Post-grouting prefabricated reinforced concrete pile

Abstract

The utility model provides a post-grouting prefabricated reinforced concrete pile. A grouting pipe is pre-buried in the prefabricated reinforced concrete pile; the grouting pipe comprises a grouting main pipe and a grouting branch pipe; the grouting main pipe extends to the head part of the prefabricated reinforced concrete pile from the tail part of the prefabricated reinforced concrete pile; the plurality of grouting branch pipes are pre-buried at the head part of the prefabricated reinforced concrete pile, and the plurality of grouting branch pipes are communicated with the grouting main pipe and diverge all around; a one-way check valve is arranged between the grouting main pipe and the grouting branch pipe; the overall cost of the prefabricated reinforced concrete pile is low, and compared with a traditional steel pile for grouting, the cost can be reduced by more than 50%. The grouted pile tip is made of solid reinforced concrete and is not prone to deformation, high in bearing capacity and resistant to corrosion. The post-grouting is realized by pre-burying the grouting pipe in the pile, so that the bearing capacity of the single pile is greatly improved, the grouting difficulty is greatly reduced, and the field workload is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of building structures, in particular to a post-grouting prefabricated reinforced concrete pile. Background Art

[0002] Post-grouting technology for cast-in-place piles is a relatively mature technology that can greatly improve the bearing capacity of the soil layer at the pile end and near the pile end, thereby greatly improving the bearing capacity of a single pile. Research and practice in recent years have found that post-grouting of prefabricated piles can also greatly improve the bearing capacity of the soil layer at the pile end and near the pile end, thereby greatly improving the bearing capacity of a single pile and reducing pile foundation settlement. Compared with post-grouting of cast-in-place piles, prefabricated piles also have the characteristics of higher and more stable bearing capacity, more convenient and environmentally friendly construction, etc.

[0003] Existing prefabricated piles that can be used for post-grouting are rarely used in construction, and no systematic products have been formed, making it difficult to promote and apply the advantages of post-grouting prefabricated piles on a large scale. Utility Model Content

[0004] The utility model aims to provide a prefabricated reinforced concrete pile capable of realizing post-grouting, thereby greatly improving the bearing capacity of a single pile and reducing pile foundation settlement.

[0005] In order to achieve the above-mentioned purpose, the utility model provides a post-grouting prefabricated reinforced concrete pile, in which a grouting pipe is pre-buried;

[0006] The grouting pipe includes a grouting main pipe and a grouting branch pipe, wherein the grouting main pipe extends from the tail of the precast reinforced concrete pile to the head of the precast reinforced concrete pile; a plurality of the grouting branch pipes are pre-buried in the head of the precast reinforced concrete pile, and the plurality of the grouting branch pipes are connected to the grouting main pipe and diverge to the surroundings;

[0007] A one-way check valve is arranged between the grouting main pipe and the grouting branch pipe.

[0008] Preferably, the prefabricated reinforced concrete pile comprises a pile body and a pile tip connected to the head of the pile body;

[0009] When the pile tip is conical, the pile body is a pile body with a circular or annular cross section;

[0010] When the pile tip is in a pyramid shape, the pile body is a pile body with a square interface.

[0011] Preferably, the pile tip is provided with a plurality of longitudinal bars and stirrups, the lower ends of the plurality of longitudinal bars are bent and welded into a bundle, and the stirrups are spirally wound around the outer circumference of the longitudinal bar bundle and fixed by welding.

[0012] Preferably, the pile body and the pile tip are fixed by welding, and a welding steel plate is provided on the top of the pile tip.

[0013] Preferably, the pile body and the pile tip are mechanically fixed, and the end of the longitudinal reinforcement extends out of the surface of the pile tip and is plugged and fixed to the pile body.

[0014] Compared with the prior art, the advantages of the present invention are:

[0015] 1. The overall cost of the prefabricated reinforced concrete piles of this utility model is low, and compared with the steel piles used for traditional grouting, the cost can be reduced by more than 50%.

[0016] 2. The pile tip after grouting is solid reinforced concrete, which is not easy to deform, has high bearing capacity and is corrosion-resistant.

[0017] 3. By pre-embedding the grouting pipe in the pile, post-grouting can be achieved, which greatly improves the bearing capacity of the single pile, while greatly reducing the difficulty of grouting and reducing the workload on site. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a perspective view of the appearance of the prefabricated reinforced concrete pile tip capable of post-grouting after being connected to the pile body in Example 1 of the utility model;

[0019] Figure 2 It is a perspective view of the conical pile tip in Example 1 of the utility model;

[0020] Figure 3 An exploded view of a prefabricated reinforced concrete pile tip and a pile body to be welded that can be post-grouted in Example 1 of the utility model;

[0021] Figure 4 It is a schematic diagram of the structure of the prefabricated reinforced concrete pile tip and the pile body after welding in Example 1 of the utility model capable of post-grouting;

[0022] Figure 5 It is a schematic diagram of the mechanism for mechanically connecting the prefabricated reinforced concrete pile tip and the pile body that can be post-grouted in Example 2 of the utility model;

[0023] Figure 6 This is a perspective view of a pyramid-shaped pile tip according to Embodiment 3 of the present utility model;

[0024] Figure 7 This is a schematic diagram of the structure after the pile tip and the hollow pile body are welded in Example 3 of the utility model;

[0025] Figure 8 A schematic diagram of the structure of the pile tip and the solid pile body after welding in Example 3 of the present invention. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution of the utility model will be further described below.

