Anti-beam-falling multistage self-emergency protection inhaul cable and emergency anti-beam-falling protection method thereof

Abstract

The invention discloses an anti-beam-falling multistage self-emergency protection inhaul cable and an emergency anti-beam-falling protection method thereof. A bridge lacks multiple processing modes related to anti-beam-falling processing. The top side of a steel sleeve is fixedly connected to the bottom face of a box girder body through a connecting cushion block, a support is vertically arranged on the outer side wall of a bridge pier, a built-in stranded wire assembly is arranged in a connecting pipe in a penetrating mode, a first metal rubber block is arranged on the outer wall of one end of the steel sleeve, and the outer side of a second metal rubber block is arranged on the inner wall of the other end of the steel sleeve. One end of the connecting pipe is connected with the support, the other end of the connecting pipe sequentially penetrates through the steel sleeve, the first metal rubber block and the second metal rubber block and then is connected with the first limiting head, and the connecting pipe is fixedly sleeved with a middle limiting steel ring; according to the method, the connecting cushion block, the steel sleeve, the connecting pipe, the built-in stranded wire assembly, the first limiting head, the support, the middle limiting steel ring, the first metal rubber block and the second metal rubber block are matched with one another to achieve the two-stage emergency protection process when the box girder body tends to fall down.

Description

Technical Field

[0001] The present invention specifically relates to a multi-stage self-emergency protection cable for preventing beams from falling and an emergency beam-falling protection method thereof, and belongs to the technical field of roads and bridges. Background Art

[0002] Falling beams on bridges can cause the superstructure to separate from the substructure, disrupting traffic and severely impacting road access. During natural disasters such as earthquakes, falling beams can hinder the passage of rescue vehicles, delaying rescue efforts and increasing the difficulty of rescue efforts. Furthermore, falling beams can damage the bridge structure. When a beam falls, it exerts a significant impact force on the piers, damaging substructures such as piers and abutments. In severe cases, the entire bridge structure may collapse. Furthermore, repairing a fallen beam is difficult, as earthquake damage is often difficult to repair and reuse. Structural repairs are costly and time-consuming. Falling beams can also cause damage to other structures, potentially breaking piers, damaging substructures, or even causing the entire bridge to collapse, leading to chain reactions and damage to surrounding buildings and facilities. After a beam falls, the bridge structure becomes unstable and at risk of collapse, posing a serious threat to pedestrians and vehicles.

[0003] The main reasons for bridge beam collapse are as follows: First, slope instability: When an earthquake or other natural disaster causes slope instability, it can cause the abutments and bridge structure to slide toward the center of the river. If this slippage is too large, the piers may break, causing the adjacent spans to fall, resulting in a fallen beam.

[0004] Second: Bearing failure: Bridge bearings are crucial components connecting the superstructure and substructure. During an earthquake, the seismic forces of the superstructure are transmitted to the substructure through the bearings. If the transmitted load exceeds the design strength of the bearings, the bearings will be damaged or destroyed. Bearing damage causes displacement between the piers and beams. If this relative displacement exceeds the beam's shelving length, the beam will detach from the piers, causing a beam fall.

[0005] Third: Excessive vibration: Under the influence of a strong earthquake, the bridge may vibrate longitudinally, and the piers may also vibrate relative to each other. When the vibration is too strong, the bridge supports are often damaged, and the superstructure may be pulled away from the piers, causing the beams to fall.

[0006] Fourth: Foundation and subgrade damage: Severe foundation and subgrade damage is also a major cause of bridge collapse and beam fall. Foundation damage primarily refers to horizontal slippage, subsidence, and fractures caused by factors such as sand liquefaction, uneven settlement, and insufficient stability under earthquake action. This damage directly affects the stability of the bridge foundation, potentially causing the entire bridge to shift, tilt, or sink, and in severe cases, beam fall.

[0007] Fifth: Failure of the limiting structure: If the limiting structure of the bridge is designed unreasonably or fails, then under the action of seismic forces, a large relative displacement may occur between the beam and the pier, leading to the occurrence of the beam falling phenomenon.

[0008] Existing chain-type anti-falling beam devices mainly rely on empirical coefficients for parameter design and response rigidity, lacking a buffer mechanism. Currently, there are shortages of durable and fast-response anti-falling beam related measures, and a standardized treatment method after the beam has fallen. Summary of the Invention

[0009] To overcome the defects of the existing technology, a multi-stage self-emergency protection cable for anti-falling beam and its emergency anti-falling beam protection method are provided to solve the above problems.

[0010] A multi-stage self-emergency protection cable for anti-falling beam includes a connecting cushion block, a steel sleeve, a connecting pipe, an internal stranded wire assembly, a first limiting head, a support, a middle limiting steel ring, a first metal rubber block and a second metal rubber block. The steel sleeve is horizontally arranged, and the top side of the steel sleeve is fixedly connected to the bottom surface of the box girder body through the connecting cushion block. The support is vertically arranged on the outer side wall of the pier. The internal stranded wire assembly is穿设在 the connecting pipe. The first metal rubber block is arranged at the outer wall of one end of the steel sleeve, and the outer side of the second metal rubber block is arranged on the inner wall of the other end of the steel sleeve. One end of the connecting pipe is connected to the support, and the other end of the connecting pipe sequentially passes through the steel sleeve, the first metal rubber block and the second metal rubber block and then is connected to the first limiting head. A middle limiting steel ring is fixedly sleeved on the connecting pipe, and the middle limiting steel ring is arranged between the first metal rubber block and the second metal rubber block. When the multi-stage self-emergency protection cable for anti-falling beam is in the primary protection state, when the steel sleeve makes a horizontal movement away from the pier along with the box girder body, the middle limiting steel ring is pressed against the first metal rubber block; when the multi-stage self-emergency protection cable for anti-falling beam is in the secondary protection state, when the steel sleeve makes a second horizontal movement away from the pier along with the box girder body, the second metal rubber block is pressed against the first limiting head, and the internal stranded wire assembly is in the dominant tensile state for anti-falling beam.

[0011] As a preferred solution: When the steel sleeve is an open-top cylindrical body, the open-top cylindrical body includes an outer shell and two first end plates. The outer shell is arranged on the bottom surface of the connecting cushion block along the length direction of the connecting cushion block. The longitudinal cross-sectional shape of the outer shell in its width direction is a U-shaped. The two first end plates are respectively arranged at both ends of the outer shell. An inner cavity is formed by enclosing between the inner wall of the outer shell and the bottom surface of the connecting cushion block. Each first end plate is processed with a first through hole along its thickness direction, and each first through hole is communicated with the inner cavity. The two first through holes are respectively arranged in cooperation with the first metal rubber block and the second metal rubber block. The middle limiting steel ring is arranged along the radial direction of the open-top cylindrical body, and the top of the middle limiting steel ring is connected to the connecting cushion block. The middle limiting steel ring is arranged with a gap from the inner wall of the inner cavity.

[0012] As a preferred solution: when the steel sleeve is a circumferentially closed cylinder, the circumferentially closed cylinder includes a steel cylinder body and two second end plates. The steel cylinder body is arranged on the bottom surface of the connecting pad along the length direction of the connecting pad, and the two second end plates are respectively arranged at both ends of the steel cylinder body. Each second end plate is processed with a second through hole along its thickness direction. The two second through holes are respectively matched with the first metal rubber block and the second metal rubber block. The central limiting steel ring is arranged along the radial direction of the top side open cylinder, and a gap is set between the outer circumferential edge of the central limiting steel ring and the inner wall of the steel cylinder body.

