A rigid frame bridge main girder closure top force applying device and closure construction method

Abstract

The present application relates to the technical fields of bridge engineering, and discloses a rigid frame bridge main girder closure gap top force applying device and closure construction method, which comprises a supporting assembly, a top locking assembly, and a main girder closure construction method based on corresponding facilities. The present application has the following advantages and effects: the supporting assembly is arranged between the top plate and the bottom plate, the supporting beam of the supporting assembly is supported on the concrete of the top plate and the bottom plate, the supporting beam evenly spreads the huge locking force to the top plate and the bottom plate of the main girder through the contact surface with the concrete of the top plate and the bottom plate, and compared with the direct support on the top plate and the bottom plate and the web of the main girder, or the support on the corbels and the embedded parts, or the force transmission mode through the cast concrete tooth blocks, the present application has the advantages of light structure, clear stress, strong bearing capacity, simple operation, no influence on the closure gap concrete pouring, no tensile stress cracks on the main girder, and low cost.

Description

Technical Field

[0001] This application relates to the field of bridge engineering technology, specifically to a device for applying top force at the closure joint of a rigid frame bridge main girder and a closure construction method. Background Technology

[0002] During the closure construction of the main beam of a continuous rigid frame bridge, a jacking force needs to be applied to the closure joint to adjust the stress state and alignment of the main beam and piers of the continuous rigid frame bridge, so that the stress and alignment of the completed bridge meet the requirements.

[0003] Patent application CN112878199A discloses a device and construction method for applying jacking force at the closure joint of a rigid frame bridge main girder, including a support tooth block, a jacking assembly and a locking assembly, as well as a construction method based on the corresponding facilities.

[0004] Patent application CN114457667A discloses a long-span, upper-bearing, perforated web-type composite rigid frame bridge, including an upper chord box girder (1), a lower chord box arch (2), and hollow piers (3). The upper chord box girder (1) and the lower chord box arch (2) form a beam-arch triangle area directly above the hollow piers (3). The upper chord box girder (1) in the beam-arch triangle area is supported by an arch column (5) set on the lower chord box arch (2) and a stable triangular frame formed with the upper chord girder (1) on the hollow piers (3). The structure is supported by V-shaped branch piers (4). The upper chord box girder includes a precast NC top plate (111), a precast NC bottom plate (121), and a precast UHPC variable cross-section straight web plate (131). The precast UHPC variable cross-section straight web plate (131) is designed such that the vertical end plate area of ​​the web plate is larger than the middle plate area. The bearing efficiency of the bridge structure is improved from the aspects of structural system and stress mechanism, overcoming the cracking and deflection problems that usually occur in conventional concrete rigid frame bridges, and further expanding the spanning capacity of concrete rigid frame bridges.

[0005] Currently, during the closure construction of the main girder of a continuous rigid frame bridge, the jacking force at the closure joint is often applied directly to the top and bottom slabs or web of the already cast beam segment using jacks and jacking struts. The jacking force is then secured to the top and bottom slabs or web of the cast beam segment by support rods. Alternatively, embedded parts are installed on the top and bottom slabs of the cast beam segment and corbels are welded on, or concrete support blocks are cast, with the support rods and jacking struts transferring the jacking force to the cast beam segment through the corbels or support blocks. However, as the bridge span increases, the jacking force also increases. The thickness of the top and bottom slabs and web of the main girder in a continuous rigid frame bridge does not increase significantly at mid-span. Under normal circumstances, the bearing capacity of the concrete top and bottom slabs, corbels, and support blocks often cannot meet the requirements, and concrete cracks are easily generated under eccentric loads. Furthermore, the limited area of ​​the closure end face of a rigid frame bridge means that the number of supporting structures that can be installed simultaneously is limited, making it difficult to exceed the jacking force tolerance. Summary of the Invention

[0006] In view of the deficiencies in the existing technology, the purpose of this application is to provide a device for applying top force at the closure joint of the main beam of a rigid frame bridge and a closure construction method, which can realize the closure of a large-span rigid frame bridge.

