Fireproof protection structure of steel box girder bridge based on security mechanism

Abstract

The application relates to a fireproof protection technology of a beam bridge, in particular to a steel box girder bridge fireproof protection structure based on a safety guarantee mechanism. The steel box girder bridge fireproof protection structure based on the safety guarantee mechanism comprises a steel box girder (1), further comprises protection pipes (2), the protection pipes (2) are fixed on each side wall and a bottom surface of the steel box girder (1) in a longitudinal and transverse interlaced and cavity-interconnected mode, each independent water storage unit and a through water flow channel are arranged in the protection pipes (2), wherein the water flow channel in the form of a Chinese character 'yi' is formed above each water storage unit in the protection pipe (2) arranged in the horizontal direction of the side wall of the steel box girder, the water flow channel is formed above and outside each water storage unit in the protection pipe (2) arranged in the horizontal direction of the bottom surface of the steel box girder, and the water flow channel in the form of a 'S-shaped' folding type is formed by each water storage unit in the protection pipe (2) arranged in the vertical direction and the side wall of the protection pipe (2). The safety guarantee effect of the application is long-lasting and effective, and the risk resistance of the bridge system is improved.

Description

Technical Field

[0001] This invention relates to fire protection technology for beam bridges, specifically a fire protection structure for steel box girder bridges based on a safety assurance mechanism. Background Technology

[0002] Steel box girders, also known as steel plate box girders, are a common structural form for long-span bridges. They are generally used on bridges with large spans. Steel box girders are generally composed of a top plate, bottom plate, web, transverse diaphragms, longitudinal diaphragms, and stiffening ribs, all connected by full welding. The top plate is an orthotropic bridge deck composed of a cover plate and longitudinal stiffening ribs.

[0003] As steel-structured bridges, steel box girder bridges have poor fire resistance. In the event of a fire, the steel structure may suffer severe damage or even collapse. Bridges are crucial links in transportation routes; damage in a fire not only seriously threatens the lives of people on the bridge but also severely disrupts the transportation system. Therefore, steel box girder bridges are typically equipped with fire protection systems. Statistics show that the fire protection system areas of steel box girder bridges are more likely to be impacted than other areas. Once an impact causes localized damage to the fire protection system, it loses its protective function and has poor resilience against fire.

[0004] CN117427293A discloses a fire protection system for steel box girder bridges (Central South University, inventors Jiang Binhui et al.). This system includes multiple hollow fireproof protective pipes surrounding the steel box girder bridge, which are crisscrossed and interconnected to form a connecting pipe. The inlet of the connecting pipe is connected to a water collection unit, which includes a water collection chamber, a water storage chamber, and a water level control chamber arranged sequentially from top to bottom and interconnected. The water collection chamber collects fluid, the water storage chamber stores the collected fluid, and the water level control chamber controls the flow rate of the fluid into the connecting pipe. By forming a connecting pipe through multiple hollow fireproof protective pipes, the fluid flowing into the connecting pipe can rapidly reduce the temperature of the steel box girder bridge, effectively protecting it and preventing large-scale damage. This buys more time for fire suppression and avoids irreversible significant economic losses and adverse social impacts after a fire.

[0005] CN117427293A has the following limitations and potential risks: Multiple hollow fireproof protective tubes are crisscrossed and interconnected to form a protective tube network. These hollow fireproof protective tubes wrap around the exterior of the steel box girder bridge to be protected. For the steel box girder bridge, the protective tube network forms a protective outer layer. When a fire occurs on the steel box girder bridge, the fluid flowing within the hollow fireproof protective tubes can flow freely between different protective tubes within the network, thus quickly reducing the temperature of the steel box girder bridge. The hollow fireproof protective tubes are made of materials with good thermal conductivity and durability, not limited to stainless steel. Good thermal conductivity and durability here refer to a thermal conductivity of 5 W / (m·℃) or higher, capable of withstanding the erosion of the outdoor natural environment in the absence of a fire. However, over time, if a leak occurs anywhere in the protective outer layer formed by the tube network, the fire protection is prone to failure. This is precisely the limitation and weakness of this technical solution.

