Horizontal and Vertical Curves Flashcards
7 cards from real FUNDAMENTAL SURVEYING practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Horizontal and Vertical Curves flashcards as text
According to the arc definition, the degree of curve (Da) is the central angle subtended by an arc of what length?
Answer: 100 feet
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.
Which formula correctly expresses the tangent length (T) of a simple circular horizontal curve?
Answer: T = R × tan(Δ/2)
The tangent length T = R × tan(Δ/2) is derived from the right triangle formed by the radius, the PI, and the PC.
The external distance (E) of a horizontal curve is the distance from:
Answer: The PI to the midpoint of the arc
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).
For a horizontal curve with R = 500 ft and intersection angle Δ = 60°, what is the arc length?
Answer: 523.6 feet
Arc length L = πRΔ/180 = π × 500 × 60/180 = 523.6 feet.
The Point of Curvature (PC) in a horizontal curve alignment is defined as:
Answer: The point where the straight tangent ends and the circular curve begins
The PC (Point of Curvature) marks where the back tangent ends and the circular curve begins; the alignment sequence is PI → PC → curve → PT.
A compound curve is best described as:
Answer: Two or more curves of different radii all curving in the same direction
A compound curve consists of two or more simple circular arcs of different radii that all turn in the same direction, joined at Points of Compound Curvature (PCC).
The middle ordinate (M) of a horizontal curve is the distance measured from:
Answer: The midpoint of the long chord to the midpoint of the arc
The middle ordinate M is the perpendicular distance from the midpoint of the long chord to the midpoint of the arc, calculated as M = R × (1 − cos(Δ/2)).