Strategies for dealing with the 'uh uh uh' people 14

[geotechguy1]

I'm not sure about other branches of engineering, but for 10 years I've fairly regularly encountered people who behave as follows:

1. We assess consolidation parameters for a site, say using one dimensional consolidation tests

"Uh uh uh, sample disturbance, the standard push tube diameter is to small to be accurate, etc. Can't use those parameters​

2. We use some simple empirical correlation between SPT - N values and some parameter

"Uh uh uh, have you applied these 300 corrections to SPT, and it's unreliable anyway, can't use those parameters​

3. We make a simple calculation using a closed form solution for bearing capacity

"Uh uh uh, here's random reason y we can't use the Terzhagi equation​

4. We make a calculation of stress distribution with depth caused by an imposed load

"Uh uh uh, you can't use bousinesq, westergaard, 1H:2V, soil isn't an elastic medium​

Essentially, never offering an alternative or solution, just throwing shade on anything and everything. Usually it's a PHD or MSC without much practical experience or alternatively just someone trying to do what I assume is assert themselves as a technical expert. I had a crack at it behaving like these people for 6 months once and I can't see the benefit of doing it.

 

[dik]

Not me... I leave geotekkie juju to those that do stranger stuff than I do...

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

-Dik

 

[Ron]

@geotechguy1....that's common. Ignore them and refer them to the fact that your interpretation of YOUR data is your prerogative, that you are the geotech of record, and that your process meets the prevailing standard of care based on your application of appropriate engineering judgment. (assuming it does!)

Geotechnical Engineering is a composition of assumptions, correlations, approximations applied with a reasonable degree of engineering certainty for the profession. Geotechnical Engineering is not exact. Soil parameters can change significantly from one borehole to the next....even within a few feet. The detractors apply unrealistic expectations to an inexact science. It's absurd to think you can accurately predict settlement to a hundredth of an inch....it's absurd to think you can predict accurate bearing capacity to within a few hundred psf....it's absurd to think you can accurately predict primary and secondary compression based on a consolidation test to within a few months.

And yes, some soils are certainly elastic...clean sands for instance.

 

[Eric C.]

Its not just in geotechnical engineering. Heck, its not just in engineering. These folks are everywhere!! No matter what is done or said the experts and critics (and expert critics) fight to get in line to tell you how you've made a mistake.

I believe I am making an accurate summary of what Ron said when I say "screw 'em!!".

 

[PEinc]

Well said, Ron. I agree. Sometimes you just have to tell people No!

http://www.PeirceEngineering.com

 

[GeoEnvGuy]

In the discipline notices in the engineering newsletter from my association. When you get into the details on some of the cases you will see expert A and expert B working for two different sides and discrediting the others work and assumptions. So its not just you and at the end of the day it is upto the owner to decide if they want your engineering opinion and accept your work or would like to do more.

 

[TigerGuy]

On any project you have 4 personalities:

The Rabbits throw out ideas fast and furious, just brainstorming, for every situation.
The Turtles are the pessimists, trying to explain why each of the Rabbit's ideas won't work.
The Squirrels just want a task to complete "Gather the nuts, gather the nuts."
We try to be the Wise Owls, with the wide view of the situation as a whole, understanding the merit of the Rabbit's ideas, the realities of the Turtle's negativities, the drive of the Squirrels to get it done.

It sounds like you are in a pond full of Turtles.

 

[PEinc]

geotechguy1, in your submissions, be thorough, clear, concise, correct, and have references backing your design. Then, you can successfully disagree with the reviewers.

http://www.PeirceEngineering.com

 

[1503-44]

Do the work as PEinc suggests.
Counter arguments with ...
"I'll be happy to draw that up for you, but you're going to have to sign it."
Or...
"Tell you what. Let's just don't build that part."

 

[BigH]

What Ron points out - ALWAYS listen to Ron!! - is right on - Geotechnical engineering still, in my view (tossing aside 5th order equations using 1st and 2nd order data) an ART. Hats off to the old timers who could show up to a site, catch the crux of the matter and make reasonable judgmental solutions to a problem (and then being found correct by the number crunchers later after much investigation and fanciful analysis). I've known a few who could do that.

Don't want to use elastic theory - then ask them to develop their models using particulate theory (see Harr's book) - now, I guess, called DEM.

