A jet grouting bag pile and a construction method thereof

Abstract

The application discloses a rotary jetting bag pile and a construction method thereof, which comprises a rotary jetting pile located in a pile foundation hole, a supporting steel pipe inserted into the rotary jetting pile which has not been solidified, a bag fixedly installed outside the supporting steel pipe, and a through hole communicated with the bag and arranged on the outer surface of the supporting steel pipe, and concrete slurry is injected into the bag through the supporting steel pipe and the through hole to make the bag expand and extrude the rotary jetting pile, and a butt joint mechanism is arranged between the upper and lower supporting steel pipes. The rotary jetting bag pile and the construction method thereof adopt a novel structure design, the supporting steel pipe is inserted into the rotary jetting pile just after the rotary jetting is completed, at this time, the rotary jetting pile has not been solidified, then a grouting device is used to inject concrete slurry into the supporting steel pipe through the uppermost injection pipe, the injected slurry is discharged through the through hole arranged on the side surface of the supporting steel pipe and enters the bag, at this time, the bag expands and extrudes the surrounding rotary jetting pile, the slurry of the rotary jetting pile is extruded and compacted, the air bubbles in the rotary jetting pile are discharged, and the overall strength of the rotary jetting pile is improved.

Description

Technical Field

[0001] This invention relates to the field of jet grouting construction technology, specifically to a jet grouting bag-type pile and its construction method. Background Technology

[0002] Jet grouting piles are an engineering technology used for foundation reinforcement and waterproofing. The full name is high-pressure jet grouting piles. They use high-pressure jet grouting to break up the soil layer and force the soil and cement to mix together to form a solid, column-like modified body. The drilling rig drills the grouting pipe with a special nozzle into the ground to a predetermined depth, and then uses a high-pressure pump to spray the cement grout from the nozzle at high speed.

[0003] For example, in the prior art, Chinese patent application number CN202211196543.6 discloses a high-pressure jet grouting pile construction process, which relates to the field of high-pressure jet grouting technology. The process includes the following steps: preparation; initial drilling, using a drilling rig to drill a construction hole at the construction site; installation of the jet grouting auxiliary device: installing the insertion drilling mechanism on the drilling rig shaft, inserting the insertion pipe into the borehole along the drilling direction; grout preparation and test spraying; secondary drilling, using the jet grouting auxiliary device to perform secondary drilling to achieve the required borehole conditions; high-pressure jet grouting: using the jet grouting auxiliary device to perform high-pressure jet grouting on the formed borehole; completion of work, removing the jet grouting auxiliary device, and moving the drilling rig to the next processing position.

[0004] For example, in the prior art, Chinese patent application number CN202210017654.X discloses a method for constructing jet grouting piles, including the following steps: drilling a hole with a pneumatic down-the-hole drill rig aligned with a preset target until the drill bit penetrates the rock-fill layer; replacing the pneumatic down-the-hole drill rig with a jet grouting drill rig and continuing to drill until the hole depth reaches the preset elevation; injecting cement slurry into the hole from bottom to top with the jet grouting drill bit to impact and break the hole wall, mixing the silt and sand with the cement slurry until the mixed slurry reaches the preset jet grouting pile elevation; before the mixed slurry in the hole solidifies, extending the jet grouting drill bit into the bottom of the hole to perform a second grouting from bottom to top, further impacting and breaking the hole wall to mix the silt and sand with the cement slurry until the mixed slurry reaches the preset jet grouting pile elevation.

[0005] For example, in the prior art, Chinese patent application number CN201911215730.2 discloses a high-pressure jet grouting pile construction process, including the following steps: S1: Determine the center point of the high-pressure jet grouting pile according to the construction drawings; S2: Vibrate and press the cylindrical limiting cylinder to the design elevation of the jet grouting pile; S3: Use a drilling machine to drill a hole at the center point of the high-pressure jet grouting pile to obtain a pilot hole; S4: Insert the jet grouting pipe into the pilot hole until the preset depth, and spray water from the jet grouting pipe during the downward insertion process; S5: After the jet grouting pipe moves downward to the design pile bottom elevation, start spraying cement slurry and water, while rotating and lifting, and the rotation speed and lifting speed are carried out according to the design specifications, until the design pile top elevation is reached; S6: Pull out the limiting cylinder.

