CN116516972A

CN116516972A - Tubular pile bottom grouting device and use method thereof

Info

Publication number: CN116516972A
Application number: CN202310722649.3A
Authority: CN
Inventors: 高永光; 高云飞
Original assignee: Individual
Current assignee: Individual
Priority date: 2023-02-13
Filing date: 2023-06-16
Publication date: 2023-08-01
Also published as: CN220117215U

Abstract

The invention relates to the technical field of foundation construction, and aims to provide a pipe pile bottom grouting device and a use method thereof. The pile bottom grouting device has a larger volume of a condensation structure formed at the bottom of the pile and can increase friction between the side wall of the pile and surrounding soil. The above-mentioned tubular pile bottom slip casting device includes: the grouting device comprises a grouting bag, at least one first grouting pipe and at least one second grouting pipe; the grouting bag is extruded and expandable by the internal slurry; the first grouting pipe is connected with the grouting bag, and one end of the first grouting pipe extends into the grouting bag; the second grouting pipe is connected with the grouting bag and penetrates through the grouting bag. The grouting device solves the problems that in the prior art, a coagulation structure formed at the bottom of the tubular pile by the grouting device has small volume, friction force between the tubular pile and surrounding soil is small, and the improvement effect on the bearing capacity of the tubular pile is poor.

Description

Tubular pile bottom grouting device and use method thereof

Technical Field

The invention relates to the technical field of foundation construction, in particular to a pipe pile bottom grouting device and a use method thereof.

Background

When the construction is carried out, if the geological conditions are poor and the bearing capacity of the foundation is small, the pipe piles are driven into the ground, so that the weight of the building above is transferred to a bearing layer with high bearing capacity below through the pipe piles, and the stability and safety of the building can be ensured. The single pile bearing capacity of the pipe piles determines the number of the pipe piles which need to be arranged when the foundation is built, and the stronger the single pile bearing capacity of the pipe piles is, the fewer the number of the pipe piles is needed.

The existing pipe pile can be additionally provided with a grouting device at the bottom during construction, and the stressed area of the bottom end of the pipe pile is increased through the grouting device, so that the single pile bearing capacity of the pipe pile is improved. The grouting device comprises a grouting bag and a grouting pipe with one end inserted into the grouting bag. After the grouting device is driven into the ground along with the pipe pile, grouting is carried out in a grouting bag through a grouting pipe, after the grouting is continuously carried out so that the grouting bag is broken, part of slurry permeates into surrounding soil, and after the slurry is solidified, the slurry at the bottom of the pipe pile and the surrounding soil are solidified into a whole. Limited by the space at the bottom of the pipe pile, the volume of a condensation structure formed after grouting is small, namely the contact area of the condensation structure and surrounding soil is small, so that the bearing capacity of the pipe pile is improved less; and only a small part of the grout can infiltrate into the soil body, so that the friction force between the coagulation structure and the surrounding soil body is small. Therefore, the grouting device has poor effect of improving the bearing capacity of the tubular pile.

Disclosure of Invention

Therefore, the technical problem to be solved by the invention is to overcome the defects that the grouting device in the prior art has small volume of a condensation structure formed at the bottom of the pipe pile and lower friction force between the grouting device and surrounding soil mass, so that the improvement effect on the bearing capacity of the pipe pile is poor, and further provide the grouting device for the bottom of the pipe pile, which can form a larger condensation structure at the bottom of the pipe pile and has larger friction resistance between the side wall of the pipe pile and the surrounding soil mass, and the use method thereof.

In order to solve the above problems, the present invention provides a pipe pile bottom grouting device, comprising:

a grouting bag which is extruded and expandable by the internal slurry;

at least one first grouting pipe, wherein the first grouting pipe is connected with the grouting bag, and one end of the first grouting pipe extends into the grouting bag;

and the second grouting pipe is connected with the grouting bag and penetrates through the grouting bag.

Optionally, the slip casting bag both ends opening, just the opening part is provided with first connecting piece and second connecting piece respectively.

