A method for synchronously lifting an overall multi-span bridge based on independent support

Abstract

This invention relates to a method for the synchronous lifting of a multi-span bridge based on independent supports. The method comprises the following steps: S1: Installing a bridge synchronous lifting system, where multiple lifting devices in the system support the opposite ends of two adjacent sections of the bridge's superstructure via lifting beams; S2: The multiple lifting devices synchronously lift the various sections of the bridge's superstructure; S3: Installing multiple cap beams; S4: The multiple lifting devices lower the various sections of the bridge's superstructure onto the multiple cap beams; S5: Modifying the bridge abutments; S6: Removing the multiple support frames and lifting devices. The advantages of this invention are its simplicity, rational design, and ability to synchronously adjust the elevation of the entire bridge deck without removing the decorative structure, while preserving the original bridge structure, significantly reducing construction costs, waste emissions, and environmental impact.

Description

Technical Field

[0001] This invention relates to the field of bridge reconstruction technology, specifically to a method for the overall synchronous lifting of multi-span bridges based on independent supports. Background Technology

[0002] In waterway renovation and highway expansion projects, the elevation of bridges crossing rivers and highways often fails to meet operational requirements. These bridges still serve a transportation function. Demolishing and rebuilding these bridges could upgrade their functionality, but it would generate a large amount of solid waste, damage the environment, and result in a long construction period and high overall costs. Adjusting the bridge deck elevation through engineering methods can preserve the original bridge structure, significantly reduce construction costs, decrease waste emissions, and mitigate adverse environmental impacts.

[0003] Currently, the main method for adjusting the elevation of old bridges is the synchronous jacking method. For overpasses, the modular vehicle jacking method can also be used to adjust the bridge deck elevation.

[0004] 1) Synchronous jacking to adjust the bridge deck elevation involves setting up a jacking construction support under the bridge and using two sets of vertical jacks to raise or lower the superstructure of the bridge by alternating jacking.

[0005] 2) Modular vehicle jacking method: Self-propelled modular vehicle sets are used to carry jacking supports to the bottom of the bridge to support the beams. The elevation of the superstructure of the bridge is adjusted by jacking and lowering the modular vehicle sets.

[0006] The above methods have the following drawbacks: (1) The demolition and reconstruction of old bridges involves a large amount of work, high cost, a lot of solid waste, and long traffic interruption time, which is neither economical nor environmentally friendly. my country has a large number of bridges, and a large number of bridges need to be raised and renovated every year.

[0007] (2) When constructing a bridge with synchronous jacking, there are many jacks and the control is difficult. The jacking construction control accuracy is affected by multiple factors such as the fabrication and installation accuracy of temporary supports, foundation settlement and uneven settlement, and distribution beam stiffness. All jacking and support operations are carried out directly under the bridge, resulting in high operational safety risks. The jacking construction uses two sets of jacks to alternate jacking operations, with a small single jacking stroke, a large workload for support operations, and a long jacking operation cycle. For some bridges with small clearance under the bridge, the installation of jacking supports is difficult due to limited working space. During bridge reconstruction, the presence of jacking supports compresses the working space for the reconstruction of the bridge substructure.

[0008] (3) The modular vehicle lifting method is expensive and is only applicable to bridges with low height, flat ground underneath, and direct access by road.

[0009] (4) "A whole-span bridge lowering and demolition system based on ground support and its construction method" This method is used for bridge demolition, and the scope of lowering and demolishing the superstructure is concentrated within a single span bridge; it requires cutting the beam and is only applicable to continuous box girder bridges, rigid frame bridges and other bridge types; this method does not consider the beam displacement and spatial posture during construction, and the construction control accuracy requirements are low. Summary of the Invention

[0010] This invention addresses the technical problems existing in the prior art by providing a method for the overall synchronous lifting of multi-span bridges based on independent support.

[0011] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A method for the overall synchronous lifting of multi-span bridges with independent supports includes the following specific steps: S1: Install a bridge synchronous lifting system, so that the lifting beams on multiple lifting devices in the bridge synchronous lifting system respectively support the opposite ends of two adjacent sections of the superstructure of the bridge. S2: The multiple lifting devices respectively drive the synchronous lifting of multiple sections of the superstructure of the bridge; S3: Install multiple cap beams; S4: The multiple lifting devices respectively drive multiple sections of the superstructure of the bridge to fall onto the multiple cap beams; S5: Renovate the bridgehead.

