Stream Cross Sections - How?

[Arizona]

Thanks for trying to help.

I am working in Land Desktop 2006.

 

The sections I need to cut are very irregular. They are not on even stations, and they are NOT Perpendicular to the Alignment. Some of them even have angle points in the section line.

 

Can you steer me to where and how I would define the sections for LDT to cut? The easiest thing would be if it let me pick polylines that defing the sections.

 

I know this sounds wierd, but anyone that has done a flood study for FEMA or the Corps knows what I mean.

 

Thanks for any help you can give,

Jeff

[BIGAL]

The software always cuts cross section perpendicular therefor you need to introduce tiny very short angle changes into your alignment and this will cut cross sections at what appears to be an angle. Working metric no longer than 5mm. Else cut multiple long sections along your chosen plines and call them cross sections.

[Arizona]

Thanks for trying to help Big Al.

We found exactly as you stated, it can only go perp to the alignment.

One friend suggested we make alignments from every section needed and cut profiles. That would take a month.....

So, since LDT CAN NOT do this efficiently, we exported every section, one at a time, from HEC RAS in DXF format, brought them into ACAD, and delt with it.

What a pain! I was really dissapointed in AutoDESK for creating a very expensive software that isn't capable of doing this. I did this with DCA back in the early 90's! I did it with Carlson's SurvCADD just 5 years ago.

 

I wonder if InRoads can do this....

[BIGAL]

If your going to do this again and know where your cross sections lie in terms of angle then it should be pretty easy to draw a pline work out the intersect pts and angle of line crossing and then redraw a new pline that has the short segments on the correct angle to get square off coss sections. Yes it would require a lisp etc

 

Even as a first step pick cross section line and draw a short perp line then play join the dots. Search here for sq line it might be something Lee Mac has done.

 

Thinking aloud write the new lines as a list then you just auto join (script) the "end to a start" etc as the lines are always drawn in the same direction.

 

I was involved as a sales rep for a leading civil software provider and found only the very odd occasion when cross sections at angles where needed, the software I was involved with did though give options about change in direction how it would traet the cross section but it was for every one not different angles.

[Arizona]

Thanks Al. I'm gonna give that a try. I'll stop back and let you know what I come up with.

[BIGAL]

I was talking to one of the other guys here and he told me you can rotate the crossections you create feature lines as part of the cross section extraction and you can grip edit rotate the end of the line to change the angle.

 

Not sure about this but will try and check it out over the next couple of days.