Larger-diameter bored pile stratum section secondary pore-forming method

Abstract

The invention relates to a deep foundation pore-forming method in civil engineering, in particular to a larger-diameter bored pile stratum section secondary pore-forming method, solving the problems that working efficiency is low, cost is high and influence, such as necking and collapse, is produced to hole wall at a peripheral weak section when the traditional large-diameter impact bit is used for drilling a stratum section. The large-diameter bored pile stratum section secondary pore-forming method comprises the following steps of: a, drilling a center hole at the center of a drill hole by adopting a small-diameter impact bit; b, placing a muck receiving basket at the bottom of the center hole; and c, drilling by adopting a large-diameter impact bit, and taking out the muck receiving basket from the drill hole to empty muck and then placing the muck receiving basket to the bottom of the center hole after the muck receiving basket is filled with drilling muck. By applying the secondary pore-forming method provided by the invention, the working efficiency is greatly improved, energy consumption is reduced while cost is saved, the problem that influence, such as necking and collapse, is produced to the hole wall at a peripheral weak bottom layer during drilling is solved, and the secondary pore-forming method is convenient and efficient to operate.

Description

technical field [0001] The invention relates to a deep foundation hole-forming method for civil engineering, in particular to a secondary hole-forming method for large-diameter bored piles in rock formations. Background technique [0002] Bored cast-in-place piles are a common form of bridge foundations, and the impact drilling mud positive circulation drilling ballast separation process is one of the simplest and easy-to-master methods in the construction of bored cast-in-place piles. It has the characteristics of mature technology, simple construction equipment, and rich experience, and is widely used in engineering circles. [0003] There is a big difference in the distribution of the hardness and softness of the formation in the vertical direction. When encountering a hard rock formation, the percussion drilling speed is significantly reduced, and it is necessary to repeatedly impact to gradually reduce all large-size drill ballast until it can be carried to the ground b...

AI Technical Summary

Problems solved by technology

[0005] In order to solve the problems of low work efficiency and high cost when the existing large-diameter percussion drill bit drills the rock formation section, and the impact of necking and collapse on the hole wall of the surrounding weak section, the present invention provides a large-diameter drilling grouting Secondary Hole Forming Method in Pile Rock Formation Section