Margin of Error
Margin of Error
(OP)
We are currently arguing with an owner over the deviation of a measurement on a plan detail. It was on a bridge project with 50 piles. The detail states that the pile lenght shall be 61.5' +/-. 14 of the piles required splicing of additional pile onto them to achieve bearing. (Some piles were as long as 93 feet) The Owner insists that +/- sign on the plans means it is open ended and the pile lenght can vary from that to whatever is needed to achieve bearing. My research indicates that it means the next significant number or 62. Does anyone know where I can get a definition or engineering opinion regarding the meaning of a +/- sign on construction drawings?





RE: Margin of Error
I don't think it "legally" means anything other than it does not need to be exact, as the correct way to specify a tolerance would have been "+/- 2 feet" or something like that. When something in the documents is not clear, the courts almost always find that the contractor is free to interpret it.
RE: Margin of Error
RE: Margin of Error
CarlB is right about proper specification on tolerances. ANSI publishes standards on tolerance for many items. Try them for something.
RE: Margin of Error
All contracts I've seen that involve piles have unit prices for all sorts of things like load tests, additional piles, additional lenth of piles/lineal foot etc. Am I correct that your contract did not?
I believe someone is trying to pull a fast one on you. No one reasonablly familiar with construction would try to make the argument they are. I think I would ask them to compare the cost of the extras you are claiming vs the cost of litigation - where even if they were to win, everybody loses.
RE: Margin of Error
RE: Margin of Error
RE: Margin of Error
In my nightmares with piling (H and various sizes of square prestressed concrete)the two goals were to achieve bearing and reach plan pile tip elevation. If build-ups/cut offs or splices were required they were paid for at an increased pre-established bid price.
It has been my experience that when "plus or minus" is used it is follwed by another value expressing the range of deviation allowed. I don't recall seeing +/- relating to pile lengths.
My guess here is you are on the hook for materials and labor for the additional lengths? Change Order No. 1.
Hope this helps.
RE: Margin of Error
However, your quote for piles should address what lengths you are furnishing and driving, if splicing is included, or if not how it gets paid, and how you get paid for both exceeding the quantity and underrunning the quantity. Typically the cost for overrunning is significantly higher than the credit for underunning, so they should be two different numbers. Quote should also address what are obstructions and how do you get paid for them, and how is driven length measured, who does cut off and how do you get paid for cut offs.
RE: Margin of Error
Forget about the overrun on the 14 piling. Look at the total linear footage that was called for (50 piling @ 61.5 ft/each = 3075 total linear feet). Base your request on the total length of piling driven versus the "contractual" quantity of 3075 ft. (I assume that the total driven was significantly higher than the contractual number?)
The Owner may be more receptive to change in the "lump sum" quantity of pile actually driven.
Since you have not mentioned the other 36 piling, the Owner may view your focus on extra payment for the 14 piling as quibbling
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RE: Margin of Error
i would hope that both sides would use "reasonable" judgement when confronted with this issue. there's a lot of if's in this scenario and perhaps there's more to the story since it's difficult to fully explain both sides of the issue via internet.
RE: Margin of Error