A precast core filling and reinforcement structure for PHC pipe piles and a construction method

Abstract

A prefabricated core-filling reinforcement structure and construction method for a PHC pipe pile, comprising a pipe pile, a core-filling structure, a grouting material and a grouting structure, wherein the core-filling structure is filled in the damaged position of the pile foundation of the pipe pile, the core-filling structure is a prefabricated cylindrical reinforced concrete structure, steel strips are obliquely inserted around the core-filling structure, a perforated steel plate is pre-buried on the top of the core-filling structure, a flat hole is opened at the bottom of the core-filling structure, a through hole is arranged between the perforated steel plate at the top and the flat hole at the bottom of the core-filling structure, a grouting ring is arranged around the bottom of the core-filling structure below the flat hole, and grouting material is filled between the core-filling structure and the inner wall of the pipe pile. The core-filling structure of the present invention can be filled to a specific damaged position of the pipe pile as required, a steel strip is arranged on the outer periphery of the core-filling structure, and after the core-filling structure is lowered into the pipe pile, the deformation of the steel strip plays a role of friction with the inner wall of the pipe pile, so that the core-filling structure can be fixed to any position, local construction, less core-filling material consumption, short maintenance time, simple construction process, and greatly improve the construction speed of the pipe pile.

Description

Technical Field

[0001] The present invention relates to the field of precast pile foundation construction, and particularly to a precast core filling and strengthening structure and construction method for PHC pipe piles. Background Art

[0002] High-strength prestressed pipe piles, namely PHC pipe piles, are precast pipe pile structures with prestress. They are widely used in foundation engineering and foundation pit support fields due to their high strength and fast construction speed. In recent years, the maximum single-section length of PHC pipe piles has reached 56m, and the total driving depth can reach up to hundreds of meters. With the increase in driving depth and the existence of hard strata during driving, PHC pipe piles are prone to quality problems such as cracking, crushing, and pile breakage within the pile body length, resulting in insufficient pile foundation integrity and bearing capacity.

[0003] In response to the above problems, the existing method can adopt the method of core filling to strengthen the pipe piles. The general way of strengthening is to lower the core filling steel reinforcement cage and pour concrete in the pile. However, the above method cannot achieve local construction, the amount of core filling material used is large, and the construction process is complex, and the concrete curing time is long, which is contrary to the characteristics of fast pipe pile construction speed. Summary of the Invention

[0004] In order to solve the above problems, the present invention provides an economic, simple and fast-constructing precast core filling and strengthening structure and construction method for PHC pipe piles.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A precast core filling and strengthening structure for PHC pipe piles includes a pipe pile, a core filling structure, grouting material, and a grouting structure. The core filling structure is stuffed at the damaged position of the pile foundation of the pipe pile. The core filling structure is a precast cylindrical reinforced concrete structure. Steel strips are obliquely inserted around the core filling structure. A perforated steel plate is embedded at the top of the core filling structure. A flat hole is opened at the lower part of the core filling structure. A through hole is provided between the perforated steel plate at the top and the flat hole at the bottom of the core filling structure. A slurry stop ring is arranged in a circle below the flat hole around the lower part of the core filling structure. Grouting material is filled between the core filling structure and the inner wall of the pipe pile. The grouting structure is connected to the perforated steel plate.

[0007] The steel strip is a long strip-shaped steel plate with a thickness of 4mm.

[0008] Half of the length of the steel strip is obliquely buried into the core filling structure at an angle of 45°.

[0009] The through hole is a reserved hole channel along the axial position of the core filling structure.

[0010] The diameter of the round hole of the perforated steel plate is the same as the diameter of the through hole.

[0011] The flat hole is a cross-shaped hole channel at the bottom of the core filling structure.

[0012] The described grouting structure includes a grouting pipe and a grouting head connected to each other. The grouting head is a magnetic ring, and the grouting head is magnetically attracted and connected to the perforated steel plate. The grouting pipe is a rubber pipe, and the length of the grouting pipe is greater than the length of the pipe pile.

[0013] The described grout stop ring is a water-swellable epoxy ring, and the grout stop ring is adhesively bonded to the core filling structure.

