Variable cross-section assembly type steel pipe pile

Abstract

The invention discloses a variable cross-section assembly type steel pipe pile, and relates to the field of bridge construction engineering, the variable cross-section assembly type steel pipe pile comprises steel pipe standard knots and variable-diameter transition knots of various specifications, the steel pipe standard knots are formed by processing common steel pipes with different diameters according to modulus, and flanges are arranged at the two ends of the steel pipe standard knots and the variable-diameter transition knots to realize connection, assembly and disassembly between the steel pipe standard knots and the variable-diameter transition knots; and the steel pipe standard sections with different diameters can be connected through the reducing transition sections to form the combined steel pipe pile. Assembled erection is carried out through the flanges, assembly and disassembly are convenient, repeated use can be achieved, continuous line production is formed through water pile forming, water pile splicing and water structure installation, and the device can adapt to pile forming construction of various terrains, landforms and geologies; cutting and welding work is avoided in the whole process; the water operation such as traditional water cutting and water welding is omitted, and standardization, mechanization, high efficiency and zero loss are achieved.

Description

Technical Field

[0001] This application relates to the field of bridge construction engineering, and particularly to a variable cross-section assembled steel pipe pile foundation for a construction trestle or a temporary traffic maintenance bridge and a water construction platform. Background Art

[0002] A construction trestle or a temporary traffic maintenance bridge and a water construction platform are key preliminary projects in bridge construction, which have an important impact on the overall project progress and cost. Especially under complex hydrogeological conditions, the construction of steel pipe piles in water faces many challenges, such as high construction difficulty, high cost, high safety risks, etc. Traditional construction methods often require a large amount of resources and are less efficient when facing complex environments such as deep water and rapid flow.

[0003] To address the above challenges, the industry usually uses means such as the "fishing method", the water vessel hammering method, and the vibration pile sinking method for steel pipe pile construction. These methods mainly include hammering or vibrating the steel pipe piles to sink through a water platform, and operations such as lengthening, cutting, and welding of steel pipe piles on the water surface.

[0004] However, the existing technical means have obvious defects in practical applications: one is that a large amount of water operations are required during the construction process, including operations such as cutting and welding, which are not only inefficient but also have large losses; the other is that when facing ultra-long piles (pile lengths exceeding 50 meters or even 100 meters) and complex hydrogeological conditions, the installation and connection of steel pipe piles become extremely difficult. Especially in the use of large-diameter steel pipe piles, the large pile diameter, thick steel plate, large consumption, high investment in pile foundations, and high construction difficulty directly affect the project progress and cost; moreover, problems such as the large water resistance area of large-diameter steel pipes and the inconvenience of installing the upper structure are particularly prominent. Therefore, there is an urgent need for a steel pipe pile solution that can adapt to complex environments, reduce water operations, and improve construction efficiency. Summary of the Invention

[0005] This application provides a variable cross-section assembled steel pipe pile, which uses flanges to implement assembled erection and intelligent installation, and forms a continuous flow operation for pile formation in water, pile connection in water, water structure, and bridge deck installation, and can adapt to pile formation construction in various terrains, landforms, and geologies; there is no cutting and welding work throughout the process; it eliminates water operations such as traditional underwater cutting and underwater welding, achieving standardized manufacturing, assembled installation, high efficiency, and zero loss.

[0006] The variable cross-section assembled steel pipe pile provided by this application adopts the following technical solutions: A variable cross-section assembled steel pipe pile, comprising: Multiple steel pipe standard sections and variable diameter transition sections, the steel pipe standard sections are processed from ordinary steel pipes with different diameters according to a modulus, and flanges are provided at both ends of the steel pipe standard sections and the variable diameter transition sections to achieve connection and disassembly between the two; Among them, different-diameter steel pipe standard sections can be connected by the diameter-changing transition section to form a combined steel pipe pile. The diameter of the steel pipe pile decreases from bottom to top. The lower part of the steel pipe pile is inserted into the soil or rock mass through the steel pipe standard section with the largest diameter. The diameter of the steel pipe pile gradually shrinks through the diameter-changing transition section in the middle to reduce the water-blocking area. The upper part of the steel pipe pile is matched with the upper bridge deck longitudinal beam through the steel pipe standard section with the smallest diameter. The diameters of the steel pipe standard section and the diameter-changing transition section are 500 mm - 3000 mm. When the diameters of the steel pipe standard section and the diameter-changing transition section are less than 1000 mm, the flanges of the steel pipe standard section and the diameter-changing transition section are set as outer flanges. When the diameters of the steel pipe standard section and the diameter-changing transition section are more than 1000 mm, the flanges of the steel pipe standard section and the diameter-changing transition section are set as inner flanges. After subsequent grouting in the steel pipe pile, the inner flanges can increase the pile-side frictional resistance.