[0007] To achieve the above objectives, one technical solution adopted is:

[0008] A device for applying jacking force at the closure joint of a rigid frame bridge main girder, used to apply jacking force to both sides of the main girder at the closure joint during the closure of the main girder, comprising:

[0009] There are several support components, which are symmetrically arranged on the left and right sides of the main beam cross-section at both ends of the closure joint. They are set at the ends of the cast main beams on both sides of the closure joint. Each support component includes a support beam, a limiting block and a support anti-damage component. The support beam is a high-strength steel structure beam welded component. The support anti-damage component is set on the end face of the opening hole of the top plate and bottom plate of the main beam. The limiting block is welded to the upper end of the support beam and is stuck in the concrete of the top plate of the main beam.

[0010] There are several top locking components, which are set inside the closure joint and correspond one-to-one with the support components. Each set of top locking components includes a top force application component, a support rod and a support steel plate. The support steel plate is set on the end face of the support beam. The support rod is a steel pipe concrete structure and abuts against the support steel plate and the top force application component. The top force application component abuts against the support rod and the support steel plate.

[0011] Preferably, the support and damage prevention component includes: a mesh reinforcement, which is embedded in the main beam opposite the damage prevention steel plate, and one end abuts against the damage prevention steel plate.

[0012] Damage-resistant steel plates are partially embedded in the main beams, and the support beams are supported by the damage-resistant steel plates.

[0013] Preferably, the top force application component includes:

[0014] The shim plate has one end abutting against the support steel plate and the other end abutting against the jack;

[0015] The jack has a self-locking function, with one end abutting against the support rod and the other end abutting against the pad steel plate;

[0016] A main beam closure construction method based on the aforementioned device includes the following steps:

[0017] S1. When pouring concrete for the beam segments on both sides of the closure joint, pre-reserve holes for the installation of the support beams on the top and bottom plates of the main beams and pre-embed support and anti-damage components.

[0018] S2. Install the template for the closure section inside the closure joint and install the support components and the top locking components;

[0019] S3. Use the jacking force application component to apply jacking force until the design requirements are met, activate the jack self-locking function, and pour the closure section concrete;

[0020] S4. After the concrete poured in step S3 reaches the design requirements, the jacks are retracted, the top locking components and support components are removed, and the reserved support beam installation holes are sealed according to the design requirements to complete the closure.

[0021] Preferably, step S3 is performed using the following method:

[0022] S31. The A-group top force application component applies the top force;

[0023] S32. The B-group top force application component is inserted into the padding steel plate and a top force is applied;

[0024] S33. After the jack of the A-group jacking component retracts, the shim steel plate is inserted and the jacking force is applied;

[0025] S34. After the jack of the B group jacking component retracts, the shim steel plate is inserted and the jacking force is applied.

[0026] S35. Repeat S33-S34, increasing the jacking force applied by the jacking component each time until the jacking force on the support rod reaches the design value. Adjust the jacking force of group A and group B so that the jacking force is equal to the design value, and activate the jack self-locking function.

[0027] Positive and beneficial effects: 1. This invention uses support beams to support the top and bottom plates of the main beam. The jacking force is transferred to the anti-damage support components through the support beams, and the pressure is then diffused to the top and bottom plates of the main beam through the anti-damage support components. Compared with the force transmission method of setting corbels, embedded parts, or toothed blocks on the main beam, this invention fully utilizes the characteristics of high compressive strength and low tensile strength of concrete, and does not generate additional bending moments on the main beam, thus avoiding tensile stress and cracks. It also has the advantages of lightweight structure, clear force distribution, strong load-bearing capacity, and flexible layout. 2. By arranging the support rods on the outside of the beam body through the support beams, the closure joint concrete can be poured in one go across the entire cross section, reducing construction joints, facilitating construction, and better ensuring the construction quality and stress performance of the closure joint concrete. 3. The distance between the support points and the point of force application of the support beam is very small, resulting in a short lever arm. Therefore, the bending moment on the support beam is small. The support beam, made of high-strength steel structural beam assembly welded components, can easily meet the load-bearing requirements. Compared with corbels, embedded parts, or toothed blocks for force transmission, it has a stronger load-bearing capacity, lighter weight, and smaller size. Moreover, all materials are conventional components, which are convenient for use in various construction scenarios, saving costs. 4. The use of a jack with a self-locking function combines the jacking support rod and the locking support rod into one, eliminating the need to switch between the force application support rod and the locking support rod, making construction convenient and reducing material input. Attached Figure Description

