The bored piles are such types of pile that are cast on the construction site. Drilling operation is used to remove the soil and rock and concrete is poured with reinforcement bar a into bore hole that was previously done by drilling. For cohesion-less soils the bore hole must be supported by either steel casing or stabilized by reactive clay suspension like bentonite.
In bored pile construction, compaction of concrete is normally depends on the self-compaction of specially designed Concrete. In some unusual cases poker vibrators as compaction device is adopted for the compaction of concrete piles. But in case of long piles an aggregate interlocking may take place due to compaction attempt which create difficulties in casing extraction.
In the most horrible situation, the temporary casings together with reinforcement cages are extracted during the lifting up of pile casings. So in case piles with casing extraction no vibrating machines are used.