AutoCAD Land Desktop

AutoCAD Land Desktop

Reply
*Don Reichle
Message 11 of 23 (1,151 Views)

Re: Grading @ Intersection - Profiles

11-17-2006 07:43 AM in reply to: bchapman
I wondered when you might be commenting on that one Jesse.
;-)

--
Don Reichle
"The only thing worse than training your staff, and having them leave is -
not training your staff, and having them stay." :-o
A reminder taken from Graphics Solution Providers' Calendar page
--------------------------------------------------------------------
!! Please discuss whatever we tell you with your SysMgr !!
!! They appreciate staying in the loop :-) !!

CivilSeries-2K4
Intel Xeon 3.2GHz 2GB RAM
XPPro 32bit SP2
Nvidia Quadro NVS 285 256MB

"The only Constant is Change".


"jd-drafter" wrote in message
news:5399742@discussion.autodesk.com...
>"Don Reichle" wrote in message
>news:5399311@discussion.autodesk.com...


>See the attached Zip file for the PNG of a sample intersection, produced
>with 3D polys.

heh... heh...

that looks vaguely familiar.... 8^)

jjd
*jd-drafter
Message 12 of 23 (1,151 Views)

Re: Grading @ Intersection - Profiles

11-17-2006 08:19 AM in reply to: bchapman
"Don Reichle" wrote in message
news:5399847@discussion.autodesk.com...
I wondered when you might be commenting on that one Jesse.
;-)

indeed....

jjd
*Don Reichle
Message 13 of 23 (1,151 Views)

Re: Grading @ Intersection - Profiles

11-17-2006 08:24 AM in reply to: bchapman
I will provide further examples of the paving c-l profiles in support of my
example later tonight.

My point of "commonality" is the gutter flowline where the rainfall
accumulates and drains to the nearest catch basin/curb inlet. Most clients
don't wish to pay for several additional catch basins/curb inlets on the
"upstream" sides of the intersections, that would become necessary if the
gutter flowline wasn't able to continue flowing across the intersections.

The "cross-gutter" is able to handle these cases quite handily, and allow
the Governing Agency's requirement for maximum spacing between catch
basins/curb inlets to handle the rainfall, without exceeding the "gutter
spread" parameter - thereby affecting the vehicular "traveled way".

Attached is a Zip file containing a PNG of the method that incorporates the
un-disrupted gutter flow through the cross-gutter. The street that forms the
Ts "brace" obviously contains the cross-gutter.

Interested parties will be able to find the paving c-l profiles attachment I
mentioned at the top of this reply sometime this weekend.

--
Don Reichle
"The only thing worse than training your staff, and having them leave is -
not training your staff, and having them stay." :-o
A reminder taken from Graphics Solution Providers' Calendar page
--------------------------------------------------------------------
!! Please discuss whatever we tell you with your SysMgr !!
!! They appreciate staying in the loop :-) !!

CivilSeries-2K4
Intel Xeon 3.2GHz 2GB RAM
XPPro 32bit SP2
Nvidia Quadro NVS 285 256MB

"The only Constant is Change".


"neilw" wrote in message
news:5399834@discussion.autodesk.com...
Hi Civilychallenged,

I just had discussions with some of our staff about this very issue last
week. The problem you are having is due to the common practice of grading
the profile centerline of the intersecting side street to meet the edge of
pavement of the main street rather than the centerline. If you think about
the effect of designing the intersection this way, at the point where the
side street meets the edge of pavement of the main road, the crown of the
side street is at the edge of pavement elevation of the main road. This
means that the edge of pavement of the side street is BELOW the edge of
pavement of the main road due to the crown slope of the side street. Now in
most cases the flowline of the main road can be projected at some minimal
grade until it catches grade with the side road, but in cases where the side
road is already at minimal grade (i.e. 0.5%) the flowlines will never meet.
Thus the "proper" way to design the intersection would be to intersect the
profiles at the CENTERLINES of the 2 roads. This places the edge of pavement
of the side road at the same elevation of the main road (assuming the roads
have identical width and crown slopes). Of course the two roads would not
actually be constructed to meet at the crowns. The side road crown would
transition from some point before the intersection (typically at the PC of
the curb radius) down to meet the edge of pavement of the main road. If you
can visualize the resulting TIN of the intersection, there would be a
triangle TIN face with a vertex at the points where the edge of pavements
meet and connecting at the crown of the side road at the PC station of the
curb return.