[0006] Based on the above information, it can be seen that the existing jet grouting construction technology generally only uses the curing of grout to achieve the purpose of forming a pile column. However, in actual use, some air may enter the grout during the jet grouting process, forming a bubble structure. If the bubbles cannot be expelled, it will affect the overall strength of the pile column. Summary of the Invention

[0007] The purpose of this invention is to provide a jet grouting bag pile and a construction method to solve the problem of low device strength mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a jet grouting bag-type pile, comprising a jet grouting pile located in a pile foundation hole, a supporting steel pipe inserted into the uncured jet grouting pile, and a bag fixedly installed on the outside of the supporting steel pipe. The supporting steel pipe is ultimately retained inside the jet grouting pile, where it acts as a reinforcing rib to better improve the strength of the jet grouting pile. A through hole communicating with the bag is provided on the outer surface of the supporting steel pipe. Concrete grout enters the bag through the supporting steel pipe and the through hole, causing the bag to expand and compress the jet grouting pile. Concrete grout is injected into the supporting steel pipe through the uppermost injection pipe using grouting equipment. The injected grout is discharged through the through hole on the side of the supporting steel pipe and enters the bag. The bag expands and compresses the surrounding jet grouting pile, compacting the grout and expelling air bubbles, thereby improving the overall strength of the jet grouting pile. A docking mechanism is provided between the upper and lower supporting steel pipes, allowing multiple supporting steel pipes to be spliced ​​together for jet grouting piles of different sizes.

[0009] Preferably, an upper mounting plate and a lower mounting plate are fixedly installed at the upper and lower ends of the supporting steel pipe, respectively, and both the upper and lower mounting plates have through holes.

[0010] Preferably, a filling pipe is fixedly installed on the upper surface of the upper mounting plate. The filling pipe is connected to the inside of the supporting steel pipe, and the concrete slurry enters the inside of the supporting steel pipe through the filling pipe.

[0011] Preferably, when the bag is folded and stored, it fits tightly against the supporting steel pipe, and after the bag is filled with concrete slurry and expands, its diameter is larger than the diameters of the upper and lower mounting plates.

[0012] Preferably, the docking mechanism includes a docking sleeve fixedly installed on the lower surface of the lower mounting plate. The docking sleeve is connected to the supporting steel pipe. The docking sleeve is fixedly connected to the threaded structure on the outer surface of the filling pipe through its inner wall thread structure. The docking sleeve of the upper device is aligned with the filling pipe of the lower device, and is tightened and fixed by the cooperation of the inner thread of the docking sleeve and the outer thread of the filling pipe.

[0013] A preferred method for constructing a jet grouting bag-type pile includes the following specific steps: S1. Jet grouting pile casting: First, drilling equipment is used to drill holes at designated locations in the pile foundation. Then, jet grouting equipment is used in conjunction with jet grouting technology to form jet grouting piles in the holes. The corresponding number of devices are selected according to the depth of the jet grouting pile. The connecting sleeve of the upper device is aligned with the injection pipe of the lower device and tightened with threads to fix it, finally forming a longer whole to achieve splicing operation. S2, Pile and Column Assembly: The entire device is inserted into the jet grouting pile using drilling equipment. At this time, the jet grouting pile will immerse the entire device. The upper and lower mounting plates at both ends of the supporting steel pipe are provided with clearance holes. When the entire device is inserted into the jet grouting pile, the clearance holes reduce the insertion resistance. S3. Grouting: Connect the concrete grouting equipment to the uppermost injection pipe, then turn on the grouting equipment to inject concrete slurry into the supporting steel pipe through the injection pipe. Then, it enters the slurry bag through the through hole opened on the side of the supporting steel pipe. At this time, the slurry bag expands due to the injection of slurry. The expanded slurry bag squeezes the surrounding jet grouting piles, making the jet grouting piles compact. At the same time, the supporting steel pipe acts as a reinforcing rib to improve the strength of the jet grouting piles.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: the jet grouting bag pile and construction method adopt a novel structural design, the specific details of which are as follows: 1. Insert the supporting steel pipe into the jet grouting pile that has just been completed. At this time, the jet grouting pile has not yet been cured. Then, use the grouting equipment to inject concrete grout into the supporting steel pipe through the top injection pipe. The injected grout is discharged through the through hole opened on the side of the supporting steel pipe and enters the bladder. At this time, the bladder expands and squeezes the surrounding jet grouting pile, compressing the grout in the jet grouting pile and expelling the air bubbles, thereby improving the overall strength of the jet grouting pile. Furthermore, the supporting steel pipe is ultimately retained inside the jet grouting pile, where it acts as a reinforcing rib to further enhance the strength of the jet grouting pile.

