ADA Curb Ramp Design, dynamically link point objects to feature line XYZ?

[torpedo99]

I've created high resolution surfaces for ADA ramps via 3D feature lines

dynamic slope labels work great

what is the best way to get dynamic point elevation info?  The idea is to display curb ramp points for contractor stake out and setting forms

I've manually created points by snap to the feature line, then a point table works, except if the feature line is modified the point table doesn't update

other ways to get curb ramp point elevations that auto update?

thx,

[BrianHailey · Accepted solution]

In a table? Not that I know of.

In the model? Sure, just add surface Spot Elevation labels.

If it has to be in a table, the only thing I can think of is points but they don't automatically update when the surface changes. It's easy enough to update them (and then the table automatically updates) but you have to remember to do it.

I was hoping we could trick a line/curve table into allowing it but the line/curve table won't display the start or end segment elevation.

[jblackwood · Accepted solution]

The best option that I can think of is to use Spot Elevation annotations with a little twist.

1.  Create a new spot elevation label style that shows x,y, and z values.  Make sure that the dragged state does not show a leader. 

2.  Create a table by hand using lines and text for header.  Create a block if you have a lot of tables to create or for future use.

3.  Annotate the points using the new label style.

4.  Drag the annotation to the table.

This way the z values will automatically adjust when the surface is updated.  The hardest part will be adjusting the spacing between x, y, and z values so that everything lines up the way you want them to.

If you are using Station/Offsets instead of x and y or northing/eastings I would use reference text that references the alignment to get station/offset/offset side values.

[Jeff_M · Accepted solution]

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@torpedo99 wrote:

what is the best way to get dynamic point elevation info?  The idea is to display curb ramp points for contractor stake out and setting forms

other ways to get curb ramp point elevations that auto update?

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Sincpac C3D's Dynamicaly Linked Points would work well for this. 

[wfberry · Accepted solution]

Labelling the feature line seems to me to be the more dynamic method.

Bill

[Mark_Castle · Accepted solution]

We've placed pipe structures at the points at then created a structure table. This works pretty well and updates when the surface is modified.

[BrianHailey · Accepted solution]

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jblackwood wrote:

2.  Create a table by hand using lines and text for header.  Create a block if you have a lot of tables to create or for future use.

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Great idea but, creating a table by hand with plines and text? Nah, use the AutoCAD table command!

[jeff_rivers · Accepted solution]

These are some great answers!  In my plans I've used the labels set to 'no leaders' in dragmode, and just dragged them out to be just adjacent to the relevant feature.  I like the structures + structure tables answer.

In the bigger picture we have generally found that there is little benefit to providing elevations for any parts of the ADA ramp.  We provide elevation tables for the proposed flowline, then provide the ramp grades only for the remaining ramp features (except we also do provide elevation points at the left and right sides of the ramp at the flowline).  We do this becase we've found over several projects that the actual as-constructed curb line elevations may vary from the as-designed curb line elevations.  And if the flowline has changed then every plan elevation for that quadrant is wrong and must be recalculated.  

We provide the contractor with as-designed grades only, no elevations beyond the flowline.  We want the contractor to hold to the ADA compliant design grades.  We do not want the contractor to build to any plan elevations because if there is any change, those elevations now may or may not provide a compliant grade.

I would be very curious to learn what others are doing: How much information they provide on their ADA curb ramp plans and any problems they've encountered in the field specifically from showing too much or too little information on those plans.

[AllenJessup · Accepted solution]

Honestly. All we show is the position and flow line grade plus the standard state DOT detail. The contractors build from that. I should mention that there is usually stakeout by the contractors Surveyor with grades based on the flow line.

I've been on the other side of things. Doing the staking. Back then all we usually had from the plans were a grade at the center of pavement and a typical section. The rest we calculated from those.

I'm not saying that more information isn't better. But the Contractors and their Surveyors are usually competent plus we have inspectors on the jobs to check them.

Allen

[jblackwood]

Lately the government agencies we do work for have been asking for more and more detail because of lawsuits and because in so many cases the curb ramps don't match a standard detail drawing exactly.

Even with all the detail contractors are still not building the ramps to ADA requirements.

My preference would be to design the ramps using feature lines to prove that they can be built to ADA requirements but only providing minimal information and letting the contractor determine exact grades.

I would only provide station/offsets of critical points and show running slope and cross slope of each part of the gutter and ramp to show design intent. The exact elevations are then to be determined by the contractor or its staker. This way if the ramp is too steep the contractor can't say that they just built it to the grades on the plan without checking if it actually works before pouring the ramp.

[AllenJessup]

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@jblackwood1 wrote:
Lately the government agencies we do work for have been asking for more and more detail

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You need to satisfy the agency that has to approve the plan. However I usually find that this method of "solving" a problem rarely works. If a contractor can't build a compliant ramp from standard specs. More information will either confuse them of they'll ignore it and still find an excuse.
 

I work for a County Highway Dept. and if one of our inspectors found that a contractor had put in a non-compliant ramp. The contractor would be tearing it out and putting it in right. The type of more information approach tells me that they're unwilling to confront the real problem and are reverting to CYA. You need to consider a contractors ability to construct the project above the bid price.

There's no problem in using Featurelines or 3D polylines for design. I have draw ramps in 3D in the past. I'm currently using Featurelines to target the bottom and back of the ramps. I just don't publish the information once I know it will work.

[joshua.jones]

We do exactly that: create automatic proposed surface elevation tables using structures.

[Joe-Bouza]

You have many many solutions here is one that WILL giveyou a dynamic point table.

dont use points. You already have this high resolution surface, so where you would place points place pipe network structures style to look accordingly and use a structure table also styled accordingly.

[Joe-Bouza]

Kind of obvious right 👍