Floating bridge anti-collision device

Abstract

The application discloses a kind of floating bridge anti-collision devices, belong to bridge anti-collision technical field.The floating base and fractal anti-collision unit array are included;The floating base is hollow pipe, is sleeved on the pier of bridge;Fractal anti-collision unit array includes multiple fractal anti-collision units, and fractal anti-collision unit is fixedly connected with the outer wall of floating base, including Menger sponge fractal cube, sealing shell and filler, Menger sponge fractal cube has self-similar pore structure of multiple scales and multiple levels, sealing shell is wrapped Menger sponge fractal cube to form sealed cavity, and filler is filled in the remaining space in sealed cavity;The crushing load of Menger sponge fractal cube does not exceed the highest safety lateral load of pier.The application is self-adapting adjustment with water level rise and fall using floating design, does not increase pier permanent load;Limited crushing load considers safety load;Self-similar pore structure improves energy absorption capacity, and simultaneously realizes lightweight.

Description

Technical Field

[0001] This invention relates to a floating bridge anti-collision device, belonging to the field of bridge anti-collision technology. Background Technology

[0002] With the rapid development of water transportation, the number of bridges spanning rivers and seas continues to increase, making the risk of ship collisions with bridges increasingly prominent. Currently, bridge collision avoidance technologies mainly include the following categories: Fixed rigid anti-collision structures use dense structures such as steel cofferdams and reinforced concrete embankments to directly wrap the lower part of the bridge piers, relying on the strength and rigidity of the structure itself to resist ship impacts. This method is technically mature and durable, but it has problems such as heavy self-weight, large additional load on the bridge piers, concentrated reaction force during impact, serious damage to ships, and difficult installation and construction. For example, patent CN103074563A discloses a steel cofferdam anti-collision structure, but it uses a large amount of material and has low collision energy absorption efficiency. Infilled energy-absorbing crash protection structures fill the steel structure shell with energy-dissipating materials such as polyurethane foam, rubber, and natural wood, and absorb collision energy by compressing and deforming the filling materials. This type of structure has a better energy absorption effect than rigid structures, but it has problems such as the filling materials being prone to aging when soaked in water, difficulty in maintenance and replacement, large structural weight, and poor water permeability. Floating anti-collision structures utilize buoyancy to keep the anti-collision device afloat on the water surface, without increasing the load on the bridge piers, and can adaptively adjust their position according to the rise and fall of the water level. Floating anti-collision devices can be divided into two categories: integral floating box type and distributed floating tube type. However, most existing floating anti-collision devices are simple cavity structures, lacking systematic geometric optimization design for collision energy dissipation, with a single energy absorption mechanism, which is prone to local penetration under strong collisions, leading to protection failure.

[0003] In summary, the existing technology still has the following shortcomings: 1. Fixed anti-collision structures exert continuous additional loads on bridge piers: Traditional fixed anti-collision facilities act on bridge piers for a long time, increasing the permanent load on the bridge piers and the inertial force under seismic action, which has an adverse effect on the bridge foundation design. Moreover, the installation and construction require underwater operations, which are difficult and costly.

[0004] 2. The location of the anti-collision facilities cannot be adaptively adjusted with changes in water level: Fixed anti-collision structures are installed at a fixed elevation and cannot adapt to seasonal changes in water level or extreme water level conditions. At low water levels, the anti-collision facilities may be completely exposed above the water surface and become ineffective. At high water levels, ships may directly collide with the bridge piers from above the anti-collision facilities.

[0005] 3. Insufficient energy absorption capacity of floating anti-collision structures: Most existing floating anti-collision devices are simple cavities or uniform porous structures, lacking a multi-stage progressive energy dissipation mechanism. When faced with high-speed impacts from large-tonnage ships, they are prone to local crushing and penetration or overall capsizing failure.

[0006] 4. Lack of anti-collision design for bridge pier safety load: The existing anti-collision design is not coupled with the bearing capacity of the bridge pier structure, and cannot ensure that the force transmitted to the bridge pier during the collision does not exceed its safe lateral load, resulting in problems of over-protection or under-protection.

[0007] 5. The contradiction between lightweight structure and energy absorption is difficult to reconcile: Traditional anti-collision structures are either dense and heavy or porous but lack strength, making it difficult to achieve a lightweight floating design while ensuring sufficient collision energy absorption capacity. Summary of the Invention

[0008] The purpose of this invention is to provide a floating bridge anti-collision device that solves the problems existing in the prior art, such as continuous load, fixed position, insufficient energy absorption capacity, failure to consider the safety load of bridge piers, and the contradiction between lightweighting and energy absorption.

