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Distinguished Contributor
SeattleCADD
Posts: 188
Registered: ‎02-27-2009
Message 1 of 5 (326 Views)

Creating a Proposed surface with Bottom and Top elevations

326 Views, 4 Replies
06-26-2013 02:04 PM

Hello All,

 

I have a existing surface. I want to create a proposal surface so I can know the volume between boths. This proposal surface is represent for a disposal area that can be filled up to a elevation. I have a bottom of P-surface as a feature line at EL 1608, and I want top of P-surface to EL 1613.

 

Could some one please show a direction of how to create this P-surface.

See attached for png and Civil 3D file.

 

Thanks much in advance!

*Expert Elite*
Joe-Bouza
Posts: 4,787
Registered: ‎12-15-2008
Message 2 of 5 (299 Views)

Re: Creating a Proposed surface with Bottom and Top elevations

06-26-2013 03:43 PM in reply to: SeattleCADD
is your problem where to draw the bottom of P or how to make the surface?
just add the FL to a P-surface then make a volume surface with existing surface and P-surface.

If you are look for the daylight point for bottom of P use a gradind from top of P to EG - in which case you can for go making P and let the grading do it automatically
Thank you

Joseph D. Bouza, P.E. (one of 'THOSE' People) Civil 3D 2012 & 2013
HP Z210 Workstation
Intel Xeon CPU E31240 @ 3.30 Hz
12 GB Ram


Note: Its all Resistentialism, so keep calm and carry on

64 Bit Win7 OS
*Expert Elite*
sboon
Posts: 2,075
Registered: ‎11-08-2005
Message 3 of 5 (287 Views)

Re: Creating a Proposed surface with Bottom and Top elevations

06-26-2013 05:32 PM in reply to: SeattleCADD

I usually have to do this in the other direction, starting from a contour elevation and projecting downward, trying to figure out where the bottom of an excavation should be in order to create a slope back up to the start line.  Looking at your sketch it appears that part of your featureline follows the 1608 contour, then it slopes up to match the existing grade at the access road.

 

Start by creating a grading object from the portion of the FL at 1608, projecting up to 1613 at your maximum specified slope.  As your starting line is jagged the resulting grading is probably going to be messy, and might cause the drawing to become unstable. (save before doing this)  The extents of the grading object defines the limit of where your top of fill line can be.

 

Draw a new FL slightly inside of this area at 1613, all the way around.  Where you don't have a grading at the access road you can approximate where you think it should be for now.  Make sure that this FL is on a new site so that there are no interferences with any of the previous work.  Erase the first grading object and create a new one, projecting outward and down to the surface to confirm that it fits within your boundary.  Now you can adjust or add PI's to tweak things.

 

At this point you can choose to use the grading object with a consitent slope but the toe probably won't land on your limit line, or you can delete the grading and just use the new top FL and your original bottom FL  as surface breaklines.

 

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

Valued Contributor
el.Topo
Posts: 53
Registered: ‎06-21-2012
Message 4 of 5 (221 Views)

Re: Creating a Proposed surface with Bottom and Top elevations

06-28-2013 06:19 AM in reply to: sboon

When it comes to create a grading from a feature line, and in the special case of a contour line that is described by anomalies, I usually do a smoothening to a direction that suits the occasion, before creating the grading, as it is not practically applicable during construction to use it (the f l) as it is drawn. (Smoothening = inserting arcs, experiment with radius, between the vertices and finaly drape it on the surface to acquire elevations). Then, there shouldn't be any problem grading to a desired elevation with a certain slope, as soon as the fl's elevations do not exceed the ceiling elevation.

 

greetings

 

 

 

MacBook Pro, Intel Core i7 CPU M 620@2.67GHz, 8GB RAM
W7Pro SP1, 64-bit / Civil3D 2013
*Expert Elite*
Joe-Bouza
Posts: 4,787
Registered: ‎12-15-2008
Message 5 of 5 (190 Views)

Re: Creating a Proposed surface with Bottom and Top elevations

06-29-2013 04:39 PM in reply to: SeattleCADD

I agree, I would that a guesstimate and hone in on it

Thank you

Joseph D. Bouza, P.E. (one of 'THOSE' People) Civil 3D 2012 & 2013
HP Z210 Workstation
Intel Xeon CPU E31240 @ 3.30 Hz
12 GB Ram


Note: Its all Resistentialism, so keep calm and carry on

64 Bit Win7 OS

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