阅读说明：本技术 一种预制管桩桩端后压浆装置及施工方法 (Post-grouting device for pile end of prefabricated pipe pile and construction method ) 是由 陈祉阳 朱建民 龚维明 薛国亚 靳朋刘 孙信锁 陈新奎 金纯� 于 2021-08-30 设计创作，主要内容包括：本发明公开了一种预制管桩桩端后压浆装置及施工方法,属于预制桩施工技术领域；压浆装置具体包括预制管桩压浆桩尖、环形压浆管以及竖向压浆管；其中,预制管桩压浆桩尖安装于预制桩的底端,且预制管桩压浆桩尖的桩周外侧连接有压浆环道,环形压浆管安装于压浆环道上,压浆环道的外侧连接有浆液扰流板,浆液扰流板与预制桩之间相对隔出向上倾斜一定角度的出浆间隙,环形压浆管的外侧设有若干个与出浆间隙相对应的出浆口；竖向压浆管内置于预制桩的中心空洞内,且其顶端延伸至地面并且连接压浆设备,竖向压浆管的底端与环形压浆管相连通。本发明具有能够在已施工的管桩上压注高压水泥浆,加固桩端及桩侧土体,大幅提高管桩承载力的优点。(The invention discloses a post-grouting device for a pile end of a precast tubular pile and a construction method, belonging to the technical field of precast pile construction; the grouting device specifically comprises a precast tubular pile grouting pile tip, an annular grouting pipe and a vertical grouting pipe; the grouting device comprises a precast pile, a grouting ring, a grouting pipe, a grouting baffle, a grouting pipe and a grouting pipe, wherein the grouting pipe is arranged at the bottom end of the precast pile; the vertical grouting pipe is arranged in a central cavity of the precast pile, the top end of the vertical grouting pipe extends to the ground and is connected with grouting equipment, and the bottom end of the vertical grouting pipe is communicated with the annular grouting pipe. The invention has the advantages that high-pressure cement paste can be injected on the constructed tubular pile by pressing, the pile end and the soil body on the pile side are reinforced, and the bearing capacity of the tubular pile is greatly improved.)

1. The utility model provides a prefabricated tubular pile stake end back mud jacking device which characterized in that includes: the pipe pile comprises a precast pipe pile mud jacking pile tip (1), an annular mud jacking pipe (2) and a vertical mud jacking pipe (6); the grouting device comprises a precast tubular pile grouting pile tip (1), a grouting loop (3), an annular grouting pipe (2), a grout spoiler (7) and a grout outlet gap (10), wherein the precast tubular pile grouting pile tip (1) is installed at the bottom end of a precast pile (9), the outer side of the pile circumference of the precast tubular pile grouting pile tip (1) is connected with the grouting loop (3), the grout outlet gap (10) is relatively separated from the precast pile (9) and is inclined upwards by a certain angle, and a plurality of grout outlets (8) corresponding to the grout outlet gap (10) are formed in the outer side of the annular grouting pipe (2); the vertical grouting pipe (6) is arranged in a central cavity of the precast pile (9), the top end of the vertical grouting pipe extends to the ground and is connected with grouting equipment, and the bottom end of the vertical grouting pipe (6) is communicated with the annular grouting pipe (2).

2. The precast tubular pile end post-grouting device according to claim 1, characterized in that the precast pile (9) is a precast tubular pile with a diameter of 600mm, the grout spoiler (7) is a wedge-shaped steel plate with a thickness of 10mm, the height of the steel plate is 60mm, and the width of the steel plate is 50 mm; the grouting device comprises a wedge section (71) and a fixed section (72), wherein the fixed section (72) is fixedly connected with the outer side of a grouting loop (3); the inclined wedge section (71) is integrally formed at the upper end of the fixed section (72), and a slurry outlet gap (10) is relatively separated between the inclined wedge surface of the inclined wedge section (71) and the precast pile (9).

