DYNAMIC HOLDING CAPACITY 



6.1 IMPULSE LOADING 



Impulse loads for cohesive soils are defined as loads greater than 

 the short-term capacity having a duration of less than 10 minutes . 

 Impulse loads for cohesionless soils are defined as loads greater than 

 the short-term capacity having a duration of less than 10 seconds. The 

 same basic procedure used for determining short-term static holding 

 capacity is followed for estimating anchor holding capacity under impul- 

 sive loading. The procedures that follow are appropriate for use with 

 circular, square, or near square (£/d = 2) anchor flukes only. Most 

 flukes in use meet this criterion. The procedures, developed by 

 Douglas (1978), consist of applying various influence factors to the 

 basic equations. These factors have been chosen to yield conservative 

 results, even for the worst conditions. No additional factors of safety 

 are required beyond those recommended for short-term static holding 

 capacity . 



6.1.1 Cohesive Soil 



To determine the impulse holding capacity of an anchor embedded 

 in cohesive soil, the short-term static holding capacity must be deter- 

 mined first. The short-term static capacity is adjusted by the equa- 

 tion: 



F I = F st I R c R I : f (6 " X) 



47 