Optionally, a first mounting hole is formed in the first connecting piece, the number of the first mounting holes is equal to the sum of the first grouting pipes and the second grouting pipes, a second mounting hole is formed in the second connecting piece, the number of the second mounting holes is equal to the number of the second grouting pipes, one end of the first grouting pipe penetrates through the first mounting hole and stretches into the grouting bag, and the second grouting pipe sequentially penetrates through the first mounting hole and the second mounting hole, and two ends of the second grouting pipe are arranged outside the grouting bag.

Optionally, the first grouting pipe is located on a pipe section side wall in the grouting bag and provided with a plurality of grouting holes, and the second grouting pipe is arranged outside the grouting bag and is close to one end pipe section side wall of the second mounting hole and provided with a plurality of grouting holes.

Optionally, a one-way grouting valve is arranged at the outer side of the grouting hole.

Optionally, the opening of the grouting bag is connected with the first connecting piece and the second connecting piece through fixing pieces respectively.

Optionally, a baffle is sleeved outside the first connecting piece.

Optionally, the baffle has a flexible skirt.

The application method of the tubular pile bottom grouting device is applied to the tubular pile bottom grouting device and comprises the following steps:

arranging the pipe pile bottom grouting device at the bottom of the pipe pile;

grouting into the second grouting pipe to enable the grouting liquid to be filled between the outer wall of the grouting bag and surrounding soil, and injecting the grouting liquid into the space between the outer wall of the pipe pile and surrounding disturbance soil to form a grouting pulse;

grouting into a first grouting pipe, expanding the grouting bag, and extruding the slurry and the soil outside the grouting bag;

the slurry injected by the first grouting pipe and the second grouting pipe is coagulated to form an enlarged head.

Optionally, the step of arranging the grouting device at the bottom of the pipe pile and the step of grouting into the second grouting pipe, so that the grouting liquid is filled between the outer wall of the grouting bag and surrounding soil, and the step of forming a grouting pulse between the outer wall of the pipe pile and surrounding disturbance soil is performed, and the step of connecting a baffle plate with the inner wall of the bottom end of the pipe pile and pouring cement slurry or cement mortar above the baffle plate is further included.

The invention has the following advantages:

1. the invention provides a pipe pile bottom grouting device which comprises a grouting bag, at least one first grouting pipe and at least one second grouting pipe, wherein the first grouting pipe is connected with the grouting bag, one end of the first grouting pipe stretches into the grouting bag, the first grouting pipe can grouting into the grouting bag, and the grouting bag expands along with the increase of the volume of internal slurry. The second grouting pipe is connected with the grouting bag and penetrates through the grouting bag, and the second grouting pipe can grouting the outside of the grouting bag. Through first slip casting pipe, second slip casting pipe respectively to slip casting bag inside, outside slip casting, can form bigger condensation structure in the tubular pile bottom after the final thick liquid solidifies, increase the area of atress of tubular pile bottom. The grout injected into the grouting bag by the first grouting pipe can extrude the grout injected into the grouting bag by the second grouting pipe, the grout permeates into surrounding soil, the friction force between the enlarged footing and the surrounding soil is improved, and the single pile bearing capacity of the pipe pile is improved.

2. According to the pipe pile bottom grouting device provided by the invention, two ends of a grouting bag are provided with openings, a first connecting piece and a second connecting piece are respectively arranged at the openings, and a first grouting pipe and a second grouting pipe are fixedly connected through the first connecting piece and the second connecting piece. The connecting structure is simple, has strong practicability and is convenient for construction operation.

3. According to the pipe pile bottom grouting device provided by the invention, the one-way grouting valve is arranged at the outer side of the grouting hole, the one-way grouting valve is preferably a rubber sleeve, and one-way grouting can be realized by arranging the rubber sleeve, namely, slurry can only flow into the grouting bag from the first grouting pipe and flow out of the grouting bag from the second grouting pipe, slurry in the first grouting pipe and the second grouting pipe flows out of the grouting hole, the rubber sleeve is jacked up by the pressure of the slurry, the slurry flows out between the rubber sleeve and the first grouting pipe and between the rubber sleeve and the second grouting pipe, and the slurry at the outer side of the rubber sleeve cannot flow into the first grouting pipe and the second grouting pipe. Through setting up one-way slip casting valve can realize one-way slip casting, prevents that thick liquid from going upward from first slip casting pipe, second slip casting pipe inside when the slip casting.

