All ow able Pil e/Pier Ax ial L oad Capac ity : Pc = 81.74 kips Pc = Qs/3 + Qb/3 - W Pt = 106.24 kips Pt = Qt/3 + W Note: F.S. = 3.0 for skin friction Formulas: Note: F.S. = 3.0 for tension (uplift)
20 10 t f 0 , n o i t 10 a v e l E 20
‐
Qs =4*Wp*fs*h Qb = NA Qc = Qs + Qb Qt = 4*W 4*Wp* p*fs fs*h *h*R *R + W
Qs = ultimate pile skin friction capacity Qb = ultimate pile end bearing capacity Qc = ultimate pile capacity in compression Qt = ult ultim imat ate e pil pile e cap capac acit ity y in in ten tensi sion on (upl (uplif ift) t)
‐
Compression
‐30
Tension
‐40
where for cohesive soils: fs = *cu = 0.5 = cu/'
if <1.0, <1.0, 0.5
‐50
fs = ultimate skin friction
0
-0.25
if >1.0
100
200
3 00
qeb = NA
qeb = ultimate end bearing pressure
where for cohesionless soils: fs = ' *K*TAN() qeb = NA
fs = ultimate skin friction, where ' = effective overburden pressure taken to midpoint of segment qeb = ultimate end bearing pressure, where = overburden pressure taken to bottom of pile/pier
Reference:
400
500
Ultimate Axial Capacity of Pile, of Pile, kips
American Petroleum Petroleum Insitute Insitute Recommended Practice forPlanning, Designing and Constructing Fixed Offshore Platforms—WorkingStress Design API RECOMMEN RECOMMENDED DED PRACTICE PRACTICE 2A-WSD (RP 2A-WSD)TWENTY-FIRST 2A-WSD)TWENTY-FIRST EDITION, EDITION, DECEMBER DECEMBER 2000 2000
