Long-span continuous steel girder bridge disconnection method

Abstract

The application relates to the field of bridge construction technology, in particular to a long-connection continuous steel beam bridge disconnection method. The method is carried out according to the following steps: S1, erecting a incremental launching assembling platform and installing a walking incremental launching device; S2, hoisting a first steel beam section to the incremental launching assembling platform; S3, hoisting a second steel beam section to the incremental launching assembling platform, installing a disconnection device between the first steel beam section and the second steel beam section, and temporarily fixing and connecting the steel beam sections; S4, sequentially connecting the remaining steel beam sections according to steps S2 and S3 and sequentially launching the steel beam sections to the designed positions; S5, adjusting the tension between the adjacent steel beam sections by the disconnection device to eliminate the bending moment, releasing the temporary fixed connection between the adjacent steel beam sections, releasing the tension of the disconnection device, and removing the disconnection device. The application applies the tension between the adjacent steel beam sections to offset the large negative bending moment value at the top of the continuous beam pier, and improves the safety and stability of the whole incremental launching construction.

Description

Technical Field

[0001] This invention relates to the field of bridge construction technology, specifically to a method for disconnecting long continuous steel beam bridges. Background Technology

[0002] The incremental launching construction technology has matured over the past few decades. Existing steel structure bridges typically use the incremental launching method to install steel beams when crossing rivers or roads. When using the incremental launching method, the steel box girder is pre-assembled on a pre-erected assembly platform to form a whole. Incremental launching equipment is set up on the assembly platform and at the top of the pier to launch the steel box girder. When the launch reaches the designated position, the next steel box girder is installed using the assembly platform and welded to the previous steel box girder to form a whole. Then the next round of launching work is carried out. This cycle is repeated until all beam segments are launched and adjusted into place before the guide beam is removed and the beams are lowered.

[0003] For multi-span continuous beams, expansion joints are required between the spans. The purpose of these joints is to ensure that the bridge structure can deform freely within a reasonable range under the influence of temperature changes, concrete shrinkage and creep, and loads, while ensuring smooth vehicle passage. During the integral jacking construction of steel box girders for this type of bridge structure, temporary connecting steel plates are used to connect the two steel box girders on both sides of the expansion joint, facilitating the integral jacking construction. After the entire steel box girder is jacked into place, the adjacent two steel box girders are separated, and expansion joints are constructed in the gap between them to meet the designed span requirements, thus completing the erection of the steel beams.

[0004] Currently, temporary connections between expansion joints typically involve using connecting steel plates to link the two steel box girders on either side of the expansion joint into a single unit. These plates are then welded to the main steel box girder, and the connecting steel plates are removed after the main steel box girder is pushed into place. Because the junctions between expansion joints are located at the pier top, the removal of these temporary connections results in large variations in positive and negative bending moments. Without additional protective measures, the removal of the connections not only damages the steel box girder structure, affecting the bridge's construction quality, but also poses a safety hazard.

[0005] To address the aforementioned technical issues, a Chinese invention patent with patent number "CN201610347569.4," entitled "Method and Device for Jacking Up the Mid-Span of a Long-Span High-Pier Prestressed Concrete Box Girder Continuous Rigid Frame Bridge," discloses a connection device for adjacent box girders during jacking construction. This device includes a composite I-beam, a base plate, welded steel plates, a composite H-beam, jacks, and a stiffening frame. The composite I-beam is formed by welding two I-beams side-by-side, and the composite H-beam is formed by welding two H-beams side-by-side. The composite I-beam is vertically embedded at both ends of the box girder to a depth of half the web length. The composite I-beam is welded to the web reinforcement mesh of the box girder. The reinforcement mesh on both sides of the top plate and the reinforcement mesh in the bottom plate of the box girder are welded to one end of the stiffening frame along the longitudinal direction of the bridge, and the opposing stiffening frames on both sides are on the same axis. In actual construction, jacks on both sides are used to apply a jacking force to reduce the additional bending moment caused by the unevenness of the concrete material or other existing jacking devices. However, in practical application, it has been found that this device is relatively cumbersome to operate and difficult to construct. First, it is necessary to pre-embed the combined I-beam steel beam during the prefabrication of the box girder. Second, there are strict requirements for the subsequent application of jacking force to the jacks on both sides. Third, the device is not a complete connecting structure and cannot effectively connect adjacent box girders into a whole.

[0006] While the aforementioned device can address the issue of localized bending moments generated during the jacking process of adjacent box girders to some extent, its construction process is complex, the device structure is difficult to install, and it can only apply jacking force along the bridge direction. Adjacent box girder segments are connected through this device, which not only needs to provide its own jacking force to dissipate bending moments but also needs to transmit the force that drives the box girder during jacking. This device structure and construction method have many limitations in application, resulting in a very narrow scope of application and making it unsuitable for widespread promotion and application. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the aforementioned background technology and provide a method for disconnecting long continuous steel beam bridges.