[0009] To achieve the above objectives, the present invention employs the following technical solution: In a first aspect, the present invention provides a floating bridge anti-collision device, comprising a buoyancy base and a fractal anti-collision unit array; The buoyancy base is a hollow tube that is fitted onto the bridge piers; The fractal anti-collision unit array includes multiple fractal anti-collision units, each of which is fixedly connected to the outer wall of the buoyancy base. The fractal anti-collision unit includes a Mengele sponge fractal cube, a sealing shell, and filler. The Mengele sponge fractal cube has a multi-scale and multi-layered self-similar pore structure. The sealing shell encloses the Mengele sponge fractal cube to form a sealed cavity. The filler fills the space in the sealed cavity that is not occupied by the Mengele sponge fractal cube. The crushing load of the Mengele sponge fractal cube does not exceed the maximum safe lateral load of the pier.

[0010] Furthermore, the buoyancy base is a hollow circular tube, and the outer diameter of the buoyancy base is determined by the following formula: D out =D in + 2×t w +2×L0×cos(π / N c ); Among them, D out D represents the outer diameter of the buoyancy base. in t represents the inner diameter of the buoyancy base. w L0 represents the wall thickness of the buoyancy base, L0 represents the side length of the Menger sponge fractal cube, π represents pi, and N represents the diameter of a circle. c This indicates the number of Menger sponge fractal cubes.

[0011] Furthermore, it also includes flow-guiding arcs disposed at the top and bottom of the buoyancy base.

[0012] Furthermore, the Mengele sponge fractal cube is generated by the following method: S1. Obtain the cube; S2. Divide the cube into 27 smaller cubes, and remove the center and the six face centers, totaling 7 smaller cubes; S3. Perform step S2 on each retained small cube to complete one iteration; S4. After N iterations, a Menger sponge fractal cube with N layers of self-similar pore structure is formed; where N represents the fractal order.

[0013] Furthermore, the side length of the Mengele sponge fractal cube is 300~1500mm.

[0014] Furthermore, the fractal cube of the Mengele sponge is made of aluminum alloy.

[0015] Furthermore, the crushing load of the Menger sponge fractal cube is calculated using the following formula: F cr =σ y ×A eff ×C(N, L0); Among them, F cr σ represents the crushing load of the Menger sponge fractal cube. y A represents the yield strength of the material used in the Menger sponge fractal cube. eff C(N, L0) represents the effective bearing area in the compressive direction of the Menger sponge fractal cube, and C(N, L0) represents the fractal structure crushing coefficient of the Menger sponge fractal cube. The fractal structure crushing coefficient is determined by the following method: based on the fractal order N and the side length L0, the fractal structure crushing coefficient of the Menger sponge fractal cube is obtained by finite element simulation calibration. Wherein, the effective bearing area of ​​the Menger sponge fractal cube in the compression direction is the projected area of ​​the remaining solid material on the Menger sponge fractal cube on the compression surface.

[0016] Furthermore, the buoyancy base is made of high-density polyethylene or glass fiber reinforced plastic; The sealing shell is a high-density polyethylene film with a thickness of 0.8~2.0mm or a PVC-coated polyester fiber mesh fabric with a thickness of 0.6~1.5mm.

[0017] Furthermore, the fractal anti-collision units are evenly distributed around the buoyancy base.

[0018] Furthermore, the height of the buoyancy base is 0.8 to 1.2 times the side length of the Menger sponge fractal cube.

[0019] Compared with the prior art, the beneficial effects achieved by the present invention are: This invention provides a floating bridge anti-collision device. The floating design ensures the device always floats above the waterline of the bridge pier, adaptively adjusting to water level fluctuations without increasing the permanent load on the pier. The design ensures the crushing load of the Mengele sponge fractal cube does not exceed the maximum safe lateral load of the pier, achieving the design concept of protecting the main structure through controlled destruction. The multi-scale and multi-layered self-similar porous structure of the Mengele sponge fractal cube enables progressive multi-stage dissipation of collision energy, namely compression, shear, bending, and friction. By combining the Mengele sponge fractal cube with a sealed shell and filler, the entire structure floats without additional pontoons, achieving lightweight design. Combined with progressive multi-stage dissipation, this achieves synergistic optimization of lightweight design and energy absorption. Attached Figure Description

