Geotechnical Report and requiring construction phase services 11

[BR0]

In my area, the geotechnical engineers typically have a section of their report about observation and testing during construction. They will require a company representative to perform direct observations/testing during all earthwork. The geotech will have a phrase that if they don't do these observations/tests, their recommendations will be rendered invalid.
The observation and testing will depend on the project but includes testing of engineered fills, compaction testing, tie-back testing, pier embedment determination, etc.

If this is a public works project, the agencies that we work with usually refuse to pay for this. They will self-perform a lot of this effort. Does anyone know if this has ever been tested in practice? As an example, if there was a failure, but the geotech didn't do observations are their recommendations invalid?

Thanks.

 

[geotechguy1]

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).

 

[Greenalleycat]

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

 

[phamENG]

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.

 

[BR0]

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.

 

[PEinc]

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.

http://www.PeirceEngineering.com

 

[MTNClimber]

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.

 

[geotechguy1]

>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.

 

[GeoEnvGuy]

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.

 

[BR0]

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.

 

[BR0]

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.

 

[phamENG]

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.

 

[theCorkster]

"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.

 

[DominicLee]

THanks for this interesting solution!

 

[GeoEnvGuy]

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.

 

[BigH]

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....BIE-Misuse-of-geotechnical-reports-letter.pdf