Construction method of long auger drilling guncreting expanded bore pile

Abstract

The invention relates to a construction method of a long auger drilling guncreting expanded bore pile, and belongs to the technical field of pile foundation construction. The construction method comprises the following steps that S1, a straight hole is drilled; S2, a bottom expansion drill bit carries out expansion construction on an expansion head at the pile end; S3, concrete is poured into a pile hole through drill rods and the bottom expansion drill bit in a pressure manner, after pouring of a bottom expansion hole part is completed, the bottom expansion drill bit shifts up and down, and concrete on the bottom expansion hole part is stirred again; S4, the bottom expansion drill bit is closed, a drill is lifted up, and concrete is poured into the pile hole continuously in a pressure manner till the drill is lifted to the ground; S5, a vibrator is used for placing a reinforcement cage into the pile hole; and S6, after pile forming, maintaining is carried out, and checking is carriedout. The construction method has the effects that construction is convenient, stability between the expanded bore pile and soil is enhanced, and the bearing capacity of the expanded bore pile is guaranteed.

Description

technical field [0001] The invention relates to the technical field of pile foundation construction, in particular to a construction method for a long auger drilled press-grown concrete bottom expansion pile. Background technique [0002] At present, the expanded bottom pile is a cast-in-situ pile whose bottom diameter is greater than the upper pile body diameter. The bearing capacity of a single pile is much higher than that of a straight pile with the same diameter of the pile body. The construction process is generally as follows: S1: Hole forming, using the drill bit to drill vertically; S2: Bottom expansion, after the hole reaches the design elevation, lift the drill bit, replace the reaming bit, and put the reaming bit into the bottom of the hole , to drive the reaming drill bit to expand, the drill pipe to rotate, and the drill bit to cut the hole wall until the designed hole diameter; S3: Clear the hole, discharge the sediment in the hole; S4: Form a pile, first pou...

AI Technical Summary

Problems solved by technology

[0013] The above existing technical solutions have the following defects: during the drilling process of the helical blade, the soil generated in the hole will be discharged out of the pile hole along with the guidance of the helical blade, but during the drilling construction process of the bottom hole, The soil dropped from the wall of the reamed hole will be outside the spiral blade, and part of the soil cannot be discharged out of the hole with the helical blade, so that the soil will fall on the bottom wall of the reamed hole. One way is to pull the drill pipe out of the pile hole Finally, the pumping method is used to remove the dregs at the bottom of the hole; however, the salary of the existing construction personnel is generally settled according to the amount of the pile foundation, and because the auger drill pipe is used to remove most of the soil, there are most construction personnel , when the auger drill pipe is used for construction, it will not waste time to use the pumping method alone to clean the bottom of the hole; in turn, in the process of subsequent pipe pile construction, there is a soft soil layer between the bottom of the pile foundation and the bottom expansion hole, which reduces the expansion. The stable connection between the bottom pile and the soil will affect the bearing capacity of the bottom pile to a certain extent

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