[0012] The beneficial effects of this invention are as follows: During construction, S1: Install a bridge synchronous lifting system, so that the lifting beams on multiple lifting devices in the bridge synchronous lifting system support the opposite ends of two adjacent sections of the superstructure of the bridge; S2: The multiple lifting devices drive the multiple sections of the superstructure of the bridge to be lifted synchronously; S3: Install multiple cap beams; S4: The multiple lifting devices drive the multiple sections of the superstructure of the bridge to fall onto the multiple cap beams; S5: Modify the bridgehead.

[0013] The method of this invention is simple and reasonably designed. It can adjust the elevation of the entire bridge deck simultaneously without removing the decorative structure on the bridge deck, while also preserving the original bridge structure, which greatly reduces construction costs, waste emissions, and adverse environmental impacts.

[0014] Based on the above technical solution, the present invention can be further improved as follows.

[0015] Furthermore, step S1 includes the following specific steps: S11: Construction of multiple enlarged foundations; S12: Install multiple support frames; S13: Install multiple of the aforementioned lifting devices.

[0016] The beneficial effect of adopting the above-mentioned further scheme is that during the construction process, the foundation is expanded according to the number of bridge piers, and multiple support frames and multiple lifting devices are installed at the same time to complete the installation of the bridge synchronous lifting system, so as to enable the synchronous lifting of multiple bridge deck sections in the subsequent process.

[0017] Furthermore, S11 includes the following specific steps: S111: Cofferdams are constructed in the corresponding water areas below multiple piers of the bridge, and the water in the cofferdam areas is pumped out. S112: Harden the foundation of each of the multiple cofferdam areas and drive in spiral ground nail piles; S113: Reinforcing steel frames are tied in the multiple cofferdam areas respectively, and concrete is injected. After the concrete solidifies, the enlarged foundation is formed.

[0018] The advantages of adopting the above-mentioned further scheme are that the method is simple and the design is reasonable. The construction of the enlarged foundation is completed by cofferdam, dewatering, base hardening, driving in spiral ground nail piles, binding steel bars and pouring concrete. The construction is convenient and can ensure the stability of the entire bridge synchronous lifting system installation, so as to ensure the normal progress of subsequent bridge multi-section bridge deck synchronous lifting operations.

[0019] Furthermore, S1 also includes S14: installation of the monitoring system.

[0020] The advantages of adopting the above-mentioned further scheme are that the method is simple, the design is reasonable, and the monitoring system can monitor the entire process of bridge lifting operations in real time, ensuring the smooth progress of bridge lifting operations.

[0021] Furthermore, step S2 includes the following specific steps: S21: The bridge is debugged and test-lifted; S22: The bridge is upgraded in stages.

[0022] The beneficial effects of adopting the above-mentioned further scheme on the debugging and trial lifting of the bridge are as follows: First, to check whether the bearing capacity of the temporary supports meets the requirements; second, to check whether the lifting system is reasonable and whether the lifting capacity meets the requirements; third, to check the constraint of the superstructure, that is, whether the constraints are released; and fourth, to ensure that the gap between the temporary facilities and the permanent structure is filled tightly, and that the deformation of the two is coordinated during the lifting process, so that the impact on the stress system of the superstructure is controlled. In addition, the bridge adopts a staged lifting method to ensure the stability and safety of the simultaneous lifting of multiple sections of the superstructure.

[0023] Furthermore, step S21 includes the following specific steps: The lifting devices are raised and tested until all connections are reliable, and then the lifting devices are tested again.

[0024] The advantages of adopting the above-mentioned further scheme are that the method is simple, the design is reasonable, and it ensures the stability and safety of the synchronous lifting of multiple sections of the bridge superstructure.

[0025] Furthermore, the specific steps of the pilot-scale improvement in S21 include: The bridge's superstructure was lifted by 1-3 cm using multiple lifting devices, and temporary support steel plates were inserted to support each section. At the same time, the stress and displacement of the bridge, the multiple support frames, and the multiple lifting devices were thoroughly inspected.

[0026] The advantages of adopting the above-mentioned further solution are that the method is simple and the design is reasonable. While lifting the bridge, temporary support steel plates are inserted, which can not only ensure the stable and synchronous lifting of multiple sections of the superstructure of the bridge, but also comprehensively check the stress and displacement status of the bridge, multiple support frames and multiple lifting devices.