[0028] Figure 1This is a view of the main beam on one side from the closure joint in this application.

[0029] Figure 2 for Figure 1 Side view of the main beam closure force application device in the illustrated embodiment.

[0030] Figure 3 for Figure 2 An enlarged structural diagram of the support component and the top locking component in the illustrated embodiment.

[0031] Figure 4 This is an enlarged structural diagram of the supporting beam and the top locking assembly, viewed from the top of the beam.

[0032] Figure 5 A magnified structural diagram of the plane at the contact point between the supporting beam and the main beam, viewed from the top of the beam.

[0033] Figure 6 for Figure 1 A schematic diagram of the overall structure of the bridge in the embodiment shown.

[0034] Reference numerals: 1. Main beam; 2. Closure joint; 3. Support component; 31. Support beam; 32. Limiting block; 33. Support and damage prevention component; 331. Reinforcing mesh; 332. Damage prevention steel plate; 4. Top locking component; 41. Support steel plate; 42. Top force application component; 421. Pad steel plate; 422. Jack; 43. Support rod; 5. Hole. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this application clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0036] In this embodiment, as Figure 1 , Figure 2As shown, it includes a support component 3 and a top-mounted component. There are several support components 3, which are symmetrically arranged on the left and right sides of the cross-section of the main beam 1 at both ends of the closure joint 2. They are set at the ends of the cast main beam 1 on both sides of the closure joint 2. Each support component 3 includes a support beam 31, a limiting block 32 and a support anti-damage component 33. The support beam 31 is a high-strength steel structure beam welded component. The support anti-damage component 33 is set on the end face of the opening hole 5 of the top plate and bottom plate of the main beam 1. The limiting block 32 is welded to the upper end of the support beam 31 and is stuck on the concrete of the top plate of the main beam 1. Several top-locking components 4 are installed within the closure joint 2, corresponding one-to-one with the support components 3. Each set of top-locking components 4 includes a top-force application component 42, a support rod 43, and a support steel plate 41. The support steel plate 41 is located on the end face of the support beam 31. The support rod 43 is a steel-concrete composite structure and abuts against the support steel plate 41 and the top-force application component 42. The top-force application component 42 abuts against the support rod 43 and the support steel plate 41. Both ends of the top-locking components 4 abut against the support beam 31. The top-force application device applies the main force to the main beam 1 through the support beam 31. The support beam 31 is supported by the support and damage prevention component 33, which protects the end face of the main beam 1 from damage by excessive top force. The support components 3 and the top-locking components 4 are symmetrically arranged along the cross-section of the main beam 1 at both ends of the closure joint 2 to ensure the left and right force balance of the main beam 1.

[0037] As an optimization of this embodiment, such as Figure 3 , Figure 4 As shown, the force application component 42 includes a jack 422 and a lifting plate 421. The jack 422 has a self-locking function, with one end abutting against the support rod 43 and the other end abutting against the lifting plate 421, for applying force and locking support. The lifting plate 421 has one end abutting against the support plate 41 and the other end abutting against the jack 422, for adjusting the stroke of the jack 422 and evenly transferring the load to the support plate 41.

[0038] Furthermore, such as Figure 3 , Figure 5 As shown, the support and anti-damage component 33 includes a mesh steel bar 331 and an anti-damage steel plate 332. The anti-damage steel plate 332 is a thick steel plate, which is partially embedded in the end face of the main beam 1. The support beam 31 is supported on the anti-damage steel plate 332. The top force is evenly transmitted to the end face of the main beam 1 through the anti-damage steel plate 332. The mesh steel bar 331 can improve the local crack resistance and local compressive bearing capacity of the concrete, so that the stress can be evenly diffused into the interior of the main beam 1 when it is under stress.

