Quote (BRO)

...if there was a failure, but the geotech didn't do observations are their recommendations invalid?

This situation probably does not occur very often. As an Owner, we retained geotech firms frequently to get their recommendations... and that's all we wanted, professional service. A proposal from a geotech firm that "insisted" on followup inspections would have had their proposal rejected as "Nonresponsive".

On the other hand, when geotech advice proved to be flawed we considered that to be routine risk with this type investigation... no legal action. However, that geotech firm would probably not get repeat business from us.

I think it's unusual to write it so bluntly; that being said, geotechnical inspections and observations are part and parcel of the business and essentially are the required standard of care (i.e. carried out independently).

Plus, there is a financial element; most of the bottom of the market is dominated by firms that essentially do reporting and design at cost or below cost in order to win follow on construction testing services where the money is made. Is that the type of company whose advice / recommendations you really want? Usually, good advice / consultants that don't require follow on services to make money is significantly more expensive.

If I prepare and sign and stamp a report for a project, my last opportunity to see if the site conditions conform with recommendations based on limited exploration, testing and analysis is during construction.

If I received a call from a client wanting me to provide construction testing and observation services for someone else's report, I'd review the existing geotechnical report and decide if I'd be able to live with it. And if not, I'd write a proposal for additional services to address either insufficient information or to clarify what was in the report. The separation of the report generator from the construction services follows government and some private practice to get some objectivity on the design report. And it's about getting another insurance contributor if there is a problem.

I've been called during construction to resolve differences in the encountered conditions versus what was anticipated based on the investigation. In some cases the conditions did differ and required additional evaluation, and in other cases, the testing personnel never looked at the geotechnical report - they were just there to test and turn in numbers to confirm or reject specification conformance.

Common practice here is to give recommendations for design etc, then to separately recommend that an 'experienced professional familiar with the contents of this report' undertakes inspections
It sits somewhere in between as it allows for an experienced structural engineer or someone else to undertake the inspection without necessarily needing the geotech

What is annoying though is that geotechs are more and more asking to review the plans before they go to council so they can issue a letter
Like, geotechs here don't know shit about foundations, so why are they reviewing the plans?
That's a separate frustration

Personally, as a structural engineer but with 13 years of field testing experience, I only recommend an inspection if I identify something of specific concern e.g. fill or variations
Usually I will just specify an 'experienced engineer' to allow the structural engineer to undertake it without needing to get me involved again
Rarely I will specify that it has to be us - that's only if the results from the testing are somewhat alarming and I genuinely believe follow up is required from us to confirm our original recommendations

I appreciate the responses. The points you have made are interesting about the objectivity issue and where geotech companies make their money.

As a structural engineer designing from a geotech report, I have always wanted the geotech who wrote the report to do the inspections. In my opinion there is a substantially better product when this happens and both myself and the client gets a better product. Perhaps that's not the case.

I just looked at 3 soils reports from different geotechs in my area and they all have statements about observing some or all of the work and if they don't the findings of their report are invalid. At least for me and the company I work for these were fairly substantial projects. The largest was a university project that had a construction cost of about $220 million dollars. The geotech company who wrote this report is fairly large locally respected company. The other two are smaller companies, but I have always thought of them as good companies. In my county there are currently about 70 emergency road repairs requiring retaining walls due to all the recent rain and these geotech companies are doing the reports on most of them.

The public works or university departments do inspections, but they often do them in house. They will say that they have the experience to do this and they may call the geotech if they feel something is out of the ordinary, but will do all the testing, etc themselves.

It sounds like this type of statement is not typical outside my area. I'm still curious if a statement like this has ever been tested in legal case.

Thanks again.

