CN114016499A

CN114016499A - Long spiral drill hole pressure-cast concrete pile and construction method and construction device thereof

Info

Publication number: CN114016499A
Application number: CN202111501551.2A
Authority: CN
Inventors: 刘录怀
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-12-09
Filing date: 2021-12-09
Publication date: 2022-02-08

Abstract

The invention discloses a long spiral drill hole pressure-cast concrete pile and a construction method and a construction device thereof, belonging to the technical field of civil engineering. The long spiral drill hole pressure-cast concrete pile comprises a pile body and a reinforcement cage therein, wherein the pile body is provided with a plurality of diameter expansion bodies; the invention also discloses a construction device and a construction method of the concrete pile, wherein the construction device utilizes the high-pressure water pipes laid on the drill rod, the soil extruder and the drill bit to carry out transverse expanding. The invention is suitable for various pile foundation construction projects, in particular for occasions where the bearing capacity of the pile foundation cannot meet the building requirements due to the limitation of the diameter and the depth of a mechanical hole.

Description

Long spiral drill hole pressure-cast concrete pile and construction method and construction device thereof

Technical Field

The invention belongs to the technical field of civil engineering, and particularly relates to a long spiral bored concrete pile and a construction method and a construction device thereof.

Background

With the continuous research and development and application of pile foundation construction technology, the process of long spiral drilling and concrete pile press-casting is more and more widely popularized and applied.

The traditional device for constructing the long spiral drilling pressure filling pile is a drill rod and comprises a hollow core pipe and a valve, wherein the valve is a cone-tip body, spiral blades are arranged on the outer circumferential surface of the core pipe, and the lower end of the core pipe is connected with the valve. The valve of the cone tip body, a section of core pipe at the lowermost end and a circle of helical blade at the lowermost part form a drill bit. When the drill bit drills downwards, the valve seals the core pipe, when concrete needs to be poured, the upper end of the core pipe is communicated with a concrete pump, the concrete is poured into the core pipe, and under the pressure of the concrete, the valve does not seal the core pipe any more, so that a discharge hole of the concrete is formed. The long spiral is a commonly used name in the industry, and essentially means that all the spiral blades are arranged on the outer circumferential surface of the core tube of the drill rod from top to bottom.

The traditional construction method of the long spiral drilling pressure-grouting pile comprises the following steps: the drilling rod drills downwards at a preset pile position, in the drilling process, the drilled soil body is extruded out from the top of the hole along with the rotation of the helical blade of the drilling rod, the drilling is continued until the drill bit reaches the elevation of the bottom of the hole, then the concrete is poured into the hole through the core pipe, the drilling rod is lifted while the concrete is continuously poured from bottom to top until the concrete is poured to a certain height above the pile top, namely the pile top is over-poured, and finally the steel reinforcement cage of the pile body is sunk into the concrete of the pile body through the vibrating rod. The traditional construction method has the following defects: when the drill bit drills, most soil in the hole is drilled, but a small amount of residual soil and slag are still remained at the bottom of the hole, so that the bearing capacity of the pile foundation is insufficient. And more importantly, the bearing capacity of the pile foundation cannot be further improved due to the limitation of the diameter and the depth of a mechanical hole.

In order to further improve the bearing capacity of the pile foundation, it is proposed to provide a grouting pipe connected to an external high-pressure grouting pump inside the core pipe, the grouting pipe extending from the inside of the core pipe at a position close to the valve. In the pile foundation construction, when the drill bit reaches the pile foundation design depth soon, open the high-pressure grouting pump, adopt the mode of jet grouting to expand the end, the last circular platform body pile end that forms the pile bottom and be big end down expands the diameter body. However, the above construction method still has major disadvantages: firstly, the grouting pipe is arranged in the core pipe, and the maintenance is difficult if the grouting pipe is blocked or broken; secondly, high-pressure cement slurry is needed to expand the bottom, so that blockage is easy to generate, the requirement on hardware equipment is too high, and the cost is higher; thirdly, the method uses high-pressure cement slurry for expanding the diameter, and because the rapid setting characteristic of the cement can only expand the diameter at the bottom of the pile foundation but cannot expand the diameter at the middle part of the pile body, only the diameter expanding body is generated at the bottom of the pile body, and the increased bearing capacity of the pile foundation is limited.

