allowable bearing capacity+width of foundation
allowable bearing capacity+width of foundation
(OP)
Can anyone tell me how I can relate allowable/safe bearing capacity to the width of a strip foundation or suggest a design chart that uses cone pnetrometer resistance as opposed to SPT 'N'?
Ta
Mike
Ta
Mike





RE: allowable bearing capacity+width of foundation
For getting the ultimate bearing capacity I would normally use the Brinch-Hansen equation which for the basic case of a vertical load on a cohesionless soil with no overburden pressure becomes
qn=1/2.g.B.Nq.dq
qn= ultimate bearing pressure
g = density of soil
B = width of footing
Nq = bearing capacity factor
dq = depth factor
Nq varies with phi, the angle of shearing resistance and you'll need to get hold of the graph. Any text book on soil mechanics has it. dq varies with the ratio of depth of foundation to width. A simplified value which holds for phi<25 degrees is dq=1 + 0.35D/B.
This is a very particular application of Brinch Hansen and I would recommend getting a text book or I understand the US army has some good technical papers on the web too.
Carl Bauer
www.bauerconsultbotswana.com
RE: allowable bearing capacity+width of foundation
mom@arrakis.es.
RE: allowable bearing capacity+width of foundation
A cue card for this chapter can be found at ...
http://www.engs-comp.com/mathserv/bowles4-3.html
Helmut
engcomp@pbq.com.au
RE: allowable bearing capacity+width of foundation
http://www.engs-comp.com/mathserv/bowles4-6.html
Helmut
engcomp@pbq.com.au