SEAFLOOR FOUNDATIONS: ANALYSIS OF CASE HISTORIES 



Technical Report R-731 



3.1310-1 



by 



D. G. Anderson and H. G. Herrmann 



ABSTRACT 



The characteristics, basic foundation design parameters, and foundation 

 performance of a number of seafloor installations are summarized. These instal- 

 lations include offshore towers, habitats, acoustic arrays, and numerous other 

 objects located in water depths from 20 to 1 2,000 feet. A number of case his- 

 tories 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 performance 

 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. 



Approved for public release; distribution unlimited. 



Copies available at the National Technical Information Service (NT IS), 

 Sills Building, 5285 Port Royal Road, Springfield, Va. 22151 