3. The post-grouting device for precast tubular pile ends according to claim 2, characterized in that the bottom end of the vertical grouting pipe (6) is connected with a horizontal connecting horizontal pipe (61) through an elbow (62), one side of the precast tubular pile grouting pile tip (1) opposite to the annular grouting pipe (2) is provided with a horizontal connecting hole (63), and one end of the connecting horizontal pipe (61) far away from the elbow (62) penetrates through the horizontal connecting hole (63) and is communicated with the annular grouting pipe (2).

4. The precast tubular pile end post-grouting device according to claim 3, characterized in that the precast tubular pile grouting pile tip (1) is a steel annular structure with openings at the upper and lower ends, the outer diameter of the precast tubular pile grouting pile tip (1) is 534mm, the length is 100mm, and the thickness is 20 mm; precast tubular pile mud jacking stake point (1) sets up a plurality of stiffening rib board I (51), every along steel ring stake point inboard circumference stiffening rib board I (51) all adopt thickness 20mm, and right angle limit length is 50mm and 100 mm's triangle-shaped steel sheet respectively.

5. The precast tubular pile end post-grouting device according to claim 4, characterized in that the grouting ring (3) is a steel ring, an annular placing groove is defined by the grouting ring (3), the grout spoiler (7) and the precast tubular pile grouting pile tip (1), and the width of an inner side notch of the placing groove is 30-40 mm; annular mud jacking pipe (2) encircle to bury underground in annular standing groove, prefabricated tubular pile mud jacking stake point (1) outside is fixed all around and is set up a plurality of stiffening rib II (52), the bottom butt of mud jacking ring way (3) is in the upside of all stiffening rib II (52), every stiffening rib II (52) all adopt thickness 20mm, right angle limit length 44 mm's isosceles triangle steel sheet.

6. The precast tubular pile end post grouting device according to claim 5, characterized in that the annular grouting pipe (2) has a diameter of 566mm, a diameter of 32mm and a pipe wall thickness of 2.5 mm; a plurality of go out angle such as thick liquid mouth (8) and equally divide and set up in the upside of annular mud jacking pipe (2), wherein the quantity of play thick liquid mouth (8) is no less than 4, the trompil diameter 12mm of play thick liquid mouth (8) and its drill way outside are sealed through the rubber sleeve.

7. The precast tubular pile end post-grouting device according to claim 6, characterized in that the vertical grouting pipe (6) has a pipe diameter of 32mm and a wall thickness of 2.5 mm; a grouting pipe guard plate (4) fixedly connected with the pile end of the precast tubular pile grouting pile tip (1) is arranged below the connecting transverse pipe (61) to support the connecting transverse pipe (61) and an elbow (62) which are communicated with the vertical grouting pipe (6) and the annular grouting pipe (2); the mud jacking pipe protection plate (4) adopts an angle iron plate of 60x 60.

8. A grouting construction method based on the grouting device as claimed in any one of claims 1 to 7, characterized by comprising the following steps:

s1: connecting the whole grouting device with the pile end of the first section of the precast tubular pile; the upper end of the precast tubular pile mud jacking pile tip (1) is fixed at the lower side pile end of the first section of pile; one end of the vertical grouting pipe (6) is connected with the annular grouting pipe (2), and the other end of the vertical grouting pipe is led out of the pile end on the upper side of the first section of pile through a central hole of the precast pile;

s2: driving a first section of prefabricated pipe pile into a pile position; before the lower-section tubular pile is installed, a second section of vertical grouting steel pipe is fixed in the lower-section tubular pile in advance, and the top end of the vertical grouting pipe (6) is connected with the second section of vertical grouting steel pipe while the lower-section tubular pile is connected;

s3: constructing the other sections of the prefabricated pipe piles in sequence according to the method of the step S2, wherein the top ends of the vertical grouting pipes (6) are upwards connected with a plurality of sections of vertical grouting steel pipes in sequence until the construction of the pipe piles is finished; the upper end of the last section of vertical grouting steel pipe is led out to the ground through a central hole in the precast tubular pile;

s4: the rear grouting equipment is connected with the last section of vertical grouting steel pipe led out of the ground; starting a high-pressure pump, pressing cement paste into the annular grouting pipe (2) through a plurality of sections of connected vertical grouting steel pipes, and then pressing the cement paste to the pile side part of the precast tubular pile through a plurality of slurry outlets (8) and slurry outlet gaps (10);

s5: and after the pressing-in amount of the cement slurry reaches the preset requirement, closing the high-pressure pump, and stopping the grouting construction.