Disclosure of Invention

The invention aims to solve the problems, and provides a long spiral drill hole pressure-cast concrete pile, a construction method and a construction device thereof.

The invention provides a construction device for a long spiral drill hole pressure-cast concrete pile, which is characterized by sequentially comprising a drill rod, an earth extruder and a drill bit from top to bottom, wherein the drill rod and the drill bit are uniform hollow cylinders, the earth extruder is a hollow cone with a large upper part and a small lower part, continuous helical blades are arranged on the outer circumferences of the drill rod, the earth extruder and the drill bit, the diameter of the large end of the earth extruder is larger than that of the drill rod and smaller than that of the outer edge of the helical blades, the diameter of the small end of the earth extruder is the same as that of the drill bit, a conical valve is arranged at the lower end of the drill bit, and the conical valve is hinged with the lower end of the drill bit.

Furthermore, a plurality of groups of high-pressure water pipes which are as long as the drill rod, the soil extruder and the drill bit and are mutually connected are laid on the outer walls of the drill rod, the soil extruder and the drill bit from top to bottom, and a nozzle for spraying high-pressure water along the radial direction of the drill bit is arranged at the position, which does not exceed the conical valve, of the lowest end of each high-pressure water pipe.

Furthermore, a plurality of gaps are arranged on the outer edge of the spiral blade at equal intervals.

Further, the drill rod is formed by splicing a plurality of sections.

Furthermore, the drill rods and the drill rods are connected with the soil extruder and the drill bit through flange plates.

Furthermore, all the sections of the high-pressure water pipe are connected by joints.

In another aspect of the present invention, there is provided a construction method using the above construction apparatus, the construction method comprising the steps of:

firstly, placing a construction device at a preset pile position, and drilling a hole from top to bottom;

when the lower end of the drill bit reaches the designed height of the top of the expansion head, a high-pressure water pump is started, and high-pressure water is sprayed outwards from a nozzle through a high-pressure water pipe;

thirdly, drilling holes downwards, and spraying high-pressure water to the inner wall of the pile hole through a nozzle to form an expanded head;

fourthly, continuously drilling downwards, forming a plurality of expanded heads in the soil body by using the third method until the lower end of the drill bit reaches the designed drilling depth, and forming the expanded heads at the bottom by using the third method;

stopping drilling, starting a concrete pump, and pouring concrete into the hole bottom by high-pressure concrete through a conical valve which is opened at the top of a hollow core pipe of a drill rod, a soil extruder and a drill bit;

sixthly, continuously rotating and lifting the drill rod according to the rotating direction when the drill bit drills down, and pouring concrete into the pile hole from bottom to top until the concrete is poured to the pile top;

and seventhly, sinking the reinforcement cage into the poured concrete by using a vibrating rod.

The invention further provides a long spiral bored concrete pile, which comprises a concrete pile body, wherein a reinforcement cage is arranged inside the concrete pile body, and a plurality of diameter expansion bodies are arranged on the concrete pile body.

Compared with the prior art, the invention has the outstanding effects that: firstly, the high-pressure water pipe is arranged outside the drill rod, the soil extruder and the drill bit, so that the inspection, the maintenance and the replacement are convenient; secondly, the pile foundation is expanded by using high-pressure water, on one hand, equipment is simple, the cost is low, on the other hand, the diameter expansion operation can be carried out in the middle of the pile body, the diameter expansion operation is not limited to the diameter expansion only at the bottom in the prior art, and the bearing capacity of the pile foundation is greatly increased under the condition of the same geological condition and drilling depth; and thirdly, the soil extruder is used, so that in the process of drilling downwards, the soil body collapsed in the pile hole is extruded into the side wall of the pile hole by the soil extruder, and in the process of drilling upwards, the soil fragments which are not extruded into the side wall in the pile hole are scraped out of the pile hole by the soil extruder.

