Field Soil Identification Tests

[upuki]

Hi there,

I am a project engineer for a local company in Argentina, specialized in service station construction. One common taks is underground tank replacements for which not always we have a soil boring test result.

We are pursuing a higher standard in construction safety and I am looking further on the area of excavation safety.

Dooes anybody know of a web site where I can look at different field soil identification tests? I want to use this section in a safety course for foreman and would like to show pictures of different stages of common tests, for them to recognize different type of soils and be able to select appropriate action to protect workers.

Thanks in advance for your help. Regards,

Upuki

 

[Grouser]

upuki

Sounds to me like you need to be more concerned with 'how' than with 'what'. Are you concerned about excavation cave-in or failure of the completed 'work'? These are completely different concerns. What type of injury are you trying to prevent?

The fastest field test for soil identification is a clear glass or plastic jar, half to 3/4 full of clear water.
1. Break up soil sample as much as possible, insert into jar.
2. Shake jar until soil sample seems to be dispursed.
3. Place jar on level non-vibrating surface. Leave there for 5 minutes.
4. Read results. Sand & gravel settled out in <5 seconds. Silt settled out in <3 minutes. Remainder is clay. Relative constituency can be estimated by layer thickness. (poor man's hydrometer)

Unfortunately, this information will provide little information regarding a soil's ability to shear, collapse, cave, or otherwise fail and cause injury or damage or both. I suggest your firm affiliate with one or more geotechnical engineering firms to properly assess each site's conditions before construction begins. Thus you will be prepared in advance for the challanges of that site.

The construction safety training should concentrate on things like laying back trench tops, not stockpiling excavation spoil next to the trench, use of trench boxes, backfill compaction equipment optimized for material placed, use of spotters, escape path planning, proper dewatering procedures, berming to protect excavations, etc. Hazmat equipment, including ventilation, may be necessary when replacing existing tanks. The excavation spoil may be contaminated and not suitable/allowed for backfill. Hazmat procedures may be necessary.

I hope this information helps but your query seemed to over-simplify the problem. People make their livings doing safety consulting. Your insurace company may be able to help with safety training info or sources. Associated General Contractors (AGC) has links to safety information. Go to

http://www.agc.org/,

click on 'Safety & Risk Mgmt.'
Good luck.

 

[BigH]

I went through this a couple of weeks ago when I saw a trench being cut with spoil piles immediately adjacent - so concerned, I stopped the work until it was remedied; being where I am, they don't worry about this much. Saskatchewan has a very good little manual about trench and trench safety. I did a search, if I remember right as &quot;trench excavation safety&quot; - got some real good hits and lots of good information. I used rediff.com for the search. The Saskatchewan manual is in the first 10 listings I believe. The manual goes through the various &quot;classes&quot; of soil. There, too, is always the &quot;thumb and fist test&quot; - it is outlined in a little manual that the Canadian Research Foundation put out eons ago. I'll look it up and post it, if I can find it! I know it is also in other publications.

 

[BigH]

I've some information - for the Saskatchewan manual try:

http://www.labour.gov.sk.ca/safety/trenches/printpage.htm

The Texas manual has some field tests: e.g. ribbon test, thumb penetration test, thread test, etc. I don't have the web site handy but the paper is:

Texas Workers' Compensation Board, Workers' Health & Safety Division, &quot;Program Guide Excavation Safety&quot;, Pub. No. HS98-121A(9-01).

Hope these help - the later might be recognizable from the search.

 

[Focht3]

Here's the link to Texas Workers' Compensation Board, Workers' Health & Safety Division, &quot;Program Guide Excavation Safety&quot;, Pub. No. HS98-121A(9-01):

http://www.twcc.state.tx.us/information/videoresources/excav.pdf

I downloaded it - the file is called 'excav.pdf' and it's size is 770 KB.



Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[Grouser]

Another general soils reference is the Asphalt Institute's MS-10 Soils Manual. Although slanted toward roadway construction, it has discussions on the AASHTO and Unified Soil Classification systems used in the USA. It is available at

http://www.asphaltinstitute.org/ShoppingCart/shopsite.html.

Click on 'Structural Design' and scroll down to it. It currently lists for $20.

I would bet that the US Army Corps of Engineers and the Navy Seabees have field manuals for soil identification to use when laboratory testing isn't available. Maybe some other forum members have particulars.
Good luck.