Method for treating excessively thick sediment at bottom of long and large pile foundation and pile body concrete interlayer or looseness

The invention discloses a method for treating excessively thick sediment at the bottom of a long and large pile foundation and a pile body concrete interlayer or looseness, and relates to the field of pile foundation construction. The method is mainly for solving the problem that at present, the effect of treating unqualified drilled piles is poor. Pile bottom concrete is verified through core drilling and sampling, high-pressure clear water is provided through a high-pressure grouting pump to conduct high-pressure cutting on defect sections of all holes, and three coring holes communicate with one another after being cut; large-displacement clear water is injected into the coring holes, the first coring hole and the second coring hole are opened, the third coring hole is sealed, the high-pressure water is injected into the first coring hole, and the water is discharged from the second coring hole to bring out sediment and impurities at the bottom; and the second coring hole is sealed, the third coring hole i