[0007] By adopting the above technical solutions, ordinary steel pipes are processed into standard sections according to the modulus and are combined with the diameter-changing transition section. The assembly and disassembly are carried out by connecting the two ends with flanges, and a combined steel pipe pile can be formed. The diameter distribution of the steel pipe pile with a large bottom and a small top enables the large-diameter standard section at the lower part to be inserted into the soil or rock mass to ensure stability. The diameter-changing transition section in the middle shrinks the diameter to reduce the water-blocking area. The small-diameter standard section at the upper part is matched with the bridge deck longitudinal beam, which is convenient for connecting with the upper structure. Limiting the diameters of the steel pipe standard section and the diameter-changing transition section to 500 mm - 3000 mm can meet the application scenarios of different hydrogeological conditions, design pile lengths, and different force requirements. Setting the flanges with a diameter less than 1000 mm as outer flanges and the flanges with a diameter more than 1000 mm as inner flanges can optimize the structural design. After subsequent grouting in the steel pipe pile, the inner flanges can increase the pile-side frictional resistance, improving the stability and bearing capacity of the steel pipe pile.

[0008] Optionally, the steel pipe pile is driven by the method of pre-boring combined with a hydraulic device. The steel pipe standard section and the diameter-changing transition section can be connected to the pile-driving end of the hydraulic device through the flanges.

[0009] By adopting the above technical solutions, the flanges can, on the one hand, play a role in connecting the steel pipe standard section and the diameter-changing transition section, and on the other hand, can play a role in quickly connecting the pile-driving end of the hydraulic device, thus greatly improving the construction efficiency. Thereby realizing the assembled erection and intelligent installation, forming a continuous flow operation for pile driving, pile splicing, and upper structure installation on the water, adapting to pile driving construction in various terrains, landforms, and geological conditions, avoiding the problems brought by the traditional on-water operation method, and achieving standardization, mechanization, high efficiency, and zero loss.

[0010] Optionally, the wall thickness of the steel pipe pile is 10 - 60 mm, the length of the standard steel pipe section is 2.5 m or 3 - 6 m, the length of the standard steel pipe section at the bottommost part of the steel pipe pile is 6 - 12 m, a flange is provided at the upper end of the bottommost standard steel pipe section, and no flange is provided at the lower end.

[0011] By adopting the above technical solution, a reasonable wall thickness of the steel pipe pile is specified to ensure that the steel pipe pile has appropriate strength and stability; an appropriate length of the standard steel pipe section is set to facilitate production, transportation and installation; the length of the bottommost standard steel pipe section is determined and a flange is provided at its upper end and no flange is provided at its lower end, which is conducive to inserting the steel pipe pile into the soil or rock mass and facilitating the pile driving construction.

[0012] Optionally, reinforcing ribs are provided on the inner flange, the reinforcing ribs extend along the axial direction of the inner flange and the extension of the reinforcing ribs does not exceed the radial inner side wall of the inner flange, and the reinforcing ribs are fixedly connected to the inner wall of the standard steel pipe section or the inner wall of the reduced-diameter transition section.

[0013] By adopting the above technical solution, reinforcing ribs that extend along the axial direction, do not exceed the radial inner side wall and are fixedly connected to the inner wall are provided on the inner flange, which can enhance the strength and stability of the inner flange and improve the overall reliability of the steel pipe pile structure.

[0014] Optionally, between the standard steel pipe sections or between the reduced-diameter transition sections, they can be connected, assembled and disassembled through flanges.

[0015] By adopting the above technical solution, the standard steel pipe sections can be connected, assembled and disassembled through flanges with the standard sections, and the reduced-diameter transition sections can be connected, assembled and disassembled through flanges with the transition sections, which can flexibly assemble and disassemble the steel pipe pile, facilitate on-demand adjustment during the construction process and later recycling and reuse, and improve the construction flexibility and material utilization rate.

[0016] Optionally, a shock-absorbing support is installed above the topmost standard steel pipe section of the combined steel pipe pile, a bridge deck longitudinal beam is installed on the shock-absorbing support; a bridge deck is installed on the bridge deck longitudinal beam.

[0017] By adopting the above technical solution, a shock-absorbing support is installed above the topmost standard steel pipe section of the combined steel pipe pile, a bridge deck longitudinal beam is installed on the shock-absorbing support, and a bridge deck is installed on the bridge deck longitudinal beam, which can play a shock-absorbing role, make the installation of the bridge deck longitudinal beam and the bridge deck more stable, and enhance the stability and safety of the entire structure.

[0018] Optionally, the standard steel pipe section is connected to the shock-absorbing support through a flange.