[0006] Based on the aforementioned technical problems, inventors Jiang Binhui et al. further proposed the technical solution of this application. Summary of the Invention

[0007] To overcome the shortcomings of existing technologies, this invention provides a fire protection structure for steel box girder bridges based on a safety assurance mechanism. This invention applies to the technical solution CN117427293A, effectively utilizing the safety assurance mechanism and enhancing the protection system's ability to resist risks.

[0008] The present invention achieves its objective through the following technical solution:

[0009] The fire protection structure for steel box girder bridges based on safety assurance mechanisms includes the steel box girder and protective pipes.

[0010] The protective pipes are crisscrossed and interconnected, and are attached to the side walls and bottom of the steel box girder through their respective side walls. The protective pipes are equipped with several independent water storage units and a through water flow channel.

[0011] Furthermore, the horizontal protective pipes are divided into two categories: horizontal protective pipes installed on the side walls of the steel box girder and horizontal protective pipes installed on the bottom surface of the steel box girder, wherein:

[0012] The water storage unit is installed in the horizontal protective pipe on the side wall of the steel box girder. The height of the water storage unit is less than the height of the inner cavity of the protective pipe. The water storage units are arranged one after another in the lower part of the inner cavity of the protective pipe. A straight water flow channel is formed above each water storage unit in the horizontal protective pipe.

[0013] The water storage unit is installed in the horizontal protective pipe at the bottom of the steel box girder. The height of the water storage unit is less than the height of the inner cavity of the protective pipe. The water storage units are arranged one after another in the lower part of the inner cavity of the protective pipe. A water flow channel is formed above and outside each water storage unit in the horizontal protective pipe.

[0014] Inside the vertical protective pipe, the width of the water storage unit is smaller than the width of the inner cavity of the protective pipe. The water storage units are arranged alternately on both sides of the inner cavity of the protective pipe. The water storage units and the side wall of the protective pipe in the vertical direction form an "S-shaped" folded water flow channel.

[0015] Furthermore, the fire protection structure for the steel box girder bridge based on the safety assurance mechanism also includes type A diaphragms, type B diaphragms, and type C diaphragms, wherein:

[0016] The A-type partition is in a straight line. Each A-type partition is arranged sequentially at the bottom of the horizontal protective pipe on the side wall of the steel box girder. Specifically, the bottom and side edges of the A-type partition are fixed to the inner side wall of the protective pipe, and each A-type partition is arranged parallel to each other. The height of the A-type partition is less than the height of the inner cavity of the protective pipe. An upward-opening water storage unit is formed between two adjacent A-type partitions, and a straight water flow channel is formed above each water storage unit.

[0017] The B-type partition consists of a horizontal plate and two vertical plates. The three plates are fixed perpendicularly to each other and share a common vertex. Each B-type partition is sequentially installed on the inner wall of the vertical protective pipe. Specifically, the two sides of the horizontal plate of the B-type partition are fixed to the adjacent inner walls of the protective pipe, and the sides of the two vertical plates of the B-type partition are respectively fixed to the adjacent inner walls of the protective pipe. The horizontal plate of the B-type partition is perpendicular to the length of the protective pipe. The horizontal length L of the B-type partition is less than the horizontal cross-sectional length of the inner cavity of the protective pipe, and the horizontal width W of the B-type partition is less than the horizontal cross-sectional width of the inner cavity of the protective pipe. The B-type partition and the inner wall of the protective pipe form an upward-opening water storage unit. The horizontal plates of each B-type partition are arranged parallel to each other, and the fixed ends of the horizontal plates of two adjacent B-type partitions and the inner wall of the protective pipe are staggered. Each water storage unit and the side wall of the protective pipe form an "S-shaped" folded water flow channel.