I suppose the context is very important to this
I am primarily a residential engineer at present so my comments were in that context

Geotechnical workers in the residential space are usually someone from a geology background (a technician) with one or two Chartered Geotechnical Engineers signing off at the high level
In my experience, they are pretty useless at actually understanding structures and the separation of the field work from its traditional role with structural engineers is a mistake
I do both and adopt the philosophy of not leaving site unless I know what foundation concept will work on the site - geotechnical technicians cannot do this as they don't know anything about design
In a residential context within a city there is also no reason why 99.9% of sites cannot be assessed by a structural engineer - we are still trained in this as part of our degrees and we understand the engineering science of the result
The above isn't referencing liability at all though - just my frustrations with the continual insistence on separation of disciplines to appease box ticking without applying thought to how that actually works

In the scale of work that you're talking though I would revise the above completely though
I would make sure that the contract is watertight with regards to liability and inspections and, as the structural engineer, I would be advocating for the geotech to be doing the inspections generally

Greenalleycat,
It seems my area is bit strange. The building departments require a letter from the geotech on submittal for a building permit. I can't remember if this was happening in the 90s, but at least for the last 20 years it has been going on. They have to write something to the effect that the plans appear to conform to the recommendations in their report.

Public works projects typically don't get building permits, so that letter isn't usually required. The geotech's still require that they can review the plans though.

Structural engineers IMO also don't know shit about foundations / soil mechanics...I'm not convinced the ones here know about designing structures either (and more alarmingly frequently think that they know alot about the latter). I see a decent number of retaining walls designed by structural engineers with a handy copy of their first year geo textbook and an ego. Then again in NZ it doesn't take much to convince someone you are a structural engineer (https://www.stuff.co.nz/national/crime/300587541/u..., https://www.rnz.co.nz/news/national/485424/probe-f...)

>They have to write something to the effect that the plans appear to conform to the recommendations in their report.

They do that because it's common for structural engineers / architects / civil designers to (generally intentionally IMO but I'm not allowed to say that :) ) mis-interpret and mis-represent what the report says without consulting the Geotech or doing any further analysis, and then someone notices during construction. It's sort of a broken system really with everything siloed and no one really understanding the entire process. There's sort of a Geotech conservativism death spiral in alot of areas where geotechs, concerned about their already-massive liability write increasingly conservative reports and recommendations because they get cut out of the process and need to protect themselves.

geotechguy1,
I respect these geotechnical engineers a lot and I'm not casting any dispersions on them. The three companies I'm talking about I would have them do the report for my house, if I could afford to build one :).

I was really just asking if that type of exclusion would hold up. Sorry if it came across in a different way.

I'm not a lawyer but I honestly doubt the exclusion would hold up in a court, if you could prove that you did all of the inspections and testing they said to do. Most of the arse-covering stuff in geotech reports is non-enforceable in an actual legal proceeding as far as I know. However it might hold up in the 'pre court, court' of opinion in the project teams - i.e. the Geotech can say, well, this is why we want to do the inspections ourselves. Perhaps enough people would buy that argument for it never to get to an actual litigation.

@geotechguy1, if you want to argue that there are a lot of shit engineers in NZ, and that EngineeringNZ / occupational regulation in general is also terrible...I will agree, don't worry
We saw the article you linked when it first came out and we weren't particularly pleased with how soft she got off - the complete lack of integrity and judgement is disgraceful to the industry

To try to be less abrasive with my point, my comments are in the context of residential buildings only really
Within this space there are not many 'geotechnical engineers' that actually practice - the majority of people employed at geotechnical firms are simply 'technicians'
As structural engineers working with these reports we find that there are obvious knowledge gaps when it comes to both the structural design and construction phases
This is particularly true in Chch where the MBIE guidance dominates so much of the geotechnical work - we find ourselves just getting MBIE recommendations thrown at us, often times lacking critical analysis of their suitability

Residential houses are generally low to medium complexity working on low to medium complexity sites within areas that have broadly well known geotechnical characteristics already
From my own experience of testing sites to design the foundations on it, I am absolutely certain that there are significant advantages when the same person is doing both roles
I see this as the desirable outcome for the industry and our clients and therefore view that we should be upskilling the foundation designers (engineers) to build on the knowledge of geotechnical conditions that we are already taught in our degrees anyway
I see this as lower risk for the project and better for the long-term future of our building stock than separating these roles

On larger scales, I completely agree with geotech involvement - the geotechnical conditions required to build a stadium or whatever are miles past the capabilities of the majority of structural engineers for sure

This is going in a different but interesting way. Greenalleycat, I was thinking you were from Australia, but sounds like you are also from New Zealand.

Do geotechs and structural engineers always battle in this way?