[0013] As a preferred solution: it also includes a third metal rubber block, which is sleeved on the connecting pipe. The third metal rubber block is arranged between the second metal rubber block and the first metal rubber block, and the third metal rubber block is arranged close to the first metal rubber block. One side of the third metal rubber block is arranged on the inner wall of one end of the steel sleeve, and the other side of the third metal rubber block is arranged toward the central limiting steel ring.

[0014] As a preferred solution: the built-in stranded wire assembly includes at least three bundles of steel strands, at least three bundles of steel strands are arranged in parallel in the connecting pipe, and at least three bundles of steel strands are evenly distributed in the connecting pipe along the circumferential direction of the connecting pipe.

[0015] As a preferred solution: a gap is set between the inner wall of the connecting pipe and the outer wall of each bundle of steel strands, and a gap is set between two adjacent steel strands.

[0016] As a preferred solution: the support is a composite seat body, the support includes a base plate, multiple support rods, an intermediate connecting plate, a through-plate and a second limit head. One side of the base plate is connected to the outer wall of the pier, and the other side of the base plate is connected to one side of the intermediate connecting plate through multiple support rods. The other side of the intermediate connecting plate is connected to one end of the through-plate, and the other end of the through-plate is connected to one side of the second limit head. The end of the connecting pipe is tightly attached to the other side of the second limit head, and the end of each bundle of steel strands close to the second limit head passes through the second limit head and the through-plate and is fixedly connected to the intermediate connecting plate.

[0017] As a preferred solution: the connecting tube is connected to the support through a columnar anchor rod, and the columnar anchor rod includes a connecting column and two anchor rods. An annular ridge is fixedly sleeved on the outer wall of the connecting column, one side of the connecting column is fixedly connected to the connecting tube and the built-in stranded wire assembly respectively, and two anchor rods are arranged in parallel on the other side of the connecting column. A connecting shaft and two ears are provided on the support, and the two ears are fixedly connected to one side of the support. The connecting shaft is passed through the two ears, and the two ends of the connecting shaft are hinged to the two ears respectively. A connecting hole is processed at one end of each anchor rod close to the connecting shaft, and each anchor rod is connected to the connecting shaft through the connecting hole. Each anchor rod makes a reciprocating swinging motion along the circumferential direction of the connecting shaft.

[0018] An emergency beam-falling protection method is implemented using the above-mentioned multi-stage self-emergency protection cable for preventing beams from falling. The method is characterized in that when two multi-stage self-emergency protection cables for preventing beams from falling are symmetrically arranged between two adjacent bridge piers, the emergency beam-falling protection method is to achieve a two-step emergency protection process when the box beam body has a tendency to fall by cooperating with each other through a connecting pad, a steel sleeve, a connecting pipe, an internal stranded wire assembly, a first limit head, a support, a central limit steel ring, a first metal rubber block and a second metal rubber block.

[0019] The emergency beam falling protection method includes the following steps, specifically: Step 1: Installation: Install the multi-stage self-emergency cable for preventing the beam from falling between the box girder and the pier. Select connection pads of appropriate thickness to ensure that the center axis of the cable in the length direction matches the height of the bottom side of the box girder. After determining the connection pads of appropriate thickness, securely connect the top side of the steel sleeve to the bottom surface of the box girder through the connection pads of appropriate thickness. The supports are vertically installed on the outer side walls of the pier. Step 2: First emergency protection process: When the multi-stage self-emergency protection cable is in the first-stage protection state, the steel sleeve moves horizontally with the box beam body away from the bridge pier, and the central limit steel ring is in close contact with the first metal rubber block; Step 3: The second emergency protection process: When the multi-level self-emergency protection cable of the anti-fall beam is in the secondary protection state, when the steel sleeve makes a secondary horizontal movement away from the pier with the box beam body, the second metal rubber block and the first limit head are in close contact, and the built-in stranded wire assembly is in the dominant tensile state of the anti-fall beam.

[0020] An emergency beam-falling protection method is implemented using the aforementioned multi-stage self-emergency protection cable. When the multi-stage self-emergency protection cable is in a unilateral arrangement adapted to a single bridge pier, the emergency beam-falling protection method implements a two-stage emergency protection process for the box girder body when it is prone to falling by cooperating with a connecting pad, a steel sleeve, a connecting pipe, an internal stranded wire assembly, a first limit head, a support, a central limit steel ring, a first metal rubber block, a second metal rubber block, and a third metal rubber block. The emergency beam falling protection method includes the following steps, specifically: Step 1: Installation: Install the multi-stage self-emergency cable for preventing the beam from falling between the box girder and the pier. Select connection pads of appropriate thickness to ensure that the center axis of the cable in the length direction matches the height of the bottom side of the box girder. After determining the connection pads of appropriate thickness, securely connect the top side of the steel sleeve to the bottom surface of the box girder through the connection pads of appropriate thickness. The supports are vertically installed on the outer side walls of the pier. Step 2: First-level emergency protection process: When the box girder moves toward the first limit head, the anti-fall beam multi-stage self-emergency protection cable is in the first-level protection state. When the steel sleeve moves horizontally with the box girder away from the pier, the central limit steel ring and the first metal rubber block are in close contact, indicating that the anti-fall beam multi-stage self-emergency protection cable is in an extreme position of the first-level protection state. Step 3: Second-level emergency protection process: When the box girder body continues to move toward the direction of the first limit head, the anti-fall beam multi-stage self-emergency protection cable is in the second-level protection state. When the steel sleeve moves away from the pier with the box girder body for a second time, the second metal rubber block is in close contact with the first limit head, and the built-in stranded wire assembly is in the anti-fall beam dominant tension state. Step 4: When the box beam moves toward the direction of the support, the steel sleeve moves with the box beam and drives the third metal rubber block to fit tightly against the central limiting steel ring, indicating that the multi-stage self-emergency protection cable for preventing the beam from falling is in another extreme position of the protection state.

[0021] The beneficial effects of the present invention are: The multi-stage self-emergency cable for preventing beam drop in the present invention is adapted between the box girder and the bridge pier. The cable, through the interaction of a connecting pad, a steel sleeve, a connecting pipe, an internal stranded wire assembly, a first stopper, a support, a central stopper steel ring, a first metal rubber block, and a second metal rubber block, forms an emergency multi-stage protection response process in the event of a box girder drop, providing the box girder with a dual-stage protection effect combining buffering and restraint. When the cable is in the primary protection state, the steel sleeve moves horizontally with the box girder away from the bridge pier, and the central stopper steel ring abuts against the first metal rubber block. When the cable is in the secondary protection state, the steel sleeve moves horizontally with the box girder away from the bridge pier, and the second metal rubber block abuts against the first stopper, and the internal stranded wire assembly is in the primary tension state for preventing beam drop.