[0019] By adopting the above technical solution, using the flange as a unified standard connecting piece between various components can effectively reduce costs, improve the convenience of disassembly and assembly, enable the bridge deck longitudinal beam and the bridge deck to be more firmly installed on the combined steel pipe piles, and facilitate the subsequent disassembly, replacement and maintenance of the shock-absorbing bearings.

[0020] Optionally, the assembled steel pipe pile is formed by the following method: S1. Design corresponding standard steel pipe sections and variable-diameter transition sections according to different hydrogeological conditions, designed pile lengths, and different force requirements; S2. Connect the standard steel pipe sections and the variable-diameter transition sections in sequence through the flange, and form a combined steel pipe pile by combining the pilot hole method with hydraulic pile driving in sequence; S3. Connect the top blind plate through the flange of the top standard steel pipe section; S4. Place the shock-absorbing bearing on the top blind plate; S5. Install the bridge deck longitudinal beam on the shock-absorbing bearing; S6. Install the bridge deck on the bridge deck longitudinal beam.

[0021] By adopting the above technical solution, it is possible to design suitable components according to different hydrogeological conditions, designed pile lengths and force requirements, connect the components using flanges and form a combined steel pipe pile by combining pilot holes with hydraulic pile driving, and then install the top blind plate, shock-absorbing bearing, bridge deck longitudinal beam and bridge deck, so as to achieve flexible design and efficient assembly construction of variable-section assembled steel pipe piles, adapt to different working conditions and complete the laying of the bridge deck; at the same time, this process can eliminate traditional water operations such as underwater cutting, welding, and assembly, achieving standardization, mechanization, high efficiency, and zero loss.

[0022] Optionally, when the combined steel pipe pile needs to be demolished subsequently, the separation of the standard steel pipe section and the variable-diameter transition section can be achieved by removing the flange.

[0023] By adopting the above technical solution, when the combined steel pipe pile needs to be demolished subsequently, the standard steel pipe section and the variable-diameter transition section can be separated by removing the flange, which is convenient for disassembling the steel pipe pile, conducive to material recycling and reuse, improves material utilization rate, and can also reduce the difficulty and cost of later maintenance and adjustment.

[0024] In summary, the present application includes at least one of the following beneficial technical effects: 1. Using ordinary steel pipes to process into standard sections and transition sections with flanges and connecting them into combined steel pipe piles, realizing assembly erection and intelligent installation, forming continuous flow operation, being able to adapt to pile construction in various terrains, landforms and geological conditions, without cutting and welding work throughout the process, improving construction efficiency, and achieving standardization, mechanization and zero loss; 2. The diameter of the combined steel pipe piles gradually shrinks through a reduced-diameter transition joint in the middle, reducing the water-blocking area. Moreover, the large-diameter piles at the lower part are inserted into the soil or rock mass, improving the bearing capacity, structural stability, and wave resistance of the piles and facilitating the installation of the upper structure. 3. Inner flanges are provided for steel pipe piles with a diameter above 1000 mm, which can increase the frictional resistance around the piles after grouting the subsequent steel pipe piles. Description of the Drawings

[0025] Figure 1 It is a schematic diagram of the variable cross-section assembled steel pipe pile of Embodiment 1 of the present application.

[0026] Figure 2 It is a structural schematic diagram of the top-section steel pipe pile of the present application.

[0027] Figure 3 It is a structural schematic diagram of the reduced-diameter transition joint of the present application.

[0028] Figure 4 It is a structural schematic diagram of the bottom-section steel pipe pile of the present application.

[0029] Figure 5 It is an elevation view of the variable cross-section assembled steel pipe pile of Embodiment 2 of the present application.

[0030] Figure 6 It is a side view of the variable cross-section assembled steel pipe pile of Embodiment 2 of the present application.

[0031] Figure 7 It is a formation schematic diagram of the variable cross-section assembled steel pipe pile of Embodiment 2 of the present application.

[0032] Description of the Reference Numerals: 1. Standard steel pipe section; 11. Top-section steel pipe pile; 12. Intermediate-section steel pipe pile; 13. Bottom-section steel pipe pile; 2. Reduced-diameter transition joint; 21. Top-section reduced-diameter transition joint; 22. Intermediate reduced-diameter transition joint; 3. Flange; 31. Outer flange; 32. Inner flange; 33. Reinforcing rib; 4. Top-section blind plate; 5. Shock-absorbing bearing; 6. Bridge deck longitudinal beam; 7. Bridge deck. Detailed Embodiments

[0033] Next, the technical solutions in the embodiments of the present invention will be further described in detail in conjunction with the attached Figure 1-7 , etc. The described embodiments are only possible technical implementations of the present invention, but are not limited thereto. Those skilled in the art can completely combine the embodiments of the present invention, and other embodiments obtained without creative labor are also within the protection scope of the present invention.

