How to read a soil boring log 1

[nickdz21]

I'm a recent graduate of college with a degree in architecture. My job requires me to go over soil boring logs, which is something I am unfamiliar with. Does anyone know of a website or have a 'roadmap' that could help me with this? Thanx

 

[fattdad]

ASTM D-2487 or D-2488 are two references that show how to describe soils based on laboratory testing or visual methods, respectivelly.

The larger question (for me) is what is your intention on being able to read the boring logs? Are you then using the data to draw conclusions or to otherwise characterize the site (i.e., make value judgements on site suitability)?

f-d

¡papá gordo ain’t no madre flaca!

 

[kenvlach]

Perhaps you've posted under 'Soil/Groundwater environmental' by accident. If EPA-required work is involved, it is likely that the original boring must be overseen by a registered geologist, PE Civil Engineer or certified engineering geologist. Also applies to the logs and interpretation thereof. Based on California laws; maybe less strict elsewhere.

 

[cvg]

I would recommend you first - ask your supervising engineer / architect to explain them to you. He isn't expecting you to just learn it by osmosis is he? If he doesn't know, then call up your soils lab and have them explain it to both of you. By the way, you should have a report that goes with the logs which would describe field and lab testing that was done and give you the conclusions that you are probably looking for...

 

[BigH]

I think it is good that you wish to understand a boring log - it does come in handy - so long as you don't try to "interpret" the soils log with respect to geotechnical aspects of the project. Basically the soils log will give you an idea of the "stratigraphy" of the soils encountered at the site - it will tell you how thick a specific geological "deposit" is - it will describe what the deposit is (such as silty clay, trace clay, stiff, grey, low plasticity). You will also find some relevant geotechnical "parameters" - Standard penetration N value - this gives you an idea if the clayey strata is soft or stiff - or if the cohesionless strata (sand) is loose or dense. It will also present, usually, information as to the classification tests carried out - Atterberg limit - etc. It will also indicate the location of the groundwater level - or, in case piezometers or standpipes are installed where the water level is at a specific date after the investigation was completed.
Pick up a basic soils book (Bowles or Das) and they have sections in their books on this. Again, learn to appreciate the boring log - but don't try to take it beyond your own level of competence. It is really a "record" of what the geotechnical investigation encountered at a specific location at a site. But the Geotechnical Engineer of Record is the one to interpret and provide recommendations for the design and construction.