Port Hueneme after it had been examined and found to be pure. This sand 

 has a specific gravity of 2.72 and a carbonate content of 86.17% with 

 1.45% organics. The grain size analysis is shown in Figure 3. 



Silica sand was obtained from a commercial source. This sand was 

 from Monterey and is referred to as Monterey sand. For the purpose of 

 this report, the sand will be referred to simply as silica sand. The 

 specific gravity for this sand is 2.65. The grain size analysis is shown 

 in Figure 4. 



Model Preparation Procedures 



The program's philosophy was to bound the geotechnical parameters 

 of the soil-pile interaction. The objective was to view the behavior of 

 the two sands during pile driving. For each soil, two densities (a loose 

 and tamped soil) and seven levels of cementation (0%, 0.25%, 0.50%, 1%, 

 2%, 4%, 8%) were used. Furthermore, a limited suite of samples were 

 tested consisting of a 50-50 mixture of the two sands with the 0%, 1%, 

 and 2% cementation levels. 



Three parameters: (1) density, (2) cementation level, and (3) car- 

 bonate content, were viewed as important factors controlling the behavior 

 of calcareous sand. First, density variations were used since engineering 

 properties of terrestrial sands behave differently at different void 

 ratios (density). For example, a dense sand undergoing shear loading 

 will expand at failure while a loose sand will usually compress into a 

 more compact state. Since this is a prominent phenomenon occurring with 

 sand, the application of density variants appeared appropriate. 



Second, the varying cementation levels were appropriate because 

 calcareous sand deposits exist in uncemented and weak-to-medium cemented 

 states. The use of the cement variants will dispel questions of how the 

 soil-pile interaction changes with different stages of induration. 



Last, as was stressed earlier (Demars et al. , 1976), the possibility 

 exists that carbonate content could be used as an index property. Thus, 

 for purposes of bounding the effects of this property, the carbonate 

 content was varied at three levels: 0%, 50%, and 100%. 



The soil preparation procedure required that enough moisture was 

 available in the mixture to hydrate the Type III cement. The calcareous 

 sand was brought up to 19% moisture content (weight of water divided by 

 weight of solids times 100) and the silica sand to 10% (these moisture 

 contents remained the same for all the combination of soil samples) . 

 The reason for the disparity of moisture contents is because the calcar- 

 eous grains have a high affinity for absorbing the interstatial water 

 before hydration is allowed to commence, thus, additional moisture was 

 needed. The amount of cement added to the mixture was measured as a 

 percent of total sample weight. After mixing thoroughly, the soil sample 

 was placed into the container as explained below and cured in a 100% 

 humidity controlled environment for 7 days. 



A raining technique, common to soil laboratory testing, was used 

 for the high void ratio (volume of voids/volume of solids) soil place- 

 ment. The prepared soil was placed in a retaining hopper above the con- 

 tainer and released, and was atomized as it passed through a sieve 

 screen. For this study, a disbursing box and a 1/2-inch Tyler screen 

 were used. The soil was placed in 1-inch depth increments (i.e., lifts). 



