Lightweight large cantilevered cover beam assembly type load-bearing main beam

Abstract

The utility model relates to bridge construction technical field especially relates to a lightweight large cantilever bent cap assembly type load -bearing girder, it mainly solved the problem that the load -bearing girder structure of prior art is poor in bending resistance and poor in shearing resistance, including at least two groups parallelly -arranged truss unit rigid connection constitutes main load -bearing frame through horizontal connecting piece, each group truss unit is spliced into by double -deck bailey along longitudinal direction, and the adjacent two bailey along longitudinal direction are connected through pin shaft, bailey has chord and web, and the splicing node of the adjacent two bailey along longitudinal direction is equipped with web, the longitudinal both sides of web are welded with connecting plate, the connecting plate is connected with the chord of bailey through bolt, the top of truss unit is equipped with I -type distribution beam, and the bottom of truss unit is connected with pier through adjustable sand box support device.

Description

Technical Field

[0001] This utility model relates to the field of bridge construction technology, and in particular to a lightweight cantilever cap beam prefabricated load-bearing main beam. Background Technology

[0002] During the construction of large cantilever cap beams, traditional load-bearing main beam structures often fail to meet the requirements for bending and shear resistance, especially when the cap beam is long. This requires increasing the size of the load-bearing main beam, which not only increases the amount of steel used, but also results in a large overall space occupied by the support structure, inflexible operation, and complex installation and dismantling processes, thus increasing construction costs and time. Summary of the Invention

[0003] Therefore, in view of the above problems, this utility model provides a lightweight cantilever cap beam prefabricated load-bearing main beam, which mainly solves the problems of poor bending resistance and poor shear resistance of the load-bearing main beam structure in the prior art.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A lightweight, cantilevered cap beam prefabricated load-bearing main beam includes at least two sets of parallel truss units rigidly connected by transverse connectors to form a main load-bearing frame. The longitudinal direction is defined as extending along the length of the main load-bearing frame, and the transverse direction is defined as extending along the width of the main load-bearing frame. Each set of truss units is spliced ​​together with double-layer Bailey panels in the longitudinal direction. Adjacent Bailey panels in the longitudinal direction are connected by pins. Each Bailey panel has a chord and a web. A web is provided at the splicing node of adjacent Bailey panels in the longitudinal direction. Connecting plates are welded to both sides of the web. The connecting plates are bolted to the chord of the Bailey panel. An I-shaped distribution beam is provided at the top of the truss unit, and the bottom of the truss unit is connected to the pier column through an adjustable sand box support device.

[0005] Furthermore, the transverse connecting member includes transverse horizontal connecting rods, cross diagonal braces, and node reinforcing plates. The transverse horizontal connecting rods are channel steel, and the spacing between two adjacent transverse horizontal connecting rods is 1.5m. The cross diagonal braces are steel pipes, and the central axis of the cross diagonal braces is arranged at a 45° angle to the horizontal plane. The node reinforcing plates connect the cross nodes, transverse horizontal connecting rods, and cross diagonal braces of the truss unit.

[0006] Furthermore, the node reinforcement plate is connected to the chord and web of the Bailey plate by welding.

[0007] Furthermore, the thickness of the web plate is not less than 12 mm.

[0008] Furthermore, the adjustable sand box support device includes a sand box body, a hydraulic jack, and a control system. The sand box body includes several steel pipes arranged in an array, each filled with concrete. The hydraulic jack is mounted on the sand box body, and a pressure sensor is installed on the top of the hydraulic jack. The pressure sensor and the hydraulic jack are electrically connected to the control system. The hydraulic jack automatically adjusts the support height based on the feedback data from the pressure sensor.

