2 or 3 Centered Compound Curve with Spirals
2 or 3 Centered Compound Curve with Spirals
(OP)
Anybody (gurus) out there able to help me with designing horizontal road alignment consists of:
1. Two-centered Compound Curve with 3 Spirals, and
2. Three-centered Compound Curve with 4 Spirals.
Thank you.
HC
1. Two-centered Compound Curve with 3 Spirals, and
2. Three-centered Compound Curve with 4 Spirals.
Thank you.
HC





RE: 2 or 3 Centered Compound Curve with Spirals
RE: 2 or 3 Centered Compound Curve with Spirals
The combined curve spiral-arc-spiral is pretty straight forward. I've managed to complete the program on this type of curve.
When it comes to compound curves with L1-R1-L2-R2-L3 and the likes, I found these formulae:
(R2+p2)-(R1+p1)cos(I) + (R1-R2-p)cos(I2)
ts1 = ----------------------------------------
sin(I)
(R1+p1)-(R2+p2)cos(I) + (R1-R2-p)cos(I1)
ts2 = ----------------------------------------
sin(I)
But how do you find I1 or I2, which are the total deflection angle up to the PCC? What data should be given prior to any further calculations?
Happy New Year and thanks.
Herm