4. According to the pipe pile bottom grouting device provided by the invention, the baffle is sleeved outside the first connecting piece and provided with the flexible skirt edge, and the flexible skirt edge of the baffle is connected with the inner wall of the pipe pile, so that the slurry injected by the first grouting pipe and the second grouting pipe can be prevented from returning into the pipe pile from the bottom of the pipe pile, and the slurry is reserved at the bottom of the pipe pile and is coagulated to form an enlarged head.

5. According to the application method of the pipe pile bottom grouting device, the pipe pile bottom grouting device is arranged at the bottom of the pipe pile, grouting is conducted between the outer wall of the grouting bag and surrounding soil bodies through the second grouting pipe, and grouting is conducted between the outer wall of the pipe pile and surrounding disturbance soil zones, so that slurry permeates into the surrounding soil bodies to form slurry veins, and friction force between the outer wall of the pipe pile and the soil bodies is increased; grouting in to the slip casting bag through first slip casting pipe can make the slip casting bag inflation to extrude the soil body around, increase the external thick liquid volume of infiltration soil body of slip casting bag, and finally can form the great expansion head of volume in the tubular pile bottom, increase tubular pile bottom area of bearing surface, improve tubular pile bearing capacity.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present invention, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic view of a pipe pile bottom grouting device according to the present invention;

FIG. 2 is a cross-sectional view of a pipe pile bottom grouting device according to the present invention;

FIG. 3 is a schematic view of pile sinking in step one of the method for using the grouting device at the bottom of a pipe pile according to the present invention;

FIG. 4 is a schematic view showing the detachment of the pile tip in step one of the method for using the pipe pile bottom grouting device of the present invention;

FIG. 5 is a schematic view of grouting above a baffle plate in the method for using the pipe pile bottom grouting device of the invention;

FIG. 6 is a schematic diagram of a second step in the method for using the pipe pile bottom grouting device according to the present invention;

FIG. 7 is a schematic diagram of a third step in the method for using the pipe pile bottom grouting device according to the present invention;

fig. 8 is a schematic diagram of a fourth step in the method for using the pipe pile bottom grouting device according to the present invention.

Reference numerals illustrate:

1. grouting bags; 2. a first grouting pipe; 3. a second grouting pipe; 4. a first connector; 5. a second connector; 6. grouting holes; 7. a fixing member; 8. a baffle 801, a flexible skirt; 9. and (5) tubular piles.

Detailed Description

The following description of the embodiments of the present invention will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the invention are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In addition, the technical features of the different embodiments of the present invention described below may be combined with each other as long as they do not collide with each other.

As shown in fig. 1 and 2, the grouting device for the bottom of the pipe pile is a preferred embodiment of the grouting device for the bottom of the pipe pile, and can be arranged at the bottom of the pipe pile during foundation construction so as to increase the single pile bearing capacity of the pipe pile, thereby reducing the number of the pipe piles used in the whole construction process and lowering the construction cost.

The above-mentioned tubular pile bottom slip casting device includes: a grouting bag 1, at least one first grouting pipe 2 and at least one second grouting pipe 3. The grouting bag 1 is expandable by being pressed by the internal slurry without breaking, i.e. the grouting bag 1 has a contracted state when no slurry is injected into the interior and an expanded state when the injected slurry expands. The first grouting pipe 2 is connected with the grouting bag 1, and one end extends into the grouting bag 1, so that grouting can be performed inside the grouting bag 1. With the continuous grouting into the grouting bag 1, the grouting bag 1 can be gradually enlarged, so that the grouting bag 1 is inflated. The second grouting pipe 3 is connected with the grouting bag 1, and the second grouting pipe 3 penetrates through the grouting bag 1, so that grouting can be performed outside the grouting bag 1 through the second grouting pipe 3.