[0009] By adopting the aforementioned technical solution, the beneficial effects of this utility model are as follows: This lightweight cantilever cap beam prefabricated load-bearing main beam, through double-layer Bailey panel splicing and web reinforcement design, significantly improves the longitudinal bending stiffness and nodal shear bearing capacity of the main beam, and enhances the shear bearing capacity compared to traditional I-beam main beams, thus meeting the unbalanced bending moment requirements during the construction period of the cantilever cap beam; the use of prefabricated truss structure reduces the amount of steel used compared to traditional solid web main beams, significantly reducing the overall weight of the support and reducing foundation treatment costs; the standardized splicing of Bailey panels and the combined design of I-beam distribution beams enable rapid assembly and disassembly, shortening the construction cycle. Attached Figure Description

[0010] Figure 1 This is a front view structural diagram of an embodiment of the present utility model; Figure 2 This is a top view of the main load-bearing frame in an embodiment of this utility model; Figure 3 This is a front view structural diagram of the Bailey sheet in an embodiment of this utility model; Figure 4 This is a right-side structural schematic diagram of the transverse connecting member in an embodiment of this utility model; Figure 5 This is a top view of the sand box body in an embodiment of this utility model; Figure 6 This is a circuit module diagram of an embodiment of the present utility model. Detailed Implementation

[0011] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0012] The embodiment of this utility model is as follows: refer to Figures 1 to 6As shown, a lightweight cantilever cap beam prefabricated load-bearing main beam includes two sets of parallel truss units 2 rigidly connected by transverse connectors 3 to form a main load-bearing frame 1. The longitudinal direction is defined as extending along the length of the main load-bearing frame 1, and the transverse direction is defined as extending along the width of the main load-bearing frame 1. Each set of truss units 2 is spliced ​​together with double-layer Bailey panels 21 in the longitudinal direction. Adjacent Bailey panels 21 in the longitudinal direction are connected by pins. Each Bailey panel 21 has a chord member 211 and a web member 2. 12. A web plate 4 is provided at the splicing node of two adjacent Bailey panels 21 along the longitudinal direction. The thickness of the web plate 4 is not less than 12mm, preferably 10mm. The web plate 4 is made of Q420 high-strength steel. Connecting plates 5 are welded to both sides of the longitudinal direction of the web plate 4. The connecting plates 5 are connected to the chords 211 of the Bailey panel 21 by bolts 9. An I-shaped distribution beam 6 is provided at the top of the truss unit 2. The bottom of the truss unit 2 is connected to the pier column 7 by an adjustable sand box support device 8.

[0013] This lightweight, cantilevered cap beam prefabricated load-bearing main beam significantly improves the longitudinal bending stiffness and nodal shear capacity of the main beam through double-layer Bailey panels (21 splicing) and web reinforcement (4-strength design). Its shear capacity is significantly enhanced compared to traditional I-beam main beams, meeting the unbalanced bending moment requirements during the construction of the cantilevered cap beam. The prefabricated truss structure reduces steel consumption compared to traditional solid-web main beams, significantly lowering the overall weight of the support structure and reducing foundation treatment costs. The standardized splicing of Bailey panels (21 splicing) combined with the I-beam distribution beam design enables rapid assembly and disassembly, shortening the construction cycle.

[0014] Furthermore, the transverse connecting member 3 includes transverse horizontal connecting rods 31, cross diagonal braces 32, and node reinforcing plates 33. The transverse horizontal connecting rods 31 are 14b channel steel, and the spacing between two adjacent transverse horizontal connecting rods 31 is 1.5m. The cross diagonal braces 32 are φ219×8mm steel pipes, and their central axes are arranged at a 45° angle to the horizontal plane. The node reinforcing plates 33 are 20mm thick Q345 steel plates, and the node reinforcing plates 33 connect the cross diagonal braces of the truss unit 2. The system comprises nodes, transverse horizontal bracing members 31, and cross bracing members 32, with the 45° cross bracing members 32 and transverse horizontal bracing members 31 forming a spatial truss system. This effectively resists transverse wind loads and construction eccentric loads, enhancing transverse stiffness. The node reinforcement plate 33 enables coordinated force distribution among the truss unit, transverse horizontal bracing members 31, and cross bracing members 32, preventing localized stress concentration and extending node fatigue life. The 1.5m spacing channel steel horizontal bracing members and steel pipe bracing members utilize a standardized design, reducing on-site welding operations and improving installation efficiency. Furthermore, the node reinforcement plate 33 is connected to the chord members 211 and web members 212 of the Bailey bridge 21 via a welded connection. This welded connection achieves full-section fusion of the node reinforcement plate 33 with the chord members 211 and web members 212 of the Bailey bridge 21, resulting in a weld shear capacity exceeding 500kN, a significant improvement over ordinary fillet welds. The welded structure effectively disperses node stress, reduces the stress concentration coefficient at the weld root, and adapts to frequent loading and unloading conditions during the cap beam construction period.

