F 



- 



A(c 



where 





F 

 A 

 c 



D 

 B 



L 





N 



, N 



The equation used to predict anchor holding capacity (Vesic, 1969) 

 with inclusion of a shape factor term (Skempton, 1951) and patterned 

 after bearing capacity equations for footings is as follows: 



= A(c N c + Y b D N )(0.84 + 0.16 B/L) (1.1) 



= holding capacity 



= fluke area 



= soil cohesion 



= soil buoyant unit weight 



= fluke embedment depth 



= fluke width or diameter 



= fluke length or diameter 



= holding capacity factors 



This is a general equation that can be applied to a variety of embed- 

 ment, soil, and loading conditions. 



The design of plate anchors can be separated into two general 

 loading conditions: static and dynamic. Static loading includes both 

 short-term loading and long-term loading. Dynamic loading includes 

 impulse loading, cyclic loading, and earthquake loading. Each can be 

 defined as follows: 



• Short-Term Loading - An increasing load to failure, such that in 

 fine-grained soils drainage does not occur. 



• Long-Term Loading - A fairly uniform static load of sufficient 

 duration that full drainage occurs in fine-grained soils. 



• Impulse Loading - Nonrhythmic loads greater than the static 

 capacity, less than 10 minutes in duration for clays or less than 

 10 seconds in duration for sands. 



• Cyclic Loading - A repetitive anchor loading with a double ampli- 

 tude magnitude greater than 5% of the static capacity. 