[0008] The technical solution of this invention is: a method for disconnecting long continuous steel beam bridges, which is carried out according to the following steps:

[0009] S1. Erect a jacking assembly platform, install walking jacking equipment on the jacking assembly platform and permanent pier, assemble guide beams on the jacking assembly platform, and jack out the guide beams after the guide beams are assembled.

[0010] S2. Hoist the first steel beam segment to the jacking assembly platform, adjust the position of the first steel beam segment and then weld it to the guide beam. After completion, push it out of the jacking assembly platform.

[0011] S3. Hoist the second steel beam segment to the jacking assembly platform, install the disconnection device between the first steel beam segment and the second steel beam segment, and temporarily fix the connecting steel beam segments.

[0012] S4. Connect the remaining steel beam segments in sequence according to steps S2 and S3 and push them to the design position in sequence.

[0013] S5. Use the disconnection device to adjust the tension between adjacent steel beam segments to eliminate bending moment, release the temporary fixed connection between adjacent steel beam segments, release the tension of the disconnection device, dismantle the disconnection device, and complete the jacking construction of the long continuous steel beam bridge.

[0014] According to the method for disconnecting a long continuous steel beam bridge provided in this application, the method of installing a disconnection device between the first steel beam segment and the second steel beam segment in step S3 includes: installing a steel beam top plate between adjacent steel beam segments; fixing the two ends of the steel beam top plate along the bridge direction to the top plates of the two sets of steel beam segments respectively by bolt structure; arranging two sets of tensioning structures on the steel beam top plate and the first and second steel beam segments respectively; the tensioning structure includes a through-hole jack fixed to the steel beam top plate; the two sets of through-hole jacks are arranged at intervals along the bridge direction and correspond one-to-one with the two sets of steel beam segments; passing the tie rod along the bridge direction through the two sets of through-hole jacks in sequence; and tensioning the tie rod with the two sets of through-hole jacks to complete the installation of the disconnection device.

[0015] According to the method for disconnecting a long continuous steel beam bridge provided in this application, the method for temporarily fixing the connecting steel beam segments in step S3 includes: welding temporary connecting steel plates between the wing plates, top plates, bottom plates and web plates of adjacent steel beam segments to temporarily fix the adjacent steel beam segments.

[0016] According to the method for disconnecting a long continuous steel beam bridge provided in this application, in step S5, the method of adjusting the tension between adjacent steel beam segments using the disconnection device to eliminate the bending moment includes: using two sets of through-hole jacks of the disconnection device to tension the tie rods in the bridge direction, and adjusting the pre-tension force of the through-hole jacks on the tie rods according to the structure of the steel beam segments until the bending moment of the adjacent steel beam segments at the permanent pier support is eliminated.

[0017] According to the method for disconnecting a long continuous steel beam bridge provided in this application, the pretension force of the tie rod of the through-hole jack is calculated according to the following formula:

[0018]

[0019] M=αqL 2

[0020] Where: M—the bending moment generated by the steel beam segment at the permanent pier support;

[0021] S—the distance between the tie rod and the horizontal centroidal axis of the steel beam;

[0022] q — Load intensity of the self-weight of the steel beam segment along the length of the steel beam segment;

[0023] L – the span of the steel beam segment;

[0024] α — The continuous pier top bending moment coefficient determined based on the number of spans of the steel beam segments;

[0025] According to the method for disconnecting a long continuous steel beam bridge provided in this application, the bending moment coefficient α at the top of the continuous pier is calculated using the following formula:

[0026] When the continuous steel girder bridge is a two-span continuous beam...

[0027] α=β(L-20) 0.07

[0028] When the continuous steel girder bridge is a continuous beam with three or more spans...

[0029]

[0030] Where: α——Continuous pier top bending moment coefficient determined based on the number of spans of the steel beam segments;

[0031] β—First empirical value;

[0032] L – the span of the steel beam segment;

[0033] γ — Second empirical value.

[0034] According to the method for disconnecting a long continuous steel beam bridge provided in this application, in step S5, the method for releasing the temporary fixed connection between adjacent steel beam segments includes: first cutting the temporary fixed connection between the wing plates of adjacent steel beam segments, then cutting the temporary fixed connection between the top plates of adjacent steel beam segments, then cutting the temporary fixed connection between the bottom plates of adjacent steel beam segments, and finally cutting the temporary fixed connection between the web plates of adjacent steel beam segments.