Na we mainly whine about each other behind closed doors/keyboards
The particular topic I've been complaining about is one that is a pet peeve in our office due to the high % of reports that we end up having to send back to the geotech to get revised recommendations for as theirs are just impractical

I don't know the answer to your actual question but I can only imagine it will be specific to your legislation
I would guess that the specific contract structure would be the first critical detail - if the geotech report tries to add in new clauses they've already contracted out of then that would presumably hurt them
Second, I would guess that it would also depend whether the identified conditions on site were actually different to what they found in their site testing
But definitely one for the lawyers, I think it's very hard to give a general answer as it will be so specific to the job, contract, and particular site conditions (especially the ones leading to the failure) that I don't think we can give much guidance here

Thanks everyone for the discussion. Sounds like I need to look elsewhere for the answer.
I wonder if insurance companies ever dictate these statements.

Quote:

>They have to write something to the effect that the plans appear to conform to the recommendations in their report.

This is what our firm focuses on in terms of what confirmation we need, wondering what the thoughts here are on this list:

- Allowable bearing capacities (for our footing designs) conform with their recommended values
- Typically need confirmation the allowable bearing capacities are actually achieved in reality once the excavation has been carried out
- Geotechnical parameters used for shoring design (i.e. WALLAP inputs) are correct (these days we're getting the parameters directly in their report and it's more just ticking off our data table matches)
- Rock profiles/layers (we show then on our shoring elevations) match their data
- Pile depths required to achieve desired socket lengths/material, as a sort of follow on from the profiles (I feel like this often ought to be confirmed on site anyway whether the right material was reached but eh)
- Groundwater levels

Can say I've not yet had values provided by one geotechnical engineer and had another doing the inspections.

Quote:

The particular topic I've been complaining about is one that is a pet peeve in our office due to the high % of reports that we end up having to send back to the geotech to get revised recommendations for as theirs are just impractical

Typically when it comes to broader recommendations (e.g. drained vs tanked basement system, the need for piled foundations, etc.) if there's a problem we raise it with the client to ask for an updated report (e.g. in one case, a site with basement 6 levels deep was recommended to be tanked, essentially threatening to kill the entire project before it even started, meanwhile every adjacent site was drained). 95% of the time however this doesn't happen, I'm wondering how/why you're running into these issues so frequently?




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Why yes, I do in fact have no idea what I'm talking about

We live in a geotechnically complex city with a high water tables, liquefiable soils all over the place, old rivers been rerouted, fill/landfills, high seismicity, variable materials
Post earthquakes the government released a bunch of 'guidance' that has standardised many approaches (good) but has also allowed many people to turn their brains off in their designs (bad)
We seem to get loads of recommendations to excavate below the water table (how do we drain it? undermining adjacent properties? cost?) for a starter

Separation of soil and foundations is a misnomer IMO as the two are fundamentally dependent on each other in the context of a building
However, there is no real pathway to becoming a 'geotechnical engineer' here - it isn't a course/degree/qualification
Maybe someone does a Civil engineering degree, enjoys the geotech papers enough that they pick up a few extra papers and maybe a masters in a geotech field?
Most likely though the people working in geotech fields come from a geology or geography background so they don't know anything about structure, only about soil
This leads to them clutching to the few reservoirs of knowledge on buildings and construction that they have, such as the government guidance

Quote:

However, there is no real pathway to becoming a 'geotechnical engineer' here - it isn't a course/degree/qualification
Maybe someone does a Civil engineering degree, enjoys the geotech papers enough that they pick up a few extra papers and maybe a masters in a geotech field?

