CN111519618A - Post-grouting device for prestressed pipe pile and construction method thereof - Google Patents

Abstract

The present invention discloses a post-grouting device for prestressed pipe piles, which relates to the field of building construction and includes: a slurry discharge steel pipe, a slurry discharge steel pipe sealing plate, a rib plate, a pile sealing plate, a grouting device, and a grouting pipe; one end of the slurry discharge steel pipe is connected to one side of the pile sealing plate, and the other end of the slurry discharge steel pipe is closed by the slurry discharge steel pipe sealing plate. The wall of the slurry discharge steel pipe includes a slurry discharge hole, and a through hole is provided on the other side of the pile sealing plate opposite to the slurry discharge steel pipe. The grouting device is inserted into the slurry discharge steel pipe through the through hole, and the coarse sand is poured into the interior of the slurry discharge steel pipe. The grouting pipe is connected to the grouting device; the rib plate is vertically connected to the pile sealing plate, and there is at least one rib plate. The technical effect of the present invention is that: there is no need to carry out cement-soil mixing pile construction, and the post-grouting of the pile bottom can be carried out at any time, does not occupy an absolute construction period, and is more efficient in construction. Compared with the existing post-grouting device, the material usage is reduced, the processing is simple, and the installation cost is low.

Description

Post-grouting device for prestressed pipe pile and construction method thereof

technical field

The invention relates to the field of building construction, in particular to a post-grouting device for prestressed pipe piles and a construction method thereof.

Background technique

The prestressed hollow square piles and prestressed tubular piles are processed by the factory, and the piles are driven by static pressure and hammering methods. They have the characteristics of high pile body strength, efficient construction and reliable quality. Because of its high-grade concrete and high compressive bearing capacity, it is widely used in compressive piles in engineering construction. However, due to the weak bond between the pile body and the weak soil layer, the bearing capacity of the foundation in many projects is far less than the strength of the pile body, resulting in a waste of resources. For this reason, engineers and technicians urgently need to develop methods to improve the bearing capacity of precast pile foundations. There are mainly two existing methods:

(1) Stiff composite pile: First, construct a cement-soil mixing pile at the design pile position, and then implant the prefabricated pile body into the cement-soil mixing pile to form a rigid composite pile. The method is mainly to reinforce the soft soil layer with cement-soil mixing piles in advance, thereby improving the occlusal force between the pile body and the soil body, thereby improving the bearing capacity of the foundation.

This method has defects that need to be improved: 1) a construction link is added, which reduces the construction work efficiency; 2) the construction of cement-soil mixing piles requires a large amount of cement, and the cost is high; 3. Prefabricated piles implanted in cement-soil mixing piles will also discharge a large amount of cement and soil. Great environmental impact.

(2) Post-grouting at the bottom of the pile: This method is inspired by the post-grouting technology of bored piles to improve the bearing capacity of the pile foundation. . The construction technology of prefabricated piles with grouting device is mainly used. After the static pressure pile driving is completed, the post-grouting of the pile side and the post-grouting of the pile bottom are carried out, so as to improve the bearing capacity of the foundation.

The method is mainly applied to prestressed pipe piles, and its key technology is a post-grouting device, which can perform post-grouting at the bottom of the pile and post-grouting at the side of the pile at the same time. Its main composition is a steel pipe with sealing plates at both ends, in which the end welded with the prefabricated pile bottom plate is welded through the grouting pipe, and then connected with the grouting pipe inserted into the pile body by threaded connection, so as to carry out grouting, and the other end can be welded to the pile. The grouting hole is set around the grouting device, and the bottom of the pile is grouted. The ear guards are set near the grouting hole to prevent the grouting pressure on the bottom of the pile after the earthwork of the side wall is compacted during the pile pressing process. Influence; 2 pile side grouting pipes are welded on the side of the grouting device close to the prefabricated pile, so that the pile side can be grouted after the pile side; the outer side of the grouting device is welded with a stiffened steel plate to improve the strength and rigidity of the grouting device and ensure the bearing during the pile pressing process. Capability; the inside of the grouting device is filled with stones at the same time to improve the compressive strength of the grouting device.

