How did you import the p-y curves generated by LPILE into SAP? I think the p-y generated by LPile would be non linear and you'd have used them in SAP as linear spring. May be this is the reason for discrepancy.
@geov86: Thanks for sharing your point, but I believe scale effect would not affect these value because the size of the footing is already considerably large compared to the soil particles. Such phenomenon is more prominent when dealing with small scale prototypes during physical modelling of...
@Okiryu: Thanks for pointing attention towards the decrease in friction angle with increasing stress. However, I don't this that this effect is significant enough compared to the overall decrease in bearing capacity. Further, I skimmed through the original paper by Hansen, and it does not...
In an attempt to find a pattern here, I have made a few more trials for which the results are shared here.
Trial-1
Sand
phi=31
c=0
Df=2m
Result: Qult (more or less) increases with foundation width
Trial-2
Sand
phi=31
c=0
Df=7.5m
Result: Qult decreases with foundation width
Trial-3
Clay...
@LeonhardEuler: See the excerpt from Bowles below where the concerned expressions have been highlighted.
If we keep the depth fixed and increase the width, these factors appear to keep on decreasing since D/B ratio would decrease (see sample calculations in the image below).
@oldestguy: Thanks for your comment. I have gone through your comment on the other thread but the discussion there is different than what I want to know. I am simply interested in knowing the physical explanation of decrease in SHEAR based bearing capacity with foundation width, as obtained...
As a general concept explained in geotechnical engineering textbooks, shear based bearing capacity is explained to be increasing with foundation width. Since the 'width' component in Terzaghi's Bearing capacity equation increases, hence is the corresponding increase in ultimate bearing capacity...