[0018] The C-shaped partition includes a first straight plate and a second straight plate. The height of the first and second straight plates is less than the height of the inner cavity of the protective tube, and the length of the second straight plate is less than the width of the inner cavity of the protective tube. The C-shaped partition is installed on the inner wall of each horizontally crisscrossing section of the protective tube on the bottom surface of the steel box girder. Specifically, the bottom edge and one side edge of the second straight plate are fixed to the bottom and inner wall of the protective tube, respectively, and each second straight plate is fixed to the bottom of the protective tube parallel and perpendicular to each other. The bottom of the first straight plate is fixed to the bottom of the protective tube along the length of the protective tube, and the right side of the first straight plate is fixed to the side edge of all the second straight plates in the same section of the protective tube. The first straight plate is vertically fixed to the bottom of the protective tube. In this way, the left side of the first straight plate forms a water flow channel with the inner cavity of the protective tube, and the right side of the first straight plate and multiple second straight plates divide the lower cavity of the protective tube into numerous upward-opening water storage units. A water flow channel is also formed above each water storage unit.

[0019] Furthermore, the protective pipe has an opening as an inlet to connect to the water source.

[0020] Furthermore, the protective pipe is also equipped with an opening as an outlet and is connected to a water circulation drive device.

[0021] The technical solution of this invention is arranged within a "communicating vessel" consisting of multiple hollow protective pipes that crisscross and interconnect, forming a connecting pipeline. These protective pipes are connected to a water replenishment device and a water circulation drive device. This invention improves the structure of the protective pipes surrounding the steel box girder bridge, forming multiple water storage units within the protective pipes and creating a unique flow channel system. When a local leak occurs in the protection system, water can still be stored in the static water storage compartments and dynamic flow channels, ensuring that the water storage and delivery systems of the pipeline system do not fail and continue to provide fire protection, thus preventing the failure of the entire fire protection system.

[0022] This invention retains the advantages of the fire protection system connector for steel box girder bridges while improving the system's ability to resist risks.

[0023] The present invention has the following beneficial effects: it provides long-lasting and effective safety protection and improves the bridge system's ability to resist risks. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of water flow in the structure and piping system of the present invention.

[0025] Figure 2 This is a schematic diagram showing the installation of type A, type B, and type C partitions inside the protective tube in this invention.

[0026] Figure 3(a) is a schematic diagram of the installation of the A-type partition inside the horizontal protective tube in this invention.

[0027] Figure 3(b) is a schematic diagram of the installation of the C-shaped baffle inside the horizontal protective tube in this invention.

[0028] Figure 4(a) is a schematic diagram of the B-type partition structure in this invention.

[0029] Figure 4(b) is a schematic diagram of the installation of the B-type baffle inside the vertical protective tube in this invention.

[0030] Figure 5 and Figure 6 This is a schematic diagram of the water flow when the vertical protective pipe is damaged during the use of this invention.

[0031] Figure 7 This is a schematic diagram of the water flow when the horizontal protective pipe is damaged during the use of this invention.

[0032] Figure 8 This is a schematic diagram of the water flow when the bottom protective pipe is damaged during the use of this invention.

[0033] Figure label:

[0034] Steel box girder 1,

[0035] Protective tube 2,

[0036] Type A partition 31, Type B partition 32, first straight panel 331, second straight panel 332.

[0037] Water storage unit 4. Detailed Implementation

[0038] The technical solutions provided in this application will be further described below with reference to specific embodiments and accompanying drawings. The advantages and features of this application will become clearer from the following description.

[0039] Example 1

[0040] A fire protection structure for a steel box girder bridge based on a safety assurance mechanism includes a steel box girder 1 and a protective pipe 2, such as... Figure 1 As shown, the specific structure is:

[0041] The protective pipes 2 are crisscrossed and interconnected, and are fixed to the side walls and bottom surface of the steel box girder 1 through their respective side walls. Each protective pipe 2 contains numerous independent water storage units 4 and a continuous water flow channel.