9. The grouting construction method according to claim 8, wherein in step S1, the upper end of the precast tubular pile grouting pile tip (1) is welded and fixed to the lower pile end of the first pile.

10. The grouting construction method according to claim 8, wherein in step S4, a plurality of the grout outlets (8) are formed by punching inclined at 45 ° with respect to the horizontal plane while ensuring that the center line of the hole intersects with the center line of the annular grouting pipe (2).

Technical Field

The invention relates to the technical field of precast tubular pile construction, in particular to a precast tubular pile end post-grouting device and a construction method.

Background

At present, the precast tubular pile has been widely applied in the fields of building engineering, bridge engineering and traffic engineering due to the advantages of high pile body strength, reliable quality, high construction speed and the like. However, in the deep soft soil layer area, because the bedrock is buried deeply, the precast pile is difficult to pass through some compact sand layers in the construction process, great difficulty is caused to pile-forming construction, and waste piles are easy to generate due to poor control. The construction application of the precast tubular pile has certain limitation, and in order to reduce the problem of environmental pollution of the traditional cast-in-situ bored pile in the pile forming process, the problem of application limitation of the precast tubular pile under specific conditions needs to be solved, the bearing capacity of the precast tubular pile is improved by post grouting within the controllable pile length range, and the aims of saving the pile length and reducing the manufacturing cost are fulfilled.

Before the invention, the Chinese utility model (patent application number: 201621422036. X) discloses a post-grouting tubular pile which is characterized in that the pile end of a tubular pile body is provided with an end plate, a T-shaped groove and a plurality of evenly distributed end plate holes are sequentially and circumferentially arranged outwards from the axis of the end plate, the ear part of the T-shaped groove forms a sealing groove for filling a rubber sealing strip, the pile tip is conical, the grouting pipe comprises two symmetrical pile end grouting pipes and two symmetrical pile side grouting pipes, and the four grouting pipes are arranged in a cross shape. The above technical solution has the following disadvantages: (1) the post-grouting pipe pile needs engineering customization, and for project engineering with short construction period, the project requirements are difficult to meet in factory production; (2) the pipe pile mould has higher precision requirement, and increases the construction difficulty of the pipe pile joint.

Chinese patent (patent application number: 201710470201.1) discloses a tubular pile with post-grouting pipes and a construction method thereof, which is characterized in that grouting holes are formed among steel piles, the grouting pipes are symmetrically arranged inside a tubular pile body by taking the axis of the tubular pile body as the center, and a plugging plate which is used for covering the grouting holes and can be pushed open by grouting pressure is spot-welded at the position corresponding to the grouting holes. The method has the following defects: (1) the grouting holes are vertically formed in the tubular pile end plates, and in the tubular pile construction process, due to the fact that vertical pressure is large, grouting plugging plates are difficult to open in the later period of grouting; (2) one grouting hole corresponds to one grouting pipe, and the number of the grouting pipes is large, so that the method is not economical. (3) The slip casting pipe sets up inside the tubular pile, and the tubular pile production degree of difficulty increases, and different model tubular piles need adjust production mould alone.

Therefore, a post-grouting device and a construction method which can fully utilize the characteristics of high strength and high construction speed of the precast tubular pile and have the advantages of cost and construction period without changing the existing tubular pile production technology are urgently needed. The invention can be used under the condition to effectively solve the technical problems.