[0022] The emergency beam-falling protection method of the present invention is to realize a two-level emergency protection process for the box girder body when the beam tends to fall by cooperating with each other through the connection pad, steel sleeve, connecting pipe, built-in stranded wire assembly, first limit head, support, central limit steel ring, first metal rubber block and second metal rubber block. The emergency beam-falling protection method can carry out corresponding graded emergency beam-falling protection effects as needed, and significantly improve the seismic safety of the bridge through the coordinated work of the two-stage protection mechanism. The present invention has achieved optimization and upgrading in structural construction and functional response, and at the same time significantly improved the seismic performance of the structure through a displacement-based design strategy. It is suitable for bridges in high-intensity areas and has strong engineering adaptability and promotion prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1This is a schematic diagram of a first top view of the structure of the multi-stage self-emergency protection cable for preventing beam drop according to the present invention. In the figure, multiple bundles of steel strands are evenly arranged along the circumference of the first limit head. The structure of the multi-stage self-emergency protection cable for preventing beam drop is designed for symmetrical arrangement. Figure 2 This is a second top view of the structure of the multi-stage self-emergency protection cable for preventing beam drop according to the present invention. In the figure, multiple bundles of steel strands are evenly arranged along the circumference of the first limit head. The structure of the multi-stage self-emergency protection cable for preventing beam drop is designed for single-side arrangement. Figure 3 This is a schematic diagram of the main structure of the connection relationship between the connecting pipe and the central limiting steel ring; Figure 4 is a side structural schematic diagram of the connection relationship between the first limiting head and the multiple bundles of steel strands; Figure 5 is a schematic side structural diagram of the first metal rubber block; Figure 6 is a schematic diagram of the three-dimensional structure of the connection relationship between the steel sleeve and the second metal rubber block; Figure 7 Schematic diagram of the three-dimensional structure of the steel sleeve; Figure 8 A side view schematic diagram of another structural form of a multi-stage self-emergency protection cable for preventing falling beams; Figure 9 This is a schematic diagram of the upward structure of another structural form of anti-falling beam multi-stage self-emergency protection cable; Figure 10 This is a schematic diagram of the use of another structural form of anti-fall beam multi-stage self-emergency protection cable; Figure 11 This is a top view of the structure of the multi-stage self-emergency protection cable for preventing beam drop in the present invention, in which multiple bundles of steel strands are arranged horizontally along the same radial line on the first limit head; Figure 12 A side view schematic diagram of the first limiting head of another structural form; Figure 13 This is a schematic diagram of the use state of the multi-stage self-emergency protection cable for preventing falling beams in the present invention, in which two multi-stage self-emergency protection cables for preventing falling beams are symmetrically arranged for use; Figure 14 This is a schematic diagram of the use status of the multi-stage self-emergency protection cable for preventing falling beams in the present invention. In the figure, there is a multi-stage self-emergency protection cable for preventing falling beams in a single-sided arrangement and use status.

[0024] In the figure: 1-connecting pad; 2-steel sleeve; 2-1-outer shell; 2-2-first end plate; 2-3-inner cavity; 2-4-first through hole; 2-5-steel cylinder body; 2-6-second end plate; 3-connecting pipe; 4-built-in stranded wire assembly; 4-1-steel stranded wire; 5-first limiting head; 6-columnar anchor rod; 6-1-connecting column; 6-2-anchor rod; 6-3-annular ridge; 7-support; 7-1-bottom plate; 7-2-support rod; 7-3-middle connecting plate; 7-4-through plate; 7-5-second limiting head; 8-center limiting steel ring; 11-first metal rubber block; 12-second metal rubber block; 13-support ear; 14-connecting shaft; 15-connecting hole; 16-third metal rubber block; 20-box girder body; 21-bridge pier; 22-expansion joint. DETAILED DESCRIPTION

[0025] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0026] Specific implementation method 1: Combination Figure 1 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8 、 Figure 9 、 Figure 10 、 Figure 11 、 Figure 12 and Figure 13Describe this embodiment. In this embodiment, the anti-fall beam multi-stage self-emergency protection cable includes a connecting pad 1, a steel sleeve 2, a connecting pipe 3, an internal stranded wire assembly 4, a first limit head 5, a support 7, a central limit steel ring 8, a first metal rubber block 11 and a second metal rubber block 12. The steel sleeve 2 is horizontally arranged, and the top side of the steel sleeve 2 is welded to the bottom surface of the box beam body 20 through the connecting pad 1. The support 7 is vertically arranged on the outer wall of the pier 21. The internal stranded wire assembly 4 is passed through the connecting pipe 3. The central limit steel ring 8 is fixedly mounted on the connecting pipe 3. The first metal rubber block 11 and the second metal rubber block 12 are respectively arranged on both sides of the central limit steel ring 8. The first metal rubber block 11 is arranged at the outer wall of one end of the steel sleeve 2, and the outer side of the second metal rubber block 12 is arranged on the steel sleeve 2 On the inner wall of the other end, one end of the connecting pipe 3 is connected to the support 7, and the other end of the connecting pipe 3 passes through the steel sleeve 2, the first metal rubber block 11 and the second metal rubber block 12 in sequence and is connected to the first limit head 5. When the multi-stage self-emergency protection cable for preventing the falling beam is in the first protection state, the steel sleeve 2 makes a horizontal movement away from the pier 21 with the box beam body 20, and the central limiting steel ring 8 is tightly attached to the first metal rubber block 11; when the multi-stage self-emergency protection cable for preventing the falling beam is in the second protection state, the steel sleeve 2 makes a second horizontal movement away from the pier 21 with the box beam body 20, and the second metal rubber block 12 is tightly attached to the first limit head 5, indicating that the multi-stage self-emergency protection cable for preventing the falling beam is in the extreme position of the second protection state, and the built-in stranded wire assembly 4 is in the dominant tensile state of the anti-falling beam.

[0027] In this embodiment, the first metal rubber block 11 and the second metal rubber block 12 are respectively fixedly connected to the steel sleeve 2 and move synchronously with the steel sleeve 2 along the length direction of the connecting pipe 3 .

[0028] In this embodiment, multiple box beam bodies 20 are arranged in sequence to form a beam body, and an expansion joint 22 is formed between two adjacent box beam bodies 20. A bridge pier 21 is arranged correspondingly below the expansion joint 22. The arrangement and connection process between the box beam body 20 and the bridge pier 21 is the same as the connection process between the existing box beam body and the bridge pier.

[0029] In this embodiment, the connection pad 1 is detachably connected to the bottom surface of the box beam body 20 by a plurality of first high-strength bolts, and the support 7 is detachably connected to the outer wall of the pier 21 by a plurality of second high-strength bolts.

[0030] This multi-stage self-supporting cable system, designed to prevent beam drop, can be used in both existing bridge reinforcement and new bridge construction projects through a pier-beam connection. In terms of seismic activity classification, the device maintains normal structural expansion and contraction during an E1 earthquake, remaining inactive. During an E2 earthquake, the dual-stage protection mechanism works in tandem, significantly enhancing the bridge's seismic safety.

[0031] In this embodiment, when the multi - level self - emergency protection cable for preventing beam falling is in the first - level protection state, as the steel sleeve 2 makes a horizontal movement away from the pier 21 along with the box girder body 20, the middle - positioned limiting steel ring 8 is pressed against the first metal rubber block 11. That is, the first - level protection provides a buffering function by the variable - stiffness first metal rubber block 11. Before the displacement reaches the set threshold, the first metal rubber block 11 and the second metal rubber block 12 cooperate together to form a two - stage buffering effect of metal rubber, effectively suppressing the impact effect of the box girder body 20 and restricting its relative displacement. When the displacement of the steel sleeve 2 reaches the set threshold, the second - level protection mechanism is activated. That is, when the multi - level self - emergency protection cable for preventing beam falling is in the second - level protection state, as the steel sleeve 2 makes a second horizontal movement away from the pier 21 along with the box girder body 20, the second metal rubber block 12 is pressed against the first limiting head 5, and the built - in stranded wire assembly 4 is in the dominant tension state for preventing beam falling, and the steel wire strand assembly is immediately stressed to provide a reliable restraint for preventing beam falling. In the multi - level self - emergency protection cable for preventing beam falling of the present invention, the connection cushion block 1, the steel sleeve 2, the connecting pipe 3, the built - in stranded wire assembly 4, the first limiting head 5, the support 7, the middle - positioned limiting steel ring 8, the first metal rubber block 11 and the second metal rubber block 12 are coaxially arranged, which can ensure that the transmission path of the protection force is clear, avoid the problem of eccentric force, and ensure that the device can be started in time according to the predetermined threshold and play a reliable role under the action of an earthquake.