Specifically, in this embodiment, the number of the first grouting pipe 2 and the second grouting pipe 3 is one. When constructing, tubular pile bottom grouting device sets up in tubular pile 9 bottom, through first slip casting pipe 2, the slip casting of second slip casting pipe 3 respectively to slip casting bag 1 inside, outside, finally can form the expansion head in tubular pile 9 bottom to the expansion head and the soil body on every side condense as an organic wholely, have increased the bearing capacity of tubular pile 9.

Furthermore, the grouting bag 1 may be made of high-strength chemical synthetic fiber cloth such as ton wrapping cloth, for example, terylene, chinlon, acrylon, etc., or plastic film material such as polyvinyl chloride, polyethylene, polypropylene, etc., or other materials suitable for containing slurry such as plastic, rubber, etc., with fixed volume in a filled state and without rupture under the designed grouting pressure value. The grouting bag can be of a single-layer structure or a multi-layer structure. Specifically, in this embodiment, the grouting bag 1 is made of ton wrapping cloth material and has a single-layer structure.

Further, both ends of the grouting bag 1 are opened, and the openings are respectively provided with a first connecting piece 4 and a second connecting piece 5. The opening of the grouting bag 1 is respectively connected with the first connecting piece 4 and the second connecting piece 5 through the fixing piece 7. In this embodiment, the fixing member 7 adopts a hoop, and the grouting bag 1 is hooped on the first connecting member 4 and the second connecting member 5 through the hoop, so that the slurry is prevented from flowing out from the opening of the grouting bag 1.

In addition, in order to prevent the grouting bag 1 from being scratched in contact with the rough inner wall of the pipe pile 9 after grouting expansion, the subsequent grouting into the grouting bag 1 is affected, and an enlarged head structure cannot be formed. The connection position of the grouting bag 1 and the first connector 4 can be adjusted to avoid the grouting bag 1 from being scratched. Specifically, after the grouting device at the bottom of the pipe pile 9 is arranged at the bottom of the pipe pile 9, the connection position of the grouting bag 1 and the first connecting piece 4 is just below the bottom surface of the pipe pile 9, and the grouting expansion of the grouting bag 1 can not contact the inner wall of the pipe pile 9, so that the grouting bag can not be scratched.

If the connection position of the grouting bag 1 and the first connecting piece 4 is located in the pipe pile 9, the geotextile shawl can be arranged at the connection position of the grouting bag 1 and the first connecting piece 4 for protection, and the geotextile shawl covers the outer part of the grouting bag 1, so that the geotextile shawl contacts with the rough inner wall of the pipe pile 9, and the grouting bag 1 is protected from being scratched.

The water stop can be arranged at the joint of the grouting bag 1 and the first connecting piece 4 and the second connecting piece 5, the water stop made of water stop materials is used for sealing, and after the slurry in the grouting bag 1 contacts with the water stop, the water stop can be hardened to seal the joint, so that leakage of the slurry is prevented.

First mounting holes are formed in the first connecting piece 4, the number of the first mounting holes is equal to the sum of the numbers of the first grouting pipes 2 and the second grouting pipes 3, second mounting holes are formed in the second connecting piece 5, and the number of the second mounting holes is equal to the number of the second grouting pipes 3. One end of the first grouting pipe 2 penetrates through the first mounting hole and stretches into the grouting bag 1, the second grouting pipe 3 sequentially penetrates through the first mounting hole and the second mounting hole, and two ends of the second grouting pipe 3 are arranged outside the grouting bag 1. Specifically, in this embodiment, since the number of the first grouting pipes 2 and the second grouting pipes 3 is one, the number of the first mounting holes on the first connecting piece 4 is two, and the two first mounting holes are disposed in close proximity, and the number of the second mounting holes on the second connecting piece 5 is one. The first connecting piece 4 and the second connecting piece 5 are cylindrical and can be made of steel cylinders with end covers at two ends _， The two end covers of the first connecting piece 4 are provided with a corresponding number of first mounting holes, and the two end covers of the second connecting piece 5 are provided with a corresponding number of second mounting holes. The joints of the first mounting hole and the second mounting hole with the first grouting pipe 2 and the second grouting pipe 3 need to be sealed, in this embodiment, the joints are welded, so that sealing and fixing of the first grouting pipe 2 and the second grouting pipe 3 are achieved.