[0027] Furthermore, step S22 includes the following specific steps: The bridge's superstructure is simultaneously and progressively lifted in stages using multiple lifting devices, with each stage lifting (1-50) cm. For each stage of lifting, a fall protection support of corresponding thickness is added below the bridge bearing. Construction monitoring is conducted at each stage until the bridge reaches the designed height.

[0028] The advantages of adopting the above-mentioned further scheme are that the method is simple and the design is reasonable. It can not only complete the synchronous and stable lifting of multiple sections of the bridge superstructure, but also ensure the safety of the operation, thereby ensuring the personal safety of the operators, which is safe and reliable.

[0029] Furthermore, S5 includes the following specific steps: Construct a retaining structure at the bridge abutment so that the top of the retaining structure is flush with the upper surface of the bridge.

[0030] The advantages of adopting the above-mentioned further scheme are that the method is simple and the design is reasonable. After the bridge is lifted, both ends of the bridgehead are raised off the ground. The bridgehead retaining structure is used to make the upper surface of the bridge flush with the ground at the bridgehead, ensuring the flatness of the bridge surface.

[0031] Furthermore, it also includes S6: removing multiple of the support frames and multiple of the lifting devices.

[0032] The advantages of adopting the above-mentioned further scheme are that the method is simple, the design is reasonable, and multiple support frames and multiple lifting devices can be removed in sequence after construction, making construction convenient. Attached Figure Description

[0033] Figure 1 This is a flowchart of the construction method of the present invention; Figure 2 This is the overall elevation layout of the temporary steel support in this invention; Figure 3 This is the overall plan layout of the temporary steel support in this invention; Figure 4 This is a side view of the steel support, hoisting system, and bridge landscaping decoration at the bridge piers in this invention. Figure 5 This is an elevation view of the steel support and hoisting system at the bridge pier in this invention. Figure 6 This is a side view of the temporary steel support and hoisting system at the bridge pier in this invention; Figure 7 This is a plan view of the temporary steel support and hoisting system at the bridge pier in this invention.

[0034] The attached diagram lists the components represented by each number as follows: 1. Lifting device; 2. Hoisting beam; 3. Bridge; 4. Spread foundation; 5. Spiral ground stake; 6. Support frame; 7. Limiting device; 8. Landscape decoration. Detailed Implementation

[0035] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0036] In the description of this application, 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0037] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this technology based on the specific circumstances.

[0038] In the description of this application, spatial relation terms such as "below," "under," "below," "below," "above," "over," etc., are used herein to describe the relationship between one element or feature shown in the figures and other elements or features. It should be understood that, in addition to the orientation shown in the figures, spatial relation terms also include different orientations of the device in use and operation. For example, if the device in the figures is flipped, an element or feature described as "below" or "under" or "below" of other elements or features will be oriented "above" other elements or features. Therefore, the exemplary terms "below" and "under" can include both upper and lower orientations. Furthermore, the device may also include other orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptive terms used herein are interpreted accordingly.

[0039] In the description of this application, the term "for example" is used to mean "used as an example, illustration, or description." Any embodiment described as "for example" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use the invention. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that the invention can be made without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the invention with unnecessary detail. Therefore, the invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0040] Example 1 like Figures 1 to 7 As shown in the figure, this embodiment provides a method for the overall synchronous lifting of a multi-span bridge based on independent supports, including the following specific steps: S1: Install a bridge synchronous lifting system, so that the lifting beams 2 on the multiple lifting devices 1 in the bridge synchronous lifting system support the opposite ends of two adjacent sections of the superstructure of the bridge 3 respectively. S2: The multiple lifting devices 1 respectively drive the multiple sections of the superstructure of the bridge 3 to be lifted synchronously; S3: Install multiple cap beams; S4: The multiple lifting devices 1 respectively drive the multiple sections of the superstructure of the bridge 3 to fall onto the multiple cap beams; S5: Renovate the bridgehead.

[0041] During construction, S1: Install a bridge synchronous lifting system, so that the lifting beams 2 on multiple lifting devices 1 in the bridge synchronous lifting system support the opposite ends of two adjacent sections of the superstructure of the bridge 3; S2: The multiple lifting devices 1 drive the multiple sections of the superstructure of the bridge 3 to be lifted synchronously; S3: Install multiple cap beams; S4: The multiple lifting devices 1 drive the multiple sections of the superstructure of the bridge 3 to fall onto the multiple cap beams; S5: Modify the bridge abutment.

