An assembled reinforcing method for three-pile independent pile foundation

Abstract

The application provides an assembled reinforcing method for three-pile independent pile foundation, and belongs to the technical field of building foundation reinforcement. The reinforcing process is as follows: soil is dug under the existing pile foundation cap, a special-shaped joist is positioned under the existing pile foundation cap, a mold is supported at the position of the anchor rod static pressure pile cap and an anchor rod for pressure pile is buried, concrete is poured, the anchor rod static pressure piles are synchronously pressed into the pressure pile holes at the three anchor rod static pressure pile caps, the pressure piles are sealed, and the gaps are backfilled with sand and soil and compacted. The application is used for reinforcing the three-pile independent pile foundation, and has the advantages of simple process, rapid construction and suitability for construction under low-clearance conditions such as basement.

Description

Technical Field

[0001] This application relates to a prefabricated reinforcement method for three independent pile foundations, belonging to the technical field of repairing damaged foundations or foundation structures. Background Technology

[0002] In my country's coastal areas, where deep, soft soil is widespread, three-pile independent foundations are one of the most widely used foundation types in various industrial and civil buildings. The bearing capacity of the pile foundation has a decisive impact on the quality of the project. During pile foundation construction, due to various reasons, such as defects in the pile body, insufficient depth of pile tip penetration, and uneven thickness of soft soil layers, insufficient bearing capacity can occur. This will bring serious safety hazards to the entire project, such as causing uneven settlement, tilting, or even collapse of the building. Therefore, it is necessary to reinforce pile foundations with insufficient bearing capacity.

[0003] Foundation reinforcement of existing buildings requires construction inside the building, making it difficult for large construction machinery to access the site. Due to construction constraints, anchored static pressure piles are often used for foundation reinforcement of existing buildings. A reasonable force transmission structure is needed between the newly added anchored static pressure piles and the existing pile foundation to effectively distribute the vertical forces from the superstructure. Furthermore, damage to the existing pile foundation should be minimized during reinforcement construction. However, current technologies lack research addressing this problem. Summary of the Invention

[0004] In view of this, this application provides a simple, fast, and suitable reinforcement method for existing three-pile independent pile foundations, applicable to low headroom conditions.

[0005] Specifically, this application is implemented through the following scheme: A prefabricated reinforcement method for a three-pile independent pile foundation, comprising three existing piles and an existing pile cap, includes the following steps: 1) Create a clearance of 0.8m to 1.0m under the existing pile foundation cap; 2) The irregularly shaped support beam is positioned under the existing pile foundation cap; 3) Set up formwork at the anchor pile cap position, install anchor bolts and pile holes for pile driving, and pour concrete; 4) After the concrete of the anchor static pressure pile cap reaches the set strength and forms an integral whole with the irregular support beam, the pile is driven synchronously at the pile driving hole and pressure sealing is carried out; 5) The gaps at the bottom of the existing pile foundation caps should be backfilled with sand and compacted.

[0006] In the above scheme, the reinforcement components used in the reinforcement method include anchor static pressure piles, anchor static pressure pile caps, and irregularly shaped support beams.

[0007] Furthermore, as a preferred option: In step 2), the irregularly shaped support beam is positioned under the existing pile foundation cap by means of the tow hook at the end.

[0008] In step 3), the upper reinforcing bar, lower reinforcing bar, and shear keyway at the end of the irregular support beam all extend into the interior of the anchor static pressure pile cap, thereby effectively transferring bending moment and shear force between the precast and cast-in-place concrete components, so that the cast-in-place anchor static pressure pile cap and the irregular support beam can form an integral whole.

[0009] The irregular support beam is Y-shaped and 0.7m high, with a triangular gap in the middle, which can effectively reduce the weight of the irregular support beam.

[0010] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention uses anchor static pressure piles, anchor static pressure pile caps, and irregularly shaped support beams to support and replace existing three-pile independent pile foundations. It can reinforce existing building pile foundations under construction conditions with low clearance, such as inside existing buildings, without damaging the existing pile foundation caps.

[0011] 2. The reinforcing components in this invention fully utilize the advantages of both cast-in-place and prefabrication processes, effectively reducing the difficulty of reinforcement construction, reducing the amount of cast-in-place work, and enabling fast construction.

[0012] 3. The irregularly shaped support beam in this invention is prefabricated, has a simple structure, is lightweight, does not require large machinery, and is easy to place under existing pile foundation caps.

[0013] 4. The irregularly shaped support beam in this invention is provided with a shear keyway at its end, which can effectively transmit the shear force at the interface between the precast and cast-in-place concrete parts, making the force transmission of the reinforced component safe and reliable. Attached Figure Description

[0014] Figure 1 This is a structural layout diagram of a three-pile independent pile foundation reinforced using the method of this invention; Figure 2 yes Figure 1 Cross-sectional view along the aa direction; Figure 3 This is a structural layout diagram of the reinforcing components in this invention; Figure 4 yes Figure 4 Cross-sectional view along the bb direction; Figure 5 yes Figure 1 Construction diagram of the irregularly shaped support beam; Figure 6 yes Figure 5 Cross-sectional view along the cc direction.