[0039] As an optimization of this embodiment, such as Figure 3 , 5As shown, one end of the jacking force application component 42 is supported on the support rod 43, and the other end abuts against the support steel plate 41 on the other side of the closure joint 2 through the padding steel plate 421. The support steel plate 41 can evenly transfer the load to the support beam 31, ensuring that the support beam 31 is evenly stressed and avoiding stress concentration. The padding steel plate 421 is loaded in groups and grades and placed in stages. By reasonably calculating the jacking force of the jacking force application component 42 and adopting a grouped cyclic loading method, the jacking force can be applied safely and accurately, and the needs of misalignment and sliding caused by the elevation change of the two beam segments at both ends of the closure beam segment during the jacking process can be met. The alignment of the main beam 1 is better controlled. By monitoring the displacement of the closure joint 2 and the pier body during the jacking force application process, the jacking locking component 4 can be aligned in time, ensuring the accurate application of the jacking force and thus ensuring the safety of the bridge after completion.

[0040] Another embodiment of the main beam 1 closure construction method based on the aforementioned device includes the following steps:

[0041] S1. When pouring concrete for the beam segments on both sides of the closure joint 2, holes 5 for installing the support beam 31 are reserved on the top and bottom plates of the main beam 1, and support anti-damage components 33 are pre-embedded. In this embodiment, the predetermined locking force is 25000kN, the temperature at the time of closure is 15℃, and a total of 8 sets of support components 3 and 16 sets of top locking components 4 are set. Each set of support components 3 corresponds to two sets of top locking components 4 on the top and bottom plates. Each top plate top force application component 42 applies a top force of 1640kN, and each bottom plate top force application component 42 applies a top force of 1485kN. The support beam 31 is a welded I-beam 500C steel component with steel grade Q420. Ribs are welded at the top force application position and the support point position.

[0042] S2. Install the template for the closure section within the closure joint 2 and install the support components 3 and the top locking components 4;

[0043] S3. Apply jacking force using jacking component 42 until the design requirements are met, activate the self-locking function of jack 422, and pour the closure section concrete.

[0044] S4. After the concrete poured in step S3 reaches the design requirements, the jack 422 retracts, the top locking component 4 and the support component 3 are removed, and the reserved support beam 31 installation hole 5 is sealed according to the design requirements to complete the closure.

[0045] In this embodiment, the jack 422 is a self-locking hydraulic jack with a maximum jacking force of 800t, and the support rod 43 is a φ529×20 steel pipe concrete component, filled with C60 high-strength micro-expansion concrete.

[0046] In some embodiments, the method used in step S2 for installing the support component 3 and the top locking component 4 is as follows:

[0047] When installing the support assembly 3, a limiting block 32 is welded to the upper side of the support beam 31 so that it is stuck in the concrete of the pre-reserved hole 5 on the top plate of the main beam 1 to prevent the support beam 31 from falling under its own weight. At the same time, this design also makes it convenient to lift and remove the support beam 31 from the top.

[0048] When installing the support locking assembly, it should be supported on the concrete of the top and bottom plates of the main beam 1 that have been poured on both sides of the closure joint 2. No additional temporary support structure is required. When reserving the holes 5 for the installation of the support beam 31, the size of the support locking assembly should be reasonably considered.

[0049] In some embodiments, step S3 is performed using the following method:

[0050] S31. The top force applying component 42 of group A applies the top force;

[0051] S32. The top force application component 42 of group B is inserted into the pad steel plate 421 and the top force is applied. Multiple pad steel plates 421 with a thickness of 10 / 20cm are prepared in advance and are inserted in batches according to the required pad thickness.