[0034] In the related art, a patent with the publication number CN 102628270 A discloses a large-diameter variable-section special-shaped resistance-increasing steel pipe pile system, which includes an offshore operation platform. An overhead crane and a high-pressure pump are provided on the offshore operation platform. The high-pressure pump is connected to a number of high-pressure jet pipes on the inner wall of the steel pipe pile. A pile cap is provided at the top of the steel pipe pile, and a vibratory hammer connected to the overhead crane is provided above the pile cap. A mud pump support is arranged in the steel pipe pile, a slurry discharge pipe is supported on the mud pump support, the lower part of the slurry discharge pipe is connected to a mud pump, and the upper part is communicated with a slurry discharge port on the side surface of the steel pipe pile. The present invention also discloses the construction method of this system. The present invention is suitable for various foundation engineering with special technical requirements such as pile foundation compression resistance, uplift resistance, and bending resistance, and has the characteristics of fast construction, low cost, and easy control of construction quality. It is particularly suitable for large single structures in marine engineering such as similar bridge piers and offshore wind turbines.

[0035] It mainly sets a large-diameter variable-section special-shaped resistance-increasing steel pipe pile at the bottom of the steel pipe pile, and combines its water jet technology and cement soil filling technology to improve the uplift resistance, compression resistance and horizontal bearing capacity of the pile. However, a large amount of offshore operations are still required during its construction process, including operations such as cutting and welding, which not only have low efficiency and large losses, but also the subsequent demolition is extremely inconvenient. At the same time, the steel pipe pile has a large pile diameter, thick steel plate, large consumption, high pile foundation investment and great construction difficulty, seriously affecting the progress and cost of the project.

[0036] This application mainly assembles steel pipe piles using detachable standard sections and transition sections with different diameters, achieving the effects of less workload, convenient and efficient installation and disassembly, and adapting to different working conditions. The following is a further detailed description of this application.

[0037] Example 1, the variable-section assembled steel pipe pile provided in the embodiment of this application, referring to Figure 1 , includes a plurality of steel pipe standard sections 1 and variable-diameter transition sections 2. Among them, the plurality of steel pipe standard sections 1 are connected together through the variable-diameter transition sections 2, realizing the combined connection of standard sections with different diameters, achieving the flexible assembly of steel pipe piles according to different hydrogeological and force requirements, making the bottom section have large bearing capacity, stable structure and good wave resistance, and the top section is convenient for the installation of steel beam structure and bridge deck structure. This is because the standard sections with different diameters can be combined as needed. The large-diameter section at the bottom ensures bearing and stability, and the small-diameter section at the top adapts to the upper structure and can save costs.

[0038] Specifically, the standard steel pipe section 1 can be divided into the top steel pipe pile 11, the middle steel pipe pile 12, and the bottom steel pipe pile 13, and their diameters decrease successively from top to bottom. The standard steel pipe section 1 is processed from ordinary steel pipes with different diameters according to the modulus. Ordinary steel pipes generally use high-strength steel, which has good toughness and strength and can withstand large pressures and external forces. For example, the common Q345 steel can of course also choose other steels with better performance according to the actual engineering requirements. For the standard steel pipe sections 1 with different diameters, precise processing will be carried out according to the design modulus to ensure the accuracy and stability of subsequent assembly.

[0039] Flanges 3 are provided at both ends of the standard steel pipe section 1, which can tightly connect the standard steel pipe section 1 with other components. The material of the flange 3 is usually the same as that of the standard steel pipe section 1 to ensure the performance matching of the two. During production, forging process will be adopted to make the flange 3 have high strength and accuracy.

[0040] Refer to Figure 1 and Figure 2 , for the standard steel pipe section 1 with a diameter below 1000mm, its flange 3 is set as the outer flange 31, and the outer flange 31 protrudes from the steel pipe surface, which is convenient for operation and positioning during connection. When the diameter of the standard steel pipe section 1 is above 1000mm, the flange 3 is set as the inner flange 32, and the inner flange 32 is located inside the steel pipe. Construction workers can enter the inside of the steel pipe to connect the flange 3. After the connection is completed, when grouting into the steel pipe pile subsequently, the inner flange 32 can increase the frictional resistance around the pile and improve the stability and bearing capacity of the steel pipe pile.