Drawings

FIG. 1 is a schematic view showing the construction apparatus according to the present invention;

fig. 2 is a schematic structural view of a concrete pile of the present invention;

in the figure: 1. a drill stem; 2. a soil extruder; 3. a drill bit; 4. a helical blade; 5. a conical valve; 6. a high pressure water pipe; 7. a nozzle; 8. opening the gap; 9. a flange plate; 10. a joint; 11. a head is expanded; 12. a reinforcement cage; 13. a pile body; 14. a diameter-expanding body.

Detailed Description

Embodiments of the present invention are further described below with reference to the accompanying drawings.

As shown in fig. 1, the embodiment of the construction device for long auger bored concrete pile press-filling in the invention sequentially comprises a drill rod 1, an earth extruder 2 and a drill bit 3 from top to bottom, wherein the drill rod 1 and the drill bit 3 are uniform hollow cylinders, the earth extruder 2 is a hollow cone with a large upper part and a small lower part, continuous helical blades 4 are arranged on the outer circumferences of the drill rod 1, the earth extruder 2 and the drill bit 3, the diameter of the large end of the earth extruder 2 is larger than that of the drill rod 1 and smaller than that of the outer edge of the helical blades 4, the diameter of the small end of the earth extruder 2 is the same as that of the drill bit 3, a conical valve 5 is arranged at the lower end of the drill bit 3, and the conical valve 5 is hinged with the lower end of the drill bit 3.

And 1 group of high-pressure water pipes 6 which are as long as the drill rod 1, the soil extruder 2 and the drill bit 3 and are mutually connected are laid on the outer walls of the drill rod 1, the soil extruder 2 and the drill bit 3 from top to bottom, and a nozzle 7 for spraying high-pressure water along the radial direction of the drill bit 3 is arranged at the lowest end of the high-pressure water pipes 6 and does not exceed the conical valve 5. The outer edge of the helical blade 4 is provided with 4 groups of openings 8 at equal intervals, and the drill rod 1 consists of 1 section. The drill rod 1, the drill rod 1 and the soil extruder 2 are connected through a flange 9, and the soil extruder 2 and the drill bit 3 are connected through a flange 9. The sections of the high-pressure water pipe 6 are connected by joints 10.

When the construction device is used for drilling, the construction device is arranged at a preset pile position to drill holes from top to bottom, in the drilling process, a part of drilled and crushed soil is squeezed into the side wall of a pile hole by the soil squeezer 2, and a part of drilled and crushed soil is discharged from a top hole along with the rotating spiral blade 4.

When the lower end of the drill bit 3 reaches the designed height of the top of the enlarged head 11, the high-pressure water pump is started. The high-pressure water pipe 6 is connected to the high-pressure water pump at the upper end of the drill rod via a high-strength leak-proof rotary joint device disclosed in the prior art CN209430126U document, whereby high-pressure water can be injected while rotating the drill. High-pressure water is sprayed outwards from the nozzle 7 through the high-pressure water pipe 6, and the soil body of the pile foundation is cut and crushed by the powerful high-pressure water column. The participation of high pressure water will be more conducive to rapid drilling if hard geological formations are encountered.

While drilling downward, the nozzle 7 sprays high-pressure water to the inner wall of the pile hole to form an enlarged head 11, and the shape of the enlarged head 11 can be changed by adjusting the pressure of the high-pressure water and the drilling speed, and the enlarged head is preferably in a truncated cone shape with a small top and a large bottom. Continuing to drill downwards, forming 1 enlarged head 11 in the soil body by using the method until the lower end of the drill bit 3 reaches the designed drilling depth, and forming the last enlarged head 11 at the bottom by using the same method;

and stopping drilling, starting a concrete pump, and pouring concrete into the hole bottom from the high-pressure concrete through the hollow core pipe top-opening conical valve 5 of the drill rod 1, the soil extruder 2 and the drill bit 3. And (3) continuously rotating and lifting the drill rod 1 according to the rotating direction of the drill bit during the downward drilling, and pouring concrete into the pile hole from bottom to top. Since the specific gravity of the concrete is greater than that of the crushed soil generated by drilling, the crushed soil floats on the concrete. Thus, during the lifting process of the drill rod 1, as the concrete liquid level rises, the broken soil is discharged from the top hole along with the rotating spiral blade 4, and in addition, the broken soil is scraped out of the pile hole by the inverted cone shape of the soil extruder 2. Thus, the drill rod 1 is lifted up while concrete is poured until the concrete is poured to the top of the pile. Finally, the reinforcement cage 12 is immersed into the poured concrete by a vibrating spear.

