Construction device and construction method of bored cast-in-place static pressure pipe pile with enlarged bottom

Abstract

A construction device of a bored cast-in-place static pressure pipe pile with an enlarged bottom comprises a static press, wherein a holder for holding the pipe pile is arranged on the static press; a rotary crane and a rotary truss are arranged on the static press on the two sides of the holder respectively; a drilling machine with an output shaft facing downwards is arranged at the top of the rotary truss; the output shaft of the drilling machine is connected with a drilling device arranged vertically; the drilling device comprises a screw casing with a screw blade; the screw casing is internally provided with a drilling core pipe; the screw casing is fixedly connected with the drilling core pipe via a bolt; a tangential air outlet is formed on one side of the bottom of the screw casing; and a telescopic drilling rod mechanism is arranged on the inner side of the bottom of the drilling core pipe. With the adoption of the scheme, the device is reasonable in structural design, simple in construction technology, low in cost and stable in quality; concrete is cast quickly after pile sinking; pile sinking equipment is removed quickly; a construction period is short; the efficiency is high; and the device is also applicable to pile foundation construction of a precast square pile, a precast bamboo joint pile, a precast polygonal pile and the like.

Description

Technical field: [0001] The invention relates to a construction device and a construction method of a borehole expansion bottom grouting static pressure pipe pile. Background technique: [0002] Most of the existing building pile foundations (except wharves and ports) use pipe piles with a diameter of less than 600. If the pipe pile construction encounters a layer with high soil density and hard ground that is difficult to penetrate, in order to avoid damage to the pipe pile, generally more Cast-in-situ piles are used, or diesel hammer hammering machines that pollute the environment are used for construction, and the soil-squeezing effect will cause secondary damage to the foundation of nearby buildings, which limits the scope of use of pipe piles. Due to the high bearing capacity of piles in a large number of super high-rise buildings, the conventional land pile machine pile foundation construction technology cannot solve the construction of large-diameter pipe piles, so la...

AI Technical Summary

Problems solved by technology

[0002] Most of the existing building pile foundations (except wharves and ports) use pipe piles with a diameter of less than 600. If the pipe pile construction encounters a layer with high soil density and hard ground that is difficult to penetrate, in order to avoid damage to the pipe pile, generally more Cast-in-situ piles are used, or diesel hammer hammering machines that pollute the environment are used for construction, and due to the effect of soil extrusion, secondary damage to the foundation of nearby buildings will occur, which limits the scope of use of pipe piles

Due to the high bearing capacity of piles in a large number of super high-rise buildings, the conventional land pile machine pile foundation construction technology cannot solve the construction of large-diameter pipe piles, so large-diameter pipe piles cannot be popularized and used on land. Cast-in-place pile construction technology

During the construction of cast-in-situ piles, large-scale drilling, soil extraction, sewage discharge, on-site tying of steel cages, and on-site pouring of concrete consume a lot of concrete and steel bars, and require a lot of labor. The labor intensity is high, the construction efficiency is low, the cost is high, and the construction period is long. Quality Unstable, the strength of concrete is only half of that of pipe piles, construction acceptance is also difficult to detect, the connection of caps is also complicated, the pile head needs to be broken to damage the pile head concrete structure, and the durability of concrete without prestress is also poor

In recent years, there is also a newly developed construction method of first drilling, bottom reaming, pouring concrete, static drilling and planting pipe piles. Since the rod is lifted after drilling and the wall is protected with mud, when lifting the rod and planting piles, the diameter of the drill hole is slightly larger than that of the pipe pile. The diameter of the pile, when planting the pile, sinks only by the self-weight of the pipe pile, and the inner wall of the hole is easily swayed and collided by the pipe pile itself (the self-heavy pipe pile, the self-weight of a pipe pile is several to ten tons), and the inner wall is caused by soil, gravel, and egg sand. The collapse caused layer separation from the poured concrete at the expanded part of the bottom. There is basically no friction between the pipe pile and the soil hole wall. During construction, it is easily affected by the weight and movement of vehicles and equipment. The pipe pile is easily displaced by extrusion, and the crust, Dislocation slip will occur when the ground moves, resulting in settlement of the pile position

Moreover, the construction period of each pile position is long, and the pipe pile must be placed after the pouring concrete is solidified in the initial setting state for 2 hours, and the pile sinking equipment must be poured into the outer wall of the pipe pile to solidify before removing the pile sinking equipment, otherwise the pipe pile will be biased. The construction is complex and the quality is not stable

This construction method is not suitable for the construction of prefabricated square piles, and has great limitations.

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