In addition, the outside cover of first connecting piece 4 is equipped with baffle 8, and baffle 8 has flexible shirt rim, and flexible shirt rim can be made by materials such as rubber, silica gel, plastics, and the middle part of baffle 8 is the rigid plate, can improve the bearing capacity and the rigidity of baffle, and flexible shirt rim sets up around the rigid plate. In this embodiment, the rigid plate is circular steel sheet, and flexible shirt rim is the annular plate of rubber, and the external diameter of flexible shirt rim slightly is greater than tubular pile 9 internal diameter, through flexible shirt rim and the laminating of tubular pile 9 inner wall, realizes the connection of baffle 8 and tubular pile 9 inner wall, and to baffle top grout again, just can prevent from going back along the cavity of tubular pile 9 from the thick liquid of first slip casting pipe and second slip casting pipe injection after the grout solidifies.

The side wall of the pipe section of the first grouting pipe 2 positioned in the grouting bag 1 is provided with a plurality of grouting holes 6, and the side wall of the pipe section of the second grouting pipe 3 positioned outside the grouting bag 1 and close to the second mounting hole is also provided with a plurality of grouting holes 6. In this embodiment, a plurality of grouting holes 6 are arranged at intervals along the side wall of the pipe section, and a plurality of grouting holes 6 are uniformly arranged at intervals in each row. The slurry injected into the first grouting pipe 2 and the second grouting pipe 3 flows out through the grouting holes 6, and a one-way grouting valve is arranged at the outer side of the grouting holes 6, so that one-way grouting can be realized. Specifically, in this embodiment, the one-way grouting valve is a rubber sleeve, and the rubber sleeve is sleeved outside the grouting hole 6, so that the flow direction of the slurry can be controlled, and the slurry is prevented from flowing into the first grouting pipe 2 and the second grouting pipe 3.

In other embodiments, the number of the first grouting pipe 2 and the second grouting pipe 3 can be two, three, etc., and the first grouting pipe 2 and the second grouting pipe 3 can be fixed-length pipes or telescopic pipes with variable lengths.

In other embodiments, the material of the grouting bag 1 may be plastic, rubber, plastic film material, etc., and the grouting bag 1 may also be a multi-layer structure.

In other embodiments, the first mounting hole and the second mounting hole may also be spaced apart.

In other embodiments, the first connecting piece and the second connecting piece may have other shapes such as square, and the material may also be stainless steel, plastic, etc.

In other embodiments, the fixing piece 7 may be a steel wire, and the grouting bag 1 is connected with the first connecting piece 4 and the second connecting piece 5 through steel wire hinging, and the fixing piece 7 may be a clamp.

In other embodiments, the flexible skirt of the baffle 8 may be made of silica gel, plastic, or other materials, and may be polygonal, so long as it can be completely attached to the inner wall of the pipe pile 9.

The embodiment also provides a method for using the pipe pile bottom grouting device, which is applied to the pipe pile bottom grouting device, and the pipe pile bottom grouting device in the above embodiment has the same structure, so that the details are not repeated.

The application method of the pipe pile bottom grouting device comprises the following steps:

step one: arranging a pipe pile bottom grouting device at the bottom of the pipe pile;

as shown in fig. 3, this step is preceded by a pile sinking step of driving the pipe pile 9 into the ground, specifically, using a pile driver to sink the pipe pile 9 into the designed elevation of the ground by hammering or static pressure, so that the pile tip of the pipe pile 9 enters the bearing layer. Thereafter, as shown in fig. 4, the pile tip is hammered through the cavity of the pile body using a round steel cylinder or a hammer to separate the pile tip from the pile tip, thereby forming a certain space between the pile tip and the pile body. However, the pile sinking process is influenced by hammers and pressures of equipment such as piles and the like, soil around the outer wall of the pipe pile 9 can form a disturbing soil band, and the soil of the disturbing soil band is loose. And part of soil at the bottom end of the pipe pile 9 collapses and is accumulated between the pile tip and the pile body.