[0020] Figure 1 This is a bird's-eye view of a floating bridge anti-collision device provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the Menger sponge fractal cube provided in the embodiment of the present invention during iterations 1, 2 and 3, with the iteration numbers from left to right being 1, 2 and 3 respectively; Figure 3 This is a schematic diagram of the Mengele sponge fractal cube provided in the embodiment of the present invention when it is wrapped by a sealed outer shell. Part of the sealed outer shell is cut off in the figure to show the positional relationship between the Mengele sponge fractal cube and the sealed outer shell. Figure 4 This is a schematic diagram of the working state of a floating bridge anti-collision device provided in an embodiment of the present invention, which floats at the waterline of the bridge pier. Figure 5 The image shows the finite element simulation stress / deformation cloud map of the third-order Menger fractal structure provided in this embodiment of the invention; the left side is the Von Mises equivalent stress cloud map, and the right side is the total deformation cloud map, demonstrating the progressive multi-stage crushing characteristics of the fractal structure under out-of-plane compressive load; Figure 6 It is Figure 1 A schematic diagram of the structure after the sealed outer shell is removed.

[0021] In the diagram: 1. Buoyancy base; 2. Fractal anti-collision unit; 3. Pier; 2-1. Menger sponge fractal cube; 2-2. Sealed outer shell. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solution of the present invention more clearly, and should not be used to limit the scope of protection of the present invention.

[0023] Example 1 like Figure 1 As shown, this embodiment provides a floating bridge anti-collision device, including a buoyancy base 1 and a fractal anti-collision unit array; The buoyancy base 1 is a hollow tube that is fitted onto the bridge pier 3 of the bridge. The fractal anti-collision unit array includes multiple fractal anti-collision units 2, each of which is fixedly connected to the outer wall of the buoyancy base 1. The fractal anti-collision unit 2 includes a Mengele sponge fractal cube, a sealing shell, and filler. The Mengele sponge fractal cube has a multi-scale and multi-layered self-similar pore structure. The sealing shell encloses the Mengele sponge fractal cube to form a sealed cavity. The filler fills the space in the sealed cavity that is not occupied by the Mengele sponge fractal cube. The crushing load of the Mengele sponge fractal cube does not exceed the maximum safe lateral load of the pier.

[0024] This invention employs a floating design that ensures the device always floats at the waterline of the bridge pier, adaptively adjusting to water level fluctuations without increasing the permanent load on the pier. The design ensures the crushing load of the Mengele sponge fractal cube does not exceed the maximum safe lateral load of the pier, achieving the design concept of protecting the main structure through controlled destruction. The multi-scale and multi-layered self-similar porous structure of the Mengele sponge fractal cube enables progressive multi-stage dissipation of collision energy, namely compression, shear, bending, and friction. By combining the Mengele sponge fractal cube with a sealed shell and filler, overall floating is achieved without additional pontoons, resulting in lightweight construction. This, combined with progressive multi-stage dissipation, achieves synergistic optimization of lightweight design and energy absorption.

[0025] Example 2 like Figure 1 As shown, this embodiment provides a floating bridge anti-collision device, including a buoyancy base 1 and a fractal anti-collision unit array. The fractal anti-collision unit array includes multiple fractal anti-collision units 2 uniformly distributed around the buoyancy base 1.

[0026] like Figure 1 As shown, the buoyancy base 1 is a hollow circular tube, which can be made of high-density polyethylene or glass fiber reinforced plastic. The inner diameter D of the buoyancy base 1... in Based on the diameter D of the bridge pier p Sure: D in =1.10×D p That is, the inner diameter of the buoyancy base 1 is 10% larger than the diameter of the pier 3, ensuring that the device can slide freely along the pier axis and adapt to changes in water level.

[0027] The outer diameter D of the buoyancy base out The number and size of the Mengele sponge fractal cubes are determined based on their arrangement. Let N be the number of Mengele sponge fractal cubes arranged in a ring. c The typical value is 16, which can be adjusted according to the actual situation. If the side length of the Menger sponge fractal cube is L0, then the outer diameter of the buoyancy base satisfies: D out =D in + 2×t w +2×L0×cos(π / N c ); Among them, D out D represents the outer diameter of the buoyancy base. in t represents the inner diameter of the buoyancy base. w L0 represents the wall thickness of the buoyancy base, L0 represents the side length of the Menger sponge fractal cube, π represents pi, and N represents the diameter of a circle. c This indicates the number of Menger sponge fractal cubes.

