

/ 





/ 



1 1 





— - 



V 



E^EEE^r 



i:;;::.™„, 



D (feet) 



Figure 20. Comparison of experimental 

 data with elastic and bearing 

 capacity solutions (Series IV, 

 p = 0.15 tsf). 





\ 







\ 







, \ 







\ ^ 



\ 





^-„\ 







\ , ■•- 



'^. 



-" 



Etelitmlu.ionK,p.t..d.llu,|^ 



Figure 21. Comparison of experimental 

 data with elastic and bearing 

 capacity solutions (Series I, 

 p = 0.20 tsf). 



experimentally determined values. 

 The largest error is only about 20%, 

 a small value for a settlement esti- 

 mating technique. The major 

 difference between the two results 

 lies in their trends. The elastic result 

 follows the experimental data along 

 a horizontal line whereas the bearing 

 capacity curve diverges from the data 

 for larger values of D. This is pro- 

 bably because the surface bearing 

 capacity pressure— settlement equa- 

 tion is no longer valid. 



Two additional examples are 

 given in Figures 20 and 21 . The first, 

 for a particular pressure at the Series 

 IV site, presents the same character- 

 istics which were apparent in Figure 

 19. Both solutions give good pre- 

 dictions for small D; but as D 

 increases, the bearing capacity 

 curve diverges while the elastic 

 curve follows the data. Here the 

 bearing capacity curve diverges even 

 more rapidly than for the last example. 



The example of Figure 21 for 

 a given pressure at the Series I site 

 shows good correlation for both 

 prediction schemes. 



In general the following 

 comments may be made about the 

 two schemes presented here: 



1. The bearing capacity equation is 

 only valid for certain relatively high 

 pressures. However, for these values 

 no additional empirical coefficients 

 2-0 are needed in order to obtain rela- 

 tively good predictions. This solution 

 would probably provide acceptable 

 predictions at sites with considerably 

 different soil profiles. 



26 



