Pile foundation is widely used deep foundation for complex geologic conditions with kinds of load conditions, especially for soft soil foundation. Pile foundation has large bearing capacity, well stability and small differential settlement compared to other foundation types. But pile foundations may also get damaged and fail specially during earthquakes.
Fig: Pile foundation failure
The failure of the pile foundation may result from any of the following causes:
- Lack of adequate boring
- Inaccurate soil classification
- Soft strata under tip of pile
- Inadequate driving formula (wrong data)
- Improper size of hammer cause insufficient penetration, too light or damaged if too heavy
- Misinterpretation of load
- Damaged of encased piles
- Buckling of piles
- Breaking of piles
- Vibration that cause lateral or vertical movement
- Flowing strata caused by adjacent excavation or bank sloughing
- Tension failure of concrete pile for lack of reinforcement
- Eccentricity due to bowing or falling out of plumb
- Decay due to lower ground water level
- Insect and marine borer attack and corrosion
- Disintegration of concrete due to poor quality of concrete or reactive aggregate
- Collapse of the thin shell of the piles
- Overweight due to earthfill.
Remedies to prevent failure of pile foundation:
- Early repair such as encasement or replacement
- Removal of partial load
- Underpinning