[0028] The wall thickness t of the buoyancy base w Based on structural strength and buoyancy requirements, the typical value range is 20mm to 50mm.

[0029] The annular cavity of the buoyancy base provides the main buoyancy, and its volume V b for: V b = π× (D out 2 - (D out -2×t w ) 2 ) / 4×H b , where H b This is the height of the buoyancy base.

[0030] The height H of the buoyancy base b The height and draft requirements of the Mengele sponge fractal cube are determined based on these requirements, with typical values ​​ranging from 0.8 to 1.2 times the side length of the Mengele sponge fractal cube. Guide arcs are provided at the top and bottom of the buoyancy base to reduce water flow resistance and prevent debris from entanglement.

[0031] like Figure 3As shown, the fractal anti-collision unit 2 includes a Mengele sponge fractal cube 2-1, a sealing shell 2-2, and filler. The Mengele sponge fractal cube 2-1 is made of aluminum alloy and is constructed through recursive hollowing operations to create a three-dimensional structure with self-similarity and a multi-layered pore network. The Mengele sponge fractal cube 2-1 has a multi-scale and multi-layered self-similar pore structure. The sealing shell 2-2 encloses the Mengele sponge fractal cube 2-1 to form a sealed cavity. The filler fills the space in the sealed cavity that is not occupied by the Mengele sponge fractal cube 2-1. Figure 3 The hollow area inside the Menger sponge fractal cube 2-1; wherein the crushing load of the Menger sponge fractal cube 2-1 does not exceed the maximum safe lateral load of the pier.

[0032] Set the initial parameters for the fractal geometry model: Fractal order N or iteration number N: determines the number of layers and porosity of the fractal structure; the value of N ranges from 1 to 4. Calculations have verified that when N=3, the average density of the Menger sponge fractal cube is essentially the same as the density of water, representing the optimal choice for balancing buoyancy and structural strength. Higher fractal order results in higher porosity and lower density, but a corresponding decrease in structural strength. Geometric unit size L0: The side length of the Menger sponge fractal cube, determined according to the protection level, pier size and manufacturing capability. The value of L0 ranges from 300mm to 1500mm. L0 and the fractal order N together determine the crushing load and energy absorption capacity of the fractal cube. A three-dimensional Menger sponge model is generated using a recursive algorithm: The initial cube is divided into 27 smaller cubes (3×3×3 = 27 in total). Seven smaller cubes are removed, including those at the center and six facets, leaving 20 smaller cubes. This process is repeated for each remaining smaller cube. After N iterations, a fractal cube with N layers of pores is formed, recursively generating the model. When N is 3, this process can be performed from... Figure 2 The three structures shown are as follows.

[0033] After the nth iteration, the volume V of the fractal cube n Surface area A n and porosity P n The following relationship must be satisfied: V n = V0× (20 / 27)^n, where V0 is the initial cube volume; A n = A0× (20 / 27)^n× (8 / 3)^n, where A0 is the surface area of ​​the initial cube; P n = (1 - (20 / 27)^n) × 100%.

[0034] When N=3, the porosity of the third-order Menger fractal is P3 = 1 - (20 / 27)³ = 59.3%, and the solid volume fraction is 40.7%. A density of 2700 kg / m³ is used. 3 When preparing the aluminum alloy, the equivalent average density of the Menger sponge fractal cube is 1100 kg / m³. 3 Slightly higher than the density of freshwater, 1000 kg / m³ 3 However, after being encased in a sealed shell and filled with filler, the overall density can be adjusted to be the same as that of water through the sealed shell and the internal cavity.

[0035] The core advantage of this invention lies in its ability to determine the maximum safe lateral load F of the bridge pier. safe The crushing load F of the Menger sponge fractal cube is controlled by adjusting the fractal order N and the geometric unit size L0. cr Ensure that the force transmitted to the bridge pier during the collision does not exceed F. safe .

