K Value

Calculate curve length by K value.

This function allows you to enter a specific K value for a certain VPI. The function then calculates the curve length to achieve this K value, and prints it to the screen or the printer depending on the option chosen.

This curve length, or a rounded equivalent thereof, can then be entered into the alignment. This is not done automatically.

K Value

The K-value is the horizontal distance required to achieve a 1% change in the slope of the vertical curve.

For Symmetrical Vertical Curves

Where:

L = length of curve

A = absolute value of difference in grades

For Asymmetrical Vertical Curves

K = the lesser of K1 and K2

Where:

d1 = distance from BVC to PI

d2 = distance from PI to EVC

so, L =  d1 + d2

Procedure

1. The K Curve Details display.

2. Fill in the desired K value and click OK to continue.

3. The following displays in the Output Bar.