Therefore, 



F £ = 0.81[(2.3)(9) + (380)(11)(6)][0.84 + 0.16(0.9/0.9)] 



= 0.81 (20.7 + 25,080)(0.0098) = 17 kN + 199 kN 

 = 216 kN (48,600 lb) 



The short-term holding capacity is the governing static condition 

 since it is less than the long-term static holding capacity. Applying 

 the factor of safety (3) recommended (paragraph 5.1) when properties 

 are not well known, the allowable static load is found to be: 



Allowable static load = 176/3 = 58.7 kN (13,200 lb) 



7.1.6 Impulse Loading Holding Capacity 



The impulse loading holding capacity is determined from 

 Equation 6-1 in paragraph 6.1.1. 



F T = FIR R T I, (6-1) 



I st c I f 



where F = 176 kN (40,600 lb) 

 st 



1=2 from Figure 6-1 for a load duration between 0.01 and 

 0.1 second and a normally consolidated, moderately 

 sensitive clay 



R = 1 (paragraph 6.1.1) 



Rj = 1.33 e" 1,15 f (6-2) 



f = average frequency, impulses per hour, over a 

 4-hour span 



Rj = 1.33 e -l."(0.25) = 1Q 



I = not used because impulse duration >0.01 second 



Therefore , 



F : = 176(2)(1)(1) = 352 kN (79,100 lb) 



64 