[0042] Preferably, in this embodiment, each of the above-mentioned lifting beams 2 has a limiting device 7 installed at both ends opposite to each other. The two pairs of limiting devices 7 limit the bridge 3 during the lifting process to ensure that the bridge 3 is lifted stably.

[0043] In addition, the aforementioned limiting device 7 can be a limiting block or the like.

[0044] The bridge synchronous lifting construction method provided in this embodiment is applicable to multi-span bridges, and the bridge has landscape decorations 8 that cannot be removed, so the bridge needs to be lifted synchronously as a whole.

[0045] Based on the above scheme, the installation process of the above-mentioned cap beam is as follows: The original retaining blocks and bearing stones on top of the bridge piers were removed using an electric pick, and the top and sides of the cap beam were ground smooth and cleaned. The steel cap beams were fabricated by a professional processing plant. The installation process of the cap beams is as follows: (1) Drilling anchor bolts 1) Positioning Mark the anchor bolt drilling locations, hole spacing, and model on the top surface of the cap beam according to the design position.

[0046] 2) Drilling Use an impact drill to drill holes according to the marked positions. When encountering interference from reinforcing bars, the hole position can be moved appropriately, but the error should not exceed ±10mm.

[0047] 3) Clean the hole ① For anchor holes of chemical anchors, the holes should be cleaned with a stiff brush first, and then clean compressed air should be used to remove dust.

[0048] ② The anchor holes should be emptied at least 3 times. If necessary, the anchor holes should be wiped clean with industrial alcohol.

[0049] ③ The borehole wall should be free of oil stains, and its dryness should meet the design requirements. ④ The surface of the anchoring substrate should be smooth and flat, free of dust and debris.

[0050] 4) Implanting chemical anchors Place the chemical anchoring agent into the hole, rotate and insert the anchor until the designed depth is reached, and ensure that the gap between the anchor and the hole wall is basically uniform. Correct the position and verticality of the anchor. The presence of adhesive overflowing from the hole opening is used as a visual inspection sign that the adhesive injection is qualified.

[0051] 5) Allow to cure statically Before the adhesive has fully cured, the anchor bolts must not be touched or vibrated to avoid affecting their bonding performance, and there should be no standing water near the holes.

[0052] (2) Steel cap beam installation The steel cap beams were transported in sections to the bottom of the beams at the piers. At the ends of the original cap beams, hoisting beams were installed on the bridge deck. The steel cap beams were then lifted by chain hoists and laterally moved to the top of the original cap beams.

[0053] The steel cap beams were assembled and connected in sections by welding.

[0054] (3) Pressure injection 1) Pressure injection adhesive is used between the steel cap beam and the original concrete cap beam, and Class A adhesive is used for the adhesive.

[0055] 2) Install adhesive injection holes and venting holes on the steel cap beam according to the site location.

[0056] 3) First, seal the area around the steel cap beam with sealant, leaving vent holes. After venting and leak testing in the grouting holes, press in the adhesive at a pressure of not less than 0.1 MPa. Stop pressurizing when grout appears in the vent holes, and seal them with edge sealant. Then maintain a lower pressure for more than 10 minutes.

[0057] 4) After the adhesive has solidified, seal the injection hole and vent hole with sealant.

[0058] To ensure accurate beam placement after the superstructure is raised, a gapless beam placement technique is employed. A gapless beam placement device is installed inside the steel structure of the heightened section of the cap beam. Once the heightened section of the cap beam is positioned, a new support is installed on the support pad. The elevation of the support pad is adjusted using the elevation adjustment function of the gapless beam placement device, ensuring that the top surface of the support pad is horizontal and the top and bottom surfaces of the support are horizontally and tightly attached to the bottom of the beam and the top surface of the pad, respectively. Then, the gapless beam placement device is locked, and the steel structure of the support pad is fixed.

[0059] The method described in this embodiment is simple and reasonably designed. It can simultaneously adjust the elevation of the entire bridge deck without removing the decorative structure on the bridge deck, while also preserving the original bridge structure, which greatly reduces construction costs, waste emissions, and adverse environmental impacts.

[0060] Example 2 Based on Example 1, in this example, step S1 includes the following specific steps: S11: Construction of multiple enlarged foundations 4; S12: Install multiple support frames 6; S13: Install multiple lifting devices 1.

