

Soil Penetration-Deceleration Force History . After some degree of 

 decelerati>on due to the water-cushion effect, the anchor shear keys will 

 touch tkce seafloor and begin to displace soil as they penetrate. The 

 soil pe^jietration generates an increasing resisting force as the shear 

 Iceys penetrate down to stronger soils, and as greater volumes of soil 

 are accelerated into motion to make way for the penetrating structure. 

 Then the anchor base itself comes into contact with the soil causing 

 still another change in the deceleration mode as the much greater area 

 of the base begins to penetrate the seafloor. 



This soil-penetration/anchor-deceleration interval must be analy- 

 tically described and modeled to obtain the load distribution on the I 

 anchor during penetration. These data along with the inertial force | 

 distribution are necessary to structurally analyze and design the anchor. 

 Development of an analytical model treating the ideal case of horizontal 

 anchor and horizontal seafloor appears an appropriate first step. • 

 Physical modeling would follow to improve the analytical model .,_ Then 

 this analytical model would be altered to include the case of the per- 

 turbed anchor and the sloping seafloor. 



Structural Analysis and Design . Once the anchor, soil, and water 

 forces are known and understood, then the development of structural 

 analysis and design techniques for the anchor can proceed. Structural 

 design concepts will make optimum use of materials and fabrication labor 

 while maintaining the stable hydrodynamic design. Also in this element, 

 the adequacy of the structural design to resist forces during transport, 

 offloading from a barge, and its service life will be determined. 



At the conclusion of this final element of the technology develop- 

 ment phase, the tools will be in hand for tba analysis and design of 

 prototype OTEC anchor systems. These tools will have been validated by 

 tests with reliably scaled models (preliminary information indicates 

 dimensional scaling of 1:30 is appropriate). Validation of the analytic 

 technique and demonstration of the concept by a full-sized, prototype 

 anchor will be the next step in ERDA development of the OTEC anchor 

 system. ' " 



15 