Disclosure of Invention

The invention provides a post-grouting device for the pile end of a precast tubular pile and a construction method thereof, aiming at the defects in the prior art.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention firstly discloses a post-grouting device for the pile end of a precast tubular pile, which comprises: prefabricating a pipe pile grouting pile tip, an annular grouting pipe and a vertical grouting pipe; the prefabricated pipe pile grouting pile comprises a prefabricated pile, a prefabricated pipe pile grouting pile tip, a grouting ring, an annular grouting pipe, a grout spoiler, a plurality of grout outlets and a plurality of grouting holes, wherein the prefabricated pipe pile grouting pile tip is arranged at the bottom end of the prefabricated pile, the outer side of the pile circumference of the prefabricated pipe pile grouting pile tip is connected with the grouting ring, the annular grouting pipe is arranged on the grouting ring, the outer side of the grouting ring is connected with the grout spoiler, the grout outlets are relatively separated from the prefabricated pile and upwards inclined by a certain angle, and the outer side of the annular grouting pipe is provided with the grout outlets corresponding to the grout outlets; the vertical grouting pipe is arranged in a central cavity of the precast pile, the top end of the vertical grouting pipe extends to the ground and is connected with grouting equipment, and the bottom end of the vertical grouting pipe is communicated with the annular grouting pipe.

In order to optimize the technical scheme, the specific measures adopted further comprise:

furthermore, the precast pile is a precast tubular pile with the diameter of 600mm, the slurry spoiler is a wedge-shaped steel plate with the thickness of 10mm, the height of the steel plate is 60mm, and the width of the steel plate is 50 mm; the grouting device comprises a wedge section and a fixed section, wherein the fixed section is fixedly connected with the outer side of a grouting loop; the wedge section is integrally formed at the upper end of the fixed section, and a slurry outlet gap is relatively separated between the wedge surface of the wedge section and the precast pile.

Further, the bottom of vertical mud jacking pipe is connected with the horizontally and connects violently the pipe through the elbow, the one side relative with annular mud jacking pipe on the precast tubular pile mud jacking stake point is equipped with the cross-connection hole, the one end of connecting violently the pipe and keeping away from the elbow passes the cross-connection hole and is linked together with annular mud jacking pipe.

Furthermore, the precast tubular pile mud jacking pile tip is of a steel annular structure with openings at the upper end and the lower end, the outer diameter of the precast tubular pile mud jacking pile tip is 534mm, the length is 100mm, and the thickness is 20 mm; precast tubular pile mud jacking stake point sets up a plurality of stiffening rib I, every along steel ring stake point inboard circumference stiffening rib I all adopts thickness 20mm, and right angle limit length is 50mm and 100 mm's triangle-shaped steel sheet respectively.

Furthermore, the grouting loop is a steel loop, an annular placing groove is defined by the grouting loop, the grout spoiler and the precast tubular pile grouting pile tip, and the width of an inner side notch of the placing groove is 30-40 mm; annular mud jacking pipe encircles and buries underground in annular standing groove, prefabricated tubular pile mud jacking stake point outside is fixed all around and is set up a plurality of stiffening rib II, the bottom butt of mud jacking ring way in the upside of all stiffening rib II, every stiffening rib II all adopts thickness 20mm, right angle limit length 44 mm's isosceles triangle steel sheet.

Further, the diameter of the annular grouting pipe is 566mm, the diameter of the annular grouting pipe is 32mm, and the pipe wall thickness is 2.5 mm; a plurality of go out the angle such as thick liquid mouth and equally divide and set up in the upside of annular mud jacking pipe, wherein the quantity of play thick liquid mouth is no less than 4, the trompil diameter 12mm of play thick liquid mouth and its drill way outside are sealed through the rubber sleeve.

Further, the diameter of the vertical grouting pipe is 32mm, and the wall thickness is 2.5 mm; a grouting pipe guard plate fixedly connected with the pointed pile end of the precast tubular pile grouting pile is arranged below the connecting transverse pipe so as to support the connecting transverse pipe and the elbow which are communicated with the vertical grouting pipe and the annular grouting pipe; the mud jacking pipe guard plate adopts a 60x60 angle iron plate.

