Results in over estimation of F and under estimation 

 of F^ by up to 25%. '^ 



Sand 



cb 



^^b^ 



d, = characteristic chain 

 or wire diameter (for 

 chain use 3 x chain size) 



Soil Friction 



Angle 



Clay 



F , = 11 s d, z 

 cb u D c 



s = soil undrained shear 

 strength 



Force components at the anchor given by: 



F = P - F 

 'h *^h *cb 



20 



3 



25 



5 



30 



8 



35 



12 



40 



22 



= 1^ 





b. Refined Analysis 



- Refer to Reese 1973 and Gault and Cox 1974. 



2. Lateral Pile Capacity 



- Depends on soil strength, stiffness, load type, pile 

 dimensions and stiffness 



- Rigid and long (semi-rigid) pile analyses are possible 



Rigid Pile Analysis . Assumes soil failure occurs as an infinitely 

 rigid pile rotates about a point on its length. 



Procedure is very conservative; results in pile with minimum deflec- 

 tion at head; can be used for preliminary pile selection for long 

 pile analysis, (Refer to Czerniak 1957). 



Long Pile Analysis 



- Many procedures available (Refer to Gill 1970, Matlock 1970, 

 Reese 1974, Broms 1964) 



- Procedures are labor intensive; generally have been computerized 



- Procedures rely on a pile/soil interaction analysis where pile/ 

 soil deflection characteristics are needed 



- Procedures rely on establishment of load-deflection (P-Y) 

 curves for soil, typically based on test experience. 



3. Pile Axial Capacity 



Capacity treated as function of shear along the pile/soil inter- 

 face. Both cohesive and cohesionless soils can be treated as 

 frictional materials. 



36 