That's exactly how it works - for present day students (myself having been one not too long ago) at the Bachelor's level there is only a civil engineering degree, get exposed to all the different fields (structural/geotechnical/transport/etc.) and maybe get some 4th year electives that ultimately don't mean too much since it's the same qualification. Doing a masters is how you get a more specific education in geotech or structural, but it's not needed to work as one so the general path is just learning everything on the job. I'd probably wager that grads fighting over grad programs results in more people looking into exploring geotechnical roles since it fits their degree, compared to genuine interest

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Why yes, I do in fact have no idea what I'm talking about

I know that the uni education barely scratches the surface of the real job for civil, structural, or geotechnical, or probably any career really
It was just a comment that true 'geotechnical engineers' are very few and far between
The majority of the people in the field come from a science background, even the ones that eventually get recognised as CPEng
So there is a lack of actual engineering knowledge in that area of the industry

FWIW the conventional pathway to Geotech (in North America at least) is a civil engineering degree + 4-5 years of experience primarily in field and lab work with heavily supervised reporting then transitioning into project management of Geotech work / reporting; for people who want to be technical specialists, a masters degree obtained at some point. It's quite common that people start off in geotech and move into something else - in Alberta they will often talk about having 3 juniors, 2 intermediates, and one senior (and then maybe one principal per 10 seniors); and they really mean it - the people who don't stick around to the next level often go on to work for clients, become generalist civil engineers, go to the contractor side or become project managers.

Or alternatively one of the relatively rare geological engineering or geotechnical engineering speciality undergrad programs - UBC and Queens I believe have them in Canada.

In NZ the system is broken IMO because they pawn off all of the 'shit jobs' (field work / lab work) on engineering geologists so we have alot of desk-jockey geotechs that don't know what gravel is or why GAP65 isn't actually free draining (if you've done any lab testing and been in the field this is self-evident). Things seem to be quite slack here about letting the geologists / science grads become CPeng engineers without any further education so it seems that maybe the knowledge is not there at either end (you have either engineers with the education background but lacking field / practical experience or geologist / science background people who do have the field / lab / practical experience but lack the technical knowledge).

Quote (geotechguy1)

you have either engineers with the education background but lacking field / practical experience or geologist / science background people who do have the field / lab / practical experience but lack the technical knowledge

I think this hits the nail on the head, and not just in geotech - structural has its issues for sure
My frustration is with the constant attempts to separate knowledge out into specialist fields
Sometimes it makes sense for sure, other times we are adding delays, cost, complexity, and risk to projects for no meaningful benefit
The needs of our residential clients particularly are best served by engineers being highly skilled across multiple areas, not drawing lines between everything and getting multiple consultants in to clip the ticket

East coast structural engineer here - I see similar 'disclaimers' on reports, but not often as pointed as that. A firm I used to work for had it, though. If we weren't engaged for construction period services, the client released us from liability. The idea being that if you don't want us around to catch and fix problems, then you must not want us to pay for them. Would it have stood up in court? Probably not if it could be proven that it was a design flaw.

One thing about geotech reports around here: they're all based on settlement. Lots of saturated clays and high water table. I've measured 7" of differential settlement across a house before, and I've heard stories of far worse. You'll have settlement issues long before an actual shear failure. Those settlement calcs, as I understand them, are highly dependent on the actual loading and the size of the footings. BUT...the geotech report is often one of the first things done and is occasionally included in the RFP for A/E services or it arrives shortly after the project is awarded. That's great - it gives us a place to start. But it's important that we go back and inform the geotechnical engineer of what the loading actually is and let them review the plans to verify footing sizes. That never happens. So if the geotechnical engineer thought we'd have 3 klf on wall footings that were 2' wide but the design changed and we went to a steel frame with high point loads, how valid are the assumptions in the report? If the owner doesn't pay to have it revisited, we'll never know.

I definitely agree with the coordination with the geotech on the report. We typically do this before the report is started to discuss the different options. We then will have the drawings reviewed to ensure we have met the requirements in the report.

This is a cities requirement for a building permit in my area. It doesn't specifically say the geotech of record has to do the inspections though:

After your geotechnical report is approved your geotechnical consultant of record must certify that the design of your structure reflects the recommendations of the geotechnical report(s) by submitting a 'PLAN REVIEW' letter to the Town prior to issuance of your building permit.

Subsequent project construction must be done under geotechnical observation and certified as having been done in conformance with the recommendations made in the report(s). Final inspection and occupancy will not be allowed until such certification (CONSTRUCTION OBSERVATION AND TESTING 'FINAL' LETTER) is received.

