Pile sinking method for prestress hollow pipe piles by aid of follow-up sleeve

Abstract

Disclosed is a pile sinking method for prestress hollow pipe piles by the aid of a follow-up sleeve. A round steel pipe sleeve is arranged on a front section of a precast pile, the sleeve and the precast pile are simultaneously pressed into soil by an embracing type pile driver, after the bottom of the round steel pipe sleeve is pressed to the preset depth, the steel sleeve is clamped and fixed on a limiting steel beam, and a pile follower is used for pressing the pile until the elevation of the top of the precast pile reaches to the preset pile following depth. As the round steel pipe sleeve protects the wall of the pile, a pile hole can be protected well for a long time, after vertical pressure-resistant bearing capacity of the precast pile is stable basically, accumulated water and impurities in the hole are discharged, vertical pressure-resistant bearing capacity of the precast pile buried in the soil by the certain depth is obtained accurately via vertical pressure-resistant static load tests, and furthermore, the steel sleeve can be recycled.

Description

[0001] Field [0002] The invention relates to a pile sinking method of a prestressed hollow pipe pile with a moving sleeve, which belongs to the technical field of construction engineering. Background technique [0003] High-strength prestressed hollow pipe pile is the most widely used prefabricated pile at present. Its cost is 30% cheaper than that of bored pile under the same bearing capacity. The single pile bearing capacity of high-strength prestressed hollow pipe pile is even higher than Steel pipe piles. In order to make full use of this feature of high-strength prestressed pipe piles, the most reliable method is to use the vertical compressive static load test to accurately obtain its vertical compressive bearing capacity. [0004] In order to meet the stability requirements of the foundation of high-rise buildings, the depth of foundation embedding is relatively deep. Therefore, in most cases, the design elevation of the prefabricated pile top is more than 3 meters ...

AI Technical Summary

Problems solved by technology

This method needs to first use the pilot hole equipment to pilot the hole, then put the corrugated pipe in, and then use the pile pressing equipment to press the pile. There are many connecting processes before and after, which reduces the construction efficiency and prolongs the construction period.

Moreover, when the soil layer is a water-containing silt, silt and gravel sand layer with good water permeability, it is necessary to leave an allowance of 0.5~1m for the pilot hole at the elevation of the pile top before the test can be carried out, and this allowance for the pilot hole will lead to prefabricated The vertical compressive static load test of tubular piles cannot be carried out. In this case, it can only be used to obtain the approximate parameters required for pile driving, and it is impossible to accurately obtain the vertical compressive bearing capacity of prefabricated piles.

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