[0032] Specific Embodiment 2: This embodiment is a further limitation of Specific Embodiment 1. In this embodiment, when the steel sleeve 2 is an open - top cylinder, the open - top cylinder includes an outer shell 2 - 1 and two first end plates 2 - 2. The outer shell 2 - 1 is arranged on the bottom surface of the connection cushion block 1 along the length direction of the connection cushion block 1. The longitudinal cross - sectional shape of the outer shell 2 - 1 in its width direction is a U - shape. The two first end plates 2 - 2 are respectively arranged at both ends of the outer shell 2 - 1. A cavity 2 - 3 is formed by enclosing between the inner wall of the outer shell 2 - 1 and the bottom surface of the connection cushion block 1. Each first end plate 2 - 2 is processed with a first through - hole 2 - 4 along its thickness direction, and each first through - hole 2 - 4 is connected to the cavity 2 - 3. The aperture of the first through - hole 2 - 4 is smaller than the outer diameters of the first metal rubber block 11 and the second metal rubber block 12. The middle - positioned limiting steel ring 8 is arranged along the radial direction of the open - top cylinder. The top of the middle - positioned limiting steel ring 8 is connected to the connection cushion block 1, and the middle - positioned limiting steel ring 8 is arranged with a gap from the inner wall of the cavity 2 - 3.

[0033] Specific embodiment three: This embodiment is a further limitation of specific embodiment one or two. In this embodiment, when the steel sleeve 2 is a circumferentially closed cylinder, the circumferentially closed cylinder includes a steel cylinder body 2-5 and two second end plates 2-6. The steel cylinder body 2-5 is arranged on the bottom surface of the connecting pad 1 along the length direction of the connecting pad 1, and the two second end plates 2-6 are respectively arranged at both ends of the steel cylinder body 2-5. Each second end plate 2-6 is processed with a second through hole along its thickness direction. The aperture of the two second through holes is smaller than the outer diameter of the first metal rubber block 11 and the second metal rubber block 12. The central limiting steel ring 8 is arranged along the radial direction of the top side open cylinder, and a gap is set between the outer circumferential edge of the central limiting steel ring 8 and the inner wall of the steel cylinder body 2-5.

[0034] Specific embodiment four: This embodiment is a further limitation of specific embodiment two or three. In this embodiment, the first metal rubber block 11 and the second metal rubber block 12 are both cylindrical blocks, respectively inserted into the connecting tube 3. The outer diameters of the first metal rubber block 11 and the second metal rubber block 12 are larger than the apertures of the first through holes 2-4. The outer diameters of the first metal rubber block 11 and the second metal rubber block 12 are larger than the second through holes, thereby forming a limiting effect on the respective extreme positions of the first metal rubber block 11 and the second metal rubber block 12.

[0035] Furthermore, the thickness of the second metal rubber block 12 is smaller than the thickness of the first metal rubber block 11 .

[0036] Specific embodiment 5: This embodiment is a further limitation of specific embodiments 1, 2, 3 or 4. In this embodiment, the built-in stranded wire assembly 4 includes at least three bundles of steel strands 4-1, and at least three bundles of steel strands 4-1 are arranged in parallel in the connecting pipe 3, combined with Figure 1 As shown, at least three bundles of steel strands 4 - 1 are evenly distributed in the connecting pipe 3 along the circumferential direction of the connecting pipe 3 .

[0037] Another structural form is that when the steel strand 4-1 is a small diameter strand, combined with Figure 11 As shown, at least three bundles of steel strands 4-1 are arranged horizontally and side by side along the same radial line of the connecting pipe 3, forming a single radial reinforcement structure on the same radial line, which is beneficial to improving the unidirectional support strength of the anti-fall beam.

[0038] Specific embodiment six: This embodiment is a further limitation of specific embodiments one, two, three, four or five. In this embodiment, a gap is set between the inner wall of the connecting tube 3 and the outer wall of each bundle of steel strands 4-1, and a gap is set between two adjacent steel strands 4-1.

[0039] Specific embodiment seven: This embodiment is a further limitation of specific embodiments one, two, three, four, five or six. In this embodiment, the support 7 is a composite seat body, and the support 7 includes a base plate 7-1, multiple support rods 7-2, an intermediate connecting plate 7-3, a penetration plate 7-4 and a second limit head 7-5. One side of the base plate 7-1 is connected to the outer wall of the pier 21, and the base plate 7-1 is connected to the outer wall of the pier 21 to realize a plate connection method, thereby avoiding causing too many connection wounds to the pier 21. The other side of the bottom plate 7-1 is connected to one side of the intermediate connecting plate 7-3 through multiple support rods 7-2, the other side of the intermediate connecting plate 7-3 is connected to one end of the through-plate 7-4, the other end of the through-plate 7-4 is connected to one side of the second limit head 7-5, the end of the connecting pipe 3 is tightly attached to the other side of the second limit head 7-5, and one end of each bundle of steel strands 4-1 close to the second limit head 7-5 passes through the second limit head 7-5 and the through-plate 7-4 and is fixedly connected to the intermediate connecting plate 7-3.

[0040] Specific embodiment eight: This embodiment is a further limitation of specific embodiments one, two, three, four, five, six or seven. The connecting pipe 3 is connected to the support 7 through a columnar anchor rod 6. The columnar anchor rod 6 includes a connecting column 6-1 and two anchor rods 6-2. An annular ridge 6-3 is fixedly sleeved on the outer wall of the connecting column 6-1. One side of the connecting column 6-1 is fixedly connected to the connecting pipe 3 and the built-in stranded wire assembly 4 respectively. Two anchor rods 6-2 are arranged in parallel on the other side of the connecting column 6-1. A connecting shaft 14 and two support ears 13 are provided on the support 7. The two support ears 13 are fixedly connected to one side of the support 7. The connecting shaft 14 is passed through the two support ears 13. The two ends of the connecting shaft 14 are hinged to the two support ears 13 respectively. A connecting hole 15 is processed at one end of each anchor rod 6-2 close to the connecting shaft 14. Each anchor rod 6-2 is connected to the connecting shaft 14 through the connecting hole 15. Each anchor rod 6-2 makes a reciprocating swinging motion along the circumferential direction of the connecting shaft 14.

[0041] The material selection process for the multi-stage self-emergency protection cable against beam drop in the present invention is as follows: the first metal rubber block 11 and the second metal rubber block 12 are both specifically made of rubber rings. The metal rubber has good resistance to high and low temperatures, aging and corrosion, and can meet the needs of long-term service of the beam drop device in the field. The steel strand 4-1 is a mature standard part, and its maintenance cycle is consistent with that of the existing chain-type beam drop prevention device. The multi-stage self-emergency protection cable against beam drop in the present invention is basically the same as the chain-type device in terms of overall cost, but can provide a double-stage protection effect of buffering and restraint for the box beam body 20, and has good engineering promotion and economy.

