AutoCAD Civil 3D General Discussion

AutoCAD Civil 3D General Discussion

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Razzmatazz
Posts: 41
Registered: ‎10-01-2013
Message 1 of 7 (346 Views)
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HELP! LONG CORRIDOR

346 Views, 6 Replies
11-11-2013 04:49 AM

I'm supposed to design a 248 km alignment but i've never done such a long alignment before. How do i break it down and also have two people work on the alignment at the same time? How do i go i go about it? data shortcuts or what? Could someone conversant with the process please break down into simple steps. Your assistance will be greatly appreciated. Thanks in advance.


Razz

Civil 3D 2013

i5, 8 GB RAM

I haven't done one quite as long as this, but I have at done at least 15 roads that were broken into segments to make it possible for multiple people to work on the project and to keep things within reasonable limits for the software/hardware.  My process has evolved over the years.  Generally it goes something like this.

 

The first thing I look at is the source data that I will be using for the surface.  Typically this is Lidar, covering a much larger area than I need.  I'll start by looking for logical places to break the surface into pieces, based on how the data files are organized and how large of a surface I'm comfortable with.  In this case I might try for 10 surfaces of 25km each.  If I have a rough idea of the alignment then I'll offset that 100m each side as a data clip boundary to make things easier.  As the alignment is refined I will go back and adjust this boundary, tightening it up so that it only covers my area of interest.

 

I usually start by running a single alignment for the entire length of the project.  This is intended to get me only about 50-75% complete, mostly to check for major problems with the horizontal and vertical design, deal with critical points like bridges and intersections etc.  Once I'm satisfied that this alignment is broadly acceptable to the client then I'll start looking at where to split the alignment.  I usually want segments of 5-10km each, and it's also logical to split the alignment at the Lidar surface boundary, so in this example I would probably be looking for 8km segments.  I like to make sure that the alignments overlap at a tangent so that the start and endpoints of each piece extend to the next PI of the adjacent alignments.  I select a point on the overlap tangent where it crosses a specific northing or easting and make that the station control point for the downstream alignment.  I always round that station up to the next km, so that there is a stationing gap between segments.  This ensures that any edits I make to the upstream alignment won't create a situation where two points on the project have the same stationing.

 

The control points above also define the limits of design and calculations for each segment.  The corridor does not cross these boundaries and volumes are calculated within them also. 

 

I've attached a sample drawing with three segments in it.  Normally each alignment would be in its own drawing and each would be referenced into its neighbors to ensure continuity during edits, but you should be able to see my intent.

 

Steve
Please use the Accept as Solution or Kudo buttons when appropriate

 

*Expert Elite*
neilyj
Posts: 3,874
Registered: ‎08-01-2008
Message 2 of 7 (325 Views)

Re: HELP! LONG CORRIDOR

11-11-2013 06:21 AM in reply to: Razzmatazz
248 km...??? Good luck with that with 8Gb RAM...:smileywink:

I've never done anywhere near that but I seem to recall reading somewhere that 15km is regarded as a practical usability limit. Data shortcuts would be the way to go but It also will depend on the complexity of the corridor and existing topography
neilyj
(No connection with Autodesk other than using the products in the real world)


IDSP Premium 2015 (mainly Civil 3D 2015 UKIE & Infraworks with some limited 3ds Max Design)
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sboon
Posts: 2,180
Registered: ‎11-08-2005
Message 3 of 7 (280 Views)

Re: HELP! LONG CORRIDOR

11-11-2013 02:45 PM in reply to: Razzmatazz

I haven't done one quite as long as this, but I have at done at least 15 roads that were broken into segments to make it possible for multiple people to work on the project and to keep things within reasonable limits for the software/hardware.  My process has evolved over the years.  Generally it goes something like this.

 

The first thing I look at is the source data that I will be using for the surface.  Typically this is Lidar, covering a much larger area than I need.  I'll start by looking for logical places to break the surface into pieces, based on how the data files are organized and how large of a surface I'm comfortable with.  In this case I might try for 10 surfaces of 25km each.  If I have a rough idea of the alignment then I'll offset that 100m each side as a data clip boundary to make things easier.  As the alignment is refined I will go back and adjust this boundary, tightening it up so that it only covers my area of interest.

