by Rick B. » Sun Jun 16, 2002 3:19 pm
Michele,
I don't know all the details (re: field computer being used, etc,) but if you have CG-Field and can stake with batch files, I've found a way to force the program to recognize vertical tangents. (I'm not sure why you'd need to do so anywhere except at the beginning of a profile where the slope break occurs when the cross slope joins the main profile.) Anyway, simply "fake" a vertical curve with the PVI station at the end of the curve. If the vertical break occurs at sta 13.5, then the "fake vc" is of length 13.5' with a PVI station of 13.5'. Along the "fake" vertical curve, the batch file generates straight interpolated grades. Past the end of the fake vertical curve, the usual vertical curve stuff applies. Only that one elevation (first vc, "fake" or otherwise is entered. Elevations on points are NOT needed.
The main thing is if you can stake using the batch file in the "Sta-Off" (option 4 under stakeout) you are can save tons of time versus generating coordinates at certain stations.
You can also slope stake when you add x-section info. And since the batch files are just text files, it's very easy to copy/cut/paste the tedious x-section info that is often duplicated from street to street to other batch files after creating/entering and checking it only once.
Other nifty stuff: when you toggle "elev" between "calc" and "enter" in Menu option screen 3/number 2, the stakeout routine will add/subtract amounts for sub-grade (@cl) or top curb (add 0.14' @ 17.5'rt for 4'o/s on curb 13.5' from cl.) And if you say station 237.498, it outputs all stakeout info for that station (at cl or at any offset) with a perfect grade for that spot after entering only one elevation during creation of the batch file.
There is never a need to put grades/elevations on points for road staking if you have a profile and horizontal coordinates along the centerline. Grades on points along the centerline are a BIG waste of time