A method for the demolition and reconstruction of a rigid frame bridge into a steel truss bridge

Abstract

This application relates to a method for the reconstruction and demolition of a rigid frame bridge into a steel truss bridge, comprising the following steps: S1: Information collection and investigation; S2: Determination of the construction plan; S3: Construction according to the construction plan and engineering requirements; wherein, in step S2, the construction plan includes the following steps: A1: Demolishing the old bridge flange and constructing new bridge pile foundations and piers; A2: Driving steel pipe piles and assembling temporary supports; A3: Hoisting and assembling the steel truss; A4: Removing the old bridge deck crash barriers, bridge deck pavement, and prefabricated bridge panels; A5: Installing lifting rings and suspension points; A6: Load transfer; A7: Demolition of the old bridge rigid frame; A8: Installation of the new bridge deck system; This method enables a more efficient, safe, and environmentally friendly reconstruction of a rigid frame bridge into a steel truss bridge.

Description

Technical Field

[0001] This application relates to the field of building construction technology, and in particular to a method for the demolition and reconstruction of a rigid frame bridge into a steel truss bridge. Background Technology

[0002] In the construction and renovation of bridges, there is often a need to convert existing rigid frame bridges into steel truss bridges. Traditional rigid frame bridge demolition and new bridge construction often employ relatively conventional and independent construction processes. When demolishing an old bridge, a temporary trestle is typically erected as a construction access road to transport construction materials and equipment. This not only consumes a significant amount of time and resources for trestle construction, but its construction may also be limited by terrain, hydrology, and other conditions. Meanwhile, during the construction of a new bridge, the conventional practice for installing the steel truss girders is to assemble them on the shore and then push them into place. This method requires a large onshore assembly area, and the pushing process demands high precision and equipment, thus increasing construction risks. Furthermore, improper handling during the demolition of an old bridge can easily create safety hazards and potentially pollute the surrounding environment. For example, without proper support and a proper demolition sequence, the old bridge structure may become unstable and collapse; carelessly discarded construction waste can pollute water bodies and soil. Therefore, there is an urgent need for a more efficient, safe, and environmentally friendly method for the reconstruction and demolition of rigid frame bridges into steel truss bridges. Summary of the Invention

[0003] To address or partially address the problems existing in related technologies, this application provides a method for the reconstruction and demolition of a rigid frame bridge into a steel truss bridge, which enables a more efficient, safe, and environmentally friendly reconstruction of a rigid frame bridge into a steel truss bridge.

[0004] This application discloses a method for the reconstruction and demolition of a rigid frame bridge into a steel truss bridge, including the following steps: S1: Information gathering and investigation; S2: Determination of construction plan; S3: Carry out construction in accordance with the construction plan and engineering construction requirements; In step S2, the construction plan includes the following steps: A1: Demolish the old bridge wing and build new bridge pile foundations and piers; A2: Drive steel pipe piles and assemble temporary supports; A3: Erection and assembly of steel truss girders; A4: Remove the old bridge's crash barriers, pavement, and precast bridge panels; A5: Installation with lifting rings or suspension points; A6: Load transfer; A7: Demolition of the old bridge frame; A8: Installation of the new bridge deck system.

[0005] Optionally, in step S1, the as-built drawings and bridge inspection reports of the old bridge are collected comprehensively, and the structure of the old bridge is investigated in depth to understand in detail the structural form, material properties, and defects of the old bridge, so as to provide an accurate basis for the formulation of subsequent construction plans.

[0006] Optionally, in step S2, a construction plan is determined based on the accurate information obtained in step S1 and the actual landform characteristics.