[0035] According to the method for disconnecting a long continuous steel beam bridge provided in this application, step S5, the method for releasing the tension force of the disconnection device includes: firstly cutting the temporary fixed connection between the flanges of adjacent steel beam segments, and adjusting the force exerted by the disconnection device on the adjacent steel beam segments to a first tension force; cutting the temporary fixed connection between the top plates of adjacent steel beam segments, and adjusting the force exerted by the disconnection device on the adjacent steel beam segments to a second tension force; cutting the temporary fixed connection between the bottom plates of adjacent steel beam segments, and adjusting the force exerted by the disconnection device on the adjacent steel beam segments to a third tension force; cutting the temporary fixed connection between the web plates of adjacent steel beam segments, and adjusting the force exerted by the disconnection device on the adjacent steel beam segments to a fourth tension force; the first tension force > the second tension force > the third tension force > the fourth tension force, and the fourth tension force is 0.

[0036] According to the method for disconnecting a long continuous steel beam bridge provided in this application, the first tension force is 0.8 times the pretension force when the disconnection device eliminates the bending moment of adjacent steel beam segments; the second tension force is 0.55 times the pretension force when the disconnection device eliminates the bending moment of adjacent steel beam segments; and the third tension force is 0.3 times the pretension force when the disconnection device eliminates the bending moment of adjacent steel beam segments.

[0037] According to the method for uncoupling a long continuous steel beam bridge provided in this application, when uncoupling adjacent steel beam segments and removing the uncoupling device, the process is carried out sequentially from both ends of the steel beam bridge to the middle of the span.

[0038] The advantages of this application are as follows: 1. In the process of launching long continuous steel beams, this application installs a disconnection device between adjacent steel beam segments and uses the disconnection device to tension the adjacent steel beam segments, so that the bending moment of the adjacent steel beam segments at the permanent pier support can be effectively eliminated. At the same time, when the adjacent steel beam segments are disconnected, the stress between the adjacent steel beam segments can be eliminated through the disconnection device, avoiding safety hazards. The disconnection device of this application applies a longitudinal tension to the adjacent steel beam segments. When the temporary consolidation of the adjacent steel beam segments is released, it can ensure the rapid dissipation of bending moment and stress between the adjacent steel beam segments, thereby improving the efficiency and safety of launching the entire long continuous steel beam. The entire construction scheme is simple, easy to operate, and has great promotional value.

[0039] 2. The disconnection device of this application has a simple structure and is extremely convenient to install and use. The entire disconnection device is fixed to the top plate of the adjacent steel beam segment by the top plate of the steel beam. The through-hole jack and the tie rod are installed on the top plate of the steel beam. The whole installation and disassembly are convenient. The two sets of through-hole jacks can realize the push-pull action in the longitudinal direction of the bridge, which is very convenient for dissipating the bending moment and stress between adjacent steel beam segments.

[0040] 3. In this application, when temporarily fixing the steel beam segments, temporary connecting steel plates are welded between the flange, top plate, web and bottom plate of the steel beam segments respectively. The adjacent steel beam segments are firmly connected, and the welded temporary connecting steel plates are independent of each other and can be removed in a distributed manner in the future, which is conducive to the dissipation of stress between adjacent steel beam segments.

[0041] 4. This application sets the pretension force generated by the disconnection device. The pretension force of the tie rod is determined by adjusting the through jack of the steel beam segment structure. It can accurately obtain the magnitude of the pretension force required to eliminate the bending moment, and the adjustment is more precise. It can effectively dissipate the bending moment of the steel beam segment at the permanent pier support, and improve the safety of the construction of the entire long continuous steel beam bridge.

[0042] 5. The pretension force of the through-hole jack adjusting tie rod in this application can be accurately calculated. Through a carefully designed formula, the pretension force of the through-hole jack adjusting tie rod can be accurately calculated, which can accurately eliminate the bending moment generated by the steel beam segment at the permanent pier support. The whole calculation method is simple and the calculation result is accurate.

[0043] 6. This application designs different calculation methods for the bending moment coefficient at the top of the continuous pier for different types of long continuous steel beam bridges. This calculation method can more accurately fit the actual bridge construction situation, ensure the elimination of bending moment to the greatest extent, and can be well applied to any type of bridge.

[0044] 7. In this application, a certain sequence is adopted when making temporary contact connections on steel beam segments, namely, cutting operations are performed in the order of flange plate, bottom plate and bottom plate. This cutting method can ensure the safety of disconnecting adjacent steel beam segments to the greatest extent.

[0045] 8. When temporarily fixing and releasing the steel beam segments, this application also adjusts the tension of the uncoupling device. By adjusting the tension of the uncoupling device, the stress between adjacent steel beam segments can be gradually released, avoiding damage and safety issues caused by stress concentration when cutting adjacent steel beam segments.

[0046] 9. In the process of adjusting the tension of the disconnection device, this application precisely controls the tension. When removing temporary fixed connections at different locations, corresponding precise tension is applied. On the one hand, the stress can be quickly dissipated, and on the other hand, safety hazards are avoided during the dismantling work.