So to answer the question, the apparently common practice of interecting the
profiles at the edge of pavement is fundamentally incorrect.

wrote in message news:5398949@discussion.autodesk.com...
I am interested learning how other drafters design and show their design of
flat road intersections (0.5%). More specifically, our city wishes to use
valley gutters but when we match profiles to the edge of pavement our
intersections will create "bird baths" due to the crown shown in our
profiles.

All the profiles are completed already so I am struggling with making our
drafters redo them (5 miles of roads and countless amount of intersections).
I feel the best solution is to start a grade break about 100' down the
intersection matching whatever grade the profile has (even on a vertical
curve), flattening the pavement along the valley gutter so theirs no crown
and do this by showing grade break lines in plan and in the profile, for
stations 0-100 show a dimension stating "see plan for grading" and if in a
vertical curve "Sta: 0-1+00 for vertical control only".

Opinions?

How does everyone else approach this issue? I've worked for the same
company for seven years but generally tend to simply show drainage arrows
and let the field kinda figure it out...but this isn't working anymore.

This part isn't the problem though. The part is I need to know if this is
standard practice.
*neilw
Message 14 of 23 (1,151 Views)

Re: Grading @ Intersection - Profiles

11-17-2006 08:38 AM in reply to: bchapman
To address the other part of the question: if the curb returns are to be
staked conventionally, the surveyor only needs the elevations at the curb
return ends and one at some point in the radius if there is to be a high or
low point in the curb return. The surveyor will then straight grade the curb
between the grade points in his staking. I know that some will create
alignments and profiles and create vertical curves for the curb return, but
this is allot of work if there are many intersections and probably not worth
the effort considering that the surveyor is not likely to calculate and
stake a vertical curve on a curb return unless you give him every stakeout
point or show every curb return profile in the pans (yikes!). Now that
automatic machine controls are becoming more common, designers are having to
create precise models for the machines to follow. In those cases the
vertical curve designs on the curb returns would be honored if the designer
felt it was worth the effort to model them.

So really there should be no need to provide more then a station/offset and
spot elevation at the curb return high or low point if needed. The surveyor
can calc the elevations of the end points of the curb returns from the FG
profile and the plan view radius dimensions and interpolate the intermediate
points in the field.
Distinguished Contributor
bchapman
Posts: 241
Registered: ‎07-14-2004
Message 15 of 23 (1,151 Views)

Re: Grading @ Intersection - Profiles

11-17-2006 08:39 AM in reply to: bchapman
Thank you everyone. We do place catch-basins / curb openings where most able on the high sides of curb. Grading the intersection is also not a problem.

Hopefully this simplifies: When construcing a profile our drafters began their vertical alignment to match either the crown of the centerline or the edge of the valley gutter (depending on the situation).

By showing this on our construction plans we are not accurately displaying the warped intersection (the grade change right there at the beginining of each road)...but the plan view represents the intent of the design quite well...accurately displaying how the intersection needs to be paved.

In everyone's experience, has this been an issue or is it standard - knowledge / judgement to refer to the grading plans in that 10,20,30,40' of pavement and ignore the fact that the profile does not accurately represent that warp section....?

Since our roads are all min. grade, having to redo the profiles will take weeks-months, which I am trying to avoid having our drafters do....

SImply: I think a note in the profile for the area that does not accurately display the warped section stating "See Plan for Grading" would be quite sufficient, both in design standard and legality. The note would also state "profile @ Intersection for vertical control only":

Opinions?
- upgrading, still
*Don Reichle
Message 16 of 23 (1,151 Views)

Re: Grading @ Intersection - Profiles

11-17-2006 10:53 AM in reply to: bchapman
snip>SImply: I think a note in the profile for the area that does not
accurately display the warped section stating "See Plan for Grading" would
be quite sufficient, both in design standard and legality. The note would
also state "profile @ Intersection for vertical control only":

Opinions?
Sounds like you've appropriately planned for the means to cover this
situation c.c.

The preparation for the cross-gutters would be adequately handled at the
Grading Plan stage of construction anyway.

--
Don Reichle
"The only thing worse than training your staff, and having them leave is -
not training your staff, and having them stay." :-o
A reminder taken from Graphics Solution Providers' Calendar page
--------------------------------------------------------------------
!! Please discuss whatever we tell you with your SysMgr !!
!! They appreciate staying in the loop :-) !!

CivilSeries-2K4
Intel Xeon 3.2GHz 2GB RAM
XPPro 32bit SP2
Nvidia Quadro NVS 285 256MB

"The only Constant is Change".


wrote in message news:5399957@discussion.autodesk.com...
Thank you everyone. We do place catch-basins / curb openings where most
able on the high sides of curb. Grading the intersection is also not a
problem.