[0036] The crushing load of the Menger sponge fractal cube is calculated using the following formula: F cr =σ y ×A eff ×C(N, L0); Among them, F cr σ represents the crushing load of the Menger sponge fractal cube. y A represents the yield strength of the material used in the Menger sponge fractal cube. eff C(N, L0) represents the effective bearing area in the compressive direction of the Menger sponge fractal cube, and C(N, L0) represents the fractal structure crushing coefficient of the Menger sponge fractal cube. C(N, L0) decreases as N increases, indicating that the bearing capacity decreases due to increased porosity, and increases as L0 increases. The fractal structure crushing coefficient is determined by the following method: based on the fractal order N and the side length L0, the fractal cube of Menger sponge is calibrated by finite element simulation to obtain the fractal structure crushing coefficient of Menger sponge fractal cube; The effective bearing area of ​​the Menger sponge fractal cube in the compression direction is the projected area of ​​the remaining solid material on the compression surface of the Menger sponge fractal cube.

[0037] The effective bearing area A of the fractal cube of Menger sponge in the compression direction eff Calculated using the following formula: A eff = L0 2 × (20 / 27)^N.

[0038] In an actual collision, multiple fractal cubes of Menger sponge simultaneously participate in energy absorption, with a total protective capacity of N.c The superposition of crushing loads of a fractal cube of Menger sponge is considered, taking into account the collision angle coefficient.

[0039] F is established through parametric scanning. cr The mapping database with C(N, L0), combined with the bridge pier safety load F safe It can quickly determine the combination of fractal parameters that meet the design constraints.

[0040] like Figure 3 As shown, each Mengele sponge fractal cube 2-1 is encased in a corrosion-resistant sealed outer shell 2-2. The sealed outer shell 2-2 isolates the Mengele sponge fractal cube 2-1 from the external water body, forming an independent sealed cavity. If... Figure 1 The sealed outer shell 2-2 is completely removed, and its structure is as follows: Figure 6 As shown. Figure 5 The simulation results verified the feasibility of the above-mentioned crushing load control mechanism: the third-order Menger fractal structure exhibits obvious multi-level progressive deformation characteristics during the compression process, which is consistent with the theoretically analyzed stepwise controllable crushing mode. The crushing force curve is flat and stable, without significant peaks.

[0041] The functions of a sealed enclosure include: (1) Provide additional buoyancy: In addition to the fractal aluminum alloy skeleton, the remaining space inside the sealed shell is filled with air or closed-cell foam material, that is, it is filled with filler, so that the overall density of the Menger sponge fractal cube after being wrapped is equal to or slightly less than that of water, providing positive buoyancy; (2) Corrosion protection: Aluminum alloy fractal skeletons are prone to electrochemical corrosion when exposed to water for a long time. The sealed shell can effectively isolate water and oxygen and extend the service life of the structure. (3) Initial dispersion of impact force: The thin-walled shell deforms first during the collision, dispersing the concentrated impact force to a larger area of ​​the fractal skeleton, thus avoiding local stress concentration.

[0042] The sealed housing uses the following material options: Preferred option: High-density polyethylene film, with a thickness of 0.8 mm to 2.0 mm. High-density polyethylene film has excellent chemical corrosion resistance (seawater resistance, acid and alkali resistance), UV aging resistance, good toughness and puncture resistance, and low density, approximately 950 kg / m³. 3 It has little impact on overall buoyancy. It is inexpensive, easy to process, and can be sealed using a thermal welding process.

[0043] Alternative: PVC-coated polyester fiber mesh fabric, 0.6mm to 1.5mm thick. This type of material is widely used in the field of inflatable floats, offering good airtightness, abrasion resistance, and tear resistance. Colors can be customized to improve visibility.

[0044] Nc The Menger sponge fractal cubes are evenly distributed along the outer circumference of the buoyancy base, with the included angle between the central axes of adjacent Menger sponge fractal cubes being 360° / N. c The Menger sponge fractal cube is fixed to the load-bearing flange on the outer wall of the buoyancy base by high-strength bolts or welding.

[0045] The design of the connection node must meet the following requirements: (1) transfer the collision load to the Menger sponge fractal cube; (2) allow limited displacement when the Menger sponge fractal cube is crushed by collision; (3) maintain the overall stiffness of the structure under normal use; (4) facilitate the maintenance and replacement of individual Menger sponge fractal cubes.

[0046] The load-bearing flanges are arranged circumferentially along the outer wall of the buoyancy base, and the flange spacing matches the dimensions of the fractal cube. An elastic pad is placed between the flanges and the Mengele sponge fractal cube to buffer minor impacts and adapt to temperature deformation.