[0015] Meanwhile, the adjustable sandbox support device 8 includes a sandbox body 81, a hydraulic jack 82, and a control system 83. The sandbox body 81 includes several steel pipes 811 arranged in an array, each filled with concrete 812. Specifically, the sandbox body 81 is made of φ600×10mm steel pipes 811 filled with C40 concrete 812. The hydraulic jack 82 is mounted on the sandbox body 81, and a pressure sensor 84 is installed on the top of the hydraulic jack 82. The pressure sensor 84 and the hydraulic jack 82 are respectively connected to the control system 83. The system 83 is electrically connected, and the hydraulic jack 82 automatically adjusts the support height based on the feedback data from the pressure sensor 84. The hydraulic jack 82 and the pressure sensor 84 are in closed-loop control, which compensates for the 0-50mm foundation settlement difference in real time and ensures the accuracy of the cap beam construction line. The pressure sensor 84 has a monitoring accuracy of ±1kN, and the hydraulic system 83 has a response time of ≤0.5s, which realizes dynamic balance of support force and avoids excessive local stress. The sand box body 81, steel pipe 811, and concrete 812 structure have a bearing capacity of up to 2000kN. The hydraulic system has a double locking function to prevent the risk of support failure.

[0016] Specifically, the sand box body 81 is a steel pipe 811 with an outer diameter of 644mm and a wall thickness of 12mm, and is filled with graded sand with a particle size of 2-5mm. Hydraulic system: Hydraulic jack with a rated pressure of 25MPa and a stroke of 500mm, equipped with an electric pump station; Control system: Built-in displacement sensor 85 and pressure sensor 84, and closed-loop control of support force and displacement is realized through PLC controller, with a response time ≤0.5s.

[0017] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0018] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0019] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0020] Although the invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the invention without departing from the spirit and scope of the invention as defined in the appended claims, all of which shall be within the scope of protection of the invention.

Claims

1. A lightweight, large cantilever cap beam prefabricated load-bearing main beam, characterized in that: The main load-bearing frame is formed by rigidly connecting at least two sets of parallel truss units via transverse connectors. The longitudinal direction is defined as extending along the length of the main load-bearing frame, and the transverse direction is defined as extending along the width of the main load-bearing frame. Each set of truss units is formed by splicing double-layer Bailey panels along the longitudinal direction. Adjacent Bailey panels along the longitudinal direction are connected by pins. Each Bailey panel has a chord and a web. A web is provided at the splicing node of adjacent Bailey panels along the longitudinal direction. Connecting plates are welded to the longitudinal sides of the web. The connecting plates are bolted to the chord of the Bailey panel. An I-shaped distribution beam is provided at the top of the truss unit, and the bottom of the truss unit is connected to the pier column through an adjustable sand box support device.

2. The lightweight cantilever cap beam prefabricated load-bearing main beam according to claim 1, characterized in that: The transverse connecting member includes transverse horizontal bracing rods, cross diagonal braces, and node reinforcing plates. The transverse horizontal bracing rods are channel steel, and the spacing between two adjacent transverse horizontal bracing rods is 1.5m. The cross diagonal braces are steel pipes, and the central axis of the cross diagonal braces is arranged at a 45° angle to the horizontal plane. The node reinforcing plates connect the cross nodes, transverse horizontal bracing rods, and cross diagonal braces of the truss unit.

3. The lightweight cantilever cap beam prefabricated load-bearing main beam according to claim 2, characterized in that: The node reinforcement plate is connected to the chord and web of the Bailey plate by welding.

4. The lightweight cantilever cap beam prefabricated load-bearing main beam according to claim 3, characterized in that: The thickness of the web plate is not less than 12 mm.

5. The lightweight cantilever cap beam prefabricated load-bearing main beam according to any one of claims 1 to 4, characterized in that: The adjustable sand box support device includes a sand box body, a hydraulic jack, and a control system. The sand box body includes several steel pipes arranged in an array, each filled with concrete. The hydraulic jack is mounted on the sand box body, and a pressure sensor is installed on the top of the hydraulic jack. The pressure sensor and the hydraulic jack are electrically connected to the control system. The hydraulic jack automatically adjusts the support height based on the feedback data from the pressure sensor.

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