[0061] During construction, the foundation 4 is enlarged according to the number of bridge piers, and multiple support frames 6 and multiple lifting devices 1 are installed at the same time to complete the installation of the synchronous lifting system of bridge 3, so as to enable the synchronous lifting of multiple sections of bridge deck of bridge 3 in the future.

[0062] Based on the above scheme, in S12, each of the above support frames 6 is composed of main parts such as steel pipe columns, horizontal bracing, diagonal bracing, longitudinal and transverse distribution beams, beam bottom support beam 2, spreader beam, pad plate, flange, and connecting bolts.

[0063] In addition, the support frame 6 uses Ø609*10mm steel pipe columns, and the distribution beam is composed of double-splittered 56a I-beams.

[0064] Furthermore, a 25t truck crane is used in conjunction with a lifting support frame made of 6 materials for assembly.

[0065] The lifting system uses reinforced concrete spread foundations 4, each of which is centrally compressed. The bearing capacity of the spread foundation 4 is treated to be no less than 110 kPa. The calculated bearing capacity of the spread foundation 4 at each pier is shown in Table 1 below.

[0066] Table 1 Bearing capacity of the spread foundation at each pier

[0067] As can be seen from the table above, the vertical bearing capacity of the enlarged foundation 4 meets the requirements.

[0068] Example 3 Based on Embodiment 2, in this embodiment, S11 includes the following specific steps: S111: Cofferdams are constructed in the corresponding water areas below the three piers of the bridge, and the water in the cofferdam areas is pumped out. S112: Harden the base of each of the multiple cofferdam areas and drive in spiral ground nail piles 5; S113: Reinforcing steel frames are tied in multiple cofferdam areas respectively, and concrete is injected. After the concrete solidifies, the enlarged foundation 4 is formed.

[0069] This method is simple and reasonably designed. It completes the construction of the enlarged foundation 4 by using cofferdams, dewatering, hardening the base, driving in spiral ground nail piles 5, binding steel bars and pouring concrete. The construction is convenient and can ensure the stability of the entire bridge synchronous lifting system installation, so as to ensure the normal progress of the subsequent multi-section bridge deck synchronous lifting operation of the bridge 3.

[0070] Based on the above scheme, a cofferdam area is set up on both sides of each pier, and multiple spiral ground nail piles 5 are driven into each cofferdam area at even intervals.

[0071] In addition, multiple steel bars are set horizontally and vertically in each cofferdam area to form a steel mesh. Four vertical steel bar areas are set at intervals within the steel mesh area. Multiple steel bars are set vertically at even intervals in each of the four vertical steel bar areas. Flanges are fixedly installed horizontally at the upper ends of the multiple steel bars in the four vertical steel bar areas. Steel columns (i.e., part of the support frame 6) are fixedly connected vertically to the four flanges.

[0072] Moreover, the steel mesh within each of the aforementioned cofferdam areas is filled with concrete, which is a reasonable design and ensures the overall stability of the enlarged foundation 4, guaranteeing the stability of the subsequent assembly of the lifting device 1.

[0073] Preferably, in this embodiment, each flange is provided with a plurality of flange bolts evenly spaced along its circumference, and each flange bolt is wrapped with tape to prevent concrete from entering.

[0074] Preferably, in this embodiment, each of the spiral ground nail piles 5 has a steel nail-like structure, its lower end has a pointed cone-shaped structure, and multiple spiral plates are fixedly installed on it at uniform intervals along its own axial direction.

[0075] Preferably, in this embodiment, the reinforcing steel is HRB400 steel. In terms of mechanical properties, HRB400 steel exhibits moderate plasticity, high strength, and good toughness.

[0076] Preferably, in this embodiment, the thickness of the concrete is preferably 70cm. To reduce the impact of construction on the original riverbed paving, spiral ground nail piles 5 plus enlarged foundations 4 are used as the foundation for temporary support.

[0077] In addition, during the foundation construction process, the pouring and vibration are carried out in layers to ensure the quality of the foundation pouring.

[0078] Preferably, in this embodiment, the spiral ground nail piles 5 are driven through holes drilled in the riverbed paving, and the bottom surface of the enlarged foundation 4 is arranged on the top surface of the existing riverbed paving. The thickness of the enlarged foundation 4 is 0.7m.

[0079] Based on the above scheme, the helical ground nail pile 5 is mainly used to improve the foundation's bearing capacity reserve, enhance foundation stability, and resist water flow impact. Only its bearing capacity is calculated here. This project uses helical ground nail pile 5 with three large blades.