Settlement? If you can predict the total settlement within 30% you have had a good day. Dr. Som has a book that took the same problem and did settlement analyses (clays) three different techniques and got three different answers - but reasonable all for the needs. Years ago, there was an article in Ground Engineering where a guy looked at 15 different ways to compute settlements in sand - finally, decided - pick your three, determine the settlement, average out the values and report the average.
SPT correlations - many of the older graphs/curves didn't really make corrections . . . used a doughnut hammer (and yes, donut vs automatic/safety hammer needs to be considered).
Bearing capacity calculations most often (pretty well always) are overruled by serviceability limits. Some structures have stringent settlement criteria - like 10 mm instead of 25 mm . . so what good is the bearing capacity (allowable) if it gives 50 mm?
One thing I have heard - a small dam is no different than a big dam if the hydraulic gradients are the same. (WOW)
Another thing I have heard - [green]"Can we reduce the required compaction level?"[/green][red] "Why"[/red] [green]"We don't have enough material and this will give me some additional material due to the less compaction."[/green]
If a person has never spent time (6 months minimum) on a drill rig or 6 months minimum on a major construction site - usually they can be ignored.

 

[geotechguy1]

What's the book, out of curiosity? I'm always trying to expand my already enormous collection

 

[BigH]

Somehow I am being denied posting an image . . . oh well - see attachment for Harr's book.

 

[dik]

They're having that problem with Millennium Towers, right now...

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

-Dik

 

[geotechguy1]

30% or 300% lol

 

[dik]

I have the same problem with calculating concrete deflections short and long term.

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

-Dik

 

[LRJ]

To be honest, the examples cited in the OP are all fair challenges - and persistently matters of debate amongst geotechnical engineers. This is somewhat inevitable in an imprecise field with still a lot of subjectivity: it is the old adage of asking 3 geotechnical engineers a question and getting 5 answers.

Nevertheless, the broader point made by the OP seems to be that there are some jobsworths out there creating unnecessary hassle. While jobsworths certainly do exist, I don't think the examples cited necessarily stray into that territory: you'd know if you ever met a bonafide jobsworth, and it would be much worse than those examples.

Moreover, such technical challenges are a necessary part of good decision-making: it is 'accountability' for the field of engineering. If you did not have good reasons for making the decisions you have, and you couldn't explain why you were doing things the way you were doing them, that should send alarm bells ringing to the recipient of your work. Furthermore, a world without such technical challenges would inevitably breed complacency. And to be frank, there is a lot of this complacency in engineering: the old 'that's how we've always done it' excuse comes up time and time again, particularly in geotechnical engineering. It's as if some companies once had one person who understood what they were doing, that person left, and the remaining people - who previously just copied that competent leaver - continued doing whatever the competent leaver had done before, unaware of the context.

Let's put this in reverse: do you think that you are so brilliant that you should not be questioned or challenged about your decisions? If the answer is 'yes', then I wouldn't want you working on my jobs, because that would be a hallmark of a dangerous decision-making process.

 

[geotechguy1]

I don't have any issue being questioned or challenged about my decisions or judgement, I think maybe you misunderstood my examples. I'm not talking about someone questioning whether we should use a modulus of 6 MPA or 8 MPa, or a bearing capacity of 300 kPa or 350 kPa.

I do think that 99.99% of jobs don't warrant having a debate about the underpinnings of the profession over. Yes, perhaps the standard push tube diameter is to small, and the standard bearing capacity equations are imperfect, and SPTs are an imprecise tool, but perhaps also the standard gauges chosen for railways in the past would have been better off being wider or narrower. There is a time and a place to try and make changes to such things, and that time is not on the clock spending someone elses money.

We can't re-invent an entire profession or litigate all the basic theories for every cut slope, embankment, and warehouse foundations. We are practitioners, we get things done and solve problems, within the confines of what is possible with the available techniques.

 

[LRJ]

The examples cited in the OP didn't seem to me to be 'reinventing the wheel' sort of stuff. Rather, they seemed to be legitimate disagreement within a highly subjective profession. Ultimately the statements indicate differences in judgement and/or preferences, and they at least seem to be reasoned. While I appreciate the time spent responding to such comments can be great and seem unproductive, I don't think anyone should take issue with reasoned disagreement.

 

[geotechguy1]

Ditching the use of standard bearing capacity formulaes on standard projects without proposing an alternative doesn't seem like a legitimate disagreement.