prevent crushing the sand grains. After the specimens were separated, 

 they were soaked in distilled water for 24 hours. Sieve analyses were 

 then performed on the soil specimens in accordance with ASTM D422-63 

 procedures (ASTM, 1981). 



Results 



Of the 20 tests performed, 5 were nonscheduled and 15 were sched- 

 uled. The nonscheduled tests were "shakedown tests" to calibrate and 

 modify various test procedures. Relevant data and characteristics of 

 all test samples, as well as certain test results, are summarized in 

 Table 7. The shakedown test data were included in Table 7 for complete- 

 ness and to qualitatively supplement the results of the scheduled tests. 



An examination of the pile driving energy data indicated that: 



1. As expected, higher driving energy was required to install the 

 pile into higher density sand samples. 



2. For higher density samples of calcareous and silica sand, the 

 following observations were made: 



• The driving energy required to install the pile increased 

 with increased cement content . 



• At each prescribed cement content, pile driving resistances 

 were on the same order of magnitude for higher density silica 

 and calcareous sand samples. 



3. For lower density samples of either silica or calcareous sand, 

 an increase in cement content did not increase pile driving 

 resistance. 



The results of maximum pullout resistance and corresponding pile 

 displacement data are also summarized in Table 7. A summary plot of the 

 maximum pullout force versus the number of blows required to advance the 

 pile 12 inches is provided in Figure 23. Based on these results, several 

 observations were made: 



1. Although the pile driving resistances for the higher density 

 silica sand and calcareous sand samples are similar, the pullout resis- 

 tance of the silica sand was two to five times greater than of the pull- 

 out resistance of the calcareous sand. The difference of the pullout 

 resistance appeared to increase with the increases of cement contents 

 and pile driving resistance. 



2. In lower density calcareous sand, pile pullout resistance 

 appeared to increase with the increase of pile driving resistance. 



3. In silica sand, pile pullout resistance increased with the 

 increase of pile driving resistance. 



17 



