Drill bit for constructing bored piles and construction method using same

Abstract

The invention discloses a drill bit for constructing bored piles and a construction method using the drill bit. The drill bit is provided with a mud scraping assembly and a detachable rib protecting block. The mud scraping assembly comprises a mud scraping plate (8) and installing plates (9), and the installing plates (9) are welded to the circumferential face of the inner circle of a block ring (3). A steel brush (17) is arranged on the outer side of the mud scraping plate (8). The mud scraping plate (8) is hung on the block ring (3) through a first clamping groove (10). An installing part (8.1) of the mud scraping plate (8) is located between the two installing plates (9) of the same set, and the installing part (8.1) of the mud scraping plate (8) and the installing plates (9) on the two sides are fixed in a threaded connection mode. The method is characterized in that in the drilling process, the mud scraping plate (8) is firstly installed on the block ring (3) so that a large hole with the size matched with that of a pile casing can be drilled, then the mud scraping plate (8) is taken down, and the rib protective block is installed so that a small hole with the size matched with the designed size of the bored piles can be drilled. By means of the drill bit and the construction method, sand soil between the pile casing and the pile holes can be effectively removed in a drilling mode.

Description

technical field [0001] The invention relates to the field of pile foundation construction, in particular to a drill bit for constructing bored piles and a construction method using the drill bit. Background technique [0002] Concrete bored piles have become a popular choice for domestic and foreign buildings (structures), especially large buildings (structures) such as bridges, The preferred foundation form for oil tanks, liquefied natural gas tanks, and nuclear power plants. The main construction process of concrete bored piles includes: forming holes, lowering steel cages, and pouring concrete. In the above-mentioned main construction process, hole forming is the key link. During the hole forming process, a three-wing scraper drill bit is usually used to drill into the formation. [0003] Such as figure 1 As shown, the three-wing scraper drill bit of the prior art includes a hollow base rod 101, a drill tip 102, a retaining ring 103, three connecting plates 104 and th...

AI Technical Summary

Problems solved by technology

[0005] However, although sinking into the casing is beneficial for drilling, within the height range of the casing, this part of the sandy soil body between the casing and the pile hole may still collapse, and there is still sediment, which buries the drill bit and drill pipe, and cannot be drilled smoothly. A series of problems such as lowering the reinforcement cage and affecting the quality of the pile body, etc., in order to completely eradicate the above-mentioned disadvantages, someone put forward the technical idea of ​​using drill bits of two sizes, one large and one small, that is, first use the large drill bit to drill the diameter of the casing at the height of the casing. Use a small drill bit to drill a large hole with the same inner diameter as the designed diameter of the bored pile

Yet the actual operability of above-mentioned assumption is not strong, and this is because two kinds of drill bits need to be prepared for each construction, which increases the construction cost, and the drill bit needs to be mentioned outside the hole every time, and then the whole drill bit is removed from the drilling rig. After unscrewing and replacing a new drill bit, the overall weight of the drill bit itself is not light, and it is even heavier after being stuck with mud, which makes the replacement process troublesome and laborious, which is very inconvenient and further delays the work process. Therefore, no matter from the perspective of time cost and economic cost, All gains outweigh the losses

Moreover, there is also a defect in this technical solution. Although the protection of the reinforcement block has avoided the wear of the retaining ring, the constant friction between the reinforcement block and the hole wall soil will also be worn. Once the reinforcement block is worn and scrapped, it can only be Cutting it off and then welding a new reinforcement block is a troublesome and laborious process, and repeated welding will cause great damage to the retaining ring

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