[0042] The design parameter setting process of the multi-stage self-emergency protection cable for preventing falling beams in the present invention is as follows: Based on the actual structure of the bridge and the maximum seismic design load, the maximum displacement of the steel sleeve 2, the free displacement, the center axis height, and the specific number of strands of the steel strand 4-1 are determined. The specific determination process is as follows: Based on the actual structure of the bridge and the maximum seismic design load, the maximum displacement of the steel sleeve 2, the free displacement, the center axis height, and the specific number of strands of the steel strand 4-1 are determined. The specific determination process of the four parameters is as follows: The maximum displacement of the steel sleeve 2 is calculated based on the distance between the end of the beam 20 and the center of the support 7 and the design limit coefficient. The specific calculation formula is: S F = C F × S E (1) Where: S F ——The maximum displacement of the anti-falling beam device; C F —design limit coefficient; S E ——Overlap length.

[0043] The support 7 is a rectangular support body, and its center position is the intersection of two diagonal lines.

[0044] The free displacement of the steel sleeve 2 is determined by subtracting the first metal rubber block 11 and the second metal rubber block 12 from the maximum displacement obtained by the above calculation process. The difference is the free displacement.

[0045] Method for determining the central axis height of the steel sleeve 2: obtain the height from the bottom of the beam to the top surface of the cap beam and half of the height occupied by the built-in stranded wire assembly 4 respectively, and the sum of the two heights is the central axis height.

[0046] The process of determining the number of steel strand 4-1 bundles is to configure the number of steel strand 4-1 bundles according to the seismic design load, thereby achieving seamless failure switching and quantitative protection. The specific calculation process of configuring the number of steel strand 4-1 bundles according to the seismic design load is as follows: First calculate the earthquake design load, the calculation formula is: H F =1.5 R d (2) Then, the specific number of strands of steel strand 4-1 is obtained according to the earthquake design load. The calculation formula is: (3) In the above formula: H F The seismic design load for the multi-stage self-emergency protection cables to prevent beam falling; R d is the vertical constant reaction force of support 7; P The design earthquake action that each strand 4-1 bears; P y Design allowable tension for strand 4-1; n It is the number of bundles of steel strands 4-1 corresponding to the multi-stage self-emergency protection cables of a single anti-fall beam.

[0047] The performance comparison process between the multi-stage self-emergency protection cable for preventing beam drop in the present invention and the existing chain-type beam drop prevention device is as follows: First, existing chain-type beam-fall prevention devices are passive and lack buffering units, which can easily cause significant impact and damage after an earthquake. This device uses metal rubber gaskets to achieve effective buffering, reducing the impact force at the beam end and controlling deformation development. Second: The design of existing chain-type anti-falling beam devices is highly dependent on empirical parameters, and the bearing capacity of the steel chain is limited, which poses a risk of insufficient reliability in preventing falling beams. This device combines the actual structural parameters of the bridge to provide a more reliable anti-falling beam safety design. The 4-1 bearing capacity of the steel strand is designed based on the maximum seismic load, which can prevent the occurrence of falling beams and has higher reliability and economy.

[0048] The results of comprehensive comparison between the multi-stage self-emergency protection cable for preventing beam drop in the present invention and the existing chain-type beam drop prevention device are as follows: Specific embodiment nine: This embodiment is a further limitation of specific embodiments one, two, three, four, five, six, seven or eight. In this embodiment, the first limit head 5 is a disc structure, and the interface structure on the first limit head 5 is consistent with the arrangement of the multiple bundles of steel strands 4-1 of the built-in strand assembly 4. Figure 4 As shown, when multiple bundles of steel strands 4-1 are evenly arranged along the circumferential direction of the first limit head 5, the first limit head 5 is processed with multiple circular interfaces along its thickness direction, and each bundle of steel strands 4-1 is passed through its corresponding circular interface, and multiple circular interfaces are evenly arranged along the circumferential direction of the first limit head 5.

[0049] Combine Figure 12 As shown, an alternative structural form of the circular interface is a circular ridge with coaxial double notches, that is, each circular ridge includes two arc bars, the two arc bars are coaxially spaced, the arc bars are elastic arc bars, and the two ends of each arc bar are spaced from the two ends of the corresponding other arc bar to form two notches, which is convenient for adapting to the stable wrapped connection process after the end of the steel strand 4-1 is deformed.

[0050] Specific implementation method ten: Combination Figure 1 、 Figure 12 Explain this embodiment. In this embodiment, an emergency anti-falling beam protection method is realized by a multi-stage self-emergency protection cable for preventing the falling beam, wherein the multi-stage self-emergency protection cable for preventing the falling beam includes a connecting pad 1, a steel sleeve 2, a connecting pipe 3, a built-in stranded wire assembly 4, a first limit head 5, a support 7, a central limit steel ring 8, a first metal rubber block 11 and a second metal rubber block 12. The steel sleeve 2 is horizontally arranged, and the top side of the steel sleeve 2 is fixedly connected to the bottom surface of the box beam body 20 through the connecting pad 1. The support 7 is vertically arranged on the outer wall of the pier 21. The connecting pipe 3 is provided with a built-in stranded wire assembly 4. The first The metal rubber block 11 and the second metal rubber block 12 are respectively arranged on both sides of the central limiting steel ring 8. The first metal rubber block 11 is passed through one end of the steel sleeve 2, and the outer side of the second metal rubber block 12 is set on the inner wall of the other end of the steel sleeve 2. One end of the connecting pipe 3 is connected to the support 7, and the other end of the connecting pipe 3 passes through the first metal rubber block 11 and the second metal rubber block 12 at both ends of the steel sleeve 2 in sequence and is connected to the first limiting head 5. A central limiting steel ring 8 is fixedly mounted on the connecting pipe 3, and the central limiting steel ring 8 is arranged between the first metal rubber block 11 and the second metal rubber block 12.

[0051] The emergency anti-falling beam protection method in this embodiment is to realize a two-level emergency protection process when the box beam body 20 has a tendency to fall by cooperating with each other through the connecting pad 1, steel sleeve 2, connecting pipe 3, built-in stranded wire assembly 4, first limit head 5, support 7, central limit steel ring 8, first metal rubber block 11 and second metal rubber block 12.

[0052] Specifically, the emergency beam-falling protection method includes the following steps: Step 1: Installation: Install the multi-stage self-emergency cable for preventing the beam from falling between the box girder 20 and the pier 21. Select a connection pad 1 of appropriate thickness to ensure that the center axis of the cable in the length direction matches the height of the bottom side of the box girder 20. After determining the connection pad 1 of appropriate thickness, the top side of the steel sleeve 2 is fixedly connected to the bottom surface of the box girder 20 via the connection pad 1 of appropriate thickness. The support 7 is vertically installed on the outer wall of the pier 21. Step 2: First-level emergency protection process: When the multi-stage self-emergency protection cable for preventing falling beams is in the first-level protection state, the steel sleeve 2 moves horizontally with the box beam body 20 away from the bridge pier 21, and the central limiting steel ring 8 is in close contact with the first metal rubber block 11, indicating that the present invention is in the limit position of the first-level protection state; Step 3: Second-level emergency protection process: When the multi-level self-emergency protection cable of the anti-fall beam is in the second-level protection state, the steel sleeve 2 makes a secondary horizontal movement away from the pier 21 with the box beam body 20, the second metal rubber block 12 is tightly attached to the first limit head 5, and the built-in stranded wire assembly 4 is in the dominant tensile state of the anti-fall beam.

