Question

A circular curve of radius equal 17.5 times of standard sub chord, deflecting right through 32°40', is to be set out between two straights having chainage of the point of intersection 1029.35. Calculate the necessary data to set out the curve by the method of deflection angles. If the length of standard sub chord is 20 m. The necessary data include:

The Tangent Length of new curve

Answer 1

To set out the curve by the method of deflection angles, we need to calculate the radius of the circular curve, the angle of rotation, and the tangent length. The radius is found to be 350m, the angle of rotation is 80°, and the tangent length is approximately 333.97m.

Step-by-step explanation:

To calculate the necessary data to set out the curve, we can use the formula Δθ = 4s, where Δθ is the angle of rotation and s is the arc length. Since the length of the standard sub chord is given as 20m, we can calculate the angle of rotation using the formula: Δθ = 4s = 4 × 20 = 80°. Next, we need to find the radius of the circular curve. Given that the radius is 17.5 times the length of the standard sub chord, we can calculate it as: Radius = 17.5 × 20 = 350m.

Finally, we can calculate the tangent length of the new curve using the formula: Tangent Length = Radius × tan(Δθ/2). Substituting the values we have, we get: Tangent Length = 350 × tan(80°/2) = 350 × tan(40°) ≈ 333.97m. The student is asking about setting out a circular curve using the method of deflection angles. The circular curve has a radius that is 17.5 times the length of a standard sub chord, with a deflection angle to the right of 32°40'. The standard sub chord length is given as 20 m. To calculate the tangent length for this new curve, we must first determine the radius of the curve.