Disadvantages:
• Susceptible to "waisting" or "necking" in "squeezing" ground.
• Concrete is not placed under ideal conditions and cannot be subsequently
inspected.
• Water under artesian pressure may pipe up pile shaft washing out cement.
• Enlarged ends cannot be formed in cohesionless materials.
• Cannot be readily extended above ground level especially in river and
marine structures.
• Boring methods may loosen sandy or gravely soils. Sinking piles may cause
loss of ground in cohesionless soils, leading to settlement of adjacent
structures.