[0015] The following are the labels in the diagram: 1. Existing pile cap; 2. Existing engineering pile; 3. Anchored static pressure pile; 4. Anchored static pressure pile cap; 5. Irregularly shaped support beam; 6. Triangular gap; 7. Tow hook; 8. Lower reinforcing bar; 9. Upper reinforcing bar; 10. Shear keyway. Detailed Implementation

[0016] Please refer to the instruction manual appendix. Figure 1 To be continued Figure 6 As shown, the three independent pile foundations involved in this case consist of an existing pile foundation cap 1 and existing engineering piles 2, of which three existing engineering piles 2 are provided.

[0017] For the prefabricated reinforcement method of three independent pile foundations, the reinforcement components used in this case consist of three parts: anchored static pressure piles 3, anchored static pressure pile caps 4, and irregularly shaped support beams 5. Among them, the anchored static pressure piles 3 and the irregularly shaped support beams 5 are prefabricated components, while the anchored static pressure pile caps 4 are cast in place. Through the irregularly shaped support beams 5 and the anchored static pressure pile caps 4, part of the load borne by the existing engineering piles 2 is transferred to the anchored static pressure piles 3.

[0018] The irregularly shaped support beam 5 is located below the existing pile cap 1 and has three ends, which are respectively connected to the three anchored static pressure pile caps 4. The ends of the irregularly shaped support beam 5 are equipped with lower reinforcing bars 8, upper reinforcing bars 9, and shear keyways 10 to facilitate connection with the post-cast anchored static pressure pile caps 4 to form a whole. The shear keyways 10 ensure the reliability of shear force transfer at the interface between the old and new concrete.

[0019] The irregularly shaped support beam 5 is Y-shaped and 0.7m high. A triangular gap 6 is provided in the middle of the irregularly shaped support beam 5 where the stress is relatively small to reduce its self-weight. The irregularly shaped support beam 5 is also equipped with a tow hook 7 to facilitate its placement under the existing pile foundation cap 1. Through optimization, the cross-sectional dimensions and length of the irregularly shaped support beam 5 are smaller than the clearance under the existing pile foundation cap 1, allowing it to avoid the existing engineering piles 2 during construction and placement without the need for large machinery.

[0020] The above-mentioned reinforced structure was obtained through the following specific construction methods: 1) A clearance of about 0.8m to 1.0m is removed from the bottom of the existing pile foundation cap 1.

[0021] 2) The irregularly shaped support beam 5 is positioned under the existing pile foundation cap 1. In this embodiment, the irregularly shaped support beam 5 is positioned under the existing building pile foundation cap 1 by means of a tow hook 7.

[0022] 3) Formwork is erected at the anchor static pressure pile cap 4. The lower reinforcing bar 8, upper reinforcing bar 9 and hook 7 of the irregular support beam 5 are inserted into the newly added anchor static pressure pile cap 4. Concrete is poured and the pile driving hole and anchor rod for pile driving are pre-embedded. 4) After the newly poured concrete reaches the set strength and forms an integral whole with the irregular support beam 5, install the reaction frame, and simultaneously drive piles at the three anchor static pressure pile caps 4, and perform pressure sealing of the piles. The pile driving hole is located in the middle of the anchor static pressure pile cap 4. After the anchor static pressure pile 3 is driven in, the vertical load borne by the existing engineering pile 2 is transferred to the anchor static pressure pile 3 through the pressure stopping and pressure sealing process.

[0023] 5) The gap at the bottom of the existing pile foundation 1 is filled with sand and compacted to complete the prefabricated reinforcement of the existing building pile foundation.

[0024] In summary, the reinforcement method described above utilizes a reinforcement structure consisting of anchored static pressure piles 3, anchored static pressure pile caps 4, and irregularly shaped support beams 5 to replace existing pile foundations. This method can complete the reinforcement of three independent pile foundations under construction conditions with low clearance, such as inside existing buildings. Furthermore, the reinforcement process does not require the installation of reinforcing bars in the existing pile caps 1, nor does it damage the existing engineering piles 2. Simultaneously, the amount of cast-in-place work is minimal; only the newly added anchored static pressure pile caps 4 needs to be poured on-site, while the rest are precast components, resulting in rapid construction.

[0025] The above-described specific embodiments are merely preferred embodiments of this invention and are not intended to limit this invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the protection scope of this invention.

Claims

1. A prefabricated reinforcement method for a three-pile independent pile foundation, the three-pile independent pile foundation comprising three existing engineering piles and an existing pile cap, characterized in that, Includes the following steps: 1) Create a clearance of 0.8m to 1.0m under the existing pile foundation cap; 2) The irregular support beam is positioned under the existing pile foundation cap. The irregular support beam is Y-shaped, with a triangular gap in the middle and upper and lower reinforcing bars and keyways at the ends to facilitate connection with the cast-in-place anchor static pressure pile cap. 3) Set up formwork at the anchor static pressure pile cap position, install anchor rods and pile holes for pile driving, and pour concrete. The pile holes are located in the middle of the anchor static pressure pile cap. 4) After the concrete of the anchor static pressure pile cap reaches the set strength and forms an integral whole with the irregular support beam, the pile is driven synchronously at the pile driving hole and pressure sealing is carried out. 5) The gaps at the bottom of the existing pile foundation caps should be backfilled with sand and compacted.

2. The prefabricated reinforcement method for three-pile independent pile foundations according to claim 1, characterized in that: In step 2), the irregularly shaped support beam is provided with a tow hook at its end to facilitate its positioning.

Images