Test Pits May No Longer Be Viable Investigation Tool
Test Pits May No Longer Be Viable Investigation Tool
(OP)
Ramifications - test pits may become too costly to be viable any longer . . .
http://www.nce.co.uk/5201397.article
http://www.nce.co.uk/5201397.article





RE: Test Pits May No Longer Be Viable Investigation Tool
So...What options are there? The information will still be needed - core drilling?
Mike McCann
MMC Engineering
RE: Test Pits May No Longer Be Viable Investigation Tool
RE: Test Pits May No Longer Be Viable Investigation Tool
RE: Test Pits May No Longer Be Viable Investigation Tool
RE: Test Pits May No Longer Be Viable Investigation Tool
RE: Test Pits May No Longer Be Viable Investigation Tool
RE: Test Pits May No Longer Be Viable Investigation Tool
Any testing and sampling that is to be done is done on intact pieces of material removed from the test pit. The geologist or engineer can watch the excavation from the surface, know where the piece came from, take a sample and make the log without entering the pit. Yes it takes a little longer, but not much.
We can easily excavate and backfill 10 test pits to 10 feet in a day.
RE: Test Pits May No Longer Be Viable Investigation Tool
RE: Test Pits May No Longer Be Viable Investigation Tool
As soon as this occured, the AGS website published a statement and included a photo from Costwold Geotechs own website with the owner Peter Eaton in the pit with only his sholders and head showing above the ground and with a ladder included to show access to the pit. Very inciminating and I am sure this will feature in the case.
For many years now the practice of getting into pits to log samples has been avoided at all cost becase of the risk of collapse, especially in the UK with our history of glacial relic slip surfaces. As soon as this happened, and with the inciminating evidence of the photos from Costwolds own website, it was conjectured that they would be hit hard.
We have had to develope practices which either eliminate the need to enter excavations, or where we do full and approrpaite protection must be taken. I would say all Geotech Companies in the UK follow this procedure, however given this sad case it does show there are still some exceptions out there. All very very sad.
RE: Test Pits May No Longer Be Viable Investigation Tool
RE: Test Pits May No Longer Be Viable Investigation Tool
I am thinking can a steel barrel, or box, be dropped into it to provide protection, similar to that used in underground pipe line construction.
RE: Test Pits May No Longer Be Viable Investigation Tool
As mentioned previously, now very uncommon to get into pits because of the known risk of collapse so when the Guy dies in a trial pit and web shows owner/employer in trial pit doing same thing it all becomes very damning. This is the first case of it leading to a prosecution case, and I am sure this is because of the liklihood of a conviction [dare I say it, as an example case?]. We do know some of the ex-emloyees of this Company, and it would appear that their Engineers were often required to enter pits to log samples, which is at odds with how most other Companies have done this for many years. As mentioned above, there are ways of avoiding the need to enter test pits, so it should have been avoided. The area where the incident [note not accident] happened is widely know for slope stability problems, well documented and noted on the geological maps, the trial pitting was also being undertaken in heavy rainfall which added to the instability, took the resuce people over a day to get him out apparently. Given the known ground conditions and likley prevailing weather [in the UK it always seems to rain], he should not have been required to enter the pit, however with the damning evidence which is now commonly know about, the Employer is found to be at sufficient fault to bring the case against him.
RE: Test Pits May No Longer Be Viable Investigation Tool
As BigH points out, we know there is a risk and that should be sufficient proof in court. Sort of like mountain climbing or maybe sky jumping.
Working from the top can be done accurately, especially if well experienced.
RE: Test Pits May No Longer Be Viable Investigation Tool
RE: Test Pits May No Longer Be Viable Investigation Tool
RE: Test Pits May No Longer Be Viable Investigation Tool
Safety is paramount to me. There are both borings and test pits that I've refused to enter. Key to this is to be on-site while said test pit or boring is being excavated to be able to get a visual of the materials coming out.
That said, I've had one close call.
RE: Test Pits May No Longer Be Viable Investigation Tool
"kslee1000 - as you know, by being able to go down into the pit, one can gain, in my view, a better handle on the microstructure that may be there - say orientation of layerings if present, and the like."