[0047] 10. This application proposes to demolish the structure step by step from the side closest to the shore to the middle of the span. This method of operation can ensure the safety and stability of the demolition work to the greatest extent and effectively improve the safety and integrity of the structure during the construction process.

[0048] In the process of launching a long continuous steel beam bridge, this application applies tension between adjacent steel beam segments to offset the bending moment at the centroid of the steel beam segment, offset the large negative bending moment at the top of the continuous beam pier, and transform the constraint between segments, thereby improving the safety and stability of the entire launching construction. Attached Figure Description

[0049] Figure 1 : A schematic diagram of the arrangement of the disconnection device and the steel beam segment in this application;

[0050] Figure 2 : Front view of the disconnection device of this application;

[0051] Figure 3 Top view of the disconnection device of this application;

[0052] Figure 4 Side view of the disconnection device of this application;

[0053] Figure 5 : A schematic diagram of the cross-section of the steel beam segment in this application;

[0054] Figure 6 This application contains a construction schematic diagram of a long continuous steel beam bridge.

[0055] Wherein: 1—jacking assembly platform; 2—permanent pier; 3—guide beam; 4—steel beam top plate; 5—through-hole jack; 6—adjusting tie rod; 7—limiting steel plate; 8—matching sleeve; 9—adjusting tie rod sleeve; 10—wing plate; 11—top plate; 12—bottom plate; 13—web plate. Detailed Implementation

[0056] Embodiments of the present invention are described in detail below, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0057] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0058] 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 at least two, such as two, three, etc., unless otherwise explicitly specified.

[0059] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0060] This application relates to a method for disconnecting long continuous steel beam bridges. The construction method of this application is mainly used in the jacking construction process of long continuous steel beam bridges. The long continuous steel beam bridge described in this application includes at least two steel beam segments. The steel beam segments in this application are steel box girder structures, including flanges, top plates, webs, and bottom plates. In actual construction, the steel beam segments are hoisted to the jacking assembly platform, and then jacked up one by one to fix adjacent steel beam segments. After all steel beam segments are jacked into place, the fixed parts between adjacent steel beam segments are removed and disconnected. During this process, adjacent steel beam segments will generate a large bending moment at the permanent pier support. In order to eliminate this bending moment, this application sets up a disconnection device between adjacent steel beam segments. The disconnection device applies a pre-tension force between adjacent steel beam segments to offset the large negative bending moment value at the top of the continuous beam pier, and changes the constraint situation between the connections. At the same time, when contacting the temporary fixed connection between adjacent steel beam segments, the disconnection device can also adjust the force between adjacent steel beam segments to ensure that the stress between adjacent steel beam segments can be effectively dissipated and avoid safety hazards.

[0061] The specific steps for disconnecting long continuous steel beam bridges described in this application are as follows:

[0062] S1. Erect a jacking assembly platform, install walking jacking equipment on the jacking assembly platform and permanent pier, assemble guide beams on the jacking assembly platform, and jack out the guide beams after the guide beams are assembled.

[0063] This application constructs a jacking and assembly platform on the bank side of the steel beam bridge. The steel beam segments complete the installation of temporary fixing and disassembly devices on the jacking and assembly platform. The walking jacking equipment is used to jack the steel beam segments to move along the bridge direction to the set position. The walking jacking equipment in this application is a conventional structure and will not be described in detail here.

[0064] The guide beam is a guide structure installed at the front end of the first steel beam segment along the bridge direction, which facilitates the longitudinal jacking of the entire steel beam bridge during the jacking construction process;

[0065] S2. Hoist the first steel beam segment to the jacking assembly platform, adjust the position of the first steel beam segment and then weld it to the guide beam. After completion, push it out of the jacking assembly platform.

[0066] The guide beam is directly welded and fixed to the front end of the first steel beam segment along the bridge direction. After welding, it can be pushed out of the jacking and assembly platform by a walking jacking device so that the jacking and assembly platform can support the second steel beam segment.

[0067] S3. Hoist the second steel beam segment to the jacking assembly platform, install the disconnection device between the first steel beam segment and the second steel beam segment, and temporarily fix the connecting steel beam segments.

[0068] The first and second steel beam segments need to be temporarily fixed and connected, that is, the first and second steel beam segments are connected into one piece to facilitate the subsequent jacking operation of the walking jacking equipment in the longitudinal direction of the bridge.

[0069] The disconnection device of this application is installed between all adjacent steel beam segments. The disconnection device can apply a longitudinal tension force to the adjacent steel beam segments, thereby offsetting the bending moment between the adjacent steel beam segments by applying a longitudinal tension force to the adjacent steel beam segments.

[0070] S4. Connect the remaining steel beam segments in sequence according to steps S2 and S3 and push them to the design position in sequence.