SUMMARY OF THE INVENTION

In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to provide a material-saving and environmentally friendly post-grouting device for prestressed pipe piles.

In order to achieve the above purpose, the present invention provides a post-grouting device for prestressed pipe piles, including: grout-out steel pipe, grout-out steel pipe sealing plate, rib plate, pile sealing plate, grouting device, grouting pipe, and coarse sand;

One end of the slurrying steel pipe is connected to one side of the pile sealing plate, the other end of the slurrying steel pipe is closed by the slurrying steel pipe sealing plate, the wall of the slurrying steel pipe includes a slurrying hole, and the pile A through hole is formed on the opposite side of the sealing plate and the slurry steel pipe, the grouting device is inserted into the slurry steel pipe through the through hole, and the coarse sand is poured into the slurry steel pipe. The grouting pipe is connected with the grouting device; the rib is vertically connected with the surface of the pile sealing plate and the periphery of the grouting steel pipe, and the rib is at least one.

Further, the ribs are cross-shaped.

Further, there are multiple pulping holes.

Further, the grouting device includes a check valve.

Further, one end of the grouting pipe connected to the grouting device includes a connecting thread.

Further, the corners of the ribs are chamfered.

The invention also discloses a construction method using the aforementioned prestressed pipe pile post-grouting device, comprising:

Weld the post-grouting device of the prestressed pipe pile with the pile body;

Connect the grouting pipe to the grouting device;

The grouting-expanded prestressed pipe pile and the grouting pipe are sunk into the soil by the direct pile driving process until the pile is driven to the design elevation;

The cement slurry is injected, and the cement slurry is grouted to the bottom of the pile through the grouting pipe and the post-grouting device of the prestressed pipe pile to form a squeeze-expanded section at the bottom of the pile.

Further, the cement slurry adopts P42.5 cement, and the water-cement ratio is between 0.55 and 0.60.

Further, the direct pile driving process is a static pressure process or a hammering process.

The technical effect of the invention is that: no cement-soil mixing pile construction is required, grouting after the pile bottom can be carried out at any time, no absolute construction period is occupied, and construction is more efficient. Especially compared with the existing post-grouting device, the material usage is reduced, the processing is simple, and the installation cost is low.

The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings, so as to fully understand the purpose, characteristics and effects of the present invention.

Description of drawings

Other features, objects and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

1 is a cross-sectional view of a post-grouting device according to an embodiment of the present invention;

2 is a top view of a post-grouting device according to an embodiment of the present invention;

3 is a sectional view of an embodiment of the present invention in a construction state.

Description of reference numerals: 100-post grouting device; 200-pile body; 1-pile sealing plate; 2-rib plate; 3-grouting steel pipe; 4-grouting steel pipe sealing plate; 5-grouting device; 6- Grouting pipe; 7-coarse sand; 10-opening; 20-welding surface.

Detailed ways

The following describes several preferred embodiments of the present invention with reference to the accompanying drawings, so as to make its technical content clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, and the protection scope of the present invention is not limited to the embodiments mentioned herein.

In the drawings, structurally identical components are denoted by the same numerals, and structurally or functionally similar components are denoted by like numerals throughout. The size and thickness of each component shown in the drawings are arbitrarily shown, and the present invention does not limit the size and thickness of each component. In order to make the illustration clearer, the thicknesses of components are appropriately exaggerated in some places in the drawings.

As shown in Figures 1 and 2, the present invention discloses a post-grouting device for prestressed pipe piles, comprising: a grout-out steel pipe 3, a grout-out steel pipe sealing plate 4, a rib plate 2, a pile sealing plate 1, and a grouting device 5. Grouting pipe 6, Coarse sand 7.

