TABLE OF CONTENTS Robert W. Stokes
The location of highway centerlines is initially laid out as a series of straight lines (tangent sections). These tangents are then joined by circular curves to allow for smooth vehicle operations at the design speed selected for the highway. The following figure shows the basic geometry of a simple circular curve. If the two tangents intersecting at the PI are laid out, and the angle ? between them is measured, only one other element of the curve must be known to calculate the remaining elements. The radius of the curve (R) is the other element most commonly used.
Q:
Given the following horizontal curve data, determine the curve radius, R, length of curve, L, stationing (sta) of the PC, stationing of the PT, the long chord, C, and the deflection angle, d, of a point on the curve 30 m ahead of the PC.
PI = sta 2 + 170.00 (km)
? = 41 10'
T = 115.00 m
Answers
Q:
PC sta = PI sta - T = 2170.00 - 115.00 = 2 + 055.00
R = T/tan( ?/2) = 115.00/0.3755 = 306.22 m
L = ( ?R)/57.2958 = 220.02 m
PT sta = PC sta + L = 2055.00 + 220.02 = 2275.02 m
C = 2R sin( ?/2) = 2(306.22)(0.3516) = 215.32 m
d = (28.64789 ?)/R = [(28.64689)(30)]/306.22 = 2.81
The minimum radius of horizontal...