[0052] S33. After the A-group jacking component 42 jack 422 retracts, the shim steel plate 421 is inserted and jacking force is applied;

[0053] S34. After the B-group jacking component 422 retracts, the padding steel plate 421 is inserted and jacking force is applied.

[0054] S35. Repeat S33-S34, each time the force applied by the force application component 42 is applied in stages at 20% of the design force, until the force on the support rod 43 reaches the design value. Adjust the force of the jacks 422 of group A and group B so that the force of the jacks 422 is equal to the design value, and activate the self-locking function of the jacks 422.

[0055] This application is not limited to the above-described embodiments. For those skilled in the art, several improvements and modifications can be made without departing from the principle of this invention, and these improvements and modifications are also considered to be within the scope of protection of this invention.

Claims

1. A device for applying jacking force at the closure joint of a rigid frame bridge main girder, used to apply jacking force to both sides of the main girder (1) at the closure joint (2) during the closure of the main girder (1), characterized in that, Also includes: Support components (3) are arranged symmetrically on the left and right sides of the cross-section of the main beams (1) at both ends of the closure joint (2). They are set at the ends of the cast main beams (1) on both sides of the closure joint (2). Each support component (3) includes a support beam (31), a limiting block (32) and a support anti-damage component (33). The support beam (31) is a high-strength steel structure beam welded component. The support anti-damage component (33) is set on the end face of the opening hole (5) of the top plate and bottom plate of the main beam (1). The limiting block (32) is welded to the upper end of the support beam (31) and is stuck on the concrete of the top plate of the main beam (1). There are several top locking components (4), which are set in the closure joint (2) and correspond one-to-one with the support components (3). Each set of top locking components (4) includes a top force application component (42), a support rod (43) and a support steel plate (41). The support steel plate (41) is set on the end face of the support beam (31). The support rod (43) is a steel pipe concrete structure and abuts against the support steel plate (41) and the top force application component (42). The top force application component (42) abuts against the support rod (43) and the support steel plate (41). The support and damage prevention component (33) includes: a mesh steel bar (331), which is embedded in the main beam (1) opposite to the damage prevention steel plate (332) and one end abuts against the damage prevention steel plate (332); the damage prevention steel plate (332), which is partially embedded in the main beam (1), and the support beam (31) is supported on the damage prevention steel plate (332); The top force application component (42) includes: a padding steel plate (421), one end of which abuts against the support steel plate (41) and the other end of which abuts against the jack (422); the jack (422) has a self-locking function, one end of which abuts against the support rod (43) and the other end of which abuts against the padding steel plate (421).

2. A method for main beam closure construction based on the device described in claim 1, characterized in that, Includes the following steps: S1. When pouring concrete for the beam segments on both sides of the closure joint (2), holes (5) for installing the support beam (31) are reserved on the top and bottom plates of the main beam (1), and support anti-damage components (33) are pre-embedded. S2. Install the template of the closure section and the support components (3) and the top locking components (4) inside the closure joint (2); S3. Use the jacking force application component (42) to apply the jacking force until the design requirements are met, activate the self-locking function of the jack (422), and pour the closure section concrete; S4. After the concrete poured in step S3 reaches the design requirements, the jack (422) retracts, the top locking component (4) and the support component (3) are removed, and the reserved support beam (31) installation hole (5) is sealed according to the design requirements to complete the closure.

3. The main beam closure construction method according to claim 2, characterized in that, Step S3 is performed using the following method: S31. The top force application component (42) of group A applies the top force; S32. The top force application component (42) of group B is inserted into the pad steel plate (421) and a top force is applied; S33. After the A-group jacking component (42) jack (422) retracts, the padding steel plate (421) is inserted and the jacking force is applied; S34. After the B group jacking component (42) retracts, the padding steel plate (421) is inserted and the jacking force is applied; S35. Repeat S33-S34, each time the force applied by the force application component (42) increases gradually until the force on the support rod (43) reaches the design value. Adjust the force of the jacks (422) of group A and group B so that the force of the jacks (422) is equal to the design value, and activate the self-locking function of the jacks (422).

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