The pulping steel pipe 3 is a hollow steel pipe, one end of the pulping steel pipe 3 is connected to one side of the pile sealing plate 1, the other end of the pulping steel pipe 3 is closed by the pulping steel pipe sealing plate 4, and the pipe wall of the pulping steel pipe 3 includes a plurality of outlet pipes. Slurry hole 30; a through hole 10 is provided on the opposite side of the pile sealing plate 1 and the slurry steel pipe 3, the grouting device 5 is inserted into the slurry steel pipe 3 through the through hole 10, and the slurry steel pipe 3 is filled with coarse sand 7, and the injection The slurry pipe 6 is connected with the grouting device 7; the rib plate 2 is vertically connected with the pile sealing plate 1, and the rib plate 2 is at least one. Preferably, the particle size of the coarse sand 7 should be larger than the diameter of the slurry outlet hole 30 to prevent the coarse sand from leaking out of the slurry outlet hole 30 .

The grout hole 30 can be multiple and distributed around the pipe wall of the grout steel pipe 30, for when the grout 5 is grouting, the cement slurry overflows from the grout hole 30 into the soil, and penetrates the soil around the pile. Therefore, the soil around the pile body undergoes top pressure and expansion under the action of high-pressure cement slurry, and gradually strengthens the circumference of the pile and changes the consolidation state of the soil around the pile. This increases the pullout resistance and bearing capacity of the pipe pile. In a preferred embodiment, there are multiple pulping holes 30, and the diameter of each pulping hole 30 is 8-10 mm.

Since the slurrying steel pipe 3 is a hollow steel pipe, since the slurrying steel pipe 3 is in direct contact with the soil and bears the most force, it needs to be reinforced during pile driving. In this embodiment, coarse sand 7 is used to fill the grout steel pipe 3 to strengthen the rigidity of the grout steel pipe 3 to ensure that the pile is not damaged. Does not affect grouting pressure. In addition, the coarse sand 7 is also used to block the slurry hole 30 during pile driving, so as to avoid the soil mass being pressed into the slurry steel pipe 3 with the pile driving during the pile driving process. Therefore, the coarse sand 7 should be in the slurry steel pipe 3. dense.

Further, the ribs 2 are multiple and cross-shaped, so as to further break the soil and increase the pressure of the pipe pile during the pile driving process.

Further, the diameter of the slurry steel pipe sealing plate 4 is larger than the diameter of the slurry steel pipe 3 . Therefore, it is convenient to connect the slurry steel pipe sealing plate 4 and the slurry steel pipe 3, preferably by welding.

Further, the grouting device 5 includes a check valve to prevent backflow of the cement slurry injected from the grouting pipe 7 .

Further, in order to fix the grouting pipe 7 and the grouting device 5 and prevent the grouting pipe 7 from deviating from the grouting device 5 during the pile driving process, threads can be machined on the end of the grouting pipe 7. The grouting device 5 is screwed.

Further, the corners of the rib 2 are chamfered to reduce the resistance of the pile body to the soil when the pile is driven.

Further, the pile body 200 and the rear grouting device 100 are separated, so the pile body 200 and the rear grouting device 100 can be manufactured separately in the factory and transported to the construction site, and directly welded and connected at the construction site, as shown in FIG. 3 . The pile body 200 and the welding surface 20 with the post grouting device 100 are formed.

The invention also discloses a construction method using the aforementioned prestressed pipe pile post-grouting device, comprising:

Step S201: welding the post-grouting device 100 and the pile body 200;

Step S202: connect the grouting pipe 6 to the grouting device 5;

Step S203: using the direct pile driving process to sink the grouting-expanded prestressed pipe pile and the grouting pipe into the soil until the pile is driven to the design elevation;

Step S204 : injecting cement slurry, and the cement slurry flows along the grouting pipe to the bottom of the post-grouting device for the prestressed pipe pile to form a squeeze-expanded section at the bottom of the pile.