[0007] Optionally, in step S2, the construction plan includes: A1: Using the old bridge as a construction access road, the flange of the old bridge was precisely cut off at the location of the main pier of the proposed new bridge. Then, a steel platform was erected on the water to carry out the construction work of the new bridge's pile foundation and piers. A2: Accurately drive steel pipe piles on both sides of the old bridge and strictly follow the construction requirements to assemble temporary supports for the steel truss bridge; A3: Utilize the good load-bearing capacity of the old bridge deck and use appropriate hoisting equipment to hoist and assemble the steel truss beams; A4: Using professional cutting equipment and tools, carefully cut and remove the old bridge deck guardrails, bridge deck paving and precast bridge panels; A5: Install lifting rings at appropriate locations on the old bridge, and at the same time install corresponding suspension points on the tie beams of the new bridge deck; A6: The old bridge is securely suspended to the new bridge grid beam using high-strength steel wire ropes or prestressed tendons, and the load is gradually applied to smoothly transfer the load of the old bridge to the new bridge grid beam. A7: Strictly follow the principle of left-right symmetry to dismantle the old bridge's rigid frame longitudinal beams and connecting cross beams one by one. After cutting, use professional lifting equipment to lower them to the water surface, and then transport them away by boat. A8: Install the new bridge deck system in an orderly manner, and finally complete the bridge construction.

[0008] Optional, the engineering requirements for the construction plan include: 1. In step A1, when cutting the flange, professional cutting equipment must be used to ensure that the cut surface is flat and does not affect the stability of the remaining structure of the old bridge; when erecting the steel platform on the water, factors such as water flow and water level must be fully considered to ensure the stability and safety of the platform. 2. In step A2, the spacing, height and other parameters of the temporary supports need to be calculated and determined based on the size and weight of the steel truss beam to ensure that they can stably support the assembly operation of the steel truss beam. 3. In step A3, during the hoisting process, the load-bearing capacity of the old bridge deck must be verified, and the hoisting points should be arranged reasonably to ensure a safe and stable hoisting process. 4. In step A4, care should be taken to protect the main structure of the old bridge during the demolition process to avoid causing unnecessary damage; 5. In step A5, the lifting force is calculated. Based on the accurate force calculation results, the material and specifications of the lifting rings and suspension points must meet the design force requirements, and the installation process must ensure that it is firm and reliable. 6. In step A6, during the application of force, the deformation of the old bridge and the new bridge should be monitored in real time to ensure structural safety; 7. In step A7, the demolition process should follow the order of secondary structures first and then main structures to ensure the stability of the demolition process; 8. In step A8, after the bridge construction is completed, check whether each indicator meets the bridge design requirements.

[0009] Optionally, during the construction of the new bridge's pile foundations and piers, as well as the assembly of the steel truss, the old bridge structure can be monitored in real time. The monitoring content includes structural deformation, stress changes, etc. The construction parameters can be adjusted in a timely manner based on the monitoring data to ensure the safety and stability of the old bridge during the construction process.

[0010] The technical solution provided in this application may include the following beneficial effects: This application utilizes the existing bridge as a construction access route for the new bridge. Compared to conventional methods, this eliminates the need for extensive resource and time expenditure on constructing temporary bridges, significantly reducing construction costs and time while minimizing the environmental impact of such construction. Uniquely, the application involves assembling the new bridge's truss on the existing bridge itself, unlike the traditional method of assembling on shore and then jacking it into place. This avoids the difficulty of finding large onshore assembly sites, reduces construction risks during the jacking process, and improves construction efficiency and safety. Based on precise calculations, lifting rings are installed on the longitudinal and transverse beams of the existing bridge. The existing bridge is then suspended using the steel grating beams of the new bridge deck for cutting and dismantling. This method ensures the stability of the existing bridge structure during dismantling, guaranteeing safety and preventing environmental pollution from construction debris.

[0011] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0012] The above and other objects, features and advantages of this application will become more apparent from the more detailed description of exemplary embodiments thereof in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments thereof.

[0013] Figure 1 This is a step diagram illustrating an embodiment of this application; Detailed Implementation Embodiments of this application will now be described in more detail with reference to the accompanying drawings. While embodiments of this application are shown in the drawings, it should be understood that this application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make this application more thorough and complete, and to fully convey the scope of this application to those skilled in the art.

[0014] It should be understood that although the terms "first," "second," "third," etc., may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0015] In the description of this application, it should be understood that the terms "length", "width", "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, and are only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application.

