for the penetration analysis to be made. It became apparent that a 

 point of diminishing returns was reached for each soil type for each 

 L/B ratio. This occurs because as fluke length increases, so does fluke 

 keying distance. Flukes eventually become less efficient with size. 

 Flukes that would receive further analysis for soil I, II, III were 

 1.5, 1.75, and 2 feet wide; flukes for soil IV, the soft clayey silt, 

 were 2, 2.25, 2.5, and 3 feet wide; the flukes for soil V were 1.5 and 

 1.75 feet wide. Both L/B = 1.5 and 2 were chosen for all soils. 

 Smaller flukes (L/B = 1) were generally not chosen because experience 

 indicates that their penetration to the required deeper depths is 

 difficult. 



4. Evaluate Penetrability of Chosen Flukes . The penetrability of 

 the most promising flukes was evaluated using the technique described 

 by True (Smith, 1971) slightly modified to agree with the results re- 

 ported by Christians, 1967. Typical results are presented in Figure 

 A-3 for the soft clayey silt soil, type IV. These data shown that the 

 curves for each L/B are practically superimposed for the fluke sizes 

 considered. This trend followed for the other soil types. 



5. Choose Fluke (s) . Table A-1 summarizes the fluke velocity and 

 energy requirements needed to satisfy the goal of 30 kips short-term 

 (20 kips long-term) holding capacity. Penetration velocities for 30 

 kips were determined from the appropriate embedment depth-penetration 

 velocity curve, such as in Figure A-3. Embedment depths used to enter 

 the curves are derived from the appropriate fluke width-embedment depth 

 curves, such as in Figure A-2. Based upon velocity and energy require- 

 ments, a different fluke is needed for each soil for optimization; this 

 however, is impractical. Two flukes were chosen to satisfy all seafloor 

 sediments; a 1.5 x 3-foot fluke for soils like Types I, II, III, and V 

 and a 2.5 X 5-ffot fluke for soft seafloor sediments, like soil IV. 

 Preliminary estimates indicate that the larger fluke will satisfy clay 

 soils with c/- ratios ranging from 0.15 to 1, and the small fluke will 

 satisfy clay Moils with c/- ratios greater than 0.6. This overlap will 

 in some cases allow the flukes to be tailored to specific situations. 



The smaller fluke, defined as the sand fluke, provides an accept- 

 able compromise for the more competent seafloors. It is small enough 

 to function in dense sand, and large enough to function in a non-plastic 

 silt. This fluke should equal or exceed design specifications in all 

 soils but soft clay. The deeper penetrations of the smaller fluke are 

 more desirable to minimize the effects of scour and to ensure "deep" 

 anchor behavior. The small size also simplifies handling and stowage. 

 A 2.5 X 5-foot fluke, defined as the clay fluke, seems to be the best 

 choice for soft clay. The required velocity and energy can be realis- 

 tically attained, and the fluke is still reasonably sized. These 

 decisions were not strictly accomplished by analyzing Table A-1. This 

 table helped eliminate many flukes due to excessive requirements, while 

 evaluation of curves of holding capacity versus penetration velocity 

 (see Figure A-4 for typical curves) resolved the decision. These curves 

 were developed by synthesizing data from holding capacity-embedment 



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