State Plane Pipeline Project

I don't believe there is an easier way to explain the resulting difference. Had a similar problem with some design engineers on an Army Corps of Engineers project nearly 20 years ago. Project was slightly over five miles long and designed in phases. Project combined scale factor was on all documents with both ground and (grid) distances were given for all easement lines and centerlines. In my experience most engineers have little concept of any type of mapping projection and the resulting effects.

Is Pay Item Per Lineal Foot Or Actual Foot Of Pipe ?

SPC foot would not hold up in a court of law.

How is the pay item specified in the contract?

Are you talking with the Project Design Engineer or the Project Construction Engineer?

Paul in PA

I would tend to believe that there may be adequate pipe left over after a 60 mile run to cover the 65 +/- feet. Are these 20' sections? Inquire if they had any extra linear feet of pipe in their error budget (shortages, cut-offs, damaged, etc.) Perhaps 4 extra sections of pipe would cut it. Any left over, weld up some BBQ pits.

Is Pay Item Per Lineal Foot Or Actual Foot Of Pipe ?

> SPC foot would not hold up in a court of law.
>
> How is the pay item specified in the contract?
>
> Are you talking with the Project Design Engineer or the Project Construction Engineer?
>
> Paul in PA

I am not sure about the contract specifics.

The project was basically designed by the city water dept and then they hired an engineering firm to be the at-risk firm to deal with the construction management of the project. So the guy i was talking to is doing the construction management and inspection side.

> I would tend to believe that there may be adequate pipe left over after a 60 mile run to cover the 65 +/- feet. Are these 20' sections? Inquire if they had any extra linear feet of pipe in their error budget (shortages, cut-offs, damaged, etc.) Perhaps 4 extra sections of pipe would cut it. Any left over, weld up some BBQ pits.

:good: :good:

33' joints, concrete encased bar wrapped steel pipe 30" dia

I think it would hold the heat pretty good!

Actually, I don't understand the big deal...

You already know there's going to be 3-4 more pipe needed just because of SPC, but what you don't know yet(?), is how much extra pipe will be needed when various pipe will not be placed perfectly horizontally or perfectly on a straight line vector.

It would be only in a perfect world where 100 sections of 20 feet long pipe would actually equal 2000'.

So . . . regardless of the SPC, they'd better have quite a bit of extra pipe anyway.

I Am Assuming Mechanically Locked Joints

There is no flexing in that pipe, all bending is at the joints or in curved pipe lengths or fittings.

Who is to verify the pay lengths?

Don't get to the end of this project and find that you should have been taking special care before or during construction.

Is there a rock clause?

Again don't wait until the project is done to find out you should have been getting rock quantities.

If the contractor submits a rock quantity in excess of the estimate and you cannot verify actual numbers the municipality may want to hold you liable for the difference. At $1,000+/CuYd you would soon run out of money.

Paul in PA

I Am Assuming Mechanically Locked Joints

> There is no flexing in that pipe, all bending is at the joints or in curved pipe lengths or fittings.
>
> Who is to verify the pay lengths?
>
> Don't get to the end of this project and find that you should have been taking special care before or during construction.
>
> Is there a rock clause?
>
> Again don't wait until the project is done to find out you should have been getting rock quantities.
>
> If the contractor submits a rock quantity in excess of the estimate and you cannot verify actual numbers the municipality may want to hold you liable for the difference. At $1,000+/CuYd you would soon run out of money.
>
> Paul in PA

The inspectors are verifying the pipe that is installed. The pipe lay drawings show each pipe joint and angle fitting associated with the alignment station. I have set all the offset hubs for the construction as per the alignment with elevation on the hubs. The construction crews have had to adjust to set the ARV and test stations in the right spots. That is where I started thinking that the pipe was built to the state plane coords.

I had EXACTLY the same issue with a big international firm on a 42-mile long 30" diameter, almost due east-west waterline project, but our average project elevation was over 4,000'. I couldn't get through to anyone in their firm - no one there had a clue. I finally gave up after writing a letter for the record to the project engineer. The project is hung up now and will likely never occur, so I'll probably never see what would have happened... I will never understand why you would design a project at this elevation (some parts over 7,000') in a SPC system.

> I had EXACTLY the same issue with a big international firm on a 42-mile long 30" diameter, almost due east-west waterline project, but our average project elevation was over 4,000'. I couldn't get through to anyone in their firm - no one there had a clue. I finally gave up after writing a letter for the record to the project engineer. The project is hung up now and will likely never occur, so I'll probably never see what would have happened... I will never understand why you would design a project at this elevation (some parts over 7,000') in a SPC system.

Jim: :good:

Because they don't know any better. You can't construct pipe based on grid distances. Won't work and never will.