The invention also discloses a grouting construction method based on the grouting device, which comprises the following steps:

s1: connecting the whole grouting device with the pile end of the first section of the precast tubular pile; the upper end of the precast tubular pile mud jacking pile tip is fixed at the lower side pile end of the first section of pile; one end of the vertical grouting pipe is connected with the annular grouting pipe, and the other end of the vertical grouting pipe is led out of the pile end on the upper side of the first pile section through a central hole of the precast pile;

s2: driving a first section of prefabricated pipe pile into a pile position; before installing a lower-section tubular pile, fixing a second section of vertical grouting steel pipe in the lower-section tubular pile in advance, and connecting the top end of the vertical grouting pipe with the second section of vertical grouting steel pipe while pile splicing of the lower-section tubular pile;

s3: constructing the other sections of the prefabricated pipe piles in sequence according to the method of the step S2, wherein the top ends of the vertical grouting pipes are upwards connected with a plurality of sections of vertical grouting steel pipes in sequence until the pipe pile construction is finished; the upper end of the last section of vertical grouting steel pipe is led out to the ground through a central hole in the precast tubular pile;

s4: the rear grouting equipment is connected with the last section of vertical grouting steel pipe led out of the ground; starting a high-pressure pump, pressing cement paste into the annular grouting pipe through a plurality of sections of connected vertical grouting steel pipes, and then pumping the cement paste to the pile side part of the precast tubular pile through a plurality of slurry outlets and slurry outlet gaps;

s5: and after the pressing-in amount of the cement slurry reaches the preset requirement, closing the high-pressure pump, and stopping the grouting construction.

In order to optimize the technical scheme, the specific measures adopted further comprise:

further, in step S1, the upper end of the precast tubular pile grouting pile tip is welded and fixed to the lower pile end of the first pile.

Further, in step S4, a plurality of the slurry outlets are formed by drilling holes inclined by 45 ° with respect to the horizontal plane, while ensuring that the center line of the holes intersects with the center line of the annular grouting pipe.

Compared with the prior art, the invention has the beneficial effects that:

1. on the premise of not changing the existing tubular pile structure, cement slurry is pressed into the pile by matching the multiple sections of vertical grouting pipes with the annular grouting pipe in the rear grouting device, wherein the grouting direction is inclined upwards by a certain angle by arranging and matching the slurry spoiler and the slurry outlet, so that the following technical problems can be solved: (1) the soil body on the upper pile side can be disturbed due to piling during piling, and the disturbed soil body can be reinforced by injecting cement slurry emulsion along the grouting direction; (2) the slurry can be prevented from entering the holes at the end part of the tubular pile, so that the reinforcing effect is reduced; (3) because the section of the tubular pile is smaller than that of a cast-in-place pile, the bearing capacity mainly depends on the friction force of the pile side, and the slurry is used for reinforcing the pile side, so that the bearing capacity of the pile foundation can be effectively improved; (4) and the grout is discharged upwards from the side surface instead of the vertical direction of the pile end, so that better filling effect can be realized with lower pressure.

2. According to the invention, on the basis of the traditional prefabricated pipe pile, the grouting device is arranged at the tail end of the pipe pile section, so that high-pressure cement slurry is injected under pressure after the pipe pile construction is completed, the stress performance of the pipe pile is improved, the low carbon and environmental protection are realized, and the design length of the pipe pile can be greatly reduced.

3. According to the invention, the traditional precast tubular pile is used, the production die does not need to be adjusted independently in the design and production of the tubular pile, the production cost is not increased, and meanwhile, the number of grouting pipes is small, so that the better economical efficiency can be ensured and the construction period advantage is achieved.

Drawings

Fig. 1 is a schematic view of an integral assembly structure of a precast pile end post-grouting device and a precast pile according to the present invention;

FIG. 2 is a schematic view of the sectional assembly structure of the precast pile end post-grouting device and the precast pile of the present invention;

fig. 3 is a schematic top view of the precast tubular pile end post-grouting device of the present invention;

FIG. 4 is a schematic structural view of the precast tubular pile grouting pile tip in FIG. 3;

FIG. 5 is a schematic view of the connection structure of the annular grouting pipe and the vertical grouting pipe in FIG. 2;

FIG. 6 is a schematic side sectional view of the slurry spoiler of FIG. 2;

FIG. 7 is a schematic front view of the slurry spoiler shown in FIG. 2;

fig. 8 is a front view schematically showing the structure of the mud jacking pipe protecting plate in fig. 1.