[0041] In a preferred embodiment, reinforcing ribs 33 are also provided on the inner flange 32. The reinforcing ribs 33 extend axially along the inner flange 32 and do not exceed the radial inner wall of the inner flange 32. The reinforcing ribs 33 are fixedly connected to the inner wall of the standard steel pipe section 1 by welding. The setting of the reinforcing ribs 33 greatly enhances the structural strength of the inner flange 32, enabling it to better withstand the acting forces from all directions. In this embodiment, the flange 3 is circular in shape. In other embodiments, the flange 3 can also be elliptical, polygonal, etc.

[0042] Among them, the stepped transition section 2 can be divided into the top stepped transition section 21 and the middle stepped transition section 22, and their diameters decrease successively from top to bottom. The main function of the stepped transition section 2 is to connect the standard steel pipe sections 1 with different diameters, so that the diameter of the entire steel pipe pile can gradually decrease from bottom to top. The stepped transition section 2 is also made of suitable steel, and the flanges 3 at both ends thereof match the flange 3 specifications of the connected standard steel pipe section 1 to achieve reliable connection.

[0043] Refer to Figure 1 and Figure 3, when the diameter of the reduced-diameter transition section 2 is less than 1000 mm, the external flange 31 is adopted; when the diameter is more than 1000 mm, the internal flange 32 is adopted. The flange 3 setting rules of the reduced-diameter transition section 2 and the steel pipe standard section 1 are the same. In a preferred embodiment, the shape of the reduced-diameter transition section 2 is a gradually changing cone, and the force is smoothly transmitted through its own conical structure, making the force transmission more uniform. This structure avoids stress concentration caused by sudden diameter changes, improves the overall stability of the steel pipe pile, and can effectively reduce the impact of external forces such as water flow on the steel pipe pile.

[0044] In other embodiments, the reduced-diameter transition section 2 can also adopt a stepped transition section. The stepped transition section is composed of multiple short pipes with different diameters connected in sequence, and flanges 3 adapted to the standard section or other short pipes are provided at both ends of each short pipe. This design can also achieve the connection of standard sections with different diameters and has advantages in some projects with special requirements for spatial layout.

[0045] During assembly, first select the steel pipe standard section 1 and the reduced-diameter transition section 2 with appropriate diameters and lengths according to different hydrogeological conditions, design pile lengths, and different force requirements. Then connect them in sequence through the flange 3. For example, first use the reduced-diameter transition section 2 to connect the steel pipe standard section 1 with a larger diameter and the steel pipe standard section 1 with a smaller diameter to form a gradually reduced-diameter structure. The steel pipe pile formed by such combination has a decreasing diameter trend from bottom to top. The lower part is inserted into the soil or rock mass through the steel pipe standard section 1 with the largest diameter, because the steel pipe standard section 1 with a large diameter can provide greater bearing capacity to ensure the stability of the steel pipe pile; the diameter is gradually reduced through the reduced-diameter transition section 2 in the middle, effectively reducing the water-blocking area and reducing the impact force of water flow on the steel pipe pile; the upper part is matched with the upper bridge deck longitudinal beam 6 through the steel pipe standard section 1 with the smallest diameter, reducing costs and facilitating the subsequent installation of the upper bridge deck longitudinal beam 6.

[0046] Specifically, there are also certain requirements for the size specifications of the steel pipe standard section 1 and the reduced-diameter transition section 2. The diameters of the steel pipe standard section 1 and the reduced-diameter transition section 2 are 500 mm - 3000 mm, and this range can meet the needs of most projects. The wall thickness of the steel pipe pile is 10 - 60 mm, and the different settings of the wall thickness can be adjusted according to different force conditions to ensure the strength and stability of the steel pipe pile. The length of the steel pipe standard section 1 is generally 2.5 m or 3 - 6 m, and such length settings are convenient for transportation and construction.

[0047] Refer to Figure 4 , and the length of the steel pipe standard section 1 at the bottom of the steel pipe pile is 6 - 12 m. A flange 3 is provided at its upper end for connection with other components, and no flange 3 is provided at the lower end, which is beneficial for entering the soil or rock and reducing the resistance of pile sinking.

[0048] In addition, between the standard steel pipe sections 1 and between the stepped transition sections 2, connection and assembly / disassembly can be achieved through the flange 3. This solution can further flexibly assemble and disassemble the steel pipe piles, facilitating on-demand adjustment during construction and later recycling and reuse, improving construction flexibility and material utilization rate.

[0049] The implementation principle of Embodiment 1 is as follows: This variable-section assembled steel pipe pile modularizes and assembles the standard steel pipe sections 1 with different diameters and the stepped transition sections 2, giving full play to the advantages of components with different diameters. The large-diameter standard steel pipe section 1 at the lower part provides strong bearing capacity, ensuring the stability of the steel pipe pile under complex geological conditions; the middle stepped transition section 2 reduces the water resistance area, improving the adaptability of the steel pipe pile in the water flow environment; the small-diameter standard steel pipe section 1 at the upper part is convenient for matching with the upper structure. Moreover, the assembled connection method realized through the flange 3 makes the construction process simpler and more efficient, greatly shortening the construction period, reducing the construction cost, and at the same time improving the repeated utilization rate of materials, showing significant improvement and enhancement compared with the traditional construction method of steel pipe piles.