[0080] Referring to the "Technical Specification for Micro Steel Pipe Piles" (DB37 / T 5158-2020) and combining geological survey data, the standard values ​​of the ultimate lateral resistance and ultimate end resistance of each soil layer are determined as shown in Table 2 below.

[0081] Table 2 Standard values ​​of ultimate lateral resistance and ultimate end resistance of each soil layer (spiral nail pile 5)

[0082] In addition, the diameter of the spiral ground nail pile 5 is 114mm, the length is 2.7m, the width of the large blade is 7cm, and each pile has 3 blades. According to the specifications, the standard value of the bearing capacity of a single spiral ground nail pile 5 at each pier and the characteristic value of the vertical bearing capacity of a single pile are calculated as shown in Table 3 below.

[0083] Table 3 Standard values ​​of bearing capacity of single helical ground nail piles at each pier.

[0084] Among them, the characteristic value R of the vertical bearing capacity of a single pile a =Q uk / K, K—Safety factor, taken as K=2; Q uk —Standard value of the ultimate vertical bearing capacity of a single pile; Standard value of vertical ultimate bearing capacity of a single pile:

[0085] u—circumference of the straight section of the pile, u=3.14*0.114=0.358m; —The projected area of ​​the i-th large blade in a discontinuous large-blade pile. The projected area of ​​the first large blade from the pile tip upwards includes the area of ​​the steel pipe; the remaining areas are the projected areas of the large blades after deducting the area of ​​the steel pipe. A p1 =0.03m 2 A P2 =0.02m 2 ; —The thickness of the i-th layer of soil along the pile; —Correction coefficient for the standard value of the ultimate resistance at the bottom of the discontinuous large blade. For a single large blade, take 0.40~0.60. For a pile with 3 large blades, take 0.25.

[0086] The calculation results show that the vertical bearing capacity of the spiral ground nail piles 5 at each pier meets the requirements of the specifications.

[0087] Example 4 Based on any one of Embodiments 2 to 3, in this embodiment, S1 further includes S14: installation of the monitoring system.

[0088] This method is simple and reasonably designed. The monitoring system can monitor the entire process of lifting Bridge 3 in real time, ensuring the smooth progress of the lifting operation.

[0089] Example 5 Based on the above embodiments, in this embodiment, step S2 includes the following specific steps: S21: Perform debugging and trial lifting on the bridge 3; S22: Perform graded lifting on the bridge 3.

[0090] The purpose of debugging and trial lifting of Bridge 3 is as follows: First, to check whether the bearing capacity of the temporary supports meets the requirements; second, to check whether the lifting system is reasonable and whether the lifting capacity meets the requirements; third, to check the constraint of the superstructure, that is, whether the constraints are released; and fourth, to ensure that the gap between the temporary facilities and the permanent structure is filled tightly, that the deformation of the two is coordinated during the lifting process, and that the impact on the stress system of the superstructure is controlled. In addition, Bridge 3 adopts a staged lifting method to ensure the stability and safety of the simultaneous lifting of multiple sections of the superstructure of Bridge 3.

[0091] Example 6 Based on Example 5, in this example, S21 includes the following specific steps: The multiple lifting devices 1 are lifted and tested until all connections are reliable, and then the multiple lifting devices 1 are tested and lifted.

[0092] This method is simple and reasonably designed, ensuring the stability and safety of the simultaneous lifting of the three sections of the bridge's superstructure.

[0093] Based on the above plan, after the lifting system is installed, it needs to be tested and adjusted until all connections are reliable before a trial lift can be performed. During the installation and adjustment of the lifting system, the lifting support, lifting device 1, and auxiliary facilities should be carefully inspected. If any abnormalities are found, they should be repaired or replaced immediately. Necessary tests should be conducted on the lifting system before the formal lift.

[0094] Example 7 Based on Example 6, in this example, the specific steps of the pilot-scale improvement in S21 include: The upper structure of the bridge 3 is lifted by (1-3) cm by multiple lifting devices 1, and temporary support steel plates are inserted. At the same time, the stress and displacement of the bridge 3, multiple support frames 6 and multiple lifting devices 1 are checked.

[0095] This method is simple and reasonably designed. While lifting the bridge 3, temporary support steel plates are inserted, which can not only ensure the stable and synchronous lifting of multiple sections of the superstructure of the bridge 3, but also comprehensively check the stress and displacement status of the bridge 3, the multiple support frames 6 and the multiple lifting devices 1.