The label names in the figure: precast tubular pile mud jacking stake point 1, annular mud jacking pipe 2, mud jacking ring road 3, mud jacking pipe backplate 4, stiffening rib board I51, stiffening rib board II 52, vertical mud jacking pipe 6, connect horizontal pipe 61, elbow 62, horizontal connecting hole 63, thick liquid spoiler 7, slide wedge section 71, fixed section 72, grout outlet 8, precast pile 9, play thick liquid clearance 10.

Detailed Description

The present invention will now be described in further detail with reference to the accompanying drawings.

It should be noted that the terms "upper", "lower", "left", "right", "front", "back", etc. used in the present invention are for clarity of description only, and are not intended to limit the scope of the present invention, and the relative relationship between the terms and the terms is not limited by the technical contents of the essential changes.

The first embodiment:

in this embodiment, the technical requirements for installation and construction of the precast tubular pile and the like are not described herein again, and the embodiments of the device related to the present invention are mainly explained; the invention will be described in detail with reference to fig. 1-8 and using a precast tubular pile with a diameter of 600mm as an example.

Referring to fig. 1 to 3, the present embodiment first discloses a post-grouting device for a precast tubular pile, which specifically includes: prefabricating a pipe pile grouting pile tip 1, an annular grouting pipe 2 and a vertical grouting pipe 6; the prefabricated pipe pile grouting pile tip 1 is installed at the bottom end of a prefabricated pile 9, the outer side of the pile periphery of the prefabricated pipe pile grouting pile tip 1 is connected with a grouting loop 3, an annular grouting pipe 2 is installed on the grouting loop 3, the outer side of the grouting loop 3 is connected with a grout spoiler 7, a grout outlet gap 10 which is inclined upwards by a certain angle is formed between the grout spoiler 7 and the prefabricated pile 9, and a plurality of grout outlets 8 corresponding to the grout outlet gap 10 are formed in the outer side of the annular grouting pipe 2; vertical mud jacking pipe 6 is arranged in the central cavity of precast pile 9, and the top end of vertical mud jacking pipe extends to the ground and is connected with mud jacking equipment, and the bottom end of vertical mud jacking pipe 6 is linked together with annular mud jacking pipe 2.

Referring to fig. 6 to 7, the slurry spoiler 7 is a wedge-shaped steel plate with a thickness of 10mm, a height of 60mm and a width of 50 mm; the grouting device comprises a wedge section 71 and a fixed section 72, wherein the fixed section 72 is fixedly connected with the outer side of the grouting loop 3; the wedge section 71 is integrally formed at the upper end of the fixed section 72, and a slurry outlet gap 10 is relatively separated between the wedge surface of the wedge section 71 and the precast pile 9.

Referring to fig. 5, the bottom end of the vertical grouting pipe 6 is connected to a horizontal connecting horizontal pipe 61 through an elbow 62, a lateral connecting hole 63 is formed in one side of the precast tubular pile grouting pile tip 1 opposite to the annular grouting pipe 2, and one end of the connecting horizontal pipe 61 far away from the elbow 62 penetrates through the lateral connecting hole 63 and is communicated with the annular grouting pipe 2.

Referring to fig. 1, 2 and 4, the precast tubular pile grouting pile tip 1 is a steel annular structure with openings at the upper end and the lower end, and the precast tubular pile grouting pile tip 1 has an outer diameter of 534mm, a length of 100mm and a thickness of 20 mm; the precast tubular pile mud jacking pile tip 1 is circumferentially provided with a plurality of stiffening rib plates I51 along the inner side of the steel ring pile tip so as to ensure the structural rigidity of the pile tip in the precast pile construction process; each stiffening rib plate I51 is a triangular steel plate with the thickness of 20mm and the lengths of right-angle sides of 50mm and 100mm respectively.

