The invention relates to the field of building precast
pile foundation construction, and discloses a precast
pile implanting double-control construction method which comprises the following steps that a long spiral drilling
machine is used for drilling a guide hole downwards in the forward direction, the
diameter of the guide hole is 50-150 mm smaller than the designed
pile diameter, and the drilling depth is equal to the value obtained by subtracting the thickness of a reserved bearing layer from the designed pile length; after drilling is stopped, the power head rotates reversely, the long spiral
drill rod lifts the
drill passively, loose soil is returned into the hole and compacted, and a dense wall
protection layer is formed; the
drill rod is jacked by the counter-acting force of the soil body to complete drill lifting, and a hole guiding channel with a compressed soil body structure is formed; then, a precast pile is implanted into the channel, and the double-control requirements of the designed pile length and the penetration / final pressure value are synchronously met; according to the construction method, through forward and reverse rotation operation, under the condition that an original soil layer on the inner side wall of a pile hole is not disturbed, loose soil
back pressure wall protection is achieved, the
soil strength is reduced, the double-control standard is met, the drilling
diameter is small, disturbance of the soil layer on the hole wall is avoided, the thickness of a bearing layer is reserved, the completeness of the bearing layer at the pile end is guaranteed, and the stability and
bearing capacity of a pile foundation are improved.