Writing Geotech SOW

[sdz]

I am a structural engineer & I have to write a scope of work for a geotechnical site investigation. I believe I saw once a book on "how to talk to a geotechnical engineer" or similar. Does anyone know of such a publication?

 

[fattdad]

The scope of work is to provide you with the recommendations that you need for your structural analyses. The scope of work should also compliment the civil engineering design with recommendations for site preparation, earth work, embankment and pavement design.

Be real careful not to follow your urging to select what you believe to be the appropriate boring locations or boring depths. It's not appropriate for you to do this and when done can actually give you a portion of any liabilities that could develop in the future.

Perhaps you want to receive multiple proposals for comparison. That's o.k., just let the geotechnical engineer provide recommendations on boring frequency and depth. You may receive everything from the rediculous (sp) to the sublime.

As a rule of thumb, I'd want borings to extend at least 15 to 20 ft below the intended bearing depth with a spacing of not much more than 200 to 250 ft. Don't fall into the trap of drilling at each building corner if you are doing a series of smaller buildings. You can just do borings on a reasonable grid that envelops the development area. That said, often "grid" layouts are not the best as if there is significant grading to develop the site, you may want to configure your borings to coincide with the earthwork.

Beware of a cookie-cutter protocol for field exporation and geotechnical analyses. Hire somebody that you trust and let them figure out how to best work with your needs.

f-d

¡papá gordo ain’t no madre flaca!

 

[msucog]

TALK TO THE GEOTECH! provide them with the project information you know (or think you might know). i've had so many instances where critical information was not revealed until the exploration was almost complete. knowing estimated loads, finish grades, settlement tolerances, oddball things (isolated heavily loaded areas, settlement critical "things", etc), etc. if you happen to have a particular area of interest or you think the plans may change (building location moving, final grades changing, etc), then mention that to the geotech. otherwise, let the geotech locate the borings and depths. keep the communication channels open (going both directions) to help the project progress efficiently and effectively. and as far as choosing a geotech, get one you or someone else knows and trusts. they might cost a little more than the cheapo geotech but it's more often well worth it. the cheapo might be able to give you an exploration for a thousand bucks less but then they throw in recommendations that add many many times that to the overall project cost...or they completely miss something because the workscope was so "slim" and the project ends up spending more money than originally anticipated. go with a reputable geotech firm.

if you happen to have MSE walls at the site, the wall designer (since they are designing geotechnical structures) should direct that portion of the work (boring locations, drilling depths, test frequency, general evaluation of settlement and internal/global stability, etc). in my opinion, the drilling, testing, evaluation of the mse walls and their construction should be included in the wall designers package so that the owner doesn't get contractually stuck with the wall designer's liability. as a geotech myself, i'm not going to take their liability (and i don't think it's professionally appropriate for them to dump the liability on the owner)...before i take their liability, i'd just design the darn thing myself and get paid for it if i'm going to be responsible for the thing.