[0050] Embodiment 2, the difference between this embodiment and Embodiment 1 lies in: In the pile driving method, the steel pipe pile in this embodiment is driven by combining the hole-drilling method with a hydraulic device, and the standard steel pipe section 1 and the stepped transition section 2 can be connected to the pile driving end of the hydraulic device through the flange 3.

[0051] When conducting hole-drilling, professional drilling equipment such as a spiral drill will be used. According to the design requirements, holes with appropriate diameters and depths are drilled at the specified positions. During the drilling process, the verticality of the holes and the accuracy of the hole diameters should be ensured to ensure the smooth insertion of the subsequent steel pipe piles. The hydraulic device is the key equipment for pile driving. It can provide strong and stable pressure to accurately drive the steel pipe pile into the hole. The hydraulic device generally consists of components such as a hydraulic pump and a hydraulic cylinder, and drives the piston movement of the hydraulic cylinder through the pressure of the hydraulic oil to achieve the function of pile driving.

[0052] During connection, the flanges 3 of the standard steel pipe section 1 and the stepped transition section 2 are tightly connected to the pile driving end of the hydraulic device through connecting parts such as bolts. This connection method ensures that during the pile driving process, the force can be evenly transmitted to the steel pipe pile, avoiding the situation of local overstress causing damage to the steel pipe pile. Through the pile driving method combining hole-drilling with a hydraulic device, the penetration depth and verticality of the steel pipe pile can be more accurately controlled, improving the quality and efficiency of pile driving, especially suitable for projects with high requirements for pile position accuracy.

[0053] The implementation principle of this embodiment is as follows: The hole-leading method is combined with a hydraulic device for pile sinking, overcoming the limitations of traditional pile-sinking methods under certain complex geological conditions. The hole-leading can create good soil-entering conditions for the steel pipe pile in advance, reducing the resistance during the pile-sinking process; the stable pressure provided by the hydraulic device can ensure that the steel pipe pile is accurately and smoothly sunk into the designated position. At the same time, through the connection between the flange 3 and the hydraulic device, the effective transmission of force and the safety of construction are guaranteed. Compared with the traditional pile-sinking method, the construction quality and efficiency are improved, and the construction difficulty and cost are reduced.

[0054] Embodiment 3. The difference between this embodiment and Embodiment 1 is that with reference to Figure 5 and Figure 6 , above the steel pipe standard section 1 at the top of the combined steel pipe pile, a top-section blind plate 4 is installed. A shock-absorbing support 5 is placed on the top-section blind plate 4, and a bridge deck longitudinal beam 6 is installed on the shock-absorbing support 5. A bridge deck 7 is installed on the bridge deck longitudinal beam 6.

[0055] The top-section blind plate 4 is used to support the upper structure components. The shock-absorbing support 5 is a device with special properties, which is generally made of elastic materials such as rubber. Rubber has good elasticity and energy-absorbing properties, and can effectively absorb and buffer the vibrations and impact forces from the bridge deck 7 and the outside world. The shape of the shock-absorbing support 5 is usually circular or square, and its size is designed according to the specifications of the bridge deck longitudinal beam 6 and the steel pipe standard section 1.

[0056] In a preferred embodiment, the shock-absorbing support 5 is tightly connected to the flange 3 at the top of the steel pipe standard section 1 through connectors such as bolts, and is also firmly connected to the bridge deck longitudinal beam 6.

[0057] The bridge deck longitudinal beam 6 is an important structural component for supporting the bridge deck 7. It is usually made of a steel beam or a reinforced concrete beam. The steel beam has the advantages of high strength and light weight, and can bear large loads; the reinforced concrete beam has better durability and stability. The bridge deck longitudinal beam 6 is installed on the shock-absorbing support 5, and through specific connection methods such as welding or bolt connection, its reliable connection with the shock-absorbing support 5 is ensured.

[0058] The bridge deck 7 is installed on the bridge deck longitudinal beam 6, and it is the part directly for vehicles and pedestrians to pass. The bridge deck 7 is generally made of a reinforced concrete slab or a steel plate, and has sufficient strength and flatness. During installation, through a certain fixing method such as bolt connection or welding, the bridge deck 7 is fixed on the bridge deck longitudinal beam 6 to form an integral bridge deck structure.

