1 . INTRODUCTION 



Plate anchors are being used more frequently in ocean construc- 

 tion. Plate anchors are identified by the way they are embedded into 

 the seafloor. Examples are propellant-embedded and vibratory- 

 embedded anchors . The Navy currently uses propellant-embedded 

 anchors. Their selection stems from three major advantages over con- 

 ventional anchors: (1) they can efficiently resist loads in any direc- 

 tion, including uplift loads; (2) they can be placed at specific points; 

 and (3) they offer a high holding capacity relative to their weight. A 

 disadvantage of plate anchors is that they offer reduced holding capa- 

 city once their ultimate capacity has been exceeded or significant move- 

 ment occurs. As a consequence, plate anchors must be designed to 

 limit upward movement by careful selection of design loads in accor- 

 dance with the types of loading expected during the anchor's life. 



This report provides procedures for determining allowable design 

 loads for plate anchors under all types of static and dynamic loading 

 conditions in sediment seafloors. The procedures presented are neces- 

 sarily simplified for broader user application. In doing so, certain soil 

 conditions and types have been excluded to prevent the procedure from 

 becoming overly conservative in other areas . Guidance in identifying 

 sites with these conditions is provided, and reference is made to 

 reports that provide additional procedures for analyzing these condi- 

 tions . Specific guidance is given and procedures are given for 

 propellant-embedded anchors . 



