agressive ground
agressive ground
(OP)
Hi,
I have a project where the Site Investigation indicated extremely acidic ground conditions with PH = 2. In the BRE special digest they say that anything below 2.5 is a problem. A contractor also highlighted that these conditions are very difficult for construction ??
Cheers
I have a project where the Site Investigation indicated extremely acidic ground conditions with PH = 2. In the BRE special digest they say that anything below 2.5 is a problem. A contractor also highlighted that these conditions are very difficult for construction ??
Cheers






RE: agressive ground
When I am working on a problem, I never think about beauty but when I have finished, if the solution is not beautiful, I know it is wrong.
-R. Buckminster Fuller
RE: agressive ground
www.PeirceEngineering.com
RE: agressive ground
TTFN

FAQ731-376: Eng-Tips.com Forum Policies
Need help writing a question or understanding a reply? forum1529: Translation Assistance for Engineers
Of course I can. I can do anything. I can do absolutely anything. I'm an expert!
RE: agressive ground
RE: agressive ground
My question is how to design and construct a building in a such acidic environment? Any guidlines or codes you guys are aware of to apply here or maybe some advises based on your previous projects?
thx
RE: agressive ground
RE: agressive ground
RE: agressive ground
We suspect that the acid is humic, coming from the peat which is present in the gravel directly below the peat, probably from oxygen getting below the peat when the groundwater level falls. Sulphate levels are low. However, based on the BRE document the humic acids are generally not below 3.5!
It seems unlikely that the acid is from man made contamination, as the soil strata are all natural (peat and gravel) sulphate values are low…
Also not all the boreholes show ph 2, there are some which indicate ph 8 so huge range here.
RE: agressive ground
Could you dig the whole site out to a few feet below the bottom of footing elev. and line it with a heavy rubber/plastic membrane? Then fill and compact back up to the footings, slabs, etc. Essentially the same as they line a solid waste dump site, but for the opposite results, to keep the bad stuff out.
RE: agressive ground
RE: agressive ground
RE: agressive ground
Plumbing: Use poly pipes for sewage away from the building; will a septic system even work in peat/swampy areas?
Water supply? Plastic pipes as well? Above ground water pipes?
Power: Telephone poles are going to fail? Going to last? Need 12 to 6" of concrete (no rebar!) around them to get to the house?
Pilings up to a suspended "above water" type wood-only structure, with a house on top of the platform?
Big thick concrete slab, and everything in the slab? Or will rebar corrode inside the slab over time?
RE: agressive ground
RE: agressive ground
In relation to the building it is a large structure (Court House). The structure needs to be piled due to bad ground conditions.
Almost each borehole indicates a low ph =2 , 5 meters below ground.
There are existing buildings in this area and we have never heard any issues but we were not the designers of those projects so it is difficult to say what approach they undertook.
RE: agressive ground
RE: agressive ground
Sample Location
Depth
Visual Classification (or you can full USCS it)
Natural Moisture Content
Resistivity AASHTO T-288
pH AASHTO T-289
Chlorides EPA Method 9056A*
Sulfates EPA Method 9056A*
*I usually would not have the EPA methods run if the resistivity was above 3,000 ohm-cms and the rest of the info seemed good
i haven't come across soils that acidic so i haven't had to deal with it professionally, but my first comment would be to make those other tests.
RE: agressive ground
http://www.nature.nps.gov/geology/soils/Understand...