[0096] Preferably, in this embodiment, the multiple lifting devices 1 are used to lift the upper structure of the bridge 3 by 2cm as a whole, and then temporarily support steel plates with a thickness of 2cm are inserted.

[0097] Alternatively, multiple lifting devices 1 can be used to lift the upper structure of multiple sections of the bridge 3 to other suitable heights, such as 3cm, and temporary support steel plates with a thickness of 3cm can be inserted into each section.

[0098] In addition, a professional construction monitoring unit will conduct comprehensive monitoring during the trial lifting process to ensure the safety and controllability of the bridge structure and lifting system during the lifting process.

[0099] Example 8 Based on any one of Embodiments 5 to 7, in this embodiment, S22 includes the following specific steps: Multiple lifting devices 1 are used to simultaneously lift multiple sections of the superstructure of the bridge 3 in stages, with each stage lifting (1-50) cm. For each stage of lifting, a fall protection support steel plate of corresponding thickness is added under the support of the bridge 3. Construction monitoring is carried out at each stage until the bridge 3 is lifted to the design height.

[0100] This method is simple and reasonably designed. It can simultaneously and stably lift multiple sections of the bridge's superstructure while ensuring the safety of the operation and the personal safety of the workers. It is safe and reliable.

[0101] Preferably, in this embodiment, the bridge is lifted 2cm at each stage. For each stage of lifting, a 2cm thick anti-fall protection steel plate is placed under the support of the bridge 3. Construction monitoring is conducted at each stage until the bridge 3 reaches the designed height, for example, 2.2m. Lifting is terminated after elevation monitoring confirms that the displacement and linearity of the bridge 3 meet the design requirements. This method ensures a relatively stable lifting process for the bridge 3 and avoids safety accidents.

[0102] Alternatively, each level can be raised to a suitable height, such as 10cm. In this case, a protective steel plate of appropriate thickness for falling protection should be added under the three supports of the bridge.

[0103] In addition, observation rulers are set up at the bridge piers (abutments) and lifting points during the lifting process. The elevation of control points is tested once during each lifting operation. If the left-right deviation (relative to the initial plane) is found to be greater than 5mm, or the overall deviation is found to be 10mm, adjustments are made to bring it parallel to the initial plane. Construction monitoring is strengthened during the lifting process. The lifting cylinder is depressurized slowly, and the asynchrony is controlled within 1cm.

[0104] Example 9 Based on the above embodiments, in this embodiment, step S5 includes the following specific steps: Construct a bridge abutment retaining structure so that the top of the bridge abutment retaining structure is flush with the upper surface of the bridge 3.

[0105] This method is simple and reasonably designed. After the bridge 3 is lifted, both ends of the bridgehead are raised off the ground. The retaining structure at the bridgehead makes the upper surface of the bridge 3 flush with the ground at the bridgehead, ensuring the flatness of the surface of the bridge 3.

[0106] Preferably, in this embodiment, the above-mentioned bridge abutment retaining structure can be constructed by: building a U-shaped retaining wall at the bridge abutment, filling the U-shaped retaining wall with soil, and laying a slab on top of the U-shaped retaining wall until it is flush with the upper surface of the bridge 3.

[0107] Alternatively, other construction methods can be used to make the upper surface of the bridge flush with the ground, such as modifying the back wall of the bridge abutment.

[0108] Example 10 Based on the above embodiments, this embodiment further includes S6: dismantling the plurality of support frames 6 and the plurality of lifting devices 1.

[0109] The method is simple and reasonably designed. After construction is completed, multiple support frames 6 and multiple lifting devices 1 are removed in sequence, making construction convenient.

[0110] This invention provides a method for the overall synchronous lifting of multi-span bridges based on independent supports, comprising the following specific steps: S1: Install a bridge synchronous lifting system, so that the lifting beams 2 on the multiple lifting devices 1 in the bridge synchronous lifting system support the opposite ends of two adjacent sections of the superstructure of the bridge 3 respectively. S2: The multiple lifting devices 1 respectively drive the multiple sections of the superstructure of the bridge 3 to be lifted synchronously; S3: Install multiple cap beams; S4: The multiple lifting devices 1 respectively drive the multiple sections of the superstructure of the bridge 3 to fall onto the multiple cap beams; S5: Modify the bridgehead, specifically by constructing a bridgehead retaining structure so that the top of the bridgehead retaining structure is flush with the upper surface of the bridge 3; S6: Remove the multiple support frames 6 and the multiple lifting devices 1.

