Treatment of common quality problems of hammered sunk pipe rammed and expanded cast-in-place pile
Poor hole quality
Phenomenon :
1) Hammering the sunk pipe cannot reach the design elevation.
2) There is water in the pipe after hammering the sinking pipe or there is water in the pipe after ramming and expanding.
Governance :
1) Reasonably choose construction machinery and pile hammers.
2) During pile group construction, the construction sequence should be arranged reasonably, and the construction sequence should be extended from the inner layer to the outer layer.
3) For piles that cannot reach the design elevation due to the small penetration of the sunk pipe, they can work with the design unit to study and formulate a remedial plan, and adjust the tamping expansion parameters and increase the amount of internal tamping expansion concrete to compensate for the pile length. insufficient.
Phenomena: The elevation of the pile reinforcement cage exceeds the design requirements and specifications.
Governance :
1) After forming the hole, hang the top of the steel cage with iron wire at the hole to prevent it from sliding down.
2) Control the installation height of the steel cage, and use the inner ram tube to press the concrete inside the tube before putting the steel cage.
3) The final charge of the concrete in the outer pipe should be higher than the top of the steel cage by a certain height. One is to reserve a certain margin, and the other is to avoid bending the steel cage with pile hammer.