[0071] S5. Use the disconnection device to adjust the tension between adjacent steel beam segments to eliminate bending moment, release the temporary fixed connection between adjacent steel beam segments, release the tension of the disconnection device, dismantle the disconnection device, and complete the jacking construction of the long continuous steel beam bridge.

[0072] After all steel beam segments are pushed into place, the uncoupling device of this application begins to pre-tension the steel beam segments. By applying a pre-tensioning force along the longitudinal direction to adjacent steel beam segments, it offsets the large negative bending moment value at the top of the continuous beam pier, changes the constraint situation between the segments, reduces the difficulty of releasing the temporary fixed connection, and avoids the safety risks that arise when adjacent steel beam segments are uncoupled.

[0073] In some embodiments of this application, the installation of the above-described disconnection device has been optimized, specifically, as follows: Figures 2-4As shown, the disconnection device of this application includes a steel beam top plate, which is installed between adjacent steel beam segments. The two ends of the steel beam top plate in the longitudinal direction are fixed to the top plates of the two sets of steel beam segments by bolt structures. In this embodiment, multiple screw holes are opened on the top plates of adjacent steel beam segments, and multiple corresponding screw hole structures are opened on the steel beam top plate. During installation, the bolts are passed through the corresponding screw holes in sequence to fix the steel beam top plate to the top plates of adjacent steel beam segments. The steel beam top plate is the load-bearing foundation of the entire disconnection device. The steel beam top plate is a structure installed on the top plates of the steel beam segments. That is to say, the disconnection device in this embodiment is installed on the top plates of the steel beam segments. This installation position is convenient for installation and dismantling, and also convenient for subsequent adjustment of tension.

[0074] Two sets of tensioning structures are installed on the top plate of the steel beam, positioned on either side of the top plate along the bridge direction. These structures are located above adjacent steel beam segments, corresponding one-to-one. Each tensioning structure includes two spaced-apart limiting steel plates along the bridge direction. These plates are vertically fixed to the top plate of the steel beam, and a matching sleeve is installed between them. The axial ends of the matching sleeve are fixed to the two limiting steel plates. In the same set of two limiting steel plates, the plate closer to the other tensioning structure has an adjusting rod sleeve on its outer side, while the plate further away has a through-hole jack on its outer side. The through-hole jack is fixed to the limiting steel plate. The through-hole jack, matching sleeve, and adjusting rod sleeve are all coaxially arranged, with their axial directions all along the bridge direction.

[0075] The tie rod passes through two sets of tensioning structures along the bridge direction. In fact, the tie rod passes through the through-hole jack, matching sleeve and tie rod sleeve of the tensioning structure along the bridge direction. The tie rod passes through the through-hole jacks on both sides at both ends along the bridge direction.

[0076] In use, by adjusting the tie rods with two sets of through-hole jacks to tension the steel beams along the bridge direction, the pretension force of the two adjacent steel beam segments can be adjusted, which can conveniently cancel the bending moment of the steel beam segments at the permanent pier support.

[0077] In some other embodiments of this application, the method for temporarily fixing the connecting steel beam segments has been optimized. In this embodiment, adjacent steel beam segments are temporarily fixedly connected on the jacking assembly platform by welding temporary connecting steel plates between the flanges, top plates, bottom plates and webs of adjacent steel beam segments to temporarily fix the adjacent steel beam segments.

[0078] The temporary connection structure between adjacent steel beam segments can be a temporary connecting steel plate or other temporary fixed connection structure, as long as it can stably fix the adjacent steel beam segments in a temporary way.

[0079] In this embodiment, the temporary connecting steel plates between the wing plates, top plates, web plates, and bottom plates are independent of each other, which facilitates the subsequent removal of the temporary connecting steel plates.

[0080] In a preferred embodiment of this application, the method of adjusting the tension between adjacent steel beam segments using a disconnection device to eliminate bending moment in step S5 above has been optimized. Specifically, this embodiment uses two sets of through-hole jacks of the disconnection device to tension the tie rods along the bridge direction, and adjusts the pre-tension of the tie rods of the through-hole jacks according to the structure of the steel beam segments until the bending moment of the adjacent steel beam segments at the permanent pier support is eliminated.

[0081] The pretension force of the through-hole jack's adjusting rod is actually calculated using the following formula:

[0082]

[0083] M=αqL 2

[0084] Where: M—the bending moment generated by the steel beam segment at the permanent pier support;

[0085] S—the distance between the tie rod and the horizontal centroidal axis of the steel beam, obtained by measurement;

[0086] q—the load intensity of the steel beam segment's self-weight along the length of the steel beam segment, calculated using the dimensions of the steel beam and its cross-section. q is a uniformly distributed load in mechanics.

[0087] L – the span of the steel beam segment, obtained through measurement;

[0088] α — The continuous pier top bending moment coefficient determined based on the number of spans of the steel beam segments.