Then, the grouting device at the bottom of the pipe pile is lowered to the bottom of the pipe pile 9 through the pile body cavity, the grouting pipe of the grouting device on the ground is communicated with the first grouting pipe 2 and the second grouting pipe 3, and the grouting pipe and the first grouting pipe 2 and the second grouting pipe 3 can be connected through modes of screw thread connection, welding, liquid welding, bonding and the like.

Step two: grouting into the second grouting pipe 3 to enable the grouting liquid to be filled between the outer wall of the grouting bag 1 and surrounding soil, and injecting the grouting liquid into the space between the outer wall of the pipe pile 9 and surrounding disturbance soil to form a grouting pulse;

as shown in fig. 5, before this step, the step of connecting the baffle plate 8 to the inner wall of the bottom end of the pipe pile 9 and pouring cement slurry or cement mortar over the baffle plate 8 is further included. The baffle plate 8 is provided with a flexible skirt edge, the outer diameter of the flexible skirt edge is slightly larger than the inner diameter of the pipe pile, and the baffle plate 8 is lowered to the bottom of the pipe pile through clamping the first grouting pipe and the second grouting pipe, so that the flexible skirt edge is tightly attached to the inner wall of the pipe pile 9. After reaching the designated position, grouting is carried out from the pile body cavity, cement paste or cement mortar with a certain height is poured above the baffle plate 8, and grouting in the second grouting pipe is started after the cement paste or cement mortar is solidified. This step can prevent the slurry from going up from the cavity of the pipe pile 9 when the slurry is injected into the first grouting pipe 2 and the second grouting pipe 3 later.

As shown in fig. 6, the grouting bag 1 is grouted through the second grouting pipe 3, so that the grouting liquid is filled between the outer wall of the grouting bag 1 and the surrounding soil, part of the grouting liquid can infiltrate into the surrounding soil, the grouting liquid can be injected between the outer wall of the pipe pile 9 and the surrounding disturbance soil, split-shaped grouting veins are formed by the grouting liquid penetrating into the surrounding soil, and when the grouting liquid is solidified, the friction force between the pipe pile 9 and the disturbance soil can be increased.

Step three: grouting into the first grouting pipe 2 to expand the grouting bag 1 and squeeze slurry and soil outside the grouting bag 1;

as shown in fig. 7, the slurry is injected into the first grouting pipe 2, and as the slurry in the grouting bag 1 is accumulated, the grouting bag 1 gradually expands, presses the slurry and the soil outside the grouting bag 1, and the amount of the slurry penetrating into the surrounding soil increases. The amount of slurry injected into the first grouting pipe 2 can be calculated in advance, and the approximate volume of the expansion head is determined according to the diameter of the pipe pile 9 and the size, the material and the volume of the grouting bag 1, so that the total amount of slurry required to be injected is determined.

During grouting, the second grouting pipe 3 can be firstly grouting, and after the grouting liquid is filled between the outer wall of the grouting bag 1 and surrounding soil bodies and between the outer wall of the injection pipe pile 9 and surrounding disturbance soil zones, grouting is carried out on the first grouting pipe 2 after a certain height is returned. Alternatively, the grouting may be performed alternately by grouting the second grouting pipe 3 and grouting the first grouting pipe 2, i.e., a predetermined amount of slurry is injected into the second grouting pipe 3, a predetermined amount of slurry is injected into the first grouting pipe 2, and a predetermined amount of slurry is injected into the second grouting pipe 3, so that the grouting is cyclically alternated.

Step four: the slurry injected by the first grouting pipe 2 and the second grouting pipe 3 is coagulated to form an enlarged head.

