This represents a "deep" anchor, 

 (c) Using Equation 4: 



F^ = A (cN + Y^ D) (0.84 + .16 B/L) 



T CD 



F = 9 [2(9) (144) + 35(15)] [ 0.84 + .16 (|)] 

 F = 28,000 pounds 



This is the estimated short-term holding capacity. 



4. The load is to be applied for several years and apparently the 

 loading will be relatively constant. Therefore, this is a case of 

 long-term static loading. 



5. (a) No triaxial tests were performed. Therefore the drained 

 friction angle (}> is estimated conservatively to be 25 j_ 



(b) Using Figure 4 with (f) = 25 and D/B = 5, N is found to be 

 4.5 ^ 



(c) Using Equation 6: 



F^^ = A Y^DN (0.84 + 0.16 B/L) 

 ID b q 



F = 9 [35(15) 4.5 ] [0.84 + 0.16 (|) ] 



"TD 



F = 21,262 pounds 

 TD 



This is the estimated long-term static holding capacity. 



(d) The long-term holding capacity is found to be less than the 

 short-term capacity. Therefore the long-term case is critical and should 

 be used in design. The estimated holding capacity for design purposes 

 is then about 21,000 pounds. If the structure were especially critical 

 or manned, this quantity would be multiplied by 0.6 to account for 

 possible creep effects. 



SUMMARY AND CONCLUSIONS 



1. The state-of-the-art of predicting direct embedment anchor 

 holding capacity is inexact at present. This report was written to 

 maximize the usefulness of existing related research so that immediate 

 use predictions can be made. The predictions given are not intended 

 to be final but rather a "best guess" given the present state of tech- 

 nology. 



2. It is important to subdivide the problem of predicting embedment 

 anchor holding capacities into several areas because the same anchor 



may produce significantly different capacities under different loading 

 and soil conditions. Two general soil types, cohesive and cohesionless, 

 and three loading conditions, short-term, long-term static, and long- 

 term repeated, were selected for investigation. Dynamic loading and 



17 