Geotechs make their big money from performing field services, not from writing site investigation reports. So, when they write that they will require a company representative to perform direct observations/testing during all earthwork......, they have two objectives: 1) Limit their liability if they are not hired to do field work, and 2) increase their work scope and income.

www.PeirceEngineering.com

Quote (PhamENG)

But it's important that we go back and inform the geotechnical engineer of what the loading actually is and let them review the plans to verify footing sizes. That never happens.

We stress this in our reports under our "Proposed Construction" section. We describe the proposed construction as dictated to us. At the end of the section, we state that if the proposed construction differs from what is described, we must be notified to ensure our recommendations are still valid. If details are vague at the time of our report, we'll have to make assumptions based on the typical loading of similar structures and then state that we must be contacted once the proposed construction is relatively finalized.

>The needs of our residential clients particularly are best served by engineers being highly skilled across multiple areas, not drawing lines between everything and getting multiple consultants in to clip the ticket

It's a difficult market - you have unlimited liability via the consumer guarantees act which may extend beyond your current employer so it's not really a desirable field to work in.

There are upsides to all of the specialists and science people; there is a much better diversity of thought in the Geotech discipline here because we have many specialists in geomorphology, engineering geology, hydrogeology, geological engineering, climate science, natural hazards etc etc and various sub disciplines / speciality areas of those fields to go along with the civil -> Geotech masters people and they are able to establish themselves pretty solidly and reach the top of the profession which historically hasn't been possible in Canada.

Just for context, to get the building permit for foundations the getoech firms are required to attend the foundation excavation and pours, usually a couple hours, to sign off on a one pager that the foundation conditions match the expected conditions. For road jobs there is the disclaimer that says here is what we found if you find anything different call us to come out to provide the recommendations, in the past the contractors wanted to just do what they wanted but they have learned that calling out the geotech justifies the extra's for the contractors.

Quote (GeoEnvGuy)

Just for context, to get the building permit for foundations the getoech firms are required to attend the foundation excavation and pours,

Does it specifically say the Geotech who wrote the report? It doesn't seem like they say that in most of the local jurisdictions around me. It can be another inspection company that is considered competent (approved) by the building department.

Quote (SlideRuleEra)

A proposal from a geotech firm that "insisted" on followup inspections would have had their proposal rejected as "Nonresponsive".

One thing to note is that the proposal never says this, but it will be in the report. I've seen some push-back, but it's too late to force the issue. The geotech has issued the report and provided his professional opinion and this includes that they should to the inspections.

Sometimes we also are the client for these reports as the geotech is a sub-consultant for us. I wonder what our liability is if our client is unwilling to pay for these inspections by the geotech of record?

Is there an Eng-tips legal forum? Just kidding about that, but I did look.

Quote (BR0)

Sometimes we also are the client for these reports as the geotech is a sub-consultant for us.

Be careful with this. My insurance provider prohibits me from hiring a geotech. I can provide the project requirements and define the scope of work, but I give that to the client to send to the geotech for a direct proposal. The risk profile is very different from a structural engineering firm. Their claims are pretty rare, but they tend to be disproportionately large when they do happen.

"Be careful with this. My insurance provider prohibits me from hiring a geotech. I can provide the project requirements and define the scope of work, but I give that to the client to send to the geotech for a direct proposal"

This is the smart way to go and provides the geotechnical direct interaction with the prospective owner. I tell clients that we help them decide where they want to be on the "cost-risk continuum." Low cost, high risk, high cost, less risk and in some cases their willingness to accept "high risk" is a red flag on working for them. They own the project, they decide. Transferring risk to you is considered good business practice.

THanks for this interesting solution!

Quote (BR0)

Does it specifically say the Geotech who wrote the report?

The municipal rules do not specify, but good luck trying to get another firm to go out to certify the foundation conditions of the first company.

From my perspective, all geotechnical reports will have an attachment outlining the limitations and conditions by which the geotechnical report can be used. Such may include having the report prepared for a 4 story apartment building but then the design is changed to a 20 story building. Obviously this is a drastic change by which the geotechnical engineer would need to review its recommendations - most geo reports are written before design, remember. Golder (now part of WSP) and many others uses such limitations and conditions - as all firms should do so.

Below is a letter of the New Zealand Geo Society addressing these issues that might be of interest.

https://fl-nzgs-media.s3.amazonaws.com/uploads/201...