Which points to include while creating surface

[chasm9a252523]

Hi i am quite new to autocad civil 3d.

Basically i am designing or rehabilitating a road.
I have a collection of PENZD (comma delimited) points which i want to use to create a surface.

These points include trees, existing road pavement edges, points taken on shoulders, points taken on a land surface, electric poles, telephone pole, inlets & outlets of culverts both pipe and box culverts, benchmark points, graveyards, water courses, retaining walls, boundary walls of houses, points on railway tracks.

Now i want to know when i create a surface, should i include all the points. (since more are the points, more is the accuracy).
OR
should i use limited set of points like points taken on land surface, existing road and shoulders of existing road to create the surface.

I have to calculate the volume of material required to create my proposed profile. I am very much confused about it.

I have tried to create a surface from only points taken on land and then another surface of points taken only pavement and shoulder only. And when i drew the profile there was like 1.0 m difference between the two surface.( the road surface was 1.0m above the EG suface) (By Road I mean the existing road and not proposed road.)

I also tried combining the points taken on land, points taken on pavement and points taken on shoulders but when i draw its profile, it was like zig zag shape.

One thing is that we have to follow the existing road alignment and is not changeable.( the current road is 3.6m wide while the new road would be 5.5m wide plus 2.0m shoulders on each side)

Please help me remove this confusion as how can i make my calculations accurate.

Thanks

[Opie]

I would use most if not all of the points. I would then adjust the triangles until the contours look like the existing surface. You may have to swap the edges of multiple triangles to get the correct look.

You could reduce some of the edge swapping by using breaklines along the road / shoulder edges. You could also add additional breaklines where needed to assist you in your modeling.

[mjfarrell]

more importantly you should also be including some breakline data, at edges of road, centerline (if clearly defined)
ditches, swales, etc, this will help the model out tremendously.

you may have to manually define those breaklines if the surveyors did not use line coding for you.

you may still need to REMOVE (delete) some points from the surface or flip some faces to refine the surface further

[chasm9a252523]

more importantly you should also be including some breakline data, at edges of road, centerline (if clearly defined)
ditches, swales, etc, this will help the model out tremendously.



I have the road edges (pavement) data but at some length of road it is missing, (where is road is destroyed by flood waters etc) there i use the right of way points to derive the centerline of road.
I have the points for my Right of Way. the surveyor gives me edges of the pavement points from which i draw the centerline through 2d polyline by averaging the distance between the lines obtained by connecting points on same side of road. (its an undivided crowned road).
(the surveyors use EAGLE POINT and i have to locate all the points myself in autocad civil 3d again and use surveyors drawing as an xref to make the features clear to me)

From the discussion in this thread, i am deriving that I need two surfaces

1) Road surface:

the center of the road should be located by drawing 3d polylines (which now i make from 2d polylines) and convert it into a breaklines. Same goes for the edges and right of way points. then add these breaklines to the surface created from (road edge points and right of way points).

2) Another surface EXISTING GROUND created from points
a) on existing ground surface which surveyors called (spot level)
b) points taken near buildings
c) inside streams or small drains

Then I will need a new surface in which i should paste these two surfaces to get the correct data.

Am I right or did I miss something?

[Opie]

Did the surveyor provide a surface model from Eagle Point? If they have created the surface, they could import the triangles into the drawing, which you could then reuse in Civil 3D.

Other than that, your steps look like they should work.

[PGP-LA]

I have a similar situation. In this case, I've got good survey information as I build an "existing conditions" model. I have a single preliminary surface built from contours and I've added some breaklines for the curb and so far it looks pretty good. On a whim, I created another surface and designated it for the curb only... ...so it's just a narrow strip of curb that looks fine in the object viewer (with another style applied to give it a gray look).

Now I'm trying to decide the best approach for picking up more of the surveyor's points as I advance the model. Should I keep adding points from the sidewalk, the grass lawn, the ramps, etc. on the primary surface? Or should I create additional surfaces with selected points to represent the grass lawn as one surface... ...the sidewalk as a separate surface... ...and so on? Seems like in the second scenario I would be getting into "hide boundaries" or "masks" in order to have tree pits, for example, show up correctly.

I guess it depends on whether the model is for presentation or for construction drawings (profiles, for example). Ideally I would like it to function for both.

Using the tree pit example... ...how would you best carve a tree pit into a sidewalk surface and have it display well for presentations?

Asked another way, should I cobble together a series of surfaces and use boundaries and/or masks to make the hardscape display correctly or is there a clever way to use the single primary surface and modify it to show sidewalks, pavers, grass, etc.?

Thanks very much.