Drilled Shaft Defects: Load Tests

Effects on Skin Friction

  • Skin friction dominated capacity
  • Defects appear to have a small effect on capacity, but further research is needed.
  • Reloading resulted in 30% reduction in capacity, possibly due to (1) Breakage of Cementation (2) Remolding of Clay, or (3) Structural Defects.

 Effects on End Bearing

  • Soft bottom resulted in 33% reduction in capacity relative to undisturbed soil
  • Reloading resulted in 20% reduction in capacity relative to undisturbed soil

 

 

 

 

 

 

 

Although undocumented differences in construction may have affected the results, the data suggests:

Load Test — Shaft 2

Load Test — Shaft 4

Load Test — Shaft 4-Reload