[0042] The horizontal protective pipes 2 are divided into two types: those installed on the side walls of the steel box girder and those installed on the bottom surface of the steel box girder. Specifically: in the horizontal protective pipes 2 installed on the side walls of the steel box girder, each water storage unit is located below the inner cavity of the protective pipe 2, and the height of each water storage unit is less than the height of the inner cavity of the protective pipe 2. A straight water flow channel is formed above each water storage unit in the horizontal protective pipe 2. In the horizontal protective pipes 2 installed on the bottom surface of the steel box girder, each water storage unit is located below the inner cavity of the protective pipe 2, and the height of each water storage unit is less than the height of the inner cavity of the protective pipe 2. A water flow channel is formed above and on the outside of each water storage unit in the horizontal protective pipe 2.

[0043] Inside the vertical protective pipe 2, the width of the water storage unit is smaller than the width of the inner cavity of the protective pipe 2. Several water storage units are arranged alternately on opposite sides of the inner cavity of the protective pipe 2, thereby forming an "S-shaped" folded water flow channel inside the vertical protective pipe 2.

[0044] The fire protection structure for the steel box girder bridge based on the safety guarantee mechanism in this embodiment also includes type A diaphragm 31, type B diaphragm 32, and type C diaphragm, such as Figure 1 , Figure 2 As shown in Figures 3(a), 3(b), 4(a), and 4(b), the specific structure and installation method are as follows:

[0045] The A-type partition 31 is in a straight line. Each A-type partition 31 is sequentially arranged on the inner side wall of the protective pipe 2 in the horizontal direction of the side wall of the steel box girder. Specifically, the bottom edge and side edge of the A-type partition 31 are welded and fixed to the inner side wall of the protective pipe 2, and each A-type partition 31 is arranged parallel to each other. The height of the A-type partition 31 is less than the height of the inner cavity of the protective pipe 2. An upward-opening water storage unit is formed between two adjacent A-type partitions 31, and a straight water flow channel is formed above each water storage unit.

[0046] The B-type partition 32 includes a horizontal plate and two vertical plates. The three plates are fixed perpendicularly to each other and share a common vertex. Each B-type partition 32 is sequentially arranged on the inner wall of the vertical protective pipe 2. Specifically, the two sides of the horizontal plate of the B-type partition 32 are welded to the adjacent inner walls of the protective pipe 2, and the sides of the two vertical plates of the B-type partition 32 are respectively welded to the adjacent inner walls of the protective pipe 2. The horizontal plate of the B-type partition 32 is perpendicular to the length direction of the protective pipe 2. The horizontal length L of the B-type partition is less than the horizontal cross-sectional length of the inner cavity of the protective pipe 2, and the horizontal width W of the B-type partition is less than the horizontal cross-sectional width of the inner cavity of the protective pipe 2. The B-type partition 32 and the inner wall of the protective pipe 2 form an upward-opening water storage unit. The horizontal plates of each B-type partition 32 are arranged parallel to each other, and the fixed ends of the horizontal plates of two adjacent B-type partitions 32 and the inner wall of the protective pipe 2 are staggered. Each water storage unit and the side wall of the protective pipe 2 form an "S-shaped" folded water flow channel.

[0047] The C-shaped partition includes a first straight plate 331 and a second straight plate 332. The height of the first straight plate 331 and the second straight plate 332 is less than the height of the inner cavity of the protective tube 2, and the length of the second straight plate 332 is less than the width of the inner cavity of the protective tube 2. The C-shaped partition is set on the inner wall of each horizontal section of the protective tube 2 that is crisscrossed on the bottom surface of the steel box girder. Specifically, the bottom edge and one side edge of the second straight plate 332 are respectively welded to the bottom and the inner wall of the protective tube 2, and each second straight plate 332 is parallel to each other and perpendicular to the bottom of the protective tube 2. The bottom of the first straight plate 331 is welded to the bottom of the protective pipe 2 along the length of the protective pipe 2, and the right side of the first straight plate 331 is welded to the side of all the second straight plates 332 in the same section of the protective pipe. The first straight plate 331 is vertically fixed to the bottom of the protective pipe 2. In this way, the left side of the first straight plate 331 and the inner cavity of the protective pipe 2 form a water flow channel. The right side of the first straight plate 331 and multiple second straight plates 332 divide the lower cavity of the protective pipe 2 into numerous upward-opening water storage units. A water flow channel is also formed above each water storage unit.