[0027] Embodiment 1:

[0028] like Figure 1 As shown, the utility model provides a post-grouting prefabricated reinforced concrete pile, which is welded and fixed by a conical pile tip 1 and a cylindrical pile body 4. Figure 2 As shown, the conical pile tip 1 is provided with 6 longitudinal bars 11 arranged at equal intervals and a stirrup 12. The lower ends of the 6 longitudinal bars 11 are bent and welded into a bundle. The stirrup 12 is spirally wound around the outer periphery of the bundle of longitudinal bars 11 and is welded and fixed to the longitudinal bars 11 to form a stable pile tip 1 structure. Figure 3 and Figure 4 As shown, the pile body 4 and the pile tip 1 are welded and fixed, and a welding steel plate 14 is provided on the top of the pile tip 1.

[0029] In order to realize the post-casting function of the precast reinforced concrete pile, a grouting pipe 2 is pre-buried inside the precast reinforced concrete pile; the grouting pipe 2 consists of a grouting main pipe 21 and a grouting branch pipe 22. The grouting main pipe 21 is buried from the head end of the pile body 4 and extends to the bottom of the pile tip 1. The grouting main pipe 21 of the pile tip 1 is diffused around and connected to the grouting branch pipe 22.

[0030] A one-way check valve 3 is provided between the grouting main pipe 21 and the grouting branch pipe 22. After the prefabricated reinforced concrete pile of the utility model is fixed, the concrete slurry is grouted through the grouting main pipe 21 to improve the bearing capacity of the soil layer at the pile end and near the pile end.

[0031] Economic comparison: Taking a 500-diameter PHC pile as an example, the pile is 58 meters long, the bearing layer at the pile end enters the gravel or pebble layer, the characteristic value of the pile end resistance is 6000 (kPa), the pile end resistance is 1177.5 (kN), the total friction resistance of each layer is 3281 (kN), and the characteristic value of the single pile bearing capacity is 2229 (kN);

[0032] If a prefabricated reinforced concrete pile tip 1 with post-grouting is used, the pile length is 50 meters, and the pile end resistance of the single pile bearing capacity characteristic value is increased by 4 times, that is, 4710 (kN), the soil friction resistance of the 12-meter reinforced section above the pile end is 864 (kN), and the soil friction resistance of the non-reinforced section is 1860 (kN), and the single pile bearing capacity characteristic value is 3717 (kN). The single pile bearing capacity characteristic value increment is 103%. The pile foundation cost can be converted to save 71.3%. Therefore, in terms of economy, the practical prefabricated reinforced concrete pile has a significant effect.

[0033] Embodiment 2:

[0034] The overall structure of Example 2 is similar to that of Example 1, and similar parts are not repeated here. The difference is that: Figure 5As shown, the pile body 4 and the pile tip 1 are connected by a mechanical structure, and the end of the longitudinal reinforcement 11 extends out of the surface of the pile tip 1 and is plugged and fixed to the pile body 4. Compared with embodiment 1, this embodiment does not require on-site welding, and the mechanical fixing method is convenient for positioning and effectively simplifies the connection structure.

[0035] Embodiment 3:

[0036] The overall structure of Example 3 is similar to that of Example 1, except that Figure 6 As shown, in Example 3, a pyramid-shaped pile tip 1 is used, and a columnar pile body 4 is used, thereby achieving structural diversity. Figure 7 and 8 As shown, a hollow pile body 4 or a solid pile body 4 can also be used inside the pile body 4. When the pile body 4 is a solid pile, a vertical grouting pipe 2 needs to be pre-buried in the pile body 4. The material of the grouting pipe 2 can be steel, or it can be rubber, PVC and other materials.

[0037] When the pile body 4 is a hollow pile, the hollow cavity of the pile body 4 can be used to place the grouting pipe 2. At this time, the grouting pipe 2 should be able to withstand an internal pressure of more than 10 MPa.

[0038] The above are only preferred embodiments of the present invention and do not limit the present invention in any way. Any technician in the relevant technical field, without departing from the scope of the technical solution of the present invention, may make any equivalent replacement or modification to the technical solution and technical content disclosed in the present invention, which shall be deemed as the content of the technical solution of the present invention and still fall within the protection scope of the present invention.

Claims

1. A post-grouting prefabricated reinforced concrete pile, characterized in that: Grouting pipes are embedded in the precast reinforced concrete piles; The grouting pipe includes a grouting main pipe and a grouting branch pipe, wherein the grouting main pipe extends from the tail of the precast reinforced concrete pile to the head of the precast reinforced concrete pile; a plurality of the grouting branch pipes are pre-buried in the head of the precast reinforced concrete pile, and the plurality of the grouting branch pipes are connected to the grouting main pipe and diverge to the surroundings; A one-way check valve is arranged between the grouting main pipe and the grouting branch pipe.

2. The post-grouting prefabricated reinforced concrete pile according to claim 1, characterized in that: The prefabricated reinforced concrete pile comprises a pile body and a pile tip connected to the head of the pile body; When the pile tip is conical, the pile body is a pile body with a circular or annular cross section; When the pile tip is in a pyramid shape, the pile body is a pile body with a square interface.

3. The post-grouting prefabricated reinforced concrete pile according to claim 2, characterized in that: The pile tip is provided with a plurality of longitudinal bars and stirrups, the lower ends of the plurality of longitudinal bars are bent and welded into a bundle, and the stirrups are spirally wound around the outer circumference of the longitudinal bar bundle and fixed by welding.

4. The post-grouting prefabricated reinforced concrete pile according to claim 2, characterized in that: The pile body and the pile tip are welded and fixed, and a welding steel plate is provided on the top of the pile tip.

5. The post-grouting prefabricated reinforced concrete pile according to claim 3, characterized in that: The pile body and the pile tip are mechanically fixed, and the end of the longitudinal reinforcement extends out of the surface of the pile tip and is plugged and fixed to the pile body.

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