Estimation of Net Allowable Bearing Presusure from SPT "N" value
Estimation of Net Allowable Bearing Presusure from SPT "N" value
(OP)
Hi all:
Is there any way a preliminary estimate of Net Allowable Bearing Pressure obtained from SPT "N" value.
In our case the footing is resting at 8 ft depth. Do we average all the SPT values for whole bore hole or we consider SPT's in the footing depth range only ??
Because we have reasonable N values at shallow depths but at deeper depths we have low N's which is followed by a SHALE layer with good N's.
Thanks
Is there any way a preliminary estimate of Net Allowable Bearing Pressure obtained from SPT "N" value.
In our case the footing is resting at 8 ft depth. Do we average all the SPT values for whole bore hole or we consider SPT's in the footing depth range only ??
Because we have reasonable N values at shallow depths but at deeper depths we have low N's which is followed by a SHALE layer with good N's.
Thanks





RE: Estimation of Net Allowable Bearing Presusure from SPT "N" value
http://www.soilstructure.com/
RE: Estimation of Net Allowable Bearing Presusure from SPT "N" value
RE: Estimation of Net Allowable Bearing Presusure from SPT "N" value
nagatalurri- You can get the paper from here: http://cedb.asce.org/cgi/WWWdisplay.cgi?11797
http://www.soilstructure.com/
RE: Estimation of Net Allowable Bearing Presusure from SPT "N" value
Naga
RE: Estimation of Net Allowable Bearing Presusure from SPT "N" value
As to how the chart was developed, it likely was based on many sources, among them building codes, his lab tests, as well as job experiences. In his text there are the results of many tests on soils generally from the New York State area. One thing I recall was his contempt for those with "diarrhea" of the pen that said nothing.
RE: Estimation of Net Allowable Bearing Presusure from SPT "N" value
RE: Estimation of Net Allowable Bearing Presusure from SPT "N" value
Thanks a lot for the information. I have one final question for you. Lets say I have a soil profile up to a depth of 100'. If I want to calculate total settlement using the constrained modulus, till what depth I need to calculate.
Is it at 10% of the stress increase or any empirical depth where there wont be any influence of footing pressure ??
Thanks
NT
RE: Estimation of Net Allowable Bearing Presusure from SPT "N" value
RE: Estimation of Net Allowable Bearing Presusure from SPT "N" value
http://www.soilstructure.com/
RE: Estimation of Net Allowable Bearing Presusure from SPT "N" value
RE: Estimation of Net Allowable Bearing Presusure from SPT "N" value