[0053] This emergency anti-falling beam protection method is used to implement a multi-stage buffer anti-falling beam protection process in a one-way moving path of the box beam body 20.

[0054] The structures and connection relationships not mentioned in this embodiment are the same as those in the first, second, third, fourth, fifth, sixth, seventh or eighth embodiment.

[0055] Specific implementation method 11: Combination Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8 、 Figure 9 、 Figure 10 、 Figure 11 Figure 13 and Figure 14 Explain this embodiment. The multi-stage self-emergency protection cable for preventing falling beams in this embodiment includes a connecting pad 1, a steel sleeve 2, a connecting pipe 3, an internal stranded wire assembly 4, a first limit head 5, a support 7, a central limit steel ring 8, a first metal rubber block 11, a second metal rubber block 12 and a third metal rubber block 16. The steel sleeve 2 is arranged horizontally, and the top side of the steel sleeve 2 is fixedly connected to the bottom surface of the box beam body 20 through the connecting pad 1. The support 7 is vertically arranged on the outer wall of the pier 21. The connecting pipe 3 is provided with an internal stranded wire assembly 4. The wire assembly 4 has a first metal rubber block 11 disposed on the outer wall of one end of the steel sleeve 2, and an outer side of the second metal rubber block 12 disposed on the inner wall of the other end of the steel sleeve 2. One end of the connecting pipe 3 is connected to the support 7, and the other end of the connecting pipe 3 passes through the steel sleeve 2, the first metal rubber block 11, and the second metal rubber block 12 in sequence before being connected to the first stopper 5. A central stopper steel ring 8 is fixedly mounted on the connecting pipe 3 and disposed between the first metal rubber block 11 and the second metal rubber block 12. When the box beam body 20 moves toward the direction of the first limit head 5, the multi-stage self-emergency protection cable for preventing the beam from falling has a bipolar protection delay effect. When the multi-stage self-emergency protection cable for preventing the beam from falling is in the first-level protection state, the steel sleeve 2 makes a horizontal movement away from the pier 21 with the box beam body 20, and the middle limiting steel ring 8 is tightly attached to the first metal rubber block 11; when the multi-stage self-emergency protection cable for preventing the beam from falling is in the second-level protection state, the steel sleeve 2 makes a secondary horizontal movement away from the pier 21 with the box beam body 20, and the second metal rubber block 12 is tightly attached to the first limit head 5, and the built-in stranded wire assembly 4 is in the dominant tensile state of the anti-beam falling.

[0056] When the box girder body 20 moves towards the direction where the bearing 7 is located, the multi-level self-emergency protection cable for preventing beam fall has a first-level protection delay effect. That is, a third metal rubber block 16 is arranged in the steel sleeve 2, and the third metal rubber block 16 and the middle-position limiting steel ring 8 cooperate with each other to achieve buffering and limiting. The third metal rubber block 16 is arranged between the second metal rubber block 12 and the first metal rubber block 11, the third metal rubber block 16 is arranged close to the first metal rubber block 11, one side of the third metal rubber block 16 is arranged at the inner wall of one end of the steel sleeve 2, and the other side of the third metal rubber block 16 faces the middle-position limiting steel ring 8.

[0057] In this embodiment, the first metal rubber block 11, the second metal rubber block 12 and the third metal rubber block 16 are all cylinders, and through holes for fitting the connecting pipe 3 are respectively machined in the axial directions of the first metal rubber block 11, the second metal rubber block 12 and the third metal rubber block 16.

[0058] In this embodiment, when the steel sleeve 2 is an open-top cylindrical body, the open-top cylindrical body includes an outer shell body 2-1 and two first end plates 2-2. The outer shell body 2-1 is arranged on the bottom surface of the connecting cushion block 1 along the length direction of the connecting cushion block 1. The longitudinal cross-sectional shape of the outer shell body 2-1 in the width direction is a U-shaped. The two first end plates 2-2 are respectively arranged at both ends of the outer shell body 2-1. An inner cavity 2-3 is formed by enclosing between the inner wall of the outer shell body 2-1 and the bottom surface of the connecting cushion block 1. A first through hole 2-4 is machined in each first end plate 2-2 along its thickness direction, and each first through hole 2-4 is communicated with the inner cavity 2-3. The two first through holes 2-4 are respectively arranged in cooperation with the first metal rubber block 11 and the second metal rubber block 12. The middle-position limiting steel ring 8 is arranged in the radial direction of the open-top cylindrical body. The top of the middle-position limiting steel ring 8 is connected to the connecting cushion block 1, and the middle-position limiting steel ring 8 is arranged with a gap from the inner wall of the inner cavity 2-3.

[0059] In this embodiment, the first metal rubber block 11, the second metal rubber block 12 and the third metal rubber block 16 are respectively fixedly connected to the steel sleeve 2 and move synchronously along the length direction of the connecting pipe 3 with the steel sleeve 2.

[0060] In this embodiment, when the steel sleeve 2 is a circumferentially closed cylindrical body, the circumferentially closed cylindrical body includes a steel cylinder body 2-5 and two second end plates 2-6. The steel cylinder body 2-5 is arranged on the bottom surface of the connecting cushion block 1 along the length direction of the connecting cushion block 1. The two second end plates 2-6 are respectively arranged at both ends of the steel cylinder body 2-5. A second through hole is machined in each second end plate 2-6 along its thickness direction, and the diameters of the two second through holes are smaller than the outer diameters of the first metal rubber block 11, the second metal rubber block 12 and the third metal rubber block 16. The middle-position limiting steel ring 8 is arranged in the radial direction of the open-top cylindrical body, and the outer peripheral edge of the middle-position limiting steel ring 8 is arranged with a gap from the inner wall of the steel cylinder body 2-5.

[0061] In this embodiment, the built-in stranded wire assembly 4 includes at least three bundles of steel strands 4 - 1 , which are arranged in parallel in the connecting tube 3 and are evenly distributed in the connecting tube 3 along the circumferential direction of the connecting tube 3 .

[0062] In this embodiment, a gap is provided between the inner wall of the connecting pipe 3 and the outer wall of each bundle of steel strands 4 - 1 , and a gap is provided between two adjacent steel strands 4 - 1 .

[0063] In this embodiment, the support 7 is a composite seat body, which includes a base plate 7-1, multiple support rods 7-2, an intermediate connecting plate 7-3, a penetration plate 7-4 and a second limit head 7-5. One side of the base plate 7-1 is connected to the outer wall of the pier 21, and the other side of the base plate 7-1 is connected to one side of the intermediate connecting plate 7-3 through multiple support rods 7-2. The other side of the intermediate connecting plate 7-3 is connected to one end of the penetration plate 7-4, and the other end of the penetration plate 7-4 is connected to one side of the second limit head 7-5. The end of the connecting pipe 3 is tightly attached to the other side of the second limit head 7-5, and the end of each bundle of steel strands 4-1 close to the second limit head 7-5 passes through the second limit head 7-5 and the penetration plate 7-4 and is fixedly connected to the intermediate connecting plate 7-3.