Referring to fig. 3, the grouting loop 3 is a steel loop, an annular placing groove is defined by the grouting loop 3, the grout spoiler 7 and the precast tubular pile grouting pile tip 1, and the width of an inner side notch of the placing groove is 30-40 mm; annular mud jacking pipe 2 encircles and buries underground in annular standing groove, because of the outstanding tubular pile outside of mud jacking ring road 3, for ensureing that it has sufficient structural rigidity in the work progress, 1 outside of mud jacking stake point is fixed all around and is set up a plurality of stiffening rib II 52, and mud jacking ring road 3's bottom butt in the upside of all stiffening rib II 52, and every stiffening rib II 52 all adopts thickness 20mm, right angle limit length 44 mm's isosceles triangle steel sheet.

In the embodiment, the diameter of the annular grouting pipe 2 is 566mm, the diameter is 32mm, and the wall thickness of the pipe is 2.5 mm; a plurality of go out thick liquid mouth 8 isoangles and equally divide and set up in the upside of annular mud jacking pipe 2, wherein the quantity of going out thick liquid mouth 8 is no less than 4, goes out the trompil diameter 12mm of thick liquid mouth 8 and passes through the rubber sleeve outside its drill way and seal.

Referring to fig. 1, 2 and 8, the vertical grouting pipe 6 has a pipe diameter of 32mm and a wall thickness of 2.5 mm; the lower part of the connecting transverse pipe 61 is provided with a mud jacking pipe guard plate 4 fixedly connected with the pile end of the precast tubular pile mud jacking pile tip 1 so as to support the connecting transverse pipe 61 and the elbow 62 which are communicated with the vertical mud jacking pipe 6 and the annular mud jacking pipe 2, and the mud jacking pipe guard plate 4 adopts an angle iron plate of 60x 60.

Second embodiment:

the embodiment also discloses a grouting construction method based on the device, which specifically comprises the following steps:

step S1: connecting the whole grouting device with the pile end of the first section of the precast tubular pile; wherein the upper end of the precast tubular pile mud jacking pile tip 1 is fixed at the lower side pile end of the first section of pile; one end of the vertical grouting pipe 6 is connected with the annular grouting pipe 2, and the other end of the vertical grouting pipe is led out of the pile end on the upper side of the first pile section through a central hole of the precast pile;

step S2: driving a first section of prefabricated pipe pile into a pile position; before the lower-section tubular pile is installed, a second section of vertical grouting steel pipe is fixed in the lower-section tubular pile in advance, and the top end of the vertical grouting pipe 6 is connected with the second section of vertical grouting steel pipe while the lower-section tubular pile is connected;

step S3: constructing the other sections of the prefabricated pipe piles in sequence according to the method of the step S2, wherein the top ends of the vertical grouting pipes 6 are sequentially connected with a plurality of sections of vertical grouting steel pipes upwards until the construction of the pipe piles is finished; the upper end of the last section of vertical grouting steel pipe is led out to the ground through a central hole in the precast tubular pile;

step S4: the rear grouting equipment is connected with the last section of vertical grouting steel pipe led out of the ground; starting the high-pressure pump, pressing cement paste into the annular grouting pipe 2 through a plurality of sections of connected vertical grouting steel pipes, then pressing the cement paste into the precast tubular pile through a plurality of slurry outlets 8 and slurry outlet gaps 10, and reinforcing soil around the pile end through the high-pressure cement paste so as to achieve the purpose of improving the bearing capacity of the tubular pile;

step S5: and after the pressing-in amount of the cement slurry reaches the preset requirement, closing the high-pressure pump, and stopping the grouting construction.

Preferably, in step S1, the upper end of the precast tubular pile grouting pile tip 1 is welded and fixed to the lower pile end of the first pile.

Preferably, referring to fig. 5, in step S4, a plurality of slurry outlets 8 are formed by punching holes inclined at 45 ° with respect to the horizontal plane, while ensuring that the center lines of the holes intersect with the center line of the annular pressing pipe 2, so as to reduce the influence of the multiple punching holes on the structural strength of the annular pressing pipe 2.

In the description of the present invention, it should be noted that unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may for example be fixedly connected, detachably connected, or integrally connected, mechanically connected, or indirectly connected through an intermediate medium. The specific meaning of the above terms in the creation of the present invention can be understood by those of ordinary skill in the art through specific situations.

The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-mentioned embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may be made by those skilled in the art without departing from the principle of the invention.