Construction process of large-diameter lock-catch steel pipe pile entering rock

Abstract

The invention discloses a construction process of a large-diameter lock-catch steel pipe pile entering rock. The construction process comprises the following steps: hole pre-forming is conducted through a rotary-drill; the steel pipe pile is prepared; the steel pipe pile is sunk to be 30 cm above the rock surface; soil in a pile core is drawn out through the rotary-drill; a down-the-hole hammer enters the rock by 3 m; after the soil in the pile core is drawn out through the rotary-drill, a hammerhead is slowly put into the pile core through a drill rod, the down-the-hole hammer is reversely rotated in the pile firstly, a remaining loose soil layer in a pipe is blown, after the hammerhead makes contact with a hoop in the pile and makes a crisp sound, the hammer is rotated forwards to open wing fins, at the moment, 4-5 air compressors are all started, the air pressure is not smaller than 1.4 Mpa, and the rotating speed is 3-4 r / min; and the steel pipe pile synchronously follows during drilling of the hammerhead, when the shape of blown-out slag is changed from yellow sludge into grey rock powder and the sinking speed is obviously decreased, the elevation of the steel pipe pile entering into a rock roof is recorded, and construction is stopped till the down-the-hole hammer enters the rock by 3 m. The problem that the hole diameter of a formed hole is larger than the pile diameteris solved, the steel pipe pile can autonomously follow along with the down-the-hole hammer, the entering-rock speed is high, and the situations of drilled hole collapse and repeated crushing are avoided.

Description

technical field [0001] The invention relates to a rock-entrying construction technology of steel pipe piles, in particular to a rock-entry construction technology of large-diameter locking steel pipe piles. Background technique [0002] There are two main domestic conventional construction methods for locking steel pipe piles into rock on such a high-strength rock foundation. One is to use the traditional percussion drill punching method, but the hole diameter after punching is smaller than the pile diameter and cannot be vibrated. Steel pipe piles; the second is the pre-hole drilling method of rotary drilling. The effect of rotary drilling in the rock formation is very slow. It takes 20 hours to penetrate 3m into the rock, and there is a lot of uncertainty. After drilling in the rock formation, it is necessary to use reaming The drill bit reams the hole again, which cannot meet the progress requirements, and the consumption of the cones is large, and the cost is huge. . ...

AI Technical Summary

Problems solved by technology

[0002] There are two main domestic conventional construction methods for locking steel pipe piles into rock on such a high-strength rock foundation. One is to use the traditional percussion drill punching method, but the hole diameter after punching is smaller than the pile diameter and cannot be vibrated. Steel pipe piles; the second is the pre-hole drilling method of rotary drilling. The effect of rotary drilling in the rock formation is very slow. It takes 20 hours to penetrate 3m into the rock, and there is a lot of uncertainty. After drilling in the rock formation, it is necessary to use reaming The drill bit reams the hole again, which cannot meet the progress requirements, and the consumption of the cones is large, and the cost is huge

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