[0048] The top of the protective pipe has an opening as an inlet for connecting to a water source, such as the water collection unit in the CN117427293A technical solution. Furthermore, to enhance the water circulation effect within the protective pipe, it also has an opening as an outlet, and a water circulation drive device is installed and connected thereon. This water circulation drive device is not a core technology of this invention and therefore will not be described in detail herein.

[0049] Based on the above structural design, the bridge safety guarantee mechanism remains intact in the event of any hazard occurring to protective pipe 2. A complete list of all possible scenarios is provided below:

[0050] i. Leaks occur in the longitudinal pipes of the piping system:

[0051] When a point of failure occurs on the side wall of the protective pipe in the vertical direction, the possible situations are as follows: Figure 5 or Figure 6 The X in the diagram represents the point of failure. At this point:

[0052] Figure 5 In the middle, the leak point appears on the wall of the protective pipe 2 opposite the water storage module 4. All the water storage modules 4 are always full. Only a small area of ​​gap may appear above the damage point of the vertical protective pipe 2, while the entire pipeline system is operating normally.

[0053] Figure 6 In the middle, the leak point appears on the wall of the protective pipe 2 on the same side as the water storage module 4. The water storage module 4 is not full, while the water storage in the other remaining water storage modules 4 is always full. A small area of ​​gap may also appear above the point of failure of the vertical protective pipe 2, while the entire pipeline system is operating normally.

[0054] ii. Leaks occur in the horizontal pipes of the piping system:

[0055] When a point of failure occurs at the bottom of one side of the horizontal protective pipe 2, the possible location of the failure is point X in 7. At this time:

[0056] The leak occurred at the bottom of a water storage module 4, where the water level was low or even empty. Meanwhile, other water storage modules 4 on the adjacent branch remained full. This branch can be considered to operate independently after being disconnected from the entire pipeline system. Functionally, the entire pipeline system continues to operate normally.

[0057] iii. A leak occurs in the bottom pipe of the piping system:

[0058] When a point of failure occurs at the very bottom of protective tube 2, the possible scenario is as shown by point X in 8, which is the location of the failure. At this time:

[0059] In this case, apart from the problem of wasting water, all water storage modules 4 will not lose or run out of water, and the entire pipeline system will maintain normal operation in terms of overall function.

[0060] It is evident that, considering all possible leak points, the pipeline system structure of this invention logically can maintain water supply functionality even if a leak occurs at any point on the protective pipe 2, thanks to the independent water storage function of each water storage module 4 and the structural design of the water flow channel. Since the pipeline system is not completely paralyzed, but only slightly weakened, it continues to protect the steel box girder 1, thus providing a possibility for subsequent rescue efforts.

[0061] The above description is merely a description of preferred embodiments of this application and is not intended to limit the scope of this application in any way. Any changes or modifications made by those skilled in the art based on the above-disclosed technical content should be considered as equivalent and valid embodiments and fall within the scope of protection of the technical solution of this application.

Claims

1. A fire protection structure for steel box girder bridges based on a safety assurance mechanism, comprising a steel box girder (1), characterized by: It also includes a protective tube (2), The protective pipes (2) are fixed to the side walls and bottom of the steel box girder (1) in a crisscrossing manner with interconnected cavities. The protective pipes (2) are equipped with several independent water storage units (4) and a through water flow channel.

2. The fire protection structure for steel box girder bridges based on a safety assurance mechanism as described in claim 1, characterized in that: Horizontal protective pipes are divided into two categories: those installed on the side walls of the steel box girder and those installed on the bottom surface of the steel box girder. The water storage unit is set in the horizontal protective pipe (2) on the side wall of the steel box girder. The height of the water storage unit is less than the height of the inner cavity of the protective pipe (2). The water storage units are set one after another in the lower part of the inner cavity of the protective pipe (2). A straight water flow channel is formed above each water storage unit in the horizontal protective pipe (2). The water storage unit is set in the horizontal protective pipe (2) at the bottom of the steel box girder. The height of the water storage unit is less than the height of the inner cavity of the protective pipe (2). The water storage units are set one after another in the lower part of the inner cavity of the protective pipe (2). A water flow channel is formed above and outside each water storage unit in the horizontal protective pipe (2). Inside the vertical protective pipe (2), the width of the water storage unit is smaller than the width of the inner cavity of the protective pipe (2). The water storage units are arranged alternately on both sides of the inner cavity of the protective pipe (2). The water storage units and the side wall of the protective pipe (2) in the vertical direction form an "S-shaped" folded water flow channel.

