Extending an Alignment

[brennsvette]

I have an existing alignment that I'm trying to extend. The problem is that I need to move the 0+00 end and have the stationing adjust. When I grip edit the alignment the stationing updates correctly but the design profiles do not update to the new stationing. Instead the design profile moves from the existing 2+00 station to the new 2+00 station instead of changing it's start station to 32+00, I'm extending the alignment by 3000 ft. I tried manually adding 3000 ft to the station of each PVI, PC, PT but I'm getting a "cannot solve" error. Any suggestions would be great. Thanks.

[sinc]

Yeah, that's been a problem with C3D for years. The way I currently deal with that problem involves third-party software, but it makes it very easy:

http://www.quux.biz/SincpacC3D_Help/SP_MoveProfiles.htm


There is also this companion routine, which also comes in handy:

http://www.quux.biz/SincpacC3D_Help/SP_StretchProfile.htm

[brian.hailey933139]

The profiles are based on station and elevation and not northing/easting. Before adjusting your profile, draw circles at all the necessary PVI's, adjust the alignment, move the cirlcels the appropriate distance (the amount you lengthened the alignment), then grip edit the PVI's back to the original location. If you have to do this a lot, look into a third party ap like suggested by Sinc.

[Coolmo]

Can I suggest next time starting ALL of your alignments at station 10+00. That's common practice at my office just in case we need to do exactly what you're talking about. That way you have 1000 feet to play with. We just recently updated a sewer outfall that must of had 40 or so manholes and we had to tweak the beginning of the alignment which added 7.5 feet to the whole thing. Starting at station 10+00 meant that we could just back out to station 9+92.50 (reassign the starting station) and everything else stayed the same. Works great.