[0089] The bending moment coefficient α at the top of the continuous pier is determined based on the number of spans of the steel beam segments. Specifically, the bending moment coefficient α at the top of the continuous pier is calculated according to the following formula:

[0090] When the continuous steel girder bridge is a two-span continuous beam...

[0091] α=β(L-20) 0.07

[0092] When the continuous steel girder bridge is a continuous beam with three or more spans...

[0093]

[0094] Where: α——Continuous pier top bending moment coefficient determined based on the number of spans of the steel beam segments;

[0095] β—First empirical value, in this embodiment β is taken as 0.08 to 0.09;

[0096] L – the span of the steel beam segment;

[0097] γ—Second empirical value; in this embodiment, γ is taken as (0.45~0.55)*10. -2 .

[0098] Based on the above construction calculations, the pretension force of the disconnection device is calculated, and then the through jacks between adjacent steel beam segments are adjusted according to the pretension force. This can effectively counteract the bending moment generated by the steel beam segments at the permanent pier support.

[0099] In a further embodiment of this application, the method for releasing the temporary fixed connection between adjacent steel beam segments in step S5 above has been optimized. In this embodiment, after all steel beam segments are pushed into place, the temporary connecting steel plates of the steel beam segments need to be removed. The removal in this embodiment is carried out in a predetermined order. Generally speaking, when unconnecting adjacent steel beam segments and removing the unconnection devices, the process proceeds sequentially from both ends of the steel beam bridge to the mid-span. That is, the temporary connecting steel plates and unconnection devices between adjacent steel beam segments on the bank side are removed first, and then the process proceeds towards the mid-span. This removal method allows stress or bending moment to dissipate as much as possible towards the bank side, avoiding the safety hazards that might arise from removing the mid-span segments first.

[0100] Individually, the removal of the temporary connecting steel plates in this embodiment also follows a predetermined sequence: first, the temporary connecting steel plates between the flanges of adjacent steel beam segments are cut; second, the temporary connecting steel plates between the top plates of adjacent steel beam segments are cut; then, the temporary connecting steel plates between the bottom plates of adjacent steel beam segments are cut; and finally, the temporary connecting steel plates between the web plates of adjacent steel beam segments are cut. Essentially, the plates on both sides are removed first, then from top to bottom, and finally the middle plates are removed. This removal sequence maximizes safety during the removal process and facilitates adjustments.

[0101] During the removal of the temporary connecting steel plate, this embodiment will adjust the tension of the dismantling device in real time to match the removal process of the temporary connecting steel plate. Specifically, in this embodiment, the temporary fixed connection between the flanges of adjacent steel beam segments is first cut, and the force exerted by the uncoupling device on the adjacent steel beam segments is adjusted to a first tension force, which is 0.8 times the pre-tension force when the uncoupling device eliminates the bending moment of the adjacent steel beam segments; the temporary fixed connection between the top plates of adjacent steel beam segments is cut, and the force exerted by the uncoupling device on the adjacent steel beam segments is adjusted to a second tension force, which is 0.55 times the pre-tension force when the uncoupling device eliminates the bending moment of the adjacent steel beam segments; the temporary fixed connection between the bottom plates of adjacent steel beam segments is cut, and the force exerted by the uncoupling device on the adjacent steel beam segments is adjusted to a third tension force, which is 0.3 times the pre-tension force when the uncoupling device eliminates the bending moment of the adjacent steel beam segments; the temporary fixed connection between the web plates of adjacent steel beam segments is cut, and the force exerted by the uncoupling device on the adjacent steel beam segments is adjusted to a fourth tension force, which is 0.

[0102] The first, second, and third tensions are determined based on the pretension force of the disconnection device used to counteract the bending moment generated by the steel beam segment at the permanent pier support. After obtaining the pretension force T as described above, the subsequent first, second, and third tensions can be obtained. In actual applications, the multiples are not limited to those mentioned above, as long as the requirements are met.

[0103] This embodiment gradually reduces the tension force on adjacent steel beam segments while gradually removing the temporary connecting steel plates. This effectively transforms the constraint situation between the joints, ensures the safety of removing the temporary connecting steel plates, and is simple, quick, and highly adjustable, thus effectively improving the safety and integrity of the structure during construction.

[0104] During actual construction, auxiliary construction structures such as the jacking assembly platform, temporary piers, and temporary trestle bridges are first erected. Walking jacking equipment is installed on the jacking assembly platform and permanent piers. The walking jacking equipment is debugged to ensure stable operation. The guide beam is assembled on the jacking assembly platform. After the assembly of the guide beam is completed, the walking jacking equipment is used to jack out the jacking assembly platform.