The cement slurry can be injected into the grouting pipe 6 using a high pressure grouting pump. The above construction method reduces the concrete pouring or mud replacement link in the conventional pile driving, the construction method is simple, and the cement slurry is directly injected through the grouting pipe 6 and overflows from the grout hole 30, which reduces the amount of cement slurry and controls. The flow path of the cement slurry is reduced, the material consumption of the cement slurry is reduced, the cost is reduced, and the impact on the environment is also very small. force. The direct pile driving process adopted in the construction method includes static pressure or hammering process, the construction equipment is simple and the adaptability is wide.

Further, the cement slurry adopts P42.5 cement, and the water-cement ratio is between 0.55 and 0.60. Among them, P42.5 refers to the strength grade of ordinary Portland cement, that is, the 28-day compressive strength standard of ordinary Portland cement is not less than 42.5 MPa.

When preparing the cement slurry, attention should be paid to stirring to ensure that the slurry does not segregate. The mixing system used should have two slurry buckets (mixing bucket and slurry bucket). Equipped with a stirring system, the slurry storage time in the slurry bucket should not exceed 3 hours. During grouting, the grouting pressure and grouting rate should be strictly controlled. The control standard for termination of grouting adopts the double control standard of grouting amount and grouting pressure. The grouting flow should not exceed 50L/min and not lower than the design requirements. The pressure is controlled at 1.0～1.8Mpa.

The preferred embodiments of the present invention have been described in detail above. It should be understood that many modifications and changes can be made according to the concept of the present invention by those skilled in the art without creative efforts. Therefore, all technical solutions that can be obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the prior art according to the concept of the present invention shall fall within the protection scope determined by the claims.

Claims (9)

1. The utility model provides a slip casting device behind prestressed pipe pile which characterized in that includes: the grouting steel pipe, the grouting steel pipe sealing plate, the rib plate, the pile sealing plate, the grouting device, the grouting pipe and coarse sand;

one end of the grout outlet steel pipe is connected with one surface of the pile sealing plate, the other end of the grout outlet steel pipe is sealed through the grout outlet steel pipe sealing plate, the pipe wall of the grout outlet steel pipe comprises a grout outlet, the other surface, opposite to the grout outlet steel pipe, of the pile sealing plate is provided with a through hole, the grouting device penetrates through the through hole and is inserted into the grout outlet steel pipe, coarse sand is poured into the grout outlet steel pipe, and the grouting pipe is connected with the grouting device; the ribbed slab is vertically connected with the surface of the pile sealing plate and the periphery of the slurry outlet steel pipe, and at least one ribbed slab is arranged.

2. The post-grouting device for the prestressed pipe pile of claim 1, wherein the rib plate is cross-shaped.

3. The post-grouting device for the prestressed pipe pile according to claim 1, wherein the number of the grout outlet holes is plural.

4. The post-grouting device for a prestressed pipe pile according to claim 1, wherein said grouting device includes a check valve.

5. The post-grouting device for a prestressed pipe pile according to claim 1, wherein one end of the grouting pipe connected with the grouting device includes a connection thread.

6. The post-grouting device for the prestressed pipe pile according to claim 1, wherein the corners of the rib plates are chamfered.

7. A construction method using the post-grouting apparatus for a prestressed pipe pile according to any one of claims 1 to 6, comprising:

welding the post-grouting device of the prestressed pipe pile with a pile body;

connecting the grouting pipe with a grouting device;

adopting a direct pile sinking process to sink the grouting squeezing-expanding prestressed pipe pile and the grouting pipe into a soil body until the pile is sunk to the designed elevation;

and (3) injecting cement slurry, wherein the cement slurry flows to the bottom of the post-grouting device of the prestressed pipe pile along the grouting pipe, and a squeezing and expanding section is formed at the bottom of the pile.

8. The construction method using the post-grouting device for the prestressed pipe pile as claimed in claim 7, wherein the cement paste is P42.5 cement, and the water cement ratio is between 0.55 and 0.60.

9. The construction method using the post-grouting device for the prestressed pipe pile according to claim 7, wherein the direct pile sinking process is a static pressure process or a hammering process.

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