[0016] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0017] To address the aforementioned problems, this application provides a method for the reconstruction and demolition of a rigid frame bridge into a steel truss bridge. The technical solution of this application embodiment is described in detail below with reference to the accompanying drawings.

[0018] like Figure 1 The method for demolition and reconstruction of a rigid frame bridge into a steel truss bridge, as shown, includes the following steps: S1: Information gathering and investigation (or preliminary preparation): We comprehensively collected as-built drawings, bridge inspection reports, and other data of the old bridge, and organized professional technicians to conduct on-site inspections of the old bridge structure. The investigation focused on the old bridge's structural form (such as angles, span of the rigid frame longitudinal beams), material properties (concrete strength grade, steel reinforcement type, etc.), and defects (crack distribution, degree of structural deformation, etc.). We also used professional testing equipment to assess the old bridge's load-bearing capacity, providing accurate data support for the development of subsequent construction plans. S2: Determination of construction plan: Based on the accurate information obtained in step S1, a construction plan is determined in combination with the actual landform characteristics.

[0019] S3: Carry out construction in accordance with the construction plan and engineering construction requirements: During construction, the construction plan includes the following steps: A1: Demolish the old bridge wing and build new bridge pile foundations and piers; A2: Drive steel pipe piles and assemble temporary supports; A3: Erection and assembly of steel truss girders; A4: Remove the old bridge's crash barriers, pavement, and precast bridge panels; A5: Installation with lifting rings or suspension points; A6: Load transfer; A7: Demolition of the old bridge frame; A8: Installation of the new bridge deck system.

[0020] Specifically, the construction includes the following steps: A1: During the foundation construction phase of the new bridge, the existing bridge was fully utilized as a construction access route, minimizing the need for temporary access roads. At the determined locations of the new bridge's main piers, specialized equipment such as plasma cutters were used to precisely remove the flanges of the existing bridge. The stability of the remaining structure of the existing bridge was monitored in real time during the cutting process to ensure a smooth and even cut surface and avoid secondary damage to the main structure. Subsequently, a steel platform was designed and constructed above water based on hydrological conditions such as water flow velocity and water level changes. The steel platform uses steel pipe piles as its support structure, and the depth of the piles into the ground was determined through calculation to ensure the platform can withstand the loads of construction equipment and materials. The new bridge's pile foundation construction (such as bored piles) was carried out on the steel platform, with strict control over the verticality of the piles and the quality of concrete pouring. After the pile foundation construction was completed, the new bridge piers were poured, and the dimensions and strength of the piers had to meet design requirements. A2: During the temporary support system construction phase, steel pipe piles are precisely driven at designated locations on both sides of the old bridge using a pile driver. The spacing, diameter, and other parameters of the steel pipe piles are determined based on the weight, dimensions, and construction load of the steel truss girder. Using the steel pipe piles as a foundation, temporary piers for the steel truss girder assembly are erected. Leveling devices are installed on the top of the temporary piers to ensure the flatness of the pier top surface. The height of the temporary piers must match the assembly height of the steel truss girder, providing a stable support platform for the assembly and ensuring its stable support during the steel truss girder assembly operation.

[0021] A3: During the steel truss assembly stage, a detailed calculation of the load-bearing capacity of the old bridge deck is performed. Based on the calculation results, appropriate hoisting equipment (such as truck cranes, crawler cranes, etc.) is selected, and the location and number of hoisting points are determined. The arrangement of hoisting points should ensure that the steel truss is subjected to uniform stress during hoisting to avoid torsional deformation. The old bridge deck is used as the hoisting operation site, and the various components of the steel truss are transported to the bridge deck and assembled using hoisting equipment. During the assembly process, total stations and other surveying equipment are used to monitor the position and elevation of the steel truss in real time to ensure that the assembly accuracy meets the design requirements. At the same time, the settlement and deformation of the old bridge deck are monitored to ensure construction safety.