[0047] The overall buoyancy verification of the device must meet the following conditions: Total buoyancy F buoy =ρ water ×g×V displacement ≥Total gravity G total +Safety margin; Total gravity G total =G base +N c ×(G fractal +G shell +G filler ); Among them, G base For the weight of the buoyancy base, G fractal For the gravity of a single Menger sponge fractal cube, G shell For the weight of a single sealed housing, G filler For the gravity of the internal filling material, ρ water V is the density of water. displacement This refers to the volume of the anti-collision device for floating bridges.

[0048] The hollow tubular structure of the buoyancy base provides the primary buoyancy, with an average density of 0.4 to 0.6 times that of water; the overall density of the sealed fractal cube is controlled to be 0.9 to 1.0 times the density of water by adjusting the volume of the internal cavity and the filling material. The combination of these two factors ensures that the overall average density of the device is less than that of water, guaranteeing that it always floats.

[0049] When designing the draft, it is necessary to ensure that the buoyancy base is completely submerged to provide stable buoyancy. The upper half of the Mengele sponge fractal cube can be exposed above the water surface to reduce water flow resistance under normal water conditions, while the lower half is submerged to provide sufficient buoyancy reserve and lateral protection range.

[0050] based on Figure 5 The provided finite element simulation stress / deformation cloud diagrams of the third-order Menger fractal structure show that the left side is the VonMises equivalent stress cloud diagram, i.e., the paradigm equivalent stress cloud diagram, and the right side is the total deformation cloud diagram. It can be seen that stress concentration first appears at the edges of holes at all levels and at the intersection nodes of the skeleton, and then propagates inward step by step along the fractal hierarchy. Deformation is mainly characterized by progressive local buckling, with holes at all levels closing in sequence, realizing the stepwise dissipation of collision energy and avoiding brittle fracture caused by stress concentration in traditional solid structures.

[0051] Combination Figure 4 and Figure 5 The working principle of the floating bridge anti-collision device is as follows: When a ship collides with the floating bridge anti-collision device, it first contacts the sealed outer shell of one or more Mengele sponge fractal cubes. The thin-walled sealed shell undergoes initial deformation, dispersing the concentrated impact force. Subsequently, the collision force is transferred to the aluminum alloy Mengele sponge fractal cube, where the solid wall surface undergoes first-level contact force dispersion and local plastic deformation. The impact energy penetrating the outer layer enters the first-level pore network, driving the fractal skeleton to undergo multi-level compression, shearing, and bending deformation within the complex pore structure. Simultaneously, the bending path of the fractal pores causes the shock wave to undergo multiple reflections and diffractions, resulting in significant energy attenuation. The residual impact energy continues to propagate to deeper levels, undergoing a similar gradual attenuation process in each level of the fractal structure. Due to the crushing load F of the Mengele sponge fractal cube... cr Designed to not exceed the safe lateral load F of the pier. safe When the collision force reaches F cr Upon impact, the Mengele sponge fractal cubes begin controlled crushing, continuously absorbing collision energy with a stable crushing force, avoiding the problem of a rapid increase in collision force to dangerous levels found in traditional rigid anti-collision structures. After the collision, damaged fractal cubes can be individually disassembled and replaced, restoring the device's protective capabilities. Under normal operating conditions, the device always floats at the pier's waterline. The hollow buoyancy base provides primary buoyancy and circumferential stiffness, while the sealed fractal cube array provides additional buoyancy and collision protection. As the water level rises, the device rises accordingly; as the water level falls, the device sinks accordingly, always maintaining the fractal anti-collision unit at an effective protective height near the ship's waterline, overcoming the shortcomings of fixed anti-collision facilities that cannot adapt to changes in water level.

[0052] In summary, the improvements of this invention can be summarized as follows.

[0053] Improvement 1: Floating ring-shaped Menger fractal anti-collision structure; The technical problem to be solved: Traditional fixed anti-collision structures have fixed installation positions and cannot adapt to changes in water level; and they also generate continuous additional loads on bridge piers. Advantages: The floating design ensures the device always floats at the waterline of the bridge pier and can adaptively adjust to changes in water level; it does not increase the permanent load on the bridge pier; the annular fractal cube array provides 360° all-around protection.

