Reducing screw displacement pile drilling tool and construction method thereof

Abstract

The invention discloses a reducing screw displacement pile drilling tool and a construction method. The drilling tool comprises a hollow inner drill stem; the inner drill stem is a cylinder on the outer wall of which external threads are formed; a displacement body with internal threads is connected to the outside of the inner drill stem by use of the threads; the displacement body is a spindle body which is thin in two ends and thick in middle part. A method for carrying out construction by using the drilling tool comprises the following steps: the power head of an in-position drilling machine rotates forward and the displacement body reaches a first supporting course depth; the inner drill stem continue drilling downwards until a screw drill bit reaches in a second supporting course position; the power head rotates backwards, concrete is poured, the drilling tool is lifted, and then the screw pile body is formed; when the screw drill bit goes up to the first supporting course position, the power head rotates forwards and concrete is poured continuously, and the displacement body rotates and is lifted so that the cylindrical pile is formed; the drilling tool is pulled out and then the pile body is formed.

Description

technical field

[0001] The invention belongs to the technical field of cast-in-place pile construction for construction engineering, railways, highways and bridges, and in particular relates to a drilling tool for a screw-squeezing soil variable-diameter pile and a construction method. Background technique

[0002] With the rapid development of the economy, buildings are gradually developing towards high-rise, large-span and large-area directions. The loads of buildings and structures are increasing. Most of the natural foundations cannot meet the requirements of building loads. It is widely used in the basic system of engineering buildings and structures.

[0003] Most of the existing cast-in-situ pile constructions follow the traditional technology, adopting the construction technology of mud retaining wall forming holes.

[0004] In the traditional construction technology, the mechanical equipment used in the construction of cast-in-place piles is mainly rotary drilling ...

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