[0105] The first steel beam segment is transported to the vicinity of the launching and assembly platform. The first steel beam segment is hoisted to the launching and assembly platform using hoisting equipment. The first steel beam segment is repositioned on the launching and assembly platform. Then, the guide beam is welded and fixed to the front end of the first steel beam segment along the bridge direction. Finally, the first steel beam segment and the guide beam are pushed out of the launching and assembly platform using a walking launching device.

[0106] The secondary steel beam segments are transported to the vicinity of the launching and assembly platform. Using hoisting equipment, these segments are lifted onto the platform, where they are repositioned. Then, temporary fixing and disconnection devices are installed between the secondary and primary steel beam segments. Specifically, temporary connecting steel plates are welded between the flanges, top plates, bottom plates, and webs of the secondary and primary steel beam segments to temporarily fix adjacent segments. The top plates of the secondary and primary steel beam segments are then installed using bolts. Finally, tie rods are passed through two sets of through-hole jacks, which are used to tension the tie rods, completing the installation of the temporary fixing and disconnection devices between the secondary and primary steel beam segments.

[0107] Following the above procedure, install the other steel beam segments in sequence until all steel beam segments are pushed to the designated position;

[0108] Tension adjustment is performed on the through-hole jacks of each set of disconnection devices, and the pre-tension force of the through-hole jacks relative to the adjusting rods is calculated according to the following formula:

[0109]

[0110] M=αqL 2

[0111] Where: M—the bending moment generated by the steel beam segment at the permanent pier support;

[0112] S—the distance between the tie rod and the horizontal centroidal axis of the steel beam;

[0113] q — Load intensity of the self-weight of the steel beam segment along the length of the steel beam segment;

[0114] L – the span of the steel beam segment;

[0115] α — The continuous pier top bending moment coefficient determined based on the number of spans of the steel beam segments.

[0116] The bending moment coefficient α at the top of the continuous pier is calculated using the following formula:

[0117] When the continuous steel girder bridge is a two-span continuous beam...

[0118] α=β(L-20) 0.07

[0119] When the continuous steel girder bridge is a continuous beam with three or more spans...

[0120]

[0121] Where: α——Continuous pier top bending moment coefficient determined based on the number of spans of the steel beam segments;

[0122] β—First empirical value, in this embodiment β is taken as 0.08 to 0.09;

[0123] L – the span of the steel beam segment;

[0124] γ—Second empirical value; in this embodiment, γ is taken as (0.45~0.55)*10. -2 .

[0125] Tension the tie rods according to the calculated pretension force until the bending moment generated by the steel beam segment at the permanent pier support is canceled out.

[0126] The removal of temporary connecting steel plates begins. First, the temporary fixed connections between the flanges of adjacent steel beam segments are cut, and the force exerted by the disconnection device on the adjacent steel beam segments is adjusted to the first tension force, which is 0.8 times the pre-tension force. Next, the temporary fixed connections between the top plates of adjacent steel beam segments are cut, and the force exerted by the disconnection device on the adjacent steel beam segments is adjusted to the second tension force, which is 0.55 times the pre-tension force. Then, the temporary fixed connections between the bottom plates of adjacent steel beam segments are cut, and the force exerted by the disconnection device on the adjacent steel beam segments is adjusted to the third tension force, which is 0.3 times the pre-tension force. Finally, the temporary fixed connections between the web plates of adjacent steel beam segments are cut, and the force exerted by the disconnection device on the adjacent steel beam segments is adjusted to the fourth tension force, which is zero.

[0127] After all the tension of the tie rods has been released, remove the bolts on the top plate of the steel beam to complete the dismantling of the disconnection device;

[0128] During the demolition work, the first step was to dismantle the steel beam segments between two adjacent spans on the shore side, such as... Figure 6 Then, proceed with the dismantling of the a and c sections of the mid-span steel beam segment, as follows: Figure 6 The b-joint shown in the figure.

[0129] The bridge direction indicated in this application Figure 1 The left and right directions in this application, the vertical direction refers to... Figure 1 The up and down directions in the middle.

