Owner geotechnical engineer problems 1

[TripleAYUDA]

Dear all

I am the client's representative, working with a 2 story building that was initially designed to be supported on a shallow foundation, no geotechnical investigation was carried out and it was simply assumed that the ground is dense sand with an allowable bearing capacity of 100 kpa.

Once I was hired for the project I immediately requested a soil investigation which in turn we found out that the soil is made of 6 m of compressible clay followed by 6 m of dense sand. SPT values in the clay layer range between 5 - 15 and 30 - 60 in the sand layer, with groundwater level close to the surface at 2 m. As a result pile foundation was chosen.

The designer is "a structural engineer", initially he was pressing that the shallow foundation will work but consolidation settlement is about 55mm. At the same time, he does not have experience in pile design. We have lateral loads up 700KN which also need to be analyzed. The designer requested additional compensation for the new foundation design which we do not agree with as it was all his fault.

I would like to hear your feedback and experience in a similar situation

Thanks

 

[phamENG]

I'm not quite clear on your role here. Are you the building owner that commissioned the building to be built, the building owner that bought the property during design, the geotechnical engineer, or some combination thereof? Or are you saying you're the owner of the geotechnical firm that has been brought into the project?

Whether or not the structural engineer (why the quotes?) is entitled to additional payment is probably dependent on their contract. For instance, my standard agreement has a clause that says, essentially, if no geotechnical report has been furnished prior to proposal for structural engineering services, I assume the foundation will be shallow footings based on presumptive bearing pressures. It will be the owner/contractor's responsibility to confirm bearing capacity and settlement characteristics of the soil prior to commencing construction. If it is determined at any time during or after design that deep foundations will be required or the presumptive bearing values are not valid, it will constitute an additional service and additional fees will be due.

I'm usually pretty careful to only push in the direction of a geotechnical report, though, since I'm a structural engineer and not a geotech. If he really made a definite claim that the soils were good enough and was then proven wrong...he probably doesn't have much of a leg to stand on.

In general, though, pile design is significantly more laborious than shallow footings, and cost a lot more to design.

 

[le99]

Usually, tHe structural engineer performs foundation design based on the soil report and the recommendation it carries, therefore, he is rightfully to request compensation for the change of foundation type from shallow footing to piles, which is usually more involved than the former type. However, if he was in charge of the preliminary soil exploration, or overlooked the need to carry out a thorough investigation (if he is obligated to, which I don't think so), then he is at fault, and the owner (your employer) can actually go after him for the cost differential.

 

[TripleAYUDA]

To clarify
I am the owner/client representative for this project. Our contract required that a soil investigation be carried out prior to designing the foundation but it was completed ignored by the designer and a shallow foundation was designed using presumptive bearing capacities which turn out to be incorrect.

 

[phamENG]

Then yes, I would say the structural engineer is entitled to additional fee. If they were told to wait for the geotechnical report, then they probably shouldn't be entitled to payment for both if they ignored that direction, but the pile foundation will require significantly more engineering time to complete and that should be paid for.

 

[le99]

"Our contract required that a soil investigation be carried out...". It shows your employer did request a soil investigation to be conducted, but "who" was the other party that signed the contract, the designer/structural engineer? Did he/she, who signed the contract, bill your employer, and received payment for the soil investigation? Also, is the designer/structural engineer self-employed, or working as a consultant to somebody/a company?

 

[TripleAYUDA]

The client was responsible for executing the geo investigation BUT the designer/structural engineer was confident that they knew the site ground condition and advised the employer to discard the investigation until I start working for the client and immediately order the investigation. The designer/structural engineer is part of a hired engineering firm for this job.

 

[le99]

The engineer did something unprofessional - offer ill advice that run against the norm. But your employer accepted his/her advice under free will, so who is really "at fault" for the follow-up mess is very difficult to judge. However, you do need to understand that it will cost more to design the pile foundations than shallow footing, so if you elect to retain the service of the designer, the cost differential needs to be addressed.

 

[dik]

From my Project Notes:

A GEOTECHNICAL REPORT HAS NOT BEEN PREPARED FOR THIS SITE. THE CLIENT IS RESPONSIBLE FOR OBTAINING A GEOTECHNICAL REPORT TO CONFIRM DESIGN ASSUMPTIONS. THE [CONSULTANT | ENGINEER] ASSUMES NO LIABILITY FOR THESE DESIGN ASSUMPTIONS OR FOR ANY FOUNDATION REDESIGN NECESSITATED BY DIFFERING SOIL CONDITIONS


If the above is the case and it is clear cut that a geotech report is required, then the EOR may be is in error. He may be liable to other costs. What is his reason for not obtaining a geotech report? Did the owner want to pay for one? Why did he use the foundation chosen? Was the foundation used common to the area? Lots of little questions.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Do you feel any better?