3. The fire protection structure for steel box girder bridges based on a safety assurance mechanism as described in claim 1, characterized in that: It also includes type A partitions (31), type B partitions (32), and type C partitions, wherein: The A-type partition (31) is in a straight line. Each A-type partition (31) is arranged sequentially at the bottom of the horizontal protective pipe (2) on the side wall of the steel box girder. Specifically, the bottom edge and side edge of the A-type partition (31) are fixed on the inner side wall of the protective pipe (2), and each A-type partition (31) is arranged parallel to each other. The height of the A-type partition (31) is less than the height of the inner cavity of the protective pipe (2). An upward-opening water storage unit is formed between two adjacent A-type partitions (31), and a straight water flow channel is formed above each water storage unit. The B-type partition (32) includes a horizontal plate and two vertical plates. The three plates are fixed perpendicularly to each other and share a common vertex. Each B-type partition (32) is sequentially installed on the inner wall of the vertical protective pipe (2). Specifically, the two sides of the horizontal plate of the B-type partition (32) are fixed to the adjacent inner walls of the protective pipe (2), and the sides of the two vertical plates of the B-type partition (32) are respectively fixed to the adjacent inner walls of the protective pipe (2). The horizontal plate of the B-type partition (32) is perpendicular to the length direction of the protective pipe (2). The horizontal length L is less than the horizontal cross-sectional length of the inner cavity of the protective tube (2), and the horizontal width W of the B-type partition is less than the horizontal cross-sectional width of the inner cavity of the protective tube (2). The B-type partition (32) and the inner wall of the protective tube (2) form an upward-opening water storage unit. The horizontal plates of each B-type partition (32) are set parallel to each other, and the horizontal plates of two adjacent B-type partitions (32) and the fixed ends of the inner wall of the protective tube (2) are staggered. Each water storage unit and the side wall of the protective tube (2) form an "S-shaped" folded water flow channel. The C-shaped partition includes a first straight plate (331) and a second straight plate (332). The height of the first straight plate (331) and the second straight plate (332) is less than the height of the inner cavity of the protective tube (2), and the length of the second straight plate (332) is less than the width of the inner cavity of the protective tube (2). The C-shaped partition is set on the inner wall of each horizontal section of the protective tube (2) that is crisscrossed on the bottom surface of the steel box girder. Specifically, the bottom edge and one side edge of the second straight plate (332) are fixed to the bottom and inner wall of the protective tube (2) respectively, and each second straight plate (332) is fixed to the bottom of the protective tube (2) in parallel and perpendicular to each other. The bottom of the first straight plate (331) is fixed to the bottom of the protective tube (2) along the length direction of the protective tube (2), and the right side of the first straight plate (331) is fixed to the side of all the second straight plates (332) in the same section of the protective tube. The first straight plate (331) is vertically fixed to the bottom of the protective tube (2). In this way, the left side of the first straight plate (331) and the inner cavity of the protective tube (2) form a water flow channel. The right side of the first straight plate (331) and multiple second straight plates (332) divide the lower cavity of the protective tube (2) into numerous water storage units with upward openings. A water flow channel is also formed above each water storage unit.

4. The fire protection structure for steel box girder bridges based on a safety assurance mechanism as described in claim 1, characterized in that: The protective pipe (2) has an opening as an inlet to connect to the water source.

5. The fire protection structure for steel box girder bridges based on a safety assurance mechanism as described in claim 1, characterized in that: The protective pipe (2) is also provided with an opening as an outlet and is equipped with a water circulation drive device.

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