Your reasoning exactly matches that I was taught in school. Thanks. Wish this tragic event won't lead to outright ban, but better, stricker rules on safety planning before jeopardize someone's life.
RE: Test Pits May No Longer Be Viable Investigation Tool
There are already strict enough rules in the uk for safety (in my opinion much stricter than the US) it is simply that they did not appear to follow them.
RE: Test Pits May No Longer Be Viable Investigation Tool
Because lack of enforcement, and sometimes the punishment for such violation is a pat on the back (cost-wise).
In my work area, the rule is simple, one strike put you (the contractor) in the penalty box (stop work) until the end of the penalty period that fits the severity of offense. The second, you are out (terminated for certain amount of time). Third, will never see you again (terminated forever).
The result, the management is less likely to push before consult with safety, the contractor has learned to say "no", incident does occur, but has been drastically reduced in number, frequency, and sevirity.
Until we all can safely say no without worring been picked on for reprieve, the rule isn't strick enough.
RE: Test Pits May No Longer Be Viable Investigation Tool
Cave-ins for test pits are common in the soils in my area. We have a high water table and generally sandy soils, but the best way to delineate old topsoil layers and other deleterious stratification in the upper few feet is with test pits.
Using reasonable care and precautions, it doesn't have to be either dangerous or prohibitively expensive. Sometimes all it takes is a larger hole to make it safe.
RE: Test Pits May No Longer Be Viable Investigation Tool
After watching many test pit wall collapses, I don't put anybody (including myself) in there. Force from collapsing pit is just massive. When I have to do some work in test pit, I make benches. I guess everybody does. I often end up making big pit though.
RE: Test Pits May No Longer Be Viable Investigation Tool
In the bucket! I would say thats even worse. Not only going into the pit but using the excavator as a means of access is dangerous.
RE: Test Pits May No Longer Be Viable Investigation Tool
I remember a mason who's work i had to inspect. I would climb his scaffolding and look at the work on a daily basis.
he watched me one day and told me that it didn't matter about my pay, reputation, or bills... no job is worth losing your life. i told him that i wasn't doing anything different than his workers. he told me i was. he said his workers didn't think they were going to die doing this, and watching me climb the scaffolding he could tell that i thought i differently.
i'm not afraid of most scaffolding anymore... but there are sometimes that i'll look at it and say "i'm not getting on these bozos scaffolding today"
everything can kill you if you let it.
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i think the death of a coworker is punishment enough. i can't see engineering managers out there doing more for actual safety improvement due to this law. if this law is at play in influencing a company's safety, i'm imagining more pages on a health and saftey program.... i'm imagining more training sessions.... i'm imagining a safety officer being assigned who has the least field experience.... i'm imagining unrealistic safety protocols that don't apply if the sun is not ecclipsed while a rooster crows...and safety lost in a sea.
RE: Test Pits May No Longer Be Viable Investigation Tool
RE: Test Pits May No Longer Be Viable Investigation Tool
Usually, if there are fine structures like sand seams in clay, the intact diggings will show them. Also a telephoto lens on a camera comes in handy.
One thing that has not been mentioned is backfilling. Believe it or not, some test pits are left open. Recently I almost fell into one with my farm tractor - left open years ago by the local transportation deparment doing aggregate sampling.
Our pits were backfilled before leaving the site.
My opinion is that I hope government will not enact carte blanche rules about this. As a rabid libertarian I say we have enought of them! :>)
RE: Test Pits May No Longer Be Viable Investigation Tool
RE: Test Pits May No Longer Be Viable Investigation Tool
Stand at the top of the pit, run the sample grabber down into the pit towards the wall, cut a circular scoop of out the wall side, then pull it back out. You have the actual undisturbed sample, the known sample point and height/depth below round, and the known alignment of the layers and whatever "fossils" are in the muck.
RE: Test Pits May No Longer Be Viable Investigation Tool
I personally profile/log my trial holes from the surface - easy and one becomes more efficient the more one does it. We are not allowed to get into a trial holes deeper than 1.0 metre. Anything deeper must be shored.