As shown in fig. 8, the slurry injected through the first grouting pipe 2 and the second grouting pipe 3 is coagulated after a period of time, the slurry outside the grouting bag 1 is coagulated with surrounding soil and the bottom end of the pipe pile 9 into a whole, the slurry in the grouting bag 1 is coagulated with the grouting bag 1 and the slurry outside the grouting bag 1 into a whole, and finally the expansion head is formed together. The volume of the enlarged footing is larger than the space between the original pile body and the pile tip, the stressed area of the bottom end of the pipe pile is enlarged, the enlarged footing and the surrounding soil are coagulated into a whole, and the friction is increased, so that the single pile bearing capacity of the pipe pile 9 is obviously improved.

It is apparent that the above examples are given by way of illustration only and are not limiting of the embodiments. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. While still being apparent from variations or modifications that may be made by those skilled in the art are within the scope of the invention.

Claims

1. A tubular pile bottom grouting device, comprising:

a grouting bag (1), the grouting bag (1) being expandable by internal slurry extrusion;

at least one first grouting pipe (2), wherein the first grouting pipe (2) is connected with the grouting bag (1), and one end of the first grouting pipe extends into the grouting bag (1);

at least one second grouting pipe (3), the second grouting pipe (3) is connected with the grouting bag (1), and the second grouting pipe (3) penetrates through the grouting bag (1).

2. The pipe pile bottom grouting device according to claim 1, characterized in that the grouting bag (1) is provided with openings at two ends, and the openings are respectively provided with a first connecting piece (4) and a second connecting piece (5).

3. The pipe pile bottom grouting device according to claim 2, wherein the first connecting piece (4) is provided with first mounting holes, the number of the first mounting holes is equal to the sum of the numbers of the first grouting pipes (2) and the second grouting pipes (3), the second connecting piece (5) is provided with second mounting holes, the number of the second mounting holes is equal to the number of the second grouting pipes (3), one end of the first grouting pipes (2) penetrates through the first mounting holes and stretches into the grouting bag (1), and the second grouting pipes (3) sequentially penetrate through the first mounting holes and the second mounting holes and the two ends of the second grouting pipes (3) are arranged outside the grouting bag (1).

4. A pipe pile bottom grouting device according to claim 3, wherein the first grouting pipe (2) is provided with a plurality of grouting holes (6) on the side wall of the pipe section positioned in the grouting bag (1), and the second grouting pipe (3) is arranged outside the grouting bag (1) and provided with a plurality of grouting holes (6) on the side wall of the pipe section near one end of the second mounting hole.

5. The pipe pile bottom grouting device according to claim 4, characterized in that a one-way grouting valve is arranged outside the grouting hole (6).

6. The pipe pile bottom grouting device according to claim 2, characterized in that the openings of the grouting bag (1) are respectively connected with the first connecting piece (4) and the second connecting piece (5) through fixing pieces (7).

7. A pipe pile bottom grouting device according to any one of claims 2-6, characterised in that the first connector (4) is externally sleeved with a baffle (8).

8. A pipe pile bottom grouting device according to claim 7, characterised in that the baffle (8) has a flexible skirt.

9. A method for using the pipe pile bottom grouting device, which is applied to the pipe pile bottom grouting device of any one of claims 1 to 8, and is characterized by comprising the following steps:

arranging the grouting device at the bottom of the pipe pile (9);

grouting into the second grouting pipe (3) to enable the grouting liquid to be filled between the outer wall of the grouting bag (1) and surrounding soil, and injecting the grouting liquid into the space between the outer wall of the pipe pile (9) and surrounding disturbance soil to form a grouting pulse;

grouting into a first grouting pipe (2), expanding the grouting bag (1), and extruding the slurry and the soil outside the grouting bag (1);

the slurry injected by the first grouting pipe (2) and the second grouting pipe (3) is coagulated to form an enlarged head.

10. The method for using the grouting device at the bottom of the pipe pile according to claim 9, wherein the step of arranging the grouting device at the bottom of the pipe pile (9) and the step of grouting into the second grouting pipe (3) to enable slurry to be filled between the outer wall of the grouting bag (1) and surrounding soil bodies and to be injected between the outer wall of the pipe pile (9) and surrounding disturbance soil strips to form slurry veins further comprises the steps of connecting a baffle plate (8) with the inner wall of the bottom end of the pipe pile (9) and filling cement slurry or cement mortar above the baffle plate (8).