[0130] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method for disconnecting long continuous steel beam bridges, characterized in that: Follow these steps: S1. Erect a jacking assembly platform, install walking jacking equipment on the jacking assembly platform and permanent pier, assemble guide beams on the jacking assembly platform, and jack out the guide beams after the guide beams are assembled. S2. Hoist the first steel beam segment to the jacking assembly platform, adjust the position of the first steel beam segment and then weld it to the guide beam. After completion, push it out of the jacking assembly platform. S3. Hoist the second steel beam segment to the jacking assembly platform, install the disconnection device between the first steel beam segment and the second steel beam segment, and temporarily fix the connecting steel beam segments. S4. Connect the remaining steel beam segments in sequence according to steps S2 and S3 and push them to the design position in sequence. S5. Use the disconnection device to adjust the tension between adjacent steel beam segments to eliminate bending moment, release the temporary fixed connection between adjacent steel beam segments, release the tension of the disconnection device, dismantle the disconnection device, and complete the jacking construction of the long continuous steel beam bridge. In step S3, the method for installing the disconnection device between the first and second steel beam segments includes: installing a steel beam top plate between adjacent steel beam segments; fixing the two ends of the steel beam top plate along the bridge direction to the top plates of the two sets of steel beam segments respectively by bolts; arranging two sets of tensioning structures on the steel beam top plate, which are placed on the first and second steel beam segments; the tensioning structures include through-hole jacks fixed to the steel beam top plate; the two sets of through-hole jacks are arranged at intervals along the bridge direction and correspond one-to-one with the two sets of steel beam segments; passing the adjusting rods along the bridge direction through the two sets of through-hole jacks in sequence; and tensioning the adjusting rods with the two sets of through-hole jacks to complete the installation of the disconnection device.

2. The method for disconnecting a long continuous steel beam bridge as described in claim 1, characterized in that: In step S3, the method for temporarily fixing the connecting steel beam segments includes: welding temporary connecting steel plates between the flanges, top plates, bottom plates and webs of adjacent steel beam segments to temporarily fix the adjacent steel beam segments.

3. The method for disconnecting a long continuous steel beam bridge as described in claim 1, characterized in that: In step S5, the method of using the disconnection device to adjust the tension between adjacent steel beam segments to eliminate the bending moment includes: using the two sets of through-hole jacks of the disconnection device to tension the tie rods in the bridge direction, and adjusting the pre-tension of the tie rods of the through-hole jacks according to the structure of the steel beam segments until the bending moment of the adjacent steel beam segments at the permanent pier support is eliminated.

4. The method for disconnecting a long continuous steel beam bridge as described in claim 3, characterized in that: Calculate the pretension force of the through-hole jack relative to the tie rod using the following formula: Where: M—the bending moment generated by the steel beam segment at the permanent pier support; S—the distance between the tie rod and the horizontal centroidal axis of the steel beam; q — Load intensity of the self-weight of the steel beam segment along the length of the steel beam segment; L – the span of the steel beam segment; α — The continuous pier top bending moment coefficient determined based on the number of spans of the steel beam segments.

5. The method for disconnecting a long continuous steel beam bridge as described in claim 4, characterized in that: The bending moment coefficient α at the top of the continuous pier is calculated using the following formula: When the continuous steel girder bridge is a two-span continuous beam... When the continuous steel girder bridge is a continuous beam with three or more spans... Where: α——Continuous pier top bending moment coefficient determined according to the number of spans of steel beam segments; β—First empirical value; L – the span of the steel beam segment; γ — Second empirical value.

6. The method for disconnecting a long continuous steel beam bridge as described in claim 1, characterized in that: In step S5, the method for releasing the temporary fixed connection between adjacent steel beam segments includes: first cutting the temporary fixed connection between the flanges of the adjacent steel beam segments, then cutting the temporary fixed connection between the top plates of the adjacent steel beam segments, then cutting the temporary fixed connection between the bottom plates of the adjacent steel beam segments, and finally cutting the temporary fixed connection between the web plates of the adjacent steel beam segments.

7. The method for disconnecting a long continuous steel beam bridge as described in claim 6, characterized in that: In step S5, the method for releasing the tension of the disconnection device includes: first, cutting the temporary fixed connection between the flanges of adjacent steel beam segments, and adjusting the force exerted by the disconnection device on the adjacent steel beam segments to a first tension; cutting the temporary fixed connection between the top plates of adjacent steel beam segments, and adjusting the force exerted by the disconnection device on the adjacent steel beam segments to a second tension; cutting the temporary fixed connection between the bottom plates of adjacent steel beam segments, and adjusting the force exerted by the disconnection device on the adjacent steel beam segments to a third tension; cutting the temporary fixed connection between the web plates of adjacent steel beam segments, and adjusting the force exerted by the disconnection device on the adjacent steel beam segments to a fourth tension; the first tension > the second tension > the third tension > the fourth tension, and the fourth tension is 0.

8. The method for disconnecting a long continuous steel beam bridge as described in claim 7, characterized in that: The first tension is 0.8 times the pretension force when the uncoupling device eliminates the bending moment of the adjacent steel beam segment; the second tension is 0.55 times the pretension force when the uncoupling device eliminates the bending moment of the adjacent steel beam segment; and the third tension is 0.3 times the pretension force when the uncoupling device eliminates the bending moment of the adjacent steel beam segment.

9. The method for disconnecting a long continuous steel beam bridge as described in claim 1, characterized in that: When disconnecting and removing the disconnection device between adjacent steel beam segments, the process is carried out sequentially from both ends of the steel beam bridge to the middle of the span.

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