[0059] The implementation principle of this Embodiment 3 is as follows: Installing a shock absorber support 5 at the top of the combined steel pipe pile can effectively reduce the impact of vibrations and impact forces generated during the use of the bridge on the steel pipe pile and the lower structure, thereby extending the service life of the bridge. The reasonable installation of the bridge deck longitudinal beam 6 and the bridge deck 7 forms a complete bridge deck structure, providing safe and stable passage conditions for vehicles and pedestrians. This structural design not only improves the comfort and safety of the bridge but also enhances the stability and reliability of the entire bridge structure.

[0060] Embodiment 4. The forming method of the variable cross-section assembled steel pipe pile provided by the embodiments of the present application is referred to Figure 7 , and includes the following steps:

[0061] S1. Design corresponding standard steel pipe sections 1 and variable diameter transition sections 2 according to different hydrogeological conditions, design pile lengths, and different force requirements.

[0062] Specifically, first, it is necessary to conduct a detailed investigation and analysis of the hydrogeological conditions at the construction site to understand information such as the nature of the soil layer and the groundwater level. At the same time, according to the design requirements of the bridge, determine the required pile length and bearing capacity. Then, based on these data, design standard steel pipe sections 1 and variable diameter transition sections 2 with appropriate diameters, lengths, and wall thicknesses. During the design process, fully consider the connection and matching relationships between different components to ensure the smooth progress of subsequent assembly.

[0063] S2. Connect the standard steel pipe sections 1 and the variable diameter transition sections 2 in sequence through the flange 3, and form a combined steel pipe pile by the method of pre-boring combined with hydraulic pile driving in sequence.

[0064] Specifically, during the connection, ensure the sealing and fastening between the flanges 3. Usually, use sealing gaskets and high-strength bolts for connection. The pre-boring operation should be carried out according to the design requirements to ensure that the diameter and depth of the holes meet the standards. During hydraulic pile driving, control the speed and force of pile driving to avoid damaging the steel pipe pile. As the standard steel pipe sections 1 and the variable diameter transition sections 2 are connected and sunk one by one, a complete combined steel pipe pile is gradually formed.

[0065] S3. Connect the top blind plate 4 through the flange 3 of the topmost standard steel pipe section 1.

[0066] Specifically, seal the standard steel pipe section 1 through the top blind plate 4, and use the top blind plate 4 to support the upper structure, which can better meet the installation requirements of the upper structure of the trestle or working platform, realize the reasonable connection between the assembled steel pipe pile and the upper structure, and facilitate the construction of the entire water trestle or water working platform.

[0067] S4. Place the shock absorber support 5 on the top blind plate 4.

[0068] Specifically, before installing the shock absorber support 5, the surface of the top blind plate 4 needs to be cleaned and leveled to ensure that the shock absorber support 5 can be installed stably. Then, the shock absorber support 5 and the top blind plate 4 are firmly connected together through bolts and other connecting parts.

[0069] S5. Install the bridge deck longitudinal beam 6 on the shock absorber support 5.

[0070] Specifically, during installation, the position of the bridge deck longitudinal beam 6 should be accurate and the connection with the shock absorber support 5 should be firm. Usually, a specific positioning device is used to ensure the installation accuracy of the bridge deck longitudinal beam 6.

[0071] S6. Install the bridge deck 7 on the bridge deck longitudinal beam 6.

[0072] Specifically, when installing the bridge deck 7, attention should be paid to the splicing and fixing between the plates to ensure the flatness and integrity of the bridge deck. The bridge deck 7 can be fixed on the bridge deck longitudinal beam 6 by means of welding, bolt connection, etc.

[0073] In addition, when it is necessary to remove the combined steel pipe pile subsequently, the separation of the standard steel pipe section 1 and the reduced-diameter transition section 2 can be achieved by removing the flange 3, or the separation of the standard steel pipe section 1 and the standard steel pipe section 1, and the reduced-diameter transition section 2 and the reduced-diameter transition section 2 can be achieved.

[0074] The implementation principle of this embodiment is as follows: This forming method is constructed in a reasonable order, starting from the design, ensuring the applicability and matching of each component. By combining the pilot hole with the hydraulic pile driving method, the pile driving accuracy and efficiency are improved. When installing the shock absorber support 5, the bridge deck longitudinal beam 6 and the bridge deck 7, the installation quality is strictly controlled to ensure the stability and safety of the entire bridge structure. Compared with the traditional construction method, this forming method is more scientific and efficient, can adapt to different engineering requirements, and reduces the uncertainty and risk during the construction process.

[0075] The above are all the preferred embodiments of this application. The protection scope of this application is not limited by this. Therefore, all equivalent changes made according to the structure, shape, and principle of this application should be covered within the protection scope of this application.