[0064] In this embodiment, the connecting tube 3 is connected to the support 7 through a columnar anchor rod 6, and the columnar anchor rod 6 includes a connecting column 6-1 and two anchor rods 6-2. An annular ridge 6-3 is fixedly sleeved on the outer wall of the connecting column 6-1. One side of the connecting column 6-1 is fixedly connected to the connecting tube 3 and the built-in stranded wire assembly 4 respectively. Two anchor rods 6-2 are arranged in parallel on the other side of the connecting column 6-1. A connecting shaft 14 and two support ears 13 are provided on the support 7. The two support ears 13 are fixedly connected to one side of the support 7. The connecting shaft 14 is passed through the two support ears 13. The two ends of the connecting shaft 14 are hinged to the two support ears 13 respectively. A connecting hole 15 is processed at one end of each anchor rod 6-2 close to the connecting shaft 14. Each anchor rod 6-2 is connected to the connecting shaft 14 through the connecting hole 15. Each anchor rod 6-2 makes a reciprocating swinging motion along the circumferential direction of the connecting shaft 14.

[0065] Specific implementation method 12: Combination Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8 、 Figure 9 、 Figure 10 、 Figure 11 Figure 13 and Figure 14This embodiment describes the following: when the multi-stage self-emergency protection cables for preventing beam drop are in a unilateral arrangement adapted to a single bridge pier 21, the emergency beam drop protection method is to achieve a two-stage emergency protection process for the box beam body 20 in the event of a beam drop through the cooperation of the connecting pad 1, steel sleeve 2, connecting pipe 3, internal stranded wire assembly 4, first limit head 5, support 7, central limit steel ring 8, first metal rubber block 11, second metal rubber block 12, and third metal rubber block 16. The emergency beam falling protection method includes the following steps, specifically: Step 1: Installation: Install the multi-stage self-emergency cable for preventing the beam from falling between the box girder 20 and the pier 21. Select a connection pad 1 of appropriate thickness to ensure that the center axis of the cable in the length direction matches the height of the bottom side of the box girder 20. After determining the connection pad 1 of appropriate thickness, the top side of the steel sleeve 2 is fixedly connected to the bottom surface of the box girder 20 via the connection pad 1 of appropriate thickness. The support 7 is vertically installed on the outer wall of the pier 21. Step 2: First-level emergency protection process: When the box girder body 20 moves toward the direction of the first limit head 5, the anti-fall beam multi-stage self-emergency protection cable is in the first-level protection state. When the steel sleeve 2 moves horizontally with the box girder body 20 away from the pier 21, the central limit steel ring 8 and the first metal rubber block 11 are in close contact, indicating that the anti-fall beam multi-stage self-emergency protection cable is in an extreme position of the first-level protection state. Step 3: Second-level emergency protection process: When the box girder body 20 continues to move toward the direction of the first limit head 5, the anti-fall beam multi-stage self-emergency protection cable is in the second-level protection state. When the steel sleeve 2 moves away from the pier 21 with the box girder body 20, the second metal rubber block 12 is in close contact with the first limit head 5, and the built-in stranded wire assembly 4 is in the anti-fall beam dominant tension state; Step 4: When the box beam body 20 moves toward the direction of the support 7, the steel sleeve 2 moves with the box beam body 20, driving the third metal rubber block 16 to be in close contact with the central limiting steel ring 8, indicating that the multi-stage self-emergency protection cable for preventing the beam from falling is in another extreme position of the protection state.

[0066] This emergency anti-falling beam protection method is used to implement the corresponding multi-stage buffer anti-falling beam protection process in the horizontal bidirectional movement path of the box beam body 20.

Claims

1. A multi-stage self-emergency protection cable for preventing falling beams, characterized by: It includes a connecting cushion block (1), a steel sleeve (2), a connecting pipe (3), an internal stranded wire assembly (4), a first limiting head (5), a support (7), a middle limiting steel ring (8), a first metal rubber block (11) and a second metal rubber block (12). The steel sleeve (2) is horizontally arranged, and the top side of the steel sleeve (2) is fixedly connected to the bottom surface of the box girder body (20) through the connecting cushion block (1). The support (7) is vertically arranged on the outer side wall of the pier (21). The connecting pipe (3) is provided with the internal stranded wire assembly (4) passing through it. The first metal rubber block (11) is arranged at the outer wall of one end of the steel sleeve (2), and the outer side of the second metal rubber block (12) is arranged on the inner wall of the other end of the steel sleeve (2). One end of the connecting pipe (3) is connected to the support (7), and the other end of the connecting pipe (3) passes through the steel sleeve (2), the first metal rubber block (11) and the second metal rubber block (12) in sequence and then is connected to the first limiting head (5). A middle limiting steel ring (8) is fixedly sleeved on the connecting pipe (3), and the middle limiting steel ring (8) is arranged between the first metal rubber block (11) and the second metal rubber block (12). When the multi-level self-emergency protection cable for preventing the falling of the beam is in the first-level protection state, when the steel sleeve (2) makes a horizontal movement away from the pier (21) along with the box girder body (20), the middle limiting steel ring (8) is in close contact with the first metal rubber block (11); when the multi-level self-emergency protection cable for preventing the falling of the beam is in the second-level protection state, when the steel sleeve (2) makes a second horizontal movement away from the pier (21) along with the box girder body (20), the second metal rubber block (12) is in close contact with the first limiting head (5), and the internal stranded wire assembly (4) is in the leading tensile state for preventing the falling of the beam.

2. The multi-stage self-emergency protection cable for preventing beams from falling according to claim 1 is characterized in that: When the steel sleeve (2) is an open-top cylinder, the open-top cylinder includes an outer shell (2-1) and two first end plates (2-2). The outer shell (2-1) is arranged on the bottom surface of the connecting cushion block (1) along the length direction of the connecting cushion block (1). The longitudinal cross-sectional shape of the outer shell (2-1) along its width direction is a U-shaped. The two first end plates (2-2) are respectively arranged at both ends of the outer shell (2-1). An inner cavity (2-3) is formed by enclosing between the inner wall of the outer shell (2-1) and the bottom surface of the connecting cushion block (1). Each first end plate (2-2) is processed with a first through hole (2-4) along its thickness direction, and each first through hole (2-4) is communicated with the inner cavity (2-3). The two first through holes (2-4) are respectively arranged in cooperation with the first metal rubber block (11) and the second metal rubber block (12). The middle limiting steel ring (8) is arranged along the radial direction of the open-top cylinder. The top of the middle limiting steel ring (8) is connected to the connecting cushion block (1), and the middle limiting steel ring (8) is arranged with a gap from the inner wall of the inner cavity (2-3).

3. The multi-stage self-emergency protection cable for preventing beams from falling according to claim 1 is characterized in that: When the steel sleeve (2) is a circumferentially sealed cylinder, the circumferentially sealed cylinder comprises a steel cylinder body (2-5) and two second end plates (2-6), the steel cylinder body (2-5) is arranged on the bottom surface of the connecting pad (1) along the length direction of the connecting pad (1), the two second end plates (2-6) are respectively arranged at both ends of the steel cylinder body (2-5), each second end plate (2-6) is processed with a second through hole along its thickness direction, the two second through holes are respectively matched with the first metal rubber block (11) and the second metal rubber block (12), the central limiting steel ring (8) is arranged along the radial direction of the top side open cylinder, and a gap is set between the outer circumferential edge of the central limiting steel ring (8) and the inner wall of the steel cylinder body (2-5).

4. The multi-stage self-emergency protection cable for preventing beams from falling according to claim 1, 2 or 3, characterized in that: The third metal rubber block (16) is also included. The third metal rubber block (16) is mounted on the connecting pipe (3). The third metal rubber block (16) is arranged between the second metal rubber block (12) and the first metal rubber block (11). The third metal rubber block (16) is arranged close to the first metal rubber block (11). One side of the third metal rubber block (16) is arranged on the inner wall of one end of the steel sleeve (2), and the other side of the third metal rubber block (16) is arranged toward the central limiting steel ring (8).