As shown in fig. 2, the embodiment of the long auger bored concrete pile of the present invention includes a concrete pile body 13, a reinforcement cage 12 is provided inside the concrete pile body 13, and three reducing bodies 14 including a bottommost reducing body 14 are provided on the concrete pile body 13.

The embodiment of the present invention is described only for the preferred embodiment of the present invention, and not for the limitation of the concept and scope of the present invention, and the technical solution of the present invention should be modified and improved by those skilled in the art without departing from the design concept of the present invention.

Claims

1. The utility model provides a construction equipment of long auger drilling pressure concrete pile, its characterized in that includes drilling rod (1), crowded native ware (2) and drill bit (3) from top to bottom in proper order, drilling rod (1) and drill bit (3) are even cavity cylinder, crowded native ware (2) are big-end-up's cavity circular cone, are provided with continuous helical blade (4) on drilling rod (1), crowded native ware (2) and drill bit (3) outer circumference, and crowded native ware (2) main aspects diameter is greater than the diameter of drilling rod (1) and is less than the outer fringe diameter of helical blade (4), and crowded native ware (2) small ends diameter is the same with the diameter of drill bit (3), and drill bit (3) lower extreme is provided with toper valve (5), toper valve (5) are articulated with drill bit (3) lower extreme.

2. The construction device according to claim 1, characterized in that a plurality of groups of mutually connected high-pressure water pipes (6) with the same length as the drill rod (1), the soil extruder (2) and the drill bit (3) are laid on the outer walls of the drill rod (1), the soil extruder (2) and the drill bit (3) from top to bottom, and a nozzle (7) for spraying high-pressure water along the radial direction of the drill bit (3) is arranged at the lowest end of the high-pressure water pipes (6) and does not exceed the conical valve (5).

3. Construction device according to claim 2, wherein the helical blades (4) are provided with notches (8) at regular intervals on the outer edge.

4. Construction device according to claim 2, wherein the drill rod (1) consists of several segments spliced together.

5. The construction device according to claim 4, wherein the sections of the drill rod (1), the drill rod (1) and the soil extruder (2), and the soil extruder (2) and the drill bit (3) are connected through a flange (9).

6. Construction equipment according to claim 2 or 4, characterized in that the sections of the high-pressure water pipe (6) are connected by joints (10).

7. A construction method using the construction apparatus according to claim 2, characterized in that the construction steps are as follows:

secondly, when the lower end of the drill bit (3) reaches the designed height of the top of the expansion head (11), a high-pressure water pump is started, and high-pressure water is sprayed outwards from the nozzle (7) through a high-pressure water pipe (6);

thirdly, drilling downwards, and spraying high-pressure water to the inner wall of the pile hole through a nozzle (7) to form an expanded head (11);

fourthly, continuously drilling downwards, forming a plurality of expanded heads (11) in the soil body by using the third step until the lower end of the drill bit (3) reaches the designed drilling depth, and forming the expanded heads (11) at the bottom by using the third step;

stopping drilling, starting a concrete pump, and pouring concrete into the hole bottom from the high-pressure concrete through a conical valve (5) which is opened at the top of a hollow core pipe of the drill rod (1), the soil extruder (2) and the drill bit (3);

sixthly, continuously rotating and lifting the drill rod (1) according to the rotating direction when the drill bit drills down, and pouring concrete into the pile hole from bottom to top until the concrete is poured to the pile top;

seventhly, a vibrating rod is used for sinking the reinforcement cage (12) into the poured concrete.

8. The long spiral drill hole pressure-cast concrete pile comprises a concrete pile body (13), wherein a reinforcement cage (12) is arranged inside the concrete pile body (13), and the long spiral drill hole pressure-cast concrete pile is characterized in that a plurality of diameter expansion bodies (14) are arranged on the concrete pile body (13).