[0015] 2. When dealing with jet grouting piles of different depths, select the corresponding number of devices and splice the devices downwards adjacent to each other. When splicing, align the docking sleeve of the upper device with the injection pipe of the lower device, and use the internal thread of the docking sleeve to cooperate with the external thread of the injection pipe to tighten and fix it, forming a whole. After docking, the upper and lower support steel pipes are connected, which does not affect the subsequent grouting operation. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the bladder in the contracted state of the present invention; Figure 2 This is a schematic diagram of the internal structure of the bag of the present invention; Figure 3 This is a schematic diagram of the structure of the bladder in the inflated state of the present invention; Figure 4 For the present invention Figure 2 Enlarged structural diagram at point A in the middle; Figure 5 This is a schematic diagram of the docking sleeve structure of the present invention; Figure 6 For the present invention Figure 5 Enlarged structural diagram at point B; Figure 7 This is a schematic diagram of the docking structure of the docking sleeve and the filling pipe in the docking state of the present invention; Figure 8 This is a schematic diagram showing the overall structure of the invention and its position relative to the jet grouting pile.

[0017] In the diagram: 1. Upper mounting plate; 2. Lower mounting plate; 3. Supporting steel pipe; 4. Bag; 5. Filling pipe; 6. Through hole; 7. Clearance hole; 8. Connecting sleeve; 9. Piling foundation; 10. Jet grouting pile. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Example 1: Please refer to Figures 1-4In order to improve the strength of the pile, this embodiment provides the following technical solution, specifically: a jet grouting pile 10 located in the 9 holes of the pile foundation, a supporting steel pipe 3 inserted into the uncured jet grouting pile 10, a bag 4 fixedly installed on the outside of the supporting steel pipe 3, and a through hole 6 communicating with the bag 4 on the outer surface of the supporting steel pipe 3. Concrete grout enters the bag 4 through the supporting steel pipe 3 and the through hole 6, causing the bag 4 to expand and squeeze the jet grouting pile 10. An upper mounting plate 1 and a lower mounting plate 2 are fixedly installed at the upper and lower ends of the supporting steel pipe 3, respectively. Both the upper mounting plate 1 and the lower mounting plate 2 have through holes 7. A filling pipe 5 is fixedly installed on the upper surface of the upper mounting plate 1. The filling pipe 5 communicates with the inside of the supporting steel pipe 3. Concrete grout enters the inside of the supporting steel pipe 3 through the filling pipe 5. When the bag 4 is folded and stored, it is tightly attached to the supporting steel pipe 3. After the bag 4 is filled with concrete grout and expands, its diameter is larger than the diameter of the upper mounting plate 1 and the lower mounting plate 2.

[0020] First, drilling equipment is used to drill holes at designated locations in the pile foundation 9. Then, jet grouting equipment and processes are used to form jet grouting piles 10 within the holes. Before the jet grouting piles 10 have hardened, the drilling equipment is used again to insert the entire device into the jet grouting piles 10. At this point, the jet grouting piles 10 completely submerge the device. Clearance holes 7 are provided inside the upper mounting plates 1 and lower mounting plates 2 at both ends of the supporting steel pipe 3. When the entire device is inserted into the jet grouting piles 10, the clearance in the clearance holes 7 reduces insertion resistance, and the grout from the jet grouting piles 10 can better encapsulate the entire device. Finally, the concrete grouting equipment is connected to the uppermost injection pipe 5. Then, the grouting equipment is turned on to inject concrete grout into the supporting steel pipe 3 through the injection pipe 5. Then, it enters the slurry bag 4 through the through hole 6 on the side of the supporting steel pipe 3. At this time, the slurry bag 4 expands due to the injection of grout. The expanded slurry bag 4 squeezes the surrounding jet grouting pile 10, making the jet grouting pile 10 compact. When the grout in the jet grouting pile 10 is squeezed, the air bubbles inside can be expelled, reducing the impact of air bubbles on the overall strength of the jet grouting pile 10. At the same time, the supporting steel pipe 3 acts as a reinforcing rib to improve the strength of the jet grouting pile 10.

