auger to test soil bearing 4

[PSlem]

A local professor had recommended an auger about 1" diameter that is screwed into the ground with a torque wrench as a quick method to determine soil strength. Who makes one and where would I find a technical discussion on the principals?

 

[rchanke]

Do a "Google" search on Hand Held Shear Vane and you will find a plethora of information.

 

[ChrisMcLean]

Two good examples of this type of equipment are the Geonor SL840 inspection vane (comes with extension rods to allow deeper testing and is very robust) and the Pilcon vane T0174/B (good but not as robust, no extension rods etc).

If by any small chance you are UK based I can give you contact details for some suppliers,

 

[PSlem]

I'm familiar with the vane test. What I'm talking about is similar to a ship auger for wood and you screw it into the ground. It would save the time of preboring. With foundation testing going for $65 a house, time is of the essence. It's interesting engineer rates are nowhere near the other professions yet we assume liability, while a lawyer would not. But I guess thats a whole other topic.

 

[BigH]

Perhaps you should think about other clients! Like industrial/heavy civil. For $65, the "lost time" on the jobs probably costs you money - unless the $65 is a loss leader! Why do geotechs keep getting pushed down the fee ladder?????????

 

[VAD]

Hello Pslem:

Your question has set me back to around 1965. At the time I conducted field work using the Bishop and Swedish shear vane testing machines. Someone from the US paid a visit and demonstrated the use of a torque wrench with a few light rods. The system could be carried in a shoulder bag. I am trying to remember if it was a vane or small auger attached.

Perhaps it was a vane at the end which could be used with torque wrenches instead of the standard equipment the time. I think this person was a University Professor and had developed the idea. It stuck to my memory as it was a quick method of determining the shear strength of soft soils without the heavy equipment. A paper was published on this equipment. Do not know the details.

Does this Prof have a calibration for same.? Then that is all that you would need plus specs for auger.

BigH is correct on pricing, but that seems to be the trend.
In 1981 one could get around $500 to do a couple hand auger holes to check soils below footing locations before deciding on depth, etc.

At least $65 could buy 5 to 6 jugs and some wings.

 

[PSlem]

Most testers just do a run by with a probe, but I do DCP to whatever depth I feel is necessary, so yes, at $75 (I charge a little more than avg.) it doesn't cover expenses, but I do it as a service to the builders I install piling for as the counties are now requiring an engr. to look at footings. I've tried to get a few more details from the prof. and even had Durham Geo call, but he's at a loss for specifics.

 

[j9576]

A.B. Chance had one a few years ago, you might try them.
Their model had about a 1" square shaft with a similar sized helix with extension rods and used a torque wrench to quantify existing soil conditions

 

[MRM]

PSlem,
Wait a second. I don't get this quite yet. You're saying you can do a little check on the foundations with hand auger borings, DCPs, site observation, and other means for as little as $65 to $75? What does that fee typically include in terms of scope of work? Is drive time and report prep included? $65-$75 doesn't even cover my expenses in getting to most nearby sites.

 

[Focht3]

I agree. The risk/reward on that work is way out of whack!



Please see FAQ731-376 by [blue]VPL[/blue] for tips on how to make the best use of Eng-Tips Fora.

 

[dirtdoctor]

PSlem -

$65 to $75 a site - now that has gone below board. You would have to do 300 houses a year to cover insurance deductibles if in a lawsuit for just one house.

Please do all consultants a favor and STOP THIS NONSENSE. It's bad enough that architects, owners, even other engineering disciplines put geotech/materials firms in bidding wars with each other. Now we have others giving it away. What a way to make a living - if I didn't love it so much, it would really be getting to me by now.

 

[BigH]

To all who wince at such low fees -

 

[Mise]

Hi ChrisMcLean,
Could you please give me the name of your supplier. I am also looking for a Hand Held Shear Vane.
Thanks.

 

[PSlem]

I buy my supplies from Durham Geo as they are in my town.

http://www.durhamgeo.com/testing/soils/field-testing-handvaneshear.html

I have found one company in town using a helical vane without preboring, but they are modifying their own augers. I have not had time to verify the readings of this device against known testing, so for now the straight vane is all I can offer.

 

[LarryMc]

$65.00 is just not enough. A single operator can only do about six sites in an 8-hour day with travel time. That is $390.00 per day. Reports, billing and record keeping has to be added on. Considering that many jurisdictions require additional regestration above the P.E., as well as professional liability insurance, there is no profit. I heard a saying from an old surveyor that I respected which went; "I may be tired or I may be hungry. I will not be tired and hungry at the same time!"

 

[ashjun]

I think, we should carry this topic to another forum ( forum765 ) "Professional Ethics in engineering" and not divert from the original topic here
(sorry guys I use dial up and it takes hell lot of time to load when the messages become longer, hence the frustration). Hope you all will understand.

 

[ChrisMcLean]

Mise - suppliers are Impact test equipment (01294 602626) for Geonor products or Controls Testing (01442 828311) for Pilcon

 

[PSlem]

To further steer this back to the original ? I received an 8 pg. article on the helical vane written by Drs. Yokel and Mayne. The only commercial model mentioned is the Chance, but they are easily made by grinding the flights of a 3/4" wood auger bit to an edge, welding it to a 3/8" rod with a nut on top and screwing it in with a 150 in-lb Snap On wrench. (It has a large gauge.) The torque reading divided by 5 gives you the N equivalent.

 

[dpa]

Hi,

I am very curious as to where you guys are located that you are doing soil testing for $65.00. In western WA it seem to me that geotechs are far mor pricey than civils or structurals. A friend called yesterday saying a geotech wanted $680.00 to check bearing capacity for a footing under a shed. He's hoping I can do it for $400 to $500. A couple of years ago I got an estimate from a geotech lab of $195.00 per hour.

DPA

 

[PSlem]

In Atlanta the eastern county had 9000 new houses last year, the northern county 16,000. When attending county meetings the inspectors state to the county they do about 20 inspections a day. I still do one to five a day.

Engineering is the art of not constructing...of doing that well with one dollar what any bungler can do well with two after a fashion.