 

I usually start by running a single alignment for the entire length of the project.  This is intended to get me only about 50-75% complete, mostly to check for major problems with the horizontal and vertical design, deal with critical points like bridges and intersections etc.  Once I'm satisfied that this alignment is broadly acceptable to the client then I'll start looking at where to split the alignment.  I usually want segments of 5-10km each, and it's also logical to split the alignment at the Lidar surface boundary, so in this example I would probably be looking for 8km segments.  I like to make sure that the alignments overlap at a tangent so that the start and endpoints of each piece extend to the next PI of the adjacent alignments.  I select a point on the overlap tangent where it crosses a specific northing or easting and make that the station control point for the downstream alignment.  I always round that station up to the next km, so that there is a stationing gap between segments.  This ensures that any edits I make to the upstream alignment won't create a situation where two points on the project have the same stationing.

 

The control points above also define the limits of design and calculations for each segment.  The corridor does not cross these boundaries and volumes are calculated within them also. 

 

I've attached a sample drawing with three segments in it.  Normally each alignment would be in its own drawing and each would be referenced into its neighbors to ensure continuity during edits, but you should be able to see my intent.

 

Steve
Please use the Accept as Solution or Kudo buttons when appropriate

 

Valued Contributor GZE
Valued Contributor
GZE
Posts: 90
Registered: ‎10-07-2008
Message 4 of 7 (239 Views)

Re: HELP! LONG CORRIDOR

11-12-2013 09:49 AM in reply to: Razzmatazz

We almost did the same as Steve, since you have 2 designers this i what I would do, split the surface and topo file into two nearly equal sections say @125km with an overlap say 200m on each, create alignments for each section, use create alignments from existing alignment to further split the two alignmnts into segments of say 60km. create profiles, create corridor in different files of @15km. We normaly export it to ACAD for xrefing it to plan& profile files.

Humphrey GZE
Civil 3D 2013 64bit SP1
Elitebook 8540w
Core i7 2.8GHz, 8Gig RAM
NVIDIA Quadro FX880
160Gb SSD
*Expert Elite*
sboon
Posts: 2,180
Registered: ‎11-08-2005
Message 5 of 7 (224 Views)

Re: HELP! LONG CORRIDOR

11-12-2013 10:26 AM in reply to: GZE

You don't use the sheet set tools for production?  Why not?

 

I prefer to keep the alignment, profile and corridor for each segment all in one file - makes it easier for design tweaks when I'm trying to fit the road in a tight spot, or balancing the mass haul.  It means that I work in shorter segments, but it suits my workflow process.

 

One other consideration is the drafter who will be producing the final prints.  That person can't do much while the designer is working on a particular segment, so it's useful to keep them small enough that both people can keep working at the same time.

 

Steve
Please use the Accept as Solution or Kudo buttons when appropriate

Valued Contributor GZE
Valued Contributor
GZE
Posts: 90
Registered: ‎10-07-2008
Message 6 of 7 (213 Views)

Re: HELP! LONG CORRIDOR

11-12-2013 11:21 AM in reply to: Razzmatazz
We use sheet set, we only export the coridor to ACAD in the end it helps to speedup plotting, any editing is still reflected to the sheets since we dont explode the alignment. In our workflow we produce sheets at the end since most of the things have been automated. When it comes to these long highways most designers here prefer LDD
Humphrey GZE
Civil 3D 2013 64bit SP1
Elitebook 8540w
Core i7 2.8GHz, 8Gig RAM
NVIDIA Quadro FX880
160Gb SSD
Active Contributor
Razzmatazz
Posts: 41
Registered: ‎10-01-2013
Message 7 of 7 (147 Views)

Re: HELP! LONG CORRIDOR

03-19-2014 05:11 AM in reply to: sboon

I know this is way too late but to everyone, thanks for your replies. Steve, Thanks alot man, your method is the way to go......the attachment was also of immense help. I got to see exactly how you did it. The overlap and the rounding off are just brilliant. You get to maintain the exact coordinates at the reference points without much hustle and you can also edit the upstream alignments without creating a mess downstream. Once again, Thanks!

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