5. The multi-stage self-emergency protection cable for preventing beams from falling according to claim 1 is characterized in that: The built-in stranded wire assembly (4) comprises at least three bundles of steel strands (4-1), the at least three bundles of steel strands (4-1) being arranged in parallel in the connecting tube (3), and the at least three bundles of steel strands (4-1) being evenly distributed in the connecting tube (3) along the circumferential direction of the connecting tube (3).

6. The multi-stage self-emergency protection cable for preventing beams from falling according to claim 5 is characterized in that: A gap is provided between the inner wall of the connecting pipe (3) and the outer wall of each bundle of steel strands (4-1), and a gap is provided between two adjacent steel strands (4-1).

7. The multi-stage self-emergency protection cable for preventing beams from falling according to claim 5 or 6 is characterized in that: The support (7) is a composite seat body, comprising a bottom plate (7-1), a plurality of support rods (7-2), an intermediate connecting plate (7-3), a through-plate (7-4) and a second limiting head (7-5). One side of the bottom plate (7-1) is connected to the outer wall of the pier (21), the other side of the bottom plate (7-1) is connected to one side of the intermediate connecting plate (7-3) through the plurality of support rods (7-2), the other side of the intermediate connecting plate (7-3) is connected to one end of the through-plate (7-4), the other end of the through-plate (7-4) is connected to one side of the second limiting head (7-5), the end of the connecting pipe (3) is closely attached to the other side of the second limiting head (7-5), and the end of each bundle of steel strands (4-1) close to the second limiting head (7-5) passes through the second limiting head (7-5) and the through-plate (7-4) and is fixedly connected to the intermediate connecting plate (7-3).

8. The multi-stage self-emergency protection cable for preventing beams from falling according to claim 1 is characterized in that: The connecting pipe (3) is connected to the support (7) through a columnar anchor rod (6), wherein the columnar anchor rod (6) comprises a connecting column (6-1) and two anchor rods (6-2), an annular ridge (6-3) is fixedly sleeved on the outer wall of the connecting column (6-1), one side of the connecting column (6-1) is fixedly connected to the connecting pipe (3) and the built-in stranded wire assembly (4), and the other side of the connecting column (6-1) is provided with two anchor rods (6-2) in parallel, and the support (7) is provided with a connecting shaft (14) and two support ears (13), two ears (13) are fixedly connected to one side of the support (7), a connecting shaft (14) is passed through the two ears (13), both ends of the connecting shaft (14) are hinged to the two ears (13), and a connecting hole (15) is processed at one end of each anchor rod (6-2) close to the connecting shaft (14). Each anchor rod (6-2) is connected to the connecting shaft (14) through the connecting hole (15), and each anchor rod (6-2) makes a reciprocating swinging motion along the circumferential direction of the connecting shaft (14).

9. An emergency beam protection method, implemented using the beam protection multi-stage self-emergency protection cable according to claim 1, 2, 3, 5, 6, 7 or 8, characterized in that: When two anti-falling beam multi-stage self-emergency protection cables are symmetrically arranged between two adjacent bridge piers (21), the emergency anti-falling beam protection method is to realize a two-stage emergency protection process when the box beam body (20) has a tendency to fall through the cooperation between the connecting pad (1), the steel sleeve (2), the connecting pipe (3), the built-in stranded wire assembly (4), the first limit head (5), the support (7), the middle limit steel ring (8), the first metal rubber block (11) and the second metal rubber block (12); The emergency beam falling protection method includes the following steps, specifically: Step 1: Installation process: Install the anti-fall beam multi-stage self-emergency protection cable between the box beam body (20) and the bridge pier (21), select a connection pad (1) of corresponding thickness to ensure that the center axis position of the anti-fall beam multi-stage self-emergency protection cable in the length direction is compatible with the height of the bottom side of the box beam body (20), and after determining the corresponding thickness of the connection pad (1), the top side of the steel sleeve (2) is fixedly connected to the bottom surface of the box beam body (20) through the connection pad (1) of corresponding thickness, and the support (7) is vertically arranged on the outer side wall of the bridge pier (21); Step 2: First-level emergency protection process: When the multi-stage self-emergency protection cable for preventing falling beams is in the first-level protection state, when the steel sleeve (2) moves horizontally away from the bridge pier (21) along with the box beam body (20), the middle limit steel ring (8) is in close contact with the first metal rubber block (11), indicating that the multi-stage self-emergency protection cable for preventing falling beams is in the limit position of the first-level protection state; Step 3: Second-level emergency protection process: When the anti-fall beam multi-stage self-emergency protection cable is in the second-level protection state, the steel sleeve (2) makes a secondary horizontal movement away from the bridge pier (21) along with the box beam body (20), the second metal rubber block (12) is in close contact with the first limit head (5), and the built-in stranded wire assembly (4) is in the anti-fall beam dominant tensile state.

10. An emergency beam protection method, implemented using the beam-falling multi-stage self-emergency protection cable according to claim 4, characterized in that: When the multi-stage self-emergency protection cable for preventing the beam from falling is in a unilateral arrangement state adapted to a single bridge pier (21), the emergency beam-falling protection method is to realize a two-stage emergency protection process when the box beam body (20) has a tendency to fall by cooperating with each other through the connection pad (1), the steel sleeve (2), the connection pipe (3), the built-in stranded wire assembly (4), the first limit head (5), the support (7), the middle limit steel ring (8), the first metal rubber block (11), the second metal rubber block (12) and the third metal rubber block (16); The emergency beam falling protection method includes the following steps, specifically: Step 1: Installation process: Install the anti-fall beam multi-stage self-emergency protection cable between the box beam body (20) and the bridge pier (21), select a connection pad (1) of corresponding thickness to ensure that the center axis position of the anti-fall beam multi-stage self-emergency protection cable in the length direction is compatible with the height of the bottom side of the box beam body (20), and after determining the corresponding thickness of the connection pad (1), the top side of the steel sleeve (2) is fixedly connected to the bottom surface of the box beam body (20) through the connection pad (1) of corresponding thickness, and the support (7) is vertically arranged on the outer side wall of the bridge pier (21); Step 2: First-level emergency protection process: when the box beam body (20) moves toward the direction where the first limit head (5) is located, the anti-fall beam multi-stage self-emergency protection cable is in the first-level protection state, and when the steel sleeve (2) moves horizontally away from the bridge pier (21) along with the box beam body (20), the middle limit steel ring (8) is in close contact with the first metal rubber block (11), indicating that the anti-fall beam multi-stage self-emergency protection cable is in an extreme position of the first-level protection state; Step 3: Second-level emergency protection process: When the box beam body (20) continues to move toward the direction of the first limit head (5), the anti-fall beam multi-stage self-emergency protection cable is in the second-level protection state, and the steel sleeve (2) makes a secondary horizontal movement away from the bridge pier (21) along with the box beam body (20), the second metal rubber block (12) is in close contact with the first limit head (5), and the built-in stranded wire assembly (4) is in the anti-fall beam dominant tensile state; Step 4: When the box beam body (20) moves toward the direction of the support (7), the steel sleeve (2) moves with the box beam body (20) to drive the third metal rubber block (16) to be in close contact with the central limit steel ring (8), indicating that the anti-fall beam multi-stage self-emergency protection cable is in another extreme position of the protection state.

Images