[0022] A4: During the demolition phase of the old bridge deck system, specialized tools such as hydraulic breakers and cutting machines were used to dismantle the old bridge deck system in the following order: first, the crash barriers; then, the bridge deck paving; and finally, the precast bridge panels. Protective measures were implemented during the demolition process to prevent construction debris from falling into the environment below the bridge. For the precast bridge panels, a segmented cutting method was used for dismantling to ensure a smooth process and avoid impacting the main structure of the old bridge.

[0023] A5: During the suspension system installation phase, the lifting forces are calculated. Based on the detailed force calculation results, the installation positions of the lifting rings are determined on the longitudinal beams and connecting beams of the old bridge's rigid frame. The lifting rings are made of high-strength steel, and their specifications and welding quality must meet the design force requirements. After welding, non-destructive testing is performed to ensure that the welds are strong and reliable. Simultaneously, suspension tie points are installed at corresponding positions on the tie beams of the new bridge deck. The structural form of the suspension tie points matches that of the lifting rings to ensure the stability of the connection between the two. A6: During the load transfer phase, high-strength steel wire ropes or prestressed tendons are used to connect the suspension rings of the old bridge to the suspension points of the new bridge's grid beams. During the connection process, the tension of the steel wire ropes or prestressed tendons is ensured to be consistent. Tension is gradually applied to the steel wire ropes or prestressed tendons, allowing the load of the old bridge to be transferred slowly and smoothly to the new bridge's grid beams. During the load transfer process, displacement sensors, stress sensors, and other equipment are used to monitor the deformation and stress changes of both the old and new bridges in real time. Based on the monitoring data, the speed and magnitude of the tension application are adjusted to ensure that the structure remains in a safe and stable state at all times. A7: During the demolition phase of the old bridge's superstructure, following the principles of left-right symmetry and removing secondary structures before primary structures, the longitudinal beams and connecting beams of the old bridge's rigid frame were cut and demolished one by one. Plasma cutting machines were used for the cutting. Temporary supports were installed below the cutting area before cutting to prevent components from suddenly falling after being cut. The cut components were then smoothly lowered onto transport vessels on the water using lifting equipment and promptly transported away from the construction site for disposal, avoiding the accumulation of construction waste and pollution to the surrounding environment. A8: During the bridge deck installation phase, bridge deck components, including bridge deck panels, railings, and expansion joints, are installed on the new bridge's steel truss according to design requirements. The bridge deck panels must be installed flat and securely, with reliable connections to the steel truss. Railing installation must comply with safety regulations to ensure their protective function. Expansion joint installation must consider the bridge's expansion and contraction to ensure good sealing performance. After all components are installed, the new bridge's performance indicators are tested to ensure they meet design standards.

[0024] Construction monitoring and adjustments are crucial. Finally, a comprehensive monitoring system is established throughout the entire construction process, including the construction of the new bridge's pile foundations and piers, the assembly of the steel truss girder, and the demolition of the old bridge. Monitoring content includes structural deformation (such as settlement and displacement), stress changes, and crack development in both the old and new bridges. Monitoring data is transmitted to the monitoring center in real time, where professionals analyze and evaluate the data. When monitoring data exceeds warning values, construction parameters are adjusted promptly, and effective reinforcement or protective measures are taken to ensure the safety and stability of the construction process.

[0025] Finally, it should be noted that in this document, relationships such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "include," "contain," or any other variations are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0026] In this application, by utilizing the existing bridge as a construction access route for the new bridge, compared to conventional methods, there is no need to expend significant resources and time constructing a temporary bridge, greatly saving construction costs and time, while also reducing the environmental impact of temporary bridge construction. The unique approach of completing the hoisting and assembly of the new bridge truss on the existing bridge, unlike the traditional method of assembling on shore and then jacking it into place, avoids the difficulty of finding a large onshore assembly site, reduces construction risks during the jacking process, and improves construction efficiency and safety. Based on precise calculations, lifting rings are installed on the longitudinal and transverse beams of the existing bridge. After the existing bridge is suspended by the steel grating beams of the new bridge deck, it is cut and dismantled. This method ensures the safety of the dismantling process by keeping the existