Recently found that me and a few others were building the surface the
wrong way. Now I am having problems trying to get things to come out
correctly. I am using AutoCad 2005 Civil, LDD, Survey and am trying to
get the contours for a road project. This is how I am attempting this
unabtainable feat. Create new surface with Terrain Model Explorer, Add
Point Group with the points the survey crew collected, drew 3D
Polylines by elevation along the lip of gutter on both sides of the
road, created breaklines using proximity by polyline and selecting the
flowline, median islands, and lane lines, built the surface using
Terrain Model Explorer, Imported 3D lines into drawing, then created
the contours and it just doesnt come out right! Maybe im missing
something or just doing it totally incorrect? Hope someone can help me
out with this one.
On 9 Aug 2005 09:56:50 -0700, bambam_13 firstname.lastname@example.org wrote:
Why do you want to produce contours anyway?
Are the surveyed points collected the existing ground?
And you want to do excavation/fill volume calcs from the data -
existing vs. proposed?
Or do you want to stakeout your new road, in which case you probably
want cross sections and/or to make a dtm from the breaklines & ponits
for the proposed road?
If you decide what it is you want to accomplish it will be much easier
to figure out how to do it.
Happy Trails To You
On 9 Aug 2005 16:06:04 -0700, bambam_13 email@example.com wrote:
Let me first state that I do not do this work in Acad - I use
I also do not do any volume calcs based on "contours" as such - I make
DTMs from points and added breaklines, use a 3D viewer to fix where I
screw up, then use a command in TM to compare surfaces and do calcs,
make an isopach layer showing cut/fill locations & volumes, etc.
Can you do the same functions in LDD? If so, this is probably what
you want to do, especially on the proposed surface, not make contours.
There are other SW pkgs around that do a good job of comparing volumes
using contours, especially for existing ground surfaces, such as
If you have the luxury, it is always a good diea to do your calcs
using at least 2 separate methods, just to see if you can get the same
answer. I really should delve a little deeper into LDD myself to do
this, but I never seem to get/take the time.
What about cross sections?
Do you have point codes on the surveyed existing ground so you can
automagically create breaklines? TM does this with very few commands
if the codes are all there - maybe LDD does also?
Did you do the original road design, or is it something someone else
did and you must do the estimates for? It makes a big difference,
because you can usually ask for (and sometimes even receive???) more
info than they initially give you, ie the cross sections at stations
with coded points - wonderful for volumes and later stakeouts.
You should also be able to get borehole info - soil & rock types at
specified depths from existing surface, so you can do those calcs
based on material types, and get the waste out of your re-use
Again, this is all easy to process im TM - LDD dunno?
Happy Trails To You
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