[0014] A construction method for repairing damaged pile foundations uses the PHC pipe pile precast core filling and strengthening structure as described, and its steps are as follows:

[0015] S1. Determine the damaged position of the pile foundation by means of acoustic emission, low strain or camera.

[0016] S2. Insert the fabricated core filling structure into the pipe pile from the pile top. One end of the grout stop ring of the core filling structure is inserted into the pipe pile, and the other end of the core filling structure is magnetically connected to the magnetic grouting head of the grouting structure through the perforated steel plate. The core filling structure is pushed into the damaged position of the pile foundation through a steel pipe. The grouting head simultaneously pulls the grouting pipe down into the pipe pile. First, water is injected through the grouting pipe. When the water flows out of the core filling structure and meets the grout stop ring, it causes the grout stop ring to expand, playing a role in sealing and stopping the grout.

[0017] S3. Grout by the grouting equipment on the ground. The grouting material reaches the through holes of the core filling structure along the grouting pipe, then passes through the through holes and flows into the gap between the core filling structure and the inner wall of the pipe pile after reaching the flat holes at the bottom. As the grouting progresses, the grouting material reaches the top position from the bottom of the gap.

[0018] S4. Pull the grouting pipe to separate the grouting head from the perforated steel plate of the core filling structure. After a short period of curing of the grouting material, the local repair work of the PHC pipe pile is completed.

[0019] Advantages of the present invention: The core filling structure of the present invention can be filled to a specific damaged position of the pipe pile as needed. Steel strips are arranged on the outer periphery of the core filling structure. After the core filling structure is lowered into the pipe pile, the steel strips are deformed to play a frictional role with the inner wall of the pipe pile, enabling the core filling structure to be fixed to any position. For local construction, the amount of core filling material used is small, the curing time is short, the construction process is simple, and the construction speed of the pipe pile is greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic structural diagram of the present invention.

[0021] Figure 2 It is Figure 1 The horizontal sectional view at A-A in

[0022] Figure 3 It is Figure 1 The horizontal sectional view at B-B in

[0023] Figure 4 It isFigure 1 Horizontal section at CC.

[0024] Figure 5 for Figure 1 Horizontal section at DD.

[0025] Figure 6 It is a schematic diagram of the core filling structure of the present invention.

[0026] Figure 7 It is a schematic diagram of the grouting structure of the present invention.

[0027] Among them: 1-pipe pile; 2-core filling structure; 201-steel plate strip; 202-flat hole; 203-through hole; 204-grouting ring; 205-perforated steel plate; 3-grouting material; 4-grouting structure; 401-grouting pipe; 402-grouting head; 5-damaged position of pile foundation. DETAILED DESCRIPTION

[0028] A prefabricated core-filling reinforcement structure for a PHC pipe pile comprises a pipe pile 1, a core-filling structure 2, a grouting material 3 and a grouting structure 4. The core-filling structure 2 is filled in a damaged position 5 of the pile foundation of the pipe pile 1. The core-filling structure 2 is a prefabricated cylindrical reinforced concrete structure, the length of which is greater than the length of the damaged position 5 of the pile foundation. A steel plate strip 201 is obliquely inserted around the core-filling structure 2, a perforated steel plate 205 is pre-buried on the top of the core-filling structure 2, a flat hole 202 is opened at the bottom of the core-filling structure 2, a through hole 203 is arranged between the perforated steel plate 205 at the top and the flat hole 202 at the bottom of the core-filling structure 2, a grouting stop ring 204 is arranged around the bottom of the core-filling structure 2 below the flat hole 202, the grouting material 3 is filled between the core-filling structure 2 and the inner wall of the pipe pile 1, and the grouting structure 4 is connected to the perforated steel plate 205.

[0029] The steel strip 201 is a long steel strip with a thickness of 4 mm, and the steel strip 201 can be a 4 mm steel wire.

[0030] The steel strip 201 is buried in the core filling structure 2 with half its length tilted at 45 degrees. After the core filling structure 2 is lowered into the pile, the steel strip 201 deforms to rub against the inner wall of the pile 1, so that the core filling structure 2 can be fixed to any position.

