Large-diameter super-long bored pile construction method for steep dip stratified rock mass with alternative smashed parts and integral parts

Abstract

The invention discloses a large-diameter super-long bored pile construction method for steep dip stratified rock mass with alternative smashed parts and integral parts. The method mainly includes the steps that firstly, a construction platform is reinforced; secondly, the periphery of a steel protection cylinder is reinforced; thirdly, surveying and sampling are conducted; fourthly, a smashed zone is reinforced; fifthly, the bottom is expanded through explosions; sixthly, drilling is conducted; seventhly, rotatable head-expanded reinforcing steel bars are placed; eighthly, a reinforcement cage is placed; and ninthly, concrete is poured. The smashed zone is reinforced in advance so that hole collapse and hole shift can be prevented, drill bit replacement is avoided by expanding the bottom in advance, and therefore the construction efficiency is greatly improved. The large-diameter super-long bored pile construction method has the beneficial effects of being high in construction speed and good in construction effect and is obvious in technical and economical benefit.

Description

technical field [0001] The invention relates to a large-diameter and super-long bored pile, in particular to the construction of a large-diameter and super-long bored pile in a steeply inclined layered rock mass alternately broken and complete. Background technique [0002] Under the conditions of broken and complete steeply inclined layered rock mass, the construction of large-diameter and super-long bored piles is on the inclined rock surface, and there is often a high water level. Most of the rock mass is located below the water level, and the construction platform is difficult to erect. The lower part of the pile passes through the floating mud layer, which may easily cause the platform to be unstable, and the hardness of each layer of rock mass is different, and the drilling accuracy is difficult to control. [0003] In the construction of traditional large-diameter super-long bored piles, the mud retaining wall is used to drill the hole, which takes a long time to dril...

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Problems solved by technology

[0002] Under the conditions of broken and complete steeply inclined layered rock mass, the construction of large-diameter and super-long bored piles is on the inclined rock surface, and there is often a high water level. Most of the rock mass is located below the water level, and the construction platform is difficult to erect. The lower part of the pile passes through the floating mud layer, which may easily cause the platform to be unstable, and the hardness of each layer of rock mass is different, and the drilling accuracy is difficult to control

[0003] In the construction of traditional large-diameter super-long bored piles, the mud retaining wall is used to drill the hole, which takes a long time to drill the hole, and the stress relaxation of the hole wall will inevitably occur, resulting in collapse of the hole; in the process of pile formation, it is often necessary to set the pile end expansion In order to improve the bearing capacity of the pile body, the setting of the enlarged head at the pile end needs to form an enlarged space at the bottom of the pile in advance during the drilling process. The traditional method is to replace it with a bottom-expanding drill bit for excavation. This measure will inevitably increase the drilling time and construction The period becomes longer, and it will lead to an increase in the standing time of the hole wall, which will affect the stability of the hole wall and greatly increase the risk of hole collapse; there is no simple and effective method for setting the reinforcement as the pile end expansion head; the broken zone and the complete phase are steep Under the geological conditions of inclined rock mass, weak layers and hard layers are distributed alternately, and the rock mass is steeply inclined. When the drill bit enters the complete rock mass zone from the broken zone, the resistance of the broken zone is weak and the rock mass has strong resistance. During the hole feeding process, due to the unbalanced force, the cross section of the drill bit perpendicular to its vertical axis changes from horizontal to inclined, causing the drilling to deviate

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