVEYING Horizontal and Vertical Curves