Unclassified 



DOCUMENT CONTROL DATA -R&D 



Naval Civil Engineering Laboratory 

 Port Hueneme, California 93043 



Unclassified 



SEAFLOOR FOUNDATIONS: ANALYSIS OF CASE HISTORIES 



i. DESCRIPTIVE NOTES (Type of report and inclusive dates) 



Not final; December 1969-June 1970 



5 AU TMORIS) (First name, middle initial, last name) 



D. G. Anderson and H. G. Herrmann 



June 1971 



84 



111 



3.1310-1 



TR-731 



Approved for public release; distribution unlimited. 



Naval Facilities Engineering Command 

 Washington, D. C. 20390 



The characteristics, basic foundation design parameters, and foundation performance of a 

 number of seafloor installations are summarized. These installations include offshore towers, habi- 

 tats, acoustic arrays, and numerous other objects located in water depths from 20 to 12,000 feet. 

 A number of case histories are analyzed. Some findings indicate behavioral problems not normally 

 considered during foundation design. Several unique foundation configurations are documented 

 which have been devised and utilized by a few to overcome the conditions imposed by the unique 

 seafloor environment. Results of this study reveal that a number of foundation failures and near 

 failures have occurred. Of the approximately 400 installations studied, 4% had experienced per- 

 formance problems and an additional 3% had experienced failure. The causes, or probable causes, 

 of several failures are examined. The value of foundation performance monitoring, both to the 

 operation of an installation and to the field of seafloor foundation design, and the value and need 

 for continued cooperation in the sharing of such information and experience are discussed. 



DD 



.,1473 



Unclassified 



S/N 010 1-807-680 1 