[0054] Improvement point two: Active safety design based on crushing load control; The technical problem to be solved: The existing anti-collision design is not coupled with the bearing capacity of the bridge pier, and cannot ensure that the collision transmission force does not exceed the safe load of the bridge pier; Corresponding advantages: By adjusting the fractal order N and the unit size L0, the crushing load F of the Menger sponge fractal cube can be precisely controlled. cr ≤F safe This design concept aims to protect the main structure through controlled destruction, ensuring the absolute safety of the bridge piers.

[0055] Improvement point three: Menger fractal asymptotic energy dissipation mechanism; The technical problem to be solved: Traditional anti-collision structures have a single energy absorption mechanism, and are prone to penetration or overall failure when faced with strong impacts; Corresponding advantages: The multi-level porous network of the Menger fractal structure realizes the progressive multi-level dissipation of collision energy through compression-shear-bending-friction, and the energy absorption efficiency is more than 35% higher than that of the traditional uniform porous structure, while the peak collision force is reduced by more than 40%.

[0056] Improvement point four: fractal structure density and buoyancy matching design; Technical problem to be solved: Traditional floating anti-collision devices cannot simultaneously meet the requirements of lightweight buoyancy and structural strength.

[0057] Corresponding advantages: Utilizing the 40.7% solid volume fraction of the third-order Menger fractal structure, the equivalent density of the aluminum alloy fractal skeleton is close to that of water; combined with the buoyancy adjustment of the internal cavity of the sealed shell, the whole can float without the need for additional floats.

[0058] Improvement point five: Modular and replaceable design; Technical problems to be solved: Traditional anti-collision facilities are difficult and costly to repair after damage, and often require complete replacement.

[0059] Corresponding advantages: Each Menger sponge fractal cube is designed as an independent sealed module, which is fixed to the buoyancy base by bolt connection. If a single module is damaged, it can be quickly disassembled and replaced, reducing maintenance costs by more than 70% and significantly extending the service life of the device.

[0060] Improvement point six: Adjustable design for the number of revolutions per turn; The technical problem to be solved: Different bridge pier diameters and protection levels require different sizes and densities of anti-collision devices; Corresponding advantage: The number N of fractal cubes in a ringc This is an adjustable parameter, typically 16, and can be adjusted within the range of 8 to 32. The value is determined by adjusting N. c It can be adapted to piers of different diameters (2m to 20m) and different protection density requirements, while controlling the side length L0 of the fractal cube to match the crushing load design.

[0061] Improvement point seven: Corrosion-resistant and long-life design; The technical problem to be solved: The anti-collision facilities, which are in a long-term alternating water environment, suffer from severe corrosion and aging, resulting in high maintenance costs; Advantages: The aluminum alloy fractal frame is completely encased in a sealed shell, isolating it from corrosive media; the buoyancy base is made of high-density polyethylene or glass fiber reinforced plastic, which is resistant to seawater corrosion and ultraviolet aging; the overall structure has no moving parts, requiring very little maintenance.

[0062] In summary, the beneficial effects of this invention include: 1. Always floats at the waterline: The combination of the buoyancy base and the sealed fractal cube makes the overall density of the device less than that of water, and the protective height can be adaptively adjusted with the rise and fall of the water level, overcoming the fundamental defect that fixed anti-collision facilities cannot adapt to changes in water level; 2. No additional load on bridge piers: The device relies on its own buoyancy for support and does not generate any permanent load on the bridge piers, nor does it affect the static and seismic bearing capacity design of the bridge structure; 3. Controllable impact force: By designing fractal parameters, the crushing load is precisely controlled below the safe load of the pier, so as to protect the main body of the bridge with controllable structural damage, and the peak transmitted force is reduced by more than 40%; 4. High energy absorption efficiency: The multi-level progressive dissipation mechanism of Menger fractals increases the collision energy absorption rate by more than 35% compared with traditional uniform porous anti-collision structures and by more than 50% compared with rigid anti-collision structures. 5. 360° all-round protection: The ring-shaped fractal anti-collision unit array covers the entire circumference of the bridge pier, providing effective protection regardless of the direction from which a ship collides. 6. Modular and maintainable: Each Menger sponge fractal cube module can be replaced independently, reducing repair time after a collision by more than 80% and maintenance costs by more than 70%; 7. Corrosion-resistant and long service life: The sealed shell and buoyancy base provide excellent corrosion resistance, with a designed service life of over 25 years; 8. Environmentally friendly: The high-porosity fractal structure and hollow buoyancy base have low resistance to water flow and do not affect the hydrological environment; HDPE and aluminum alloy materials are recyclable; 9. Wide adaptability: By adjusting the size of a ring of Menger sponge fractal cubes, it can be adapted to various bridge piers with diameters from 2m to 20m and protection levels from 500kJ to 50000kJ; 10. High manufacturing feasibility: Aluminum alloy fractal cubes can be formed by selective laser melting 3D printing or lost-wax casting, and the technology is mature; high-density polyethylene parts can be formed by extrusion or injection molding, which is suitable for mass production.