-Dik

 

[TripleAYUDA]

Hi dik
The was no EOR when the decision was made.
I only came to take this job after decisions were already in place by the designer mostly.
A nearby building foundation was also designed on a shallow foundation but also without any soil report. The building owner complained about wall cracks etc...

Now we have started the pile design work and we will not pay the engineering firm.

 

[dik]

Depending on the jurisdiction, that may be illegal, or improper. Can the engineer file a lien in your jurisdiction?

By designer, are you referring to the building designer or the EOR? What prompted the choice in foundations? Even geotech reports often have clauses that reduce liability for geotekkies... site conditions can change for a single structure. I've worked on sites where there have been different foundations for different structures on site.

If there was no engineer when the decision was made to use a shallow foundation, who made the decision? the Owner? How about other buildings in the area? Similar foundations? What is the cause of cracking in the adjacent building? Is the soil profile unusual for the area? Why did the owner not insist on a geotech report? or was that part of the contract that was breeched? Did he expect the EOR to pay for it as part of the contract? Why was it breeched? Since the project has gone 'off the wire' a bit, did the original engineer ask for a geotech report that the owner did not pay for? Just too many questions...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Do you feel any better?

-Dik

 

[phamENG]

A few questions:

1) Were detailed design/construction drawings of the shallow foundation prepared?
2) Were the shallow foundations built?
3) It's unreasonable to think a structural engineer would perform a soil investigation, so the fact that the soil investigation didn't come until a geotechnical engineer was hired is not surprising. Did the structural engineer attempt to downplay the investigation or say it was wrong?

If the answer to any of these 3 is yes, then I might be able to understand holding it against the structural engineer. If the answers are all no, then the structural engineer is very likely due compensation for the additional work.

In a perfect world, the preliminary structural design would precede the geotechnical report anyway. Those settlement calculations depend on foundation loading, which needs to come from the structural first. Estimating shallow foundation size from that data might take an hour?

We don't have the full picture, and never will (unless the other parties involved come on here and share their story, and even then we might have 80% of it), but it sounds like refusing to pay the structural engineer will probably end up being more expensive in the long run. If I were him, I'd probably tell you to pack sand and refuse to complete the design if you refuse to pay me.

 

[Settingsun]

Our contract required that a soil investigation be carried out prior to designing the foundation but it was completed ignored by the designer

This isn't clear. Which contract? Who was required to carry out the soil investigation? Did the designer ignore the contract or the findings of the soil investigation? Active voice communicates these things better: "do a soil investigation" vs "a soil investigation shall be done".

No-one here has enough information the answer this. I think some of the opinions are quite specific to North America, eg the title/function of EOR isn't universal, a structural engineer could be required to do a soil investigation (subcontract the work if not able to do in-house), and Dik's notes wouldn't change the contract/responsibilities (doubt it would stand up in North America for that matter).

 

[Settingsun]

However, if he was in charge of the preliminary soil exploration, or overlooked the need to carry out a thorough investigation (if he is obligated to, which I don't think so), then he is at fault, and the owner (your employer) can actually go after him for the cost differential.

This is another that isn't universal. The damage is often (I would say usually) the excess cost. If the structural engineer had done the soil investigation and found that piles were required, the owner's cost is exactly what they're spending now on the piled foundation. The damage is in the range of design fees, not construction costs. If they abandon the project due to this higher foundation cost, the damage is cost since they should have been informed - still design fee range of money.

 

[TripleAYUDA]

A detailed shallow foundation drawing was prepared by the structural engineer. There was no analysis of shallow foundation e.g. settlement etc...
Shallow foundation not yet constructed since we decided to stop until piles are designed
In terms of cost, the client has no problem paying for piles as long settlements are controlled

 

[dik]

There are a bunch of questions you haven't provided answers for...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Do you feel any better?

-Dik

 

[JedClampett]

There's never time (or money) to do it right, but there's always time to do it over.
Bet you saved a lot on not doing the Geotechnical Report.

 

[le99]

This is not a clear-cut case. As mentioned before, since the designer has already delivered his design per the previous agreement (whether the decision was correct or not), then, if you intend to retain his service for the redesign, you need to negotiate with him to cover the difference. It sounds like you are considering hiring another designer and not paying for the design rendered, if this is the case, watch out for legal ramifications.

 

[TripleAYUDA]

Le99
No one agreed with the shallow foundations solution. It was the designer alone decision. If this was found during construction, the client would probably suffer more aggravated costs with delays etc...

 

[le99]

If he indeed acted alone and was able, unilaterally, to direct the contractor to start the construction, then he's fully responsible for all losses suffered by the owner. But I am afraid it wasn't the case, as you have failed to disclose the full story (maybe too long to cover) that explains why the "communication" between the two parties was broken.