Construction method of geological pile punching hole with expansion soil layer

Abstract

The invention discloses a construction method of a geological pile punching hole with an expansion soil layer. The expansion soil layer fully absorbs water in a pile hole before punching, and expansion soil fully absorbs the water for expansion to prevent the hole shrinkage phenomenon; the hole expansion is performed after shallow-stroke punching to guarantee no hole shrinkage phenomenon after completion of a pulping protection wall after the hole expansion; and the pulping protection wall is constructed after the hole expansion is finished to prevent the hole shrinkage phenomenon, so that theexpansion soil layer cannot infiltrate a pile entity in subsequent casting to prevent a residual pile.

Description

technical field [0001] The invention relates to the technical field of pile hole punching, in particular to a construction method for geological pile hole punching with expansive soil layer. Background technique [0002] The mineral composition of expansive soil is mainly montmorillonite, which is a kind of highly plastic clay with high bearing capacity in general. Extremely unstable. It often causes uneven vertical or horizontal expansion and contraction deformation of buildings, causing displacement, cracking, tilting and even destruction, and often occurs in groups. [0003] Since the percussion drilling method uses mud to protect the wall, there will be a certain amount of water in the pile hole. In view of the characteristics of expansive soil that expands with water and shrinks when it loses water, the following three situations often occur during the pile hole punching process: 1) After the impact hammer enters the expansive soil layer, due to the impact force of th...

AI Technical Summary

Problems solved by technology

[0003] Since the percussion drilling method uses mud to protect the wall, there will be a certain amount of water in the pile hole. In view of the characteristics of expansive soil that expands with water and shrinks when it loses water, the following three situations often occur during the pile hole punching process: 1) After the impact hammer enters the expansive soil layer, due to the impact force of the impact hammer, the impact hammer will enter the expansive soil layer. When the expansive soil layer is deep, the expansive soil above the impact hammer will expand after being exposed to water, resulting in pile holes that have been punched in the upper part. Shrinkage cavity phenomenon will appear when the hole diameter becomes smaller, and the impact hammer cannot be lifted out of the expansive soil layer, and the hammer phenomenon will occur; 2) Even if the impact hammer is forcibly lifted out, when the hole is cleaned and the reinforcement cage is lowered, due to the shrinkage cavity in the pile hole, Reinforcement cages cannot be placed at the designed bottom mark height

3) Even if the reinforcement cage is put into the pile hole by hole reaming, shrinkage cavities will appear in the pile hole after the hole is cleared (usually about 2 days), and the expansive soil will occupy part of the pile entity, and the concrete of the poured pile will decrease. , leading directly to the stump