Station Equations

[gdonovan]

Good Day.
I am wanting to insert a station equation at the very begining of my horiz alignment. What am I being asked for when it prompts me to enter station back and station ahead? What is now Sta. 0+108.542 should be Sta. 0+000.


Figured it out...no reply necessary thanks!

[Opie]

Greg,

Could you post your solution to your problem. It may help others with this same problem.

Thanks,
Richard

[MHultgren]

To work with Station Equations, you would enter the station that you want to "reset" as the Station Back and then enter the "New" Station as the Station Ahead. So ref. gdonovan's problem, you would enter 108.542 as the Station Back and then 000.000 as the Station Ahead to get the equation you want.

[sinc]

Can you have overlapping stations like that? I thought I tried it at one time. The engineer had created a station equation like 5+72.63=5+68.80, and I couldn't get it entered. Maybe I just did something wrong... Eventually I created two different alignments. Luckily, it was a small project, and this didn't cause much of a hassle.

[MHultgren]

Here is a capture of the command line procedures.
Starting Station: 0.00 Ending Station: 2289.61
Starting Station: 0.00
Select operation [Clear/Add/eXit/Modify/Delete] <eXit>: a

Select point on alignment for station equation:
Enter station back <731.02>:

Enter station ahead: 100.00

Select stationing order [Increase/Decrease] <Increase>:

Starting Station: 0.00
EQUATION STATION-BACK STATION-AHEAD ORDER
-------- ------------ ------------- ---------
1 731.02 100.00 INCREASING
This will place a station eq at 7+31.02 and reset it to 1+00 with increasing stations from that point on, until you place another equation or Clear it.

[sinc]

Yeah, the same project had a station equation that was something like 11+24.56 bk = 18+00 ah, and I got that station equation to work fine. It was just the other station equation, with overlapping stations, that seemed to be problematic.

Oh well, must've been something I did. But that project is long-dead at this point, so I'm not going to go back and try to figure out what was happening. Luckily, overlapping stations is something most engineers (wisely) avoid, if at all possible.

[MHultgren]

The trick I found, is to use the dialog box to select the station ranges instead of trying to type them in. Otherwise I kept getting the wrong segments showing up and being labelled. Then when I was ready to place the labels, I would place the entire alignment and Start with the 0+00 = 0+00 and end at the last equation segment.

[Ammon]

Yeah, the same project had a station equation that was something like 11+24.56 bk = 18+00 ah, and I got that station equation to work fine. It was just the other station equation, with overlapping stations, that seemed to be problematic.

Oh well, must've been something I did. But that project is long-dead at this point, so I'm not going to go back and try to figure out what was happening. Luckily, overlapping stations is something most engineers (wisely) avoid, if at all possible.

If there was a case of double stations, I would probably do what you did and create two alignments. A station equation isn't overlapping stations, it's just a shift in the station numbering.

[silveraq]

I read all the posts you put here and I think you can help me with some trouble at C3D 2008. I have an alignment with a station equation overlaped, i'm also working with and index factor of 20 (brazilian way of chainage). at my profile views it al gets fine, but at the fg profile, the labels of horizontal geometry point get crazy and don't stay at the right place. to ilustrate my explanation, i'm indexing two pictures, one of the alignment in a top view, and another of the profile view. You can notice that the points at the stations 51227+19.93 and 51232+9.93 are in the profile at the point 51227+1.73 and 51231+11.73 respectively. I'd already tried so many things, see if my labels were with raw station, but they weren't, and all things. If someone can help me i'd be thankful.