Hopefully this simplifies: When construcing a profile our drafters began
their vertical alignment to match either the crown of the centerline or the
edge of the valley gutter (depending on the situation).

By showing this on our construction plans we are not accurately displaying
the warped intersection (the grade change right there at the beginining of
each road)...but the plan view represents the intent of the design quite
well...accurately displaying how the intersection needs to be paved.

In everyone's experience, has this been an issue or is it standard -
knowledge / judgement to refer to the grading plans in that 10,20,30,40' of
pavement and ignore the fact that the profile does not accurately represent
that warp section....?

Since our roads are all min. grade, having to redo the profiles will take
weeks-months, which I am trying to avoid having our drafters do....

SImply: I think a note in the profile for the area that does not accurately
display the warped section stating "See Plan for Grading" would be quite
sufficient, both in design standard and legality. The note would also state
"profile @ Intersection for vertical control only":

Opinions?
Distinguished Contributor
bchapman
Posts: 241
Registered: ‎07-14-2004
Message 17 of 23 (1,151 Views)

Re: Grading @ Intersection - Profiles

11-17-2006 12:11 PM in reply to: bchapman
That's the point I am hoping to make; but would also like to know what else does...likes to do...what the industry standard is...if there is one.
- upgrading, still
Distinguished Contributor
annw2
Posts: 1,263
Registered: ‎03-07-2006
Message 18 of 23 (1,151 Views)

Re: Grading @ Intersection - Profiles

11-26-2006 11:32 AM in reply to: bchapman
From reading previous posts. Standard practice from CTDOT mid 80's to 2000 transitioning from hand drafting to Civil2004.

Profiles ALWAYS match at CL. Side road profiles start at cross slope of main road & transition with appropriately designed vertical curves. Low points to be out of intersections when ever possible.

Catch basins/inlets ALWAYS pick up stormwater uphill of intersection unless physically impossible to do. Cost of inlet cheap compared to cost of law suit from stormwater causing accident by running across intersection!

Grading of intersections shown via Intersection Grading plans showing contours at intersections at 0.1 or 0.2 contours at 10 or 20 scale. (Days of work of hand drafting way back when.)

Way I would do now, as I haven't needed in years.

Try everything to avoid having non crowned roads intersect.

Create alignments, profiles & templates. Create separate scratch file & audit hourly as file WILL corrupt.

Import roadway 3d poly lines from roadway templates. TRIM 3dpoly lines at curb returns. On X-FAULT junk layer, snap to mid point of 2d curb return. Isolate X-FAULT junk layer & 3d template polyline gutter layer. Use Terrain 3d poly line by elevation curve function. Snap PC, Midpoint & PT of curb return. Check that grade is a MINIMUM of 1/2% , 1 % better going around curve. If not, figure out best place for inlet & grade minimum 1% to inlet along curb return. 3d poly line by elevation to complete rest of curb return.

3dpoly line curb to create curbs and shoulders along curb returns for large scale modeling. Use grading objects to intersect to existing surface around curb returns. (Depending on how tight the curb return is to existing grade, you may need to fillet poly line contours from main roads) (I have yet to figure out an advantage to contour objects. You can't do this with them & I don't do uniform cross section grading any more.)

For intersection grading contours, copy proposed tin to junk Intersection TIN. Create a series of back of curb (for margin or error) poly line boundaries. For each intersection, rebuild the proposed model using the polyline as outer boundary. Generate proposed contours at 0.2 or 0.1 intervals on special Intersection contour layers. Make sure you don't erase your large scale contours or the previous intersections. I will leave it to your staff if they want each intersection on own layer. Trim/extend the contours to match face of curb to compensate for series of chords used to approximate curve. Set up viewports for each intersection.

I have to use a similar technique for subdivisions here in the mountains. Some townships here require each lot to prove that it contains a minimum adjusted tract acreage. This is an acreage of X % of slopes above steep, another % of slopes of mildly steep all of flat portion and no wetlands, flood plains, lakes, etc. They want a reasonable guarantee a homeowner has a prayer of putting up a house on a lot. I have to create a TIN of each lot & use the slope shading functions to do. Then I need to set aside 10 minutes for each project to listen to my boss yell that the slope shadings are not perpendicular to the contour lines.

I didn't know whether to laugh or cry watching the web cast showing how Civil 3D can automate subdivisions. Around here the prime question of whether you can subdivide or not is if you have a point of existing storm water discharge. If you don't, you can subdivide.
Ann Wingert, P.E.
*Don Reichle
Message 19 of 23 (1,151 Views)

Re: Grading @ Intersection - Profiles

11-27-2006 07:00 PM in reply to: bchapman
snip>Then I need to set aside 10 minutes for each project to listen to my
boss yell that the slope shadings are not perpendicular to the contour
lines.
Maybe they (your boss) need to attempt this procedure at a Workstation, so
that they can show you the necessary steps to accomplish this?