[0021] Example 2: Please refer to Figures 5-8 In order to adapt to different sizes, this embodiment provides the following technical solution, which specifically discloses that: a docking mechanism is provided between the upper and lower support steel pipes 3, and multiple support steel pipes 3 are spliced ​​together by the docking mechanism for jet grouting piles 10 of different sizes. The docking mechanism includes a docking sleeve 8 fixedly installed on the lower surface of the lower mounting plate 2. The docking sleeve 8 is connected to the support steel pipe 3, and the docking sleeve 8 is docked and fixed with the threaded structure on the outer surface of the injection pipe 5 through its inner wall threaded structure.

[0022] Select the corresponding number of devices according to the depth of the jet grouting pile 10. Align the upper device's docking sleeve 8 with the lower device's injection pipe 5 and tighten them with threads to form a longer whole and achieve splicing operation. When spliced ​​to the length corresponding to the jet grouting pile 10, the device is then placed inside the jet grouting pile 10. The docking sleeve 8 and the injection pipe 5 are connected, so that the grout can fill all the bags 4 during grouting.

[0023] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A jet grouting bag-type pile, comprising a jet grouting pile (10) located in a hole in a pile foundation (9), characterized in that, Also includes: The supporting steel pipe (3) is inserted into the uncured jet grouting pile (10). A bag (4) is fixedly installed on the outside of the supporting steel pipe (3), and a through hole (6) communicating with the bag (4) is opened on the outer surface of the supporting steel pipe (3). The concrete slurry enters the bag (4) through the supporting steel pipe (3) and the through hole (6), causing the bag (4) to expand and squeeze the jet grouting pile (10). A docking mechanism is provided between the upper and lower two supporting steel pipes (3). Multiple supporting steel pipes (3) are spliced ​​together using the docking mechanism for jet grouting piles (10) of different sizes.

2. The jet grouting bag-type pile according to claim 1, characterized in that: The upper and lower mounting plates (1) and (2) are fixedly installed at the upper and lower ends of the supporting steel pipe (3), respectively. Both the upper mounting plate (1) and the lower mounting plate (2) have through holes (7) that pass through vertically.

3. A jet grouting bag-type pile according to claim 2, characterized in that: The upper surface of the upper mounting plate (1) is fixedly installed with a filling pipe (5), which is connected to the inside of the supporting steel pipe (3). The concrete slurry enters the inside of the supporting steel pipe (3) through the filling pipe (5).

4. A jet grouting bag-type pile according to claim 3, characterized in that: When the bag (4) is folded and stored, it is close to the supporting steel pipe (3). After the bag (4) is filled with concrete slurry and expands, its diameter is larger than the diameter of the upper mounting plate (1) and the lower mounting plate (2).

5. A jet grouting bag-type pile according to claim 1, characterized in that: The docking mechanism includes a docking sleeve (8) fixedly installed on the lower surface of the lower mounting plate (2), and the docking sleeve (8) is connected to the supporting steel pipe (3).

6. A jet grouting bag-type pile according to claim 5, characterized in that: The docking sleeve (8) is fixed to the outer surface thread structure of the filling pipe (5) through its inner wall thread structure.

7. A jet grouting bag pile and a construction method thereof, applicable to the construction of jet grouting bag piles as described in any one of claims 1-6, characterized in that, The specific steps of this construction method are as follows: S1. Jet grouting pile casting: First, drilling equipment is used to drill holes in the designated location of the pile foundation (9). Then, jet grouting equipment is used in conjunction with jet grouting process to form jet grouting piles (10) in the holes. The corresponding number of devices are selected according to the depth of the jet grouting pile (10). The connecting sleeve (8) of the upper device is aligned with the injection pipe (5) of the lower device and tightened with threads to finally form a longer whole to achieve splicing operation. S2, pile and column combination, the whole device is placed into the jet grouting pile (10) using drilling equipment. At this time, the jet grouting pile (10) will immerse the whole device. The upper mounting plate (1) and lower mounting plate (2) at both ends of the supporting steel pipe (3) are provided with clearance holes (7). When the whole device is inserted into the jet grouting pile (10), the gap of the clearance hole (7) reduces the insertion resistance. S3. Grouting: Connect the concrete grouting equipment to the uppermost injection pipe (5), then turn on the grouting equipment to inject the concrete slurry into the supporting steel pipe (3) through the injection pipe (5), and then enter the bladder (4) through the through hole (6) on the side of the supporting steel pipe (3). At this time, the bladder (4) expands due to the injected slurry, and the expanded bladder (4) squeezes the surrounding jet grouting piles (10), making the jet grouting piles (10) compact. At the same time, the supporting steel pipe (3) acts as a reinforcing bar to improve the strength of the jet grouting piles (10).

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