Claims

1. A variable-section assembled steel pipe pile, characterized in that: include: A plurality of steel pipe standard sections (1) and variable diameter transition sections (2), wherein the steel pipe standard sections (1) are made of ordinary steel pipes of different diameters processed according to a module, and flanges (3) are provided at both ends of the steel pipe standard sections (1) and the variable diameter transition sections (2) to achieve connection and assembly and disassembly between the two; The variable diameter transition section (2) can be used to connect steel pipe standard sections (1) of different diameters to form a combined steel pipe pile, wherein the diameter of the steel pipe pile decreases from bottom to top, the lower portion of the steel pipe pile is inserted into the soil or rock mass through the steel pipe standard section (1) with the largest diameter, the middle portion of the steel pipe pile gradually shrinks in diameter through the variable diameter transition section (2) to reduce the water blocking area, and the upper portion of the steel pipe pile is matched with the upper bridge deck longitudinal beam (6) through the steel pipe standard section (1) with the smallest diameter; The diameters of the steel pipe standard section (1) and the variable diameter transition section (2) are 500 mm to 3000 mm. When the diameters of the steel pipe standard section (1) and the variable diameter transition section (2) are less than 1000 mm, the flanges (3) of the steel pipe standard section (1) and the variable diameter transition section (2) are set as outer flanges (31). When the diameters of the steel pipe standard section (1) and the variable diameter transition section (2) are greater than 1000 mm, the flanges (3) of the steel pipe standard section (1) and the variable diameter transition section (2) are set as inner flanges (32). After grouting is subsequently performed in the steel pipe pile, the inner flange (32) can increase the friction resistance around the pile.

2. The variable cross-section assembled steel pipe pile according to claim 1, characterized in that: The steel pipe pile is sunk by a hole-guiding method combined with a hydraulic device, and the steel pipe standard section (1) and the variable diameter transition section (2) can be connected to the pile-driving end of the hydraulic device via the flange (3).

3. The variable cross-section assembled steel pipe pile according to claim 1, characterized in that: The wall thickness of the steel pipe pile is 10-60 mm, the length of the steel pipe standard section (1) is 2.5 m or 3-6 m, the length of the lowest steel pipe standard section (1) of the steel pipe pile is 6-12 m, a flange (3) is arranged at the upper end of the lowest steel pipe standard section (1), and no flange (3) is arranged at the lower end.

4. The variable-section assembled steel pipe pile according to claim 1, characterized in that: The inner flange (32) is provided with a reinforcing rib (33), the reinforcing rib (33) extending axially along the inner flange (32) and the reinforcing rib (33) extending no further than the radial inner wall of the inner flange (32), the reinforcing rib (33) being fixedly connected to the steel pipe standard section (1) or the reinforcing rib (33) being fixedly connected to the inner wall of the diameter-changing transition section (2).

5. The variable cross-section assembled steel pipe pile according to claim 1, characterized in that: The steel pipe standard sections (1) and the steel pipe standard sections (1), or the reducing transition sections (2) and the reducing transition sections (2), can be connected and assembled and disassembled via flanges (3).

6. The variable cross-section assembled steel pipe pile according to claim 1, characterized in that: A shock-absorbing support (5) is installed above the topmost steel pipe standard section (1) of the combined steel pipe pile, and a bridge deck longitudinal beam (6) is installed on the shock-absorbing support (5); and a bridge deck (7) is installed on the bridge deck longitudinal beam (6).

7. The variable cross-section assembled steel pipe pile according to claim 6, characterized in that: The steel pipe standard section (1) is connected to the shock absorbing support (5) via a flange (3).

8. The variable-section assembled steel pipe pile according to claim 1, characterized in that: The fabricated steel pipe pile is formed by the following method: S1. Design corresponding steel pipe standard sections (1) and variable diameter transition sections (2) according to different hydrogeological conditions, designed pile lengths, and different force requirements; S2, sequentially connecting the steel pipe standard section (1) and the variable diameter transition section (2) through the flange (3), and sequentially forming a combined steel pipe pile by a hole-guiding method combined with hydraulic pile sinking; S3, connecting the top section blind plate (4) through the flange (3) of the topmost steel pipe standard section (1); S4, placing a shock-absorbing support (5) on the top blind plate (4); S5, installing a bridge deck longitudinal beam (6) on the shock-absorbing support (5); S6. Installing the bridge deck (7) on the bridge deck longitudinal beam (6).

9. The variable-section assembled steel pipe pile according to claim 8, characterized in that: When the combined steel pipe pile needs to be dismantled later, the flange (3) can be removed to separate the steel pipe standard section (1) from the variable diameter transition section (2).

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