[0031] The through hole 203 is a reserved channel along the axis of the core filling structure 2 . The diameter of the through hole 203 is 3 cm, and the length of the through hole 203 is consistent with the length of the core filling structure 2 .

[0032] The diameter of the circular hole of the perforated steel plate 205 is consistent with the diameter of the through hole 203 .

[0033] The flat hole 202 is a cross channel at the bottom of the core filling structure 2.

[0034] The described grouting structure 4 includes a grouting pipe 401 and a grouting head 402 connected by socket connection. The grouting head 402 is a magnetic ring. The grouting head 402 is magnetically attracted and connected to the perforated steel plate 205. The grouting pipe 401 is a rubber hose, and the length of the grouting pipe 401 is greater than the length of the pipe pile 1. The grouting pipe 401 is connected to the ground grouting machinery.

[0035] The described grout stop ring 204 is a water-swellable epoxy ring, and the grout stop ring 204 is bonded to the core filling structure 2.

[0036] A construction method for repairing damaged pile foundations uses the aforementioned PHC pipe pile precast core filling and strengthening structure, and its steps are as follows:

[0037] S1. Determine the damaged position 5 of the pile foundation by means of acoustic emission, low strain or camera. The pipe pile 1 is a high-strength prestressed pipe pile 1 with a diameter of 0.9m, an inner diameter of 0.6m, and a length of 50m. The damaged position 5 of the pile foundation is 20m below the ground and has a length of 0.5m.

[0038] S2. Insert the fabricated core filling structure 2 into the pipe pile 1 from the pile top. The length of the core filling structure 2 is 1m and the diameter is 0.5m. One end of the grout stop ring 204 of the core filling structure 2 is inserted into the pipe pile 1, and the other end of the core filling structure 2 is magnetically connected to the magnetic grouting head 402 of the grouting structure 4 through the perforated steel plate 205. The diameter of the perforated steel plate 205 is 10cm and the thickness is 6mm. It is embedded at the top of the core filling structure 2. The steel plate strip 201 has an inclined angle of 45° with the outer wall of the core filling structure 2, and the outer extension length of the steel plate strip 201 is 0.14m, so that the core filling structure 2 with the steel plate strip 201 has a diameter of 0.7m, which is 0.1m larger than the inner diameter of the pipe pile 1. The deformation of the steel plate strip 201 plays a frictional role with the inner wall of the pipe pile 1. The core filling structure 2 is pushed into the damaged position 5 of the pile foundation through a steel pipe. The grouting head 402 simultaneously pulls the grouting pipe 401 down into the pipe pile 1. First, water is injected through the grouting pipe 401. After the water flows out of the core filling structure 2, it meets the grout stop ring 204. The thickness of the grout stop ring 204 is 3cm. The grout stop ring 204 is pasted around the bottom of the core filling structure 2, causing the grout stop ring 204 to expand to play a role of sealing and stopping grout. The grout stop ring 204 can be an airbag ring or a rubber cotton ring to seal the gap between the core filling structure 2 and the inner pipe wall of the pipe pile 1.

[0039] S3. Grout by the ground grouting equipment. The grouting material 3 reaches the through hole 203 of the core filling structure 2 along the grouting pipe 401. Steel fibers can be filled in the grouting material 3 to increase the strength of the gap grouting material 3 and further improve the bearing capacity of the cross-section of the strengthened pipe pile 1. The diameter of the through hole 203 is 3cm, and then it passes through the through hole 203 to reach the bottom flat hole 202 and then flows into the gap between the core filling structure 2 and the inner wall of the pipe pile 1. The diameter of the flat hole 202 is 2cm. As the grouting progresses, the grouting material 3 reaches the top position from the bottom of the gap.

[0040] S4. Pull the grouting pipe 401 to separate the grouting head 42 from the perforated steel plate 205 of the core filling structure 2. After the grouting material 3 is briefly cured, the local repair work of the PHC pipe pile 1 is completed.

[0041] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0042] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0043] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or communicable with each other; it may be directly connected, or indirectly connected through an intermediate medium, and may be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] The above has described the embodiments of the present invention in detail, but the content described is only the preferred embodiments of the present invention and should not be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of the application of the present invention should still fall within the scope covered by the patent of the present invention.

