Question

1. (17.5 pts) A highway is being designed for a speed of 65mph. At one horizontal curve, it is know that the maximum superelevation that can be build is 6% and the side friction for the whole project is 0.10. The geometry of the area is such that the Intersection Angle is 20 degrees and the station of the Point of Intersection is 52+19.00ft a. Determine the minimum radius of curvature that will provide for safe vehicle operation. b. Calculate L, D, T, LC, E, M, PC and PT for this horizontal curve. 2. (17.5 pts) A highway is being designed for a speed of 60mph. At one horizontal curve, it is know that the maximum superelevation that can be build is 9% and the side friction for the whole project is 0.12. The geometry of the area is such that the Intersection Angle is 30 degrees and the station of the Point of Intersection is 33+39.00ft. a. Determine the minimum radius of curvature that will provide for safe vehicle operation. b. Calculate L, D, T, LC, E, M, PC and PT for this horizontal curve. 3. (15 pts) You have been asked to design a horizontal curve with a degree of curvature of 5 degrees. The geometry of the area is such that the Intersection Angle is 15 degrees 30 seconds and the station of the Point of Intersection is 33 +39.00ft a. Calculate L,R,T,LC,E,M,PC and PT for this horizontal curve.

Answer 1

To determine the minimum radius of curvature for safe vehicle operation, use the formula: R = (V^2) / (g * tan(α)), where R is the radius of curvature, V is the velocity of the vehicle, g is the acceleration due to gravity, and α is the angle of banking.

Step-by-step explanation:

To determine the minimum radius of curvature that ensures safe vehicle operation, we can use the following formula:

R = (V^2) / (g * tan(α))

where R is the radius of curvature, V is the velocity of the vehicle, g is the acceleration due to gravity, and α is the angle of banking.

For example, if we know that the maximum superelevation is 6% and the side friction is 0.10, we can calculate the minimum radius of curvature using the given values.

Answer 2

The questions involve the engineering design of a highway's horizontal curve, including the calculation of the minimum radius of curvature for safe vehicle operation and other parameters like L, D, T, LC, E, M, PC, and PT, using roadway engineering principles.

Step-by-step explanation:

The questions provided relate to the design of a horizontal curve for a highway, and involve the calculation of various parameters that are essential in roadway engineering and highway design. To determine the minimum radius of curvature for safe vehicle operation, factors such as speed, the maximum superelevation, and the coefficient of side friction need to be considered. The radius is crucial because it affects the necessary banking of the road (superelevation) to help vehicles negotiate the curve without relying excessively on friction.

For the computational aspects like calculating the length of the curve (L), degree of curvature (D), tangent length (T), length of the curve (LC), external distance (E), middle ordinate (M), point of curvature (PC), and point of tangency (PT), specific civil engineering formulas are utilized, which are derived from principles of circular motion and forces acting on vehicles during turning.

Additionally, for scenarios like a frictionless road or different road conditions (dry, wet, icy), the ideal speed for a curve of a known radius and banking angle can be found by analyzing the forces in circular motion. The necessary coefficient of side friction can also be calculated if a vehicle is moving slower than the ideal speed for a given curve. These calculations ensure that the roadway design accommodates vehicles' safety and performance in various conditions.