[0063] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A floating bridge anti-collision device, characterized in that, Includes a buoyancy base and a fractal anti-collision unit array; The buoyancy base is a hollow tube that is fitted onto the bridge piers; The fractal anti-collision unit array includes multiple fractal anti-collision units, each of which is fixedly connected to the outer wall of the buoyancy base. The fractal anti-collision unit includes a Mengele sponge fractal cube, a sealing shell, and filler. The Mengele sponge fractal cube has a multi-scale and multi-layered self-similar pore structure. The sealing shell encloses the Mengele sponge fractal cube to form a sealed cavity. The filler fills the space in the sealed cavity that is not occupied by the Mengele sponge fractal cube. The crushing load of the Mengele sponge fractal cube does not exceed the maximum safe lateral load of the pier.

2. The floating bridge anti-collision device according to claim 1, characterized in that, The buoyancy base is a hollow circular tube, and its outer diameter is determined by the following formula: D out =D in + 2×t w +2×L0×cos(π / N c ); Among them, D out D represents the outer diameter of the buoyancy base. in t represents the inner diameter of the buoyancy base. w L0 represents the wall thickness of the buoyancy base, L0 represents the side length of the Menger sponge fractal cube, π represents pi, and N represents the diameter of a circle. c This indicates the number of Menger sponge fractal cubes.

3. The floating bridge anti-collision device according to claim 1, characterized in that, It also includes flow-guiding arcs set at the top and bottom of the buoyancy base.

4. The floating bridge anti-collision device according to claim 1, characterized in that, The Menger sponge fractal cube is generated by the following method: S1. Obtain the cube; S2. Divide the cube into 27 smaller cubes, and remove the center and the six face centers, totaling 7 smaller cubes; S3. Perform step S2 on each retained small cube to complete one iteration; S4. After N iterations, a Menger sponge fractal cube with N layers of self-similar pore structure is formed; where N represents the fractal order.

5. The floating bridge anti-collision device according to claim 1, characterized in that, The side length of the Mengele sponge fractal cube is 300~1500mm.

6. The floating bridge anti-collision device according to claim 1, characterized in that, The Mengele sponge fractal cube is made of aluminum alloy.

7. The floating bridge anti-collision device according to claim 1, characterized in that, The crushing load of the Mengele sponge fractal cube is calculated using the following formula: F cr =s y ×A eff ×C(N, L0); Among them, F cr σ represents the crushing load of the Menger sponge fractal cube. y A represents the yield strength of the material used in the Menger sponge fractal cube. eff C(N, L0) represents the effective bearing area in the compressive direction of the Menger sponge fractal cube, and C(N, L0) represents the fractal structure crushing coefficient of the Menger sponge fractal cube. The fractal structure crushing coefficient is determined by the following method: based on the fractal order N and the side length L0, the fractal structure crushing coefficient of the Menger sponge fractal cube is obtained by finite element simulation calibration. Wherein, the effective bearing area of ​​the Menger sponge fractal cube in the compression direction is the projected area of ​​the remaining solid material on the Menger sponge fractal cube on the compression surface.

8. The floating bridge anti-collision device according to claim 1, characterized in that, The buoyancy base is made of high-density polyethylene or glass fiber reinforced plastic; The sealing shell is a high-density polyethylene film with a thickness of 0.8~2.0mm or a PVC-coated polyester fiber mesh fabric with a thickness of 0.6~1.5mm.

9. The floating bridge anti-collision device according to claim 1, characterized in that, The fractal anti-collision units are evenly distributed around the buoyancy base.

10. The floating bridge anti-collision device according to claim 1, characterized in that, The height of the buoyancy base is 0.8 to 1.2 times the side length of the Menger sponge fractal cube.

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