Claims

1. A precast core filling and reinforcement structure for PHC pipe piles, characterized in that, The invention comprises a pipe pile (1), a core filling structure (2), a grouting material (3) and a grouting structure (4), wherein the core filling structure (2) is filled in a damaged position (5) of the pile foundation of the pipe pile (1), the core filling structure (2) is a prefabricated cylindrical reinforced concrete structure, steel strips (201) are obliquely inserted around the core filling structure (2), a perforated steel plate (205) is pre-embedded on the top of the core filling structure (2), a flat hole (202) is opened at the bottom of the core filling structure (2), and the core filling structure (2) is provided from the top. A through hole (203) is provided between the perforated steel plate (205) and the flat hole (202) at the bottom; a grouting ring (204) is provided around the lower part of the core filling structure (2) below the flat hole (202); a grouting material (3) is filled between the core filling structure (2) and the inner wall of the pipe pile (1); and the grouting structure (4) is connected to the perforated steel plate (205); the grouting ring (204) is a water-expandable epoxy ring, and the grouting ring (204) is bonded to the core filling structure (2).

2. The precast core filling and reinforcement structure of PHC pipe pile according to claim 1, characterized in that, The steel plate strip (201) is a long steel plate with a thickness of 4 mm.

3. The PHC pipe pile precast core filling and reinforcement structure according to claim 2, characterized in that, The steel strip (201) is embedded in the core filling structure (2) at an angle of 45° with half its length.

4. The precast core filling and reinforcement structure of PHC pipe pile according to claim 3, characterized in that The through hole (203) is a reserved channel along the axis of the core filling structure (2).

5. The PHC pipe pile precast core filling and reinforcement structure according to claim 4, wherein, The diameter of the circular hole of the perforated steel plate (205) is consistent with the diameter of the through hole (203).

6. The precast core filling and reinforcement structure of PHC pipe pile according to claim 5, characterized in that, The flat hole (202) is a cross hole at the bottom of the core filling structure (2).

7. The PHC pipe pile precast core filling and reinforcement structure according to claim 5, characterized in that, The grouting structure (4) comprises a grouting pipe (401) and a grouting head (402) which are connected to each other. The grouting head (402) is a magnetic ring. The grouting head (402) is connected to the perforated steel plate (205) by magnetic attraction. The grouting pipe (401) is a rubber hose. The length of the grouting pipe (401) is greater than the length of the pipe pile (1).

8. A construction method for repairing damaged pile foundations, characterized in that, The prefabricated core-filling reinforcement structure of the PHC pile as claimed in claim 7 is provided by: S1. Determine the location of pile damage by acoustic emission, low strain or video (5); S2. The prepared core filling structure (2) is inserted into the tubular pile (1) from the top of the pile, one end of the stop grouting ring (204) of the core filling structure (2) is inserted into the tubular pile (1), and the other end of the core filling structure (2) is magnetically connected to the magnetic grouting head (402) of the grouting structure (4) through the perforated steel plate (205). The core filling structure (2) is pushed into the damaged position (5) of the pile foundation through the steel pipe. The grouting head (402) simultaneously pulls the grouting pipe (401) down into the tubular pile (1), and water is first injected through the grouting pipe (401). After the water flows out of the core filling structure (2), it meets the stop grouting ring (204), causing the stop grouting ring (204) to expand and play a role in sealing and stopping grouting; S3. Grouting is performed by grouting equipment on the ground. The grouting material (3) flows along the grouting pipe (401) to the through hole (203) of the core filling structure (2), then passes through the through hole (203) to the flat hole (202) at the bottom, and then flows into the gap between the core filling structure (2) and the inner wall of the pipe pile (1). As the grouting progresses, the grouting material (3) moves from the bottom of the gap to the top; S4. Pull the grouting pipe (401) to disengage the grouting head (42) from the perforated steel plate (205) of the core filling structure (2). After the grouting material (3) is briefly cured, the local repair work of the PHC pipe pile (1) is completed.

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