mechanism for input to the new design methodology. An additional portion 

 of the work should include obtaining cone penetrometer data for correla- 

 tion with static pile load capacity. Analysis of the cone data may lead 

 to improved in-situ soil survey methods for calcareous sand deposits. 

 The end product of this work should be a predictive methodology for 

 driven piles in calcareous sand in the form of guidelines and formulas 

 based on in-situ soil survey data of specific sites. 



2. Scaled up tests using centrifuge testing is recommended to initiate 

 validation of the new design methodology and to evaluate conceptual 

 alternative pile systems. This method of testing avoids similitude 

 problems associated with testing small size models under earth's gravity, 

 i.e., the stress and strain in the centrifuge model are identical to 

 those in the prototype. Since soil has stress-dependent behavior and 

 the ratio of body forces to gravity forces has a significant influence 

 on both the mechanism and magnitude of failure stress, a centrifuge test 

 program will be a good interim step from the laboratory to the expensive 

 full scale testing. Results of this program will: (1) improve the con- 

 fidence level of the new design methodology, (2) provide information for 

 designing a more effective pile load test program, and (3) reduce the 

 cost of the full scale pile load test program. 



3. A full scale pile load test program is recommended to complete vali- 

 dation and provide the specifications and guidelines. This program may 

 require two sites depending on the centrifuge test results to confirm 

 valid design methodologies: a non-cemented calcareous sand deposit 

 without voids, and a weakly cemented deposits with large voids filled 

 with loose calcareous sediments. 



ACKNOWLEDGMENTS 



The contributions of Dr. Philip Valent, NORDA (formerly of NCEL) , 

 and Dr. James Bailard, NCEL, in the early planning of the work are 

 acknowledged. The section on sediment distribution was drawn from the 

 work of Richard Malloy, NCEL. The general behavior laboratory testing 

 and data analyses is largely attributed to Professor Charles E. O'Bannon, 

 Arizona State University. And to Mr. Howard Johnson, Key West Naval Air 

 Station, who found the supply of excellent calcareous sand used for this 

 study. 



REFERENCES 



Agarwal, S.L., A.K. Malhotra, R. Banerjie (1977). "Engineering properties 

 of calcareous soils affecting the design of deep penetration piles for 

 offshore structures," paper presented at Offshore Technology Conference, 

 Houston, Texas, May 1977. (OTC Paper 2792) 



American Society for Testing and Materials (1981). Annual book of ASTM 

 standards, Part 19. Philadelphia, Penn. , Dec 1981. 



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