How many Hatch Boundaries might you think would be necessary to get them the
"picture" that they want?
:-o

--
Don Reichle
"The only thing worse than training your staff, and having them leave is -
not training your staff, and having them stay." :-o
A reminder taken from Graphics Solution Providers' Calendar page
--------------------------------------------------------------------
!! Please discuss whatever we tell you with your SysMgr !!
!! They appreciate staying in the loop :-) !!

CivilSeries-2K4
Intel Xeon 3.2GHz 2GB RAM
XPPro 32bit SP2
Nvidia Quadro NVS 285 256MB

"The only Constant is Change".


wrote in message news:5406603@discussion.autodesk.com...
From reading previous posts. Standard practice from CTDOT mid 80's to 2000
transitioning from hand drafting to Civil2004.

Profiles ALWAYS match at CL. Side road profiles start at cross slope of
main road & transition with appropriately designed vertical curves. Low
points to be out of intersections when ever possible.

Catch basins/inlets ALWAYS pick up stormwater uphill of intersection unless
physically impossible to do. Cost of inlet cheap compared to cost of law
suit from stormwater causing accident by running across intersection!

Grading of intersections shown via Intersection Grading plans showing
contours at intersections at 0.1 or 0.2 contours at 10 or 20 scale. (Days
of work of hand drafting way back when.)

Way I would do now, as I haven't needed in years.

Try everything to avoid having non crowned roads intersect.

Create alignments, profiles & templates. Create separate scratch file &
audit hourly as file WILL corrupt.

Import roadway 3d poly lines from roadway templates. TRIM 3dpoly lines at
curb returns. On X-FAULT junk layer, snap to mid point of 2d curb return.
Isolate X-FAULT junk layer & 3d template polyline gutter layer. Use Terrain
3d poly line by elevation curve function. Snap PC, Midpoint & PT of curb
return. Check that grade is a MINIMUM of 1/2% , 1 % better going around
curve. If not, figure out best place for inlet & grade minimum 1% to inlet
along curb return. 3d poly line by elevation to complete rest of curb
return.

3dpoly line curb to create curbs and shoulders along curb returns for large
scale modeling. Use grading objects to intersect to existing surface around
curb returns. (Depending on how tight the curb return is to existing grade,
you may need to fillet poly line contours from main roads) (I have yet to
figure out an advantage to contour objects. You can't do this with them & I
don't do uniform cross section grading any more.)

For intersection grading contours, copy proposed tin to junk Intersection
TIN. Create a series of back of curb (for margin or error) poly line
boundaries. For each intersection, rebuild the proposed model using the
polyline as outer boundary. Generate proposed contours at 0.2 or 0.1
intervals on special Intersection contour layers. Make sure you don't erase
your large scale contours or the previous intersections. I will leave it to
your staff if they want each intersection on own layer. Trim/extend the
contours to match face of curb to compensate for series of chords used to
approximate curve. Set up viewports for each intersection.

I have to use a similar technique for subdivisions here in the mountains.
Some townships here require each lot to prove that it contains a minimum
adjusted tract acreage. This is an acreage of X % of slopes above steep,
another % of slopes of mildly steep all of flat portion and no wetlands,
flood plains, lakes, etc. They want a reasonable guarantee a homeowner has
a prayer of putting up a house on a lot. I have to create a TIN of each lot
& use the slope shading functions to do. Then I need to set aside 10
minutes for each project to listen to my boss yell that the slope shadings
are not perpendicular to the contour lines.

I didn't know whether to laugh or cry watching the web cast showing how
Civil 3D can automate subdivisions. Around here the prime question of
whether you can subdivide or not is if you have a point of existing storm
water discharge. If you don't, you can subdivide.
Distinguished Contributor
annw2
Posts: 1,263
Registered: ‎03-07-2006
Message 20 of 23 (1,151 Views)

Re: Grading @ Intersection - Profiles

11-28-2006 04:50 AM in reply to: bchapman
Boss works entirely by hand sketches. I'm not sure he even knows how to open CAD file.
Ann Wingert, P.E.
Announcements
Are you familiar with the Autodesk Expert Elites? The Expert Elite program is made up of customers that help other customers by sharing knowledge and exemplifying an engaging style of collaboration. To learn more, please visit our Expert Elite website.
Need installation help?

Start with some of our most frequented solutions or visit the Installation and Licensing Forum to get help installing your software.