[0111] This invention provides a method for synchronously lifting a multi-span bridge based on independent support. The method is simple and reasonably designed. It can synchronously adjust the elevation of the entire bridge deck without removing the decorative structure on the bridge deck, while also preserving the original bridge structure, significantly reducing construction costs, waste emissions, and adverse environmental impacts.

[0112] While embodiments or examples of this disclosure have been described with reference to the accompanying drawings, it should be understood that the above embodiments are merely exemplary embodiments or examples, and the scope of the invention is not limited by these embodiments or examples, but only by the granted claims and their equivalents. Various elements in the embodiments or examples may be omitted or replaced by their equivalents. Furthermore, the steps may be performed in a different order than that described in this disclosure. Further, various elements in the embodiments or examples may be combined in various ways. Importantly, as the technology evolves, many elements described herein can be replaced by equivalents that appear after this disclosure.

Claims

1. A method for synchronously lifting a multi-span bridge with independent supports, characterized in that, The specific steps include the following: S1: Install a bridge synchronous lifting system so that the lifting beams (2) on the multiple lifting devices (1) in the bridge synchronous lifting system support the opposite ends of the two adjacent sections of the superstructure of the bridge (3); S2: The multiple lifting devices (1) respectively drive the multiple sections of the superstructure of the bridge (3) to be lifted synchronously; S3: Install multiple cap beams; S4: The multiple lifting devices (1) respectively drive the multiple sections of the superstructure of the bridge (3) to fall onto the multiple cap beams; S5: Renovate the bridgehead.

2. The method for synchronous lifting of a multi-span bridge based on independent support as described in claim 1, characterized in that, S1 includes the following specific steps: S11: Construction of multiple enlarged foundations (4); S12: Install multiple support frames (6); S13: Install multiple of the aforementioned lifting devices (1).

3. The method for synchronous lifting of a multi-span bridge based on independent support as described in claim 2, characterized in that, S11 includes the following specific steps: S111: Cofferdams are constructed in the corresponding water areas below multiple piers of the bridge (3), and the water in the multiple cofferdam areas is pumped out. S112: Harden the base of each of the cofferdam areas and drive in spiral ground nails (5). S113: Tie steel reinforcement cages in multiple cofferdam areas respectively, and inject concrete. After the concrete solidifies, the enlarged foundation (4) is formed.

4. The method for synchronous lifting of a multi-span bridge based on independent support as described in claim 2, characterized in that, S1 also includes S14: installation of the monitoring system.

5. The method for synchronous lifting of a multi-span bridge with independent support according to any one of claims 1-4, characterized in that, S2 includes the following specific steps: S21: The bridge (3) is debugged and tested; S22: The bridge (3) is upgraded in stages.

6. The method for synchronous lifting of a multi-span bridge based on independent support as described in claim 5, characterized in that, S21 includes the following specific steps: The multiple lifting devices (1) are lifted and debugged until all connections are reliable, and then the multiple lifting devices (1) are tested and lifted.

7. The method for synchronous lifting of a multi-span bridge based on independent support as described in claim 6, characterized in that, The specific steps for the pilot-scale improvement of S21 include: The bridge (3) was lifted by 1-3 cm by multiple lifting devices (1) and temporary support steel plates were inserted. At the same time, the stress and displacement of the bridge (3), multiple support frames (6) and multiple lifting devices (1) were checked.

8. The method for synchronous lifting of a multi-span bridge based on independent support according to claim 5, characterized in that, S22 includes the following specific steps: Multiple lifting devices (1) are used to simultaneously lift multiple sections of the superstructure of the bridge (3) in stages. Each stage is lifted by (1-50) cm. For each stage, a corresponding thickness of anti-fall protection support steel plate is added under the support of the bridge (3). Construction monitoring is carried out at each stage until the bridge (3) is lifted to the design height.

9. The method for synchronous lifting of a multi-span bridge based on independent support according to any one of claims 1-4, characterized in that, S5 includes the following specific steps: Construct a retaining structure at the bridge abutment so that the top of the retaining structure at the bridge abutment is flush with the upper surface of the bridge (3).

10. The method for synchronous lifting of a multi-span bridge based on independent support according to any one of claims 1-4, characterized in that, It also includes S6: removing multiple of the said support frames (6) and multiple of the said lifting devices (1).

Images