> I had EXACTLY the same issue with a big international firm on a 42-mile long 30" diameter, almost due east-west waterline project, but our average project elevation was over 4,000'. I couldn't get through to anyone in their firm - no one there had a clue. I finally gave up after writing a letter for the record to the project engineer. The project is hung up now and will likely never occur, so I'll probably never see what would have happened... I will never understand why you would design a project at this elevation (some parts over 7,000') in a SPC system.

Many utilities, state and local government agencies are including requirements for survey control and design mapping to be done in state plane. Primary reason I have seen is coordination of multiple projects over many years. Secondary reason is inclusion of the as built projects in the management GIS of the utility or government agency. The Building Information Modeling (BIM) model is being adopted by these organizations. The electronic mapping, construction databases and easements for projects becomes their maintenance management tool after construction. BIM concepts require the use of a standard coordinate system by all involved in the project. For architectural plans and even large site (shopping mall) developments the distances are small enough that problems are not created. With government parcel mapping driving most of these SPC becomes an automatic requirement.

The design software from most companies supports multiple mapping projections and make the use of these very simple. Just specify the correct stand projection and everything works. The problem arises when design engineers do not understand the basic principles operating in the software. The "CAD monkeys" add another layer to this problem as they are convinced surveyors are a step below them in understanding the software. They usually work for the engineer and blindly back the idea that the program is a "magic black box" that takes care of all the calculations.

I Am Assuming Mechanically Locked Joints

Pipe will actually flex.

The latest two pipelines that passed thru this area had several runs across swamp land that was not properly anchored and floated up out of the ground and had to be sunk back into the swamps.

The used precast concrete anchors and large bags that were filled with concrete on location.

Does less than 1/8 inch per joint really screw up the stationing that much to worry about? As long as everybody uses SPC to layout and build it I'd think it wouldn't really be noticeable. If you have different layout artists using different systems things might get a bit off. I suppose if the contractor really whines about the extra 65 feet they could just pay him. I doubt they can actually lay jointed pipe to less than 1/8 inch tolerance per joint. If you run out of pipe at the end you just need to buy some more. Usually they order a bit extra. Was slope distance considered in the design? A little bit of grade will change the horizontal lay length also. That could be more than the grid/ground factor.

> Does less than 1/8 inch per joint really screw up the stationing that much to worry about? As long as everybody uses SPC to layout and build it I'd think it wouldn't really be noticeable. If you have different layout artists using different systems things might get a bit off. I suppose if the contractor really whines about the extra 65 feet they could just pay him. I doubt they can actually lay jointed pipe to less than 1/8 inch tolerance per joint. If you run out of pipe at the end you just need to buy some more. Usually they order a bit extra. Was slope distance considered in the design? A little bit of grade will change the horizontal lay length also. That could be more than the grid/ground factor.

I was wondering the same thing, about slope distance. Since stationing is usually on horizontal distance.

> > Does less than 1/8 inch per joint really screw up the stationing that much to worry about? As long as everybody uses SPC to layout and build it I'd think it wouldn't really be noticeable. If you have different layout artists using different systems things might get a bit off. I suppose if the contractor really whines about the extra 65 feet they could just pay him. I doubt they can actually lay jointed pipe to less than 1/8 inch tolerance per joint. If you run out of pipe at the end you just need to buy some more. Usually they order a bit extra. Was slope distance considered in the design? A little bit of grade will change the horizontal lay length also. That could be more than the grid/ground factor.
>
> I was wondering the same thing, about slope distance. Since stationing is usually on horizontal distance.

I have been wondering the exact same thing. I would think that their pipe design software would use all the 3D topology that we provided for the design drawings. I am pretty sure that it does take into account for the slope distances. If it didn't, the contractors would be screaming when the plans require them to go near vertical, 20 foot down with a 10 foot pipe.

This brings on the point that maybe the profile in the SPC cad drawings adjust for the elevation and distance somehow. I would not know how to check other than skimming the profile settings for scale factors and adjustments. Any suggestions?

I'm guessing that in TX, it's not much of an issue, though.

But in other areas, it could be a major difference between horizontal and slope (actual pipe length).

> I am working on a water line project that is set up in SPC. It is approximately 60 miles from west to east with an average elevation of 1950’

> meaning the ground distance is going to be about 65+- feet longer than the SPC coordinates show.

65 feet over 60 miles, forget the Surveying World you're now living in a Contractor's world. Any prudent estimator would have allowed for at least 2% waste in the pipe lengths. By reporting your findings you've done your due diligence.
Reality is that on a run this long, "It amounts to Dick"

Are the pipe run distances from center box to center box or from the edge of the boxes? This will make a difference in the slopes.

:good: :good: :good: