Deep water composite pile cap construction method

Abstract

The application belongs to the technical field of bridge engineering, and particularly relates to a deep water superimposed pile cap construction method. The method comprises the following steps: S1, installing a pile top pre-buried support, and then pouring pile foundation concrete; installing a prefabricated pile cap, wall pile cap steel bars and pre-buried vertical rods in a prefabrication yard, and then installing a steel bottom plate; pouring prefabricated pile cap concrete and curing, so that the prefabricated pile cap is fixedly connected with lower ends of the two pre-buried vertical rods; S2, assembling a base plate and a cross beam at upper ends of the two pre-buried vertical rods to form a suspension assembly; the application does not need to set cofferdams, bottom seals, auxiliary piles and other components, simplifies site formwork erection and formwork removal processes, and saves engineering materials; compared with full prefabricated components, the pile cap plastic hinge area is a cast-in-place structure, which not only has higher overall stability and safety, but also has lower hoisting weight, further reducing construction risks and construction difficulties; the application not only avoids the problem of insufficient space for processes such as steel bar binding and pile head breaking, but also has higher stability and safety.

Description

Technical Field

[0001] This invention belongs to the field of bridge engineering technology, specifically relating to a method for constructing deep-water composite pier caps. Background Technology

[0002] A pier cap is a structural member located beneath a bridge pier that directly bears the pier load and transfers it to the pile foundation. In deep-water environments, pier caps are typically constructed using the caisson method or the cofferdam method.

[0003] Chinese Patent Application No. 202111569197.7 discloses a deep-water pier rectangular sheet pile cofferdam structure and its construction method, relating to the field of cofferdam construction technology. The proposed solution includes an L-shaped counterweight base. Vertically distributed positioning rods are welded to both ends of the bottom of the L-shaped counterweight base. Symmetrically distributed first reinforcing rods are welded to one side of the outer wall of the L-shaped counterweight base along an inclined direction, and symmetrically distributed second reinforcing rods are welded to the same side. The patent also features an arc-shaped buffer plate on the back of the rectangular sheet pile. The cooperation between the arc-shaped buffer plate and the buffer spring effectively reduces the impact of water flow on the connection point of the rectangular sheet pile, thus preventing shaking at the connection point and increasing internal sealing performance. Furthermore, detachable splicing steel components are provided on both sides of the rectangular sheet pile. When deformation occurs on one side and the sealing performance decreases, it can be replaced, maintaining good sealing performance while reducing maintenance costs.

[0004] Currently, the pier cap structures of deep-water bridges are mainly constructed using steel cofferdams with concrete bottom sealing, or concrete cofferdams with attached piles. Both methods are material-intensive, complex, and costly, while also causing significant environmental pollution. With the deepening and development of green infrastructure concepts, there is a growing demand for improved design and construction techniques to save engineering materials, reduce resource waste, conserve energy, reduce emissions, and minimize environmental pollution. Therefore, there is an urgent need for a new construction method for deep-water composite pier caps. Simultaneously, ensuring and improving safety while saving on procedures and materials is also a key research focus. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a deep-water composite pile cap construction method. This invention utilizes a semi-innovative precast component + hoisting method, leveraging the advantages of precast components by eliminating the need for cofferdams, bottom sealing, and auxiliary piles, simplifying on-site formwork erection and dismantling processes, and saving engineering materials. Furthermore, compared to fully precast components, the plastic hinge area of ​​the pile cap is a cast-in-place structure, resulting in greater overall stability and safety, while also reducing hoisting weight, further lowering construction risks and difficulty. This deep-water composite pile cap construction method avoids the problem of insufficient space for processes such as breaking pile heads after rebar tying, while also offering greater stability and safety. The material cost of this invention is significantly lower than traditional cofferdam methods and fully precast construction, and it does not require special construction equipment or complex construction processes, saving substantial amounts of steel or concrete, resulting in higher efficiency and faster progress.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for constructing deep-water composite foundations includes the following steps:

[0008] S1. Install the pre-embedded bracket at the top of the pile, and then pour the pile foundation concrete; install the precast bearing platform, the inner bearing platform reinforcement and the pre-embedded vertical rods in the prefabrication yard, and then install the steel base plate; pour the precast bearing platform concrete and cure it so that the precast bearing platform is fixedly connected to the lower end of the two pre-embedded vertical rods.

[0009] S2. Assemble the base plate and crossbeam at the upper end of the two pre-embedded vertical rods to form a suspension assembly;

[0010] S3. Using lifting equipment, the precast foundation is lowered through the suspension assembly, so that the base plate falls onto the pre-embedded support on the top of the pile and is reinforced by welding. At this time, the top surface of the steel base plate is at the design bottom elevation of the foundation.

[0011] S4. Fill the holes in the steel base plate and around the pile foundation with sealing material. After completing the underwater sealing, pump out the water, break the pile head, tie the reinforcement of the outer wall bearing platform, and pour concrete after construction.

[0012] Furthermore, a precast pier is used as a cofferdam and side formwork, and a steel base plate is used as a bottom formwork. The precast pier is connected to the pre-embedded support at the top of the pile via a suspension assembly.

[0013] Furthermore, the inner wall reinforcement is placed inside the wall of the precast foundation, while the outer wall reinforcement is placed in the middle of the precast foundation.

[0014] Furthermore, the pre-embedded support at the top of the pile adopts a lattice structure and is installed before the pile foundation is poured.

[0015] Furthermore, the suspension assembly includes a base plate, a crossbeam, and a pre-embedded vertical rod, wherein one end of the pre-embedded vertical rod is pre-embedded in the prefabricated support platform.

[0016] Furthermore, after the concrete for the pile foundation in S1 is poured and the concrete has reached the required curing time, the excess steel casing is removed.

[0017] Furthermore, the pile foundation is a cylindrical structure with multiple pile foundations, and pre-embedded supports are installed on the pile tops of the corresponding pile foundations according to the stress requirements.

[0018] Furthermore, the pile foundation has four or more piles.

[0019] Furthermore, the suspension assembly in S1 has multiple sets, and each set of suspension assembly has two or more pre-embedded supports at the pile top.

[0020] Furthermore, the suspension assembly has two sets.

[0021] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0022] (1) This invention utilizes a semi-innovative precast component + hoisting method, which leverages the characteristics of precast components, eliminating the need for cofferdams, bottom sealing, and pile attachments, simplifying on-site formwork erection and dismantling processes, and saving engineering materials. Furthermore, compared to fully precast components, the plastic hinge area of ​​the pile abutment is a cast-in-place structure, resulting in stronger overall stability and higher safety, while also reducing hoisting weight, further lowering construction risks and difficulties. Specifically, the traditional steel cofferdam + bottom sealing concrete method involves first enclosing the construction area with a cofferdam, then reinforcing it with concrete, followed by pumping out the water from the cofferdam area, and finally sealing the bottom with concrete. This method requires a large amount of concrete pouring, resulting in high costs, complex construction processes, and significant safety risks. Moreover, this method causes significant damage to aquatic areas. In contrast, this application only requires pouring the pile foundation. By installing a pre-embedded support on the pile top before pouring the pile foundation concrete, the pre-embedded support can subsequently support the precast components and... The process involves bringing the precast components to the designated height, then installing the precast foundation, internal reinforcement bars, and embedded vertical rods at the prefabrication yard. A steel base plate is installed at the bottom of the internal reinforcement bars. The precast foundation is then fixedly connected to the lower ends of the two embedded vertical rods by pouring concrete, forming a basket-like structure. A suspension assembly is formed by assembling a base plate and crossbeam at the upper ends of the two embedded vertical rods. This assembly, in conjunction with the embedded brackets at the pile top, facilitates the subsequent hoisting and fixing of the precast components, while also reducing the hoisting weight and construction risks and difficulties. Furthermore, the basket-like structure facilitates subsequent sealing and concrete pouring. Compared to the cofferdam + bottom sealing concrete method, this invention is simpler, requiring only the designed volume of concrete for the foundation to be poured on-site, significantly reducing engineering materials. Since the plastic hinge area of ​​the pile foundation is a cast-in-place structure, it offers greater stability, strength, and safety. Moreover, the absence of an additional cofferdam reduces water pollution and benefits the ecological environment.

[0023] (2) The present invention provides a deep-water composite pile cap construction method, which uses the precast pile cap as the side formwork and the steel base plate as the bottom formwork. The pile cap reinforcement can be tied in two stages according to the actual construction needs. This avoids the problem of insufficient space for processes such as breaking pile heads after the reinforcement is tied. At the same time, the two-stage tying method greatly reduces the weight of the precast components, which is beneficial for hoisting construction. It also enables the plastic hinge area of ​​the pile cap to be a cast-in-place structure, which is more stable, stronger, and safer.

[0024] (3) The deep-water composite pier structure and construction method of the present invention have significantly lower material costs than the traditional cofferdam method and fully prefabricated construction, and do not require special construction equipment and complicated construction processes, thus saving a lot of steel or concrete, with higher efficiency and faster progress. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the construction method for deep-water composite foundations according to the present invention;

[0026] Figure 2 This is a schematic diagram of the main structure of a pier cap according to the construction method of a deep-water composite pier cap of the present invention;

[0027] Figure 3 This is a schematic diagram of the suspension component structure of a deep-water composite foundation construction method according to the present invention;

[0028] Figure 4 This is a schematic diagram of the external wall reinforcement and concrete structure of a deep-water composite foundation construction method according to the present invention.

[0029] Figure 5 This is a schematic diagram of the internal cross-sectional structure of the main body of the pier in the deep-water composite pier construction method of the present invention.

[0030] The attached figures are labeled as follows:

[0031] Precast pile cap-1, suspension assembly-2, pile top embedded bracket-3, steel base plate-4, sealing material-5, concrete-6, inner pile cap reinforcement-11, outer pile cap reinforcement-12, base plate-21, crossbeam-22, embedded vertical rod-23. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. Of course, the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0033] Although the steps in this invention are arranged with numbers, they are not intended to limit the order of the steps. Unless the order of the steps is explicitly stated or the execution of a certain step requires other steps as a basis, the relative order of the steps can be adjusted.

[0034] Example

[0035] like Figures 1-5 As shown, a method for constructing deep-water composite foundations includes the following steps:

[0036] S1. Install the pre-embedded support 3 on the top of the pile, and then pour the pile foundation concrete; install the precast bearing platform 1, the inner bearing platform reinforcement 11 and the pre-embedded vertical rod 23 in the prefabrication yard, and then install the steel base plate 4; pour the precast bearing platform 1 concrete and cure it so that the precast bearing platform 1 is fixedly connected to the lower end of the two pre-embedded vertical rods 23.

[0037] S2. Assemble the base plate 21 and the crossbeam 22 at the upper end of the two pre-embedded vertical rods 23 to form the suspension assembly 2;

[0038] S3. Using lifting equipment, the precast bearing platform 1 is lowered through the suspension assembly, so that the base plate 21 falls onto the pre-embedded support 3 at the top of the pile and is reinforced by welding. At this time, the top surface of the steel base plate 4 is at the design bottom elevation of the bearing platform.

[0039] S4. Fill the four holes in the steel base plate and the surrounding area of ​​the pile foundation with sealing material 5. After completing the underwater leak sealing, pump out the water, break the pile head, then tie the outer wall bearing plate reinforcement 12, and pour concrete 6 after construction.

[0040] This invention utilizes an innovative semi-prefabricated component + hoisting method, leveraging the advantages of prefabricated components by eliminating the need for cofferdams, bottom sealing, and auxiliary piles, simplifying on-site formwork erection and dismantling processes, and saving engineering materials. Furthermore, compared to fully prefabricated components, the plastic hinge area of ​​the pile abutment is a cast-in-place structure, resulting in stronger overall stability and higher safety, while also reducing hoisting weight, further lowering construction risks and difficulty. Specifically, the traditional steel cofferdam + bottom sealing concrete method involves first constructing the cofferdam, then lowering and pouring the bottom sealing concrete. This method wastes a large amount of concrete, is costly, has complex construction processes, and poses significant safety risks; moreover, this method causes considerable damage to water bodies. In contrast, this application only requires pouring the pile foundation. By installing a pre-embedded support 3 on the pile top before pouring the pile foundation concrete, the pre-embedded support 3 can subsequently bear the weight of the prefabricated components and enable the prefabricated components to... The components reach the designated height; then, the precast foundation 1, the inner wall foundation reinforcement 11, and the embedded vertical rods 23 are installed in the prefabrication yard, and the steel base plate 4 is installed at the bottom of the inner wall foundation reinforcement 11. By pouring concrete for the precast foundation 1, the precast foundation 1 is fixedly connected to the lower ends of the two embedded vertical rods 23, thus forming a basket-like structure. By assembling the base plate 21 and the crossbeam 22 at the upper ends of the two embedded vertical rods 23, a suspension assembly 2 is formed. By cooperating with the embedded bracket 3 at the top of the pile, it is not only beneficial for the subsequent hoisting and fixing of the precast components, but also further reduces construction risks and difficulties. Compared with the cofferdam + bottom sealing concrete method, the process of this invention is simple, the amount of engineering materials used is less, and since the plastic hinge area of ​​the pile platform is a cast-in-place structure, it is more stable and stronger, and safer. Moreover, there is no need to install or dismantle the cofferdam, which reduces water pollution and is beneficial to the ecological environment.

[0041] It is worth noting that sealing material 5 can be a waterstop, sealing plate, etc., as long as the sealing is achieved, and no further limitations are made here.

[0042] Furthermore, the precast pier 1 serves as the cofferdam and side formwork, and the steel base plate 4 serves as the bottom formwork. The precast pier 1 is connected to the pre-embedded support 3 at the top of the pile via the suspension assembly 2.

[0043] Furthermore, the inner wall bearing reinforcement 11 is set inside the wall of the precast bearing 1, and the outer wall bearing reinforcement 12 is set in the middle of the precast bearing 1.

[0044] This invention discloses a deep-water composite pile cap construction method. The precast pile cap 1 is used as the side formwork, and the steel base plate 4 is used as the bottom formwork. The pile cap reinforcement can be tied in two stages according to the actual construction needs. This avoids the problem of insufficient space for processes such as breaking pile heads after the reinforcement is tied. At the same time, the two-stage tying method greatly reduces the weight of the precast components, which is beneficial for hoisting construction. It also enables the plastic hinge area of ​​the pile cap to be a cast-in-place structure, which is more stable, stronger, and safer.

[0045] Furthermore, the pre-embedded support 3 at the top of the pile adopts a lattice structure and is installed before the pile foundation is poured.

[0046] Furthermore, the suspension assembly 2 includes a base plate 21, a crossbeam 22, and a pre-embedded vertical rod 23, wherein one end of the pre-embedded vertical rod 23 is pre-embedded in the prefabricated support platform 1.

[0047] The present invention provides a deep-water composite pier structure and construction method, which has significantly lower material costs than traditional cofferdam methods and fully prefabricated construction, and does not require special construction equipment or complicated construction processes, thus saving a large amount of steel or concrete, resulting in higher efficiency and faster progress.

[0048] Furthermore, after the concrete for the pile foundation in S1 is poured and the concrete has reached the required curing time, the excess steel casing is removed.

[0049] Furthermore, the pile foundation is a cylindrical structure, and there are multiple pile foundations. As needed, each pile foundation is equipped with a pre-embedded support 3 at the pile top.

[0050] Furthermore, the pile foundation has multiple piles.

[0051] Furthermore, the suspension assembly 2 in S1 has multiple sets, and each set of suspension assembly 2 has two or more pre-embedded supports 3 on the pile top as needed.

[0052] Furthermore, the suspension assembly 2 has two sets.

[0053] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and modifications without departing from the inventive concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A method for constructing deep-water composite foundation piers, characterized in that, Includes the following steps: S1. Install the pre-embedded bracket (3) on the top of the pile, and then pour the pile foundation concrete; install the precast pile cap (1), the inner pile cap reinforcement (11) and the pre-embedded vertical rod (23) in the prefabrication yard, and then install the steel base plate (4); pour the precast pile cap (1) concrete and cure it so that the precast pile cap (1) is fixedly connected to the lower end of the two pre-embedded vertical rods (23); S2. Assemble the base plate (21) and crossbeam (22) at the upper end of the two pre-embedded vertical rods (23) to form the suspension assembly (2); S3. Using a lifting device, the precast foundation (1) is lowered through the suspension assembly, so that the base plate (21) falls onto the pre-embedded support (3) on the top of the pile and is reinforced by welding. At this time, the top surface of the steel base plate (4) is at the design bottom elevation of the foundation. S4. Fill the holes in the steel base plate (4) and around the pile foundation with sealing material (5). After completing the underwater plugging, pump out the water, break the pile head, tie the outer wall bearing reinforcement (12), and pour concrete after construction (6).

2. The method for constructing a deep-water composite pier cap according to claim 1, characterized in that, The precast pier (1) is used as the cofferdam and side formwork, and the steel base plate (4) is used as the bottom formwork. The precast pier (1) is connected to the pre-embedded support (3) on the pile top through the suspension assembly (2).

3. The method for constructing a deep-water composite pier according to claim 1, characterized in that, The inner wall reinforcement (11) is set inside the wall of the precast foundation (1), and the outer wall reinforcement (12) is set in the middle of the precast foundation (1).

4. The method for constructing a deep-water composite pier according to claim 1, characterized in that, The pre-embedded support (3) at the top of the pile adopts a lattice structure and is installed before the pile foundation is poured.

5. The method for constructing a deep-water composite pier cap according to claim 1, characterized in that, The suspension assembly (2) includes a base plate (21), a crossbeam (22) and a pre-embedded vertical rod (23), wherein one end of the pre-embedded vertical rod (23) is pre-embedded in the prefabricated support platform (1).

6. The method for constructing a deep-water composite pier according to claim 1, characterized in that, After the concrete for the pile foundation in S1 is poured and the concrete has reached the required curing time, the excess steel casing is removed.

7. The method for constructing a deep-water composite pier cap according to claim 1, characterized in that, The pile foundation is a cylindrical structure and there are multiple pile foundations. As needed, a pre-embedded support is installed at the top of the pile (3).

8. The method for constructing a deep-water composite pier according to claim 7, characterized in that, The pile foundation has multiple piles.

9. The method for constructing a deep-water composite pier cap according to claim 7, characterized in that, S1 has multiple sets of suspension components (2), and each set of suspension components (2) has at least 2 pre-embedded supports (3) at the top of the pile.

10. The method for constructing a deep-water composite pier according to claim 9, characterized in that, The suspension assembly (2) has two sets.

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