Steel Pipe Piles Question

[StructENG82]

I am a structural engineer working on a project with steel pipe driven piles. An issue has come up with the capacities of the steel pipe piles that were recommended by the geotechnical report. The geotechnical report made a recommendation of a pipe diameter and thickness (along with grade) that can't reach the required capacity. The pile supplier used the geotech report as the basis of the piles they supplied and claim this is industry standard. The geotechincal engineer admits their recommendation is incorrect but counters that the pile supplier should have hired their own engineer to do the pile design. As the structural engineer I am not involved with the disagreement but would like to know who is correct.

The question I have is it "industry standard" for pile suppliers to go off the recommendations of the geotechnical report or is it more standard for them to hire and engineer to design the piles? Also, is it required by code for the steel piles to be designed and certified by an engineer?

Thank you for responses!

 

[PEinc]

Usually, the piles are already designed by the project's structural engineer with input from the geotech. The pile supplier just provides piling that meets the specifications for type of pile, type of steel, length, and yield strength. The supplier does not design the piles. On some jobs, it is clearly stated that the contractor also has to provide the design for the piles. (This is more commonly done for micropile jobs.) In this case, the contractor either has a professional engineer on staff to design the piles or hires a professional engineering consultant to design the piles. In my experience, suppliers do not design the piles.

http://www.PeirceEngineering.com

 

[BigHarvey]

Is there a contractor and a pile supplier. If it is the case, the pile supplier is just supplying according to the spécifications he was given. He is generally not qualified to design a pile. If you are talking of the contractor, if he was not asked to check the design, he should have advised his client if the design was obviously wrong.

 

[LRJ]

I am also not familiar with suppliers doing the design.

The blame for this depends on what the contract specifies are the responsibilities of each party. Usually a designer (consultant) would not accept unlimited liabilities for their design, so I would expect there is some limitation of liability (LoL) clause in the contract. As such, I would expect the contractor would be responsible for rectifying this issue.

 

[msquared48]

It is "industry standard" for the pile driver to refer to the recommendations of the Geotech Report referred to in the Structural Notes of an approved plan set that was signed and sealed by the project Structural Engineer of record.

My question is who is the EOR here who should have prepared the piling plan?

Mike McCann, PE, SE (WA)

 

[PEinc]

I respectfully disagree with msquared48. The geotech report usually contains recommendations and alternate foundation discussion for the project designers. The geotech report is often noted to be for informational purposes only. Unless the contract documents (plans and specs) instruct the contractor to design the piles, all the contractor needs to do is buy the specified piling and properly drive it to achieve the required capacity and/or minimum tip elevation without damaging the pile. If the pipe pile fails or is insufficient, it should not be the contractor's problem, although the design team will try to place the blame on the contractor. If the pile fails during driving because the pile hammer is not sized properly, that would be the contractor's problem. I have not seen pile suppliers provide sealed, engineering designs.

http://www.PeirceEngineering.com

 

[msquared48]

PE Inc.

Clarification. The EOR still designs the pile, but there are ALWAYS other recommendations in the report besides the Recommended pile size and type.

Mike McCann, PE, SE (WA)

 

[cvg]

frankly, I am surprised that a geotech report would have recommended a pipe size and type at all. The EOR should have done that and the correct size should have been shown on the approved project plans. Unless the geotechnical engineer stamped the pile plans, you have a problem. As stated, geotech reports are generally for information only and are not contract documents.

 

[msquared48]

CVG.

One or more Pipe sizes with the diameter and type WITH ALLOWABLE LOADS is normal, and expected for design purposes in a Geotech report.

The structural EOR still sets the spacing and any other structural requirements consistent with the recommendations of the Geotech.

Mike McCann, PE, SE (WA)

 

[BigH]

@BigHarvey - isn't it normal European practice that the piling contractor design the piling?? At least this is the impression I had from an international conference years ago . . . please advise.

 

[hokie66]

As a design engineer, what in the US is called an "EOR", the only type piles I have designed are bored piles. The other common types I have used are precast driven piles and timber piles, and the design capacities were given on the contract documents, with a minimum size, but were designed by the piling contractor. I would think the same procedure would logically apply to steel piles.

 

[msquared48]

Hokie... EOR = Engineer Of Record


Mike McCann, PE, SE (WA)

 

[hokie66]

Yes, I know what that acronym means, but the responsible design engineer in other countries is not always designated in that manner.

 

[BigHarvey]

BigH
In France we, contractors, generally do the design from SI report and loads given to us. Sometimes we are also given a design that we always check because as "knowledgeable" people we have a duty to warn our client that he is specifying something wrong if it goes to court !

 

[Okiryu]

Perhaps, we can divide this issue in 2 type of projects: Design-Build (D-B) and Design-Bid-Build (D-B-B) projects?

My experience is that for D-B, the geotech works together with the pile contractor to give specific information for pile size and capacity to the structural based on the structural's requirements.

For D-B-B, the geotech gives several options for pile sizes to the structural so the structural can complete the design with the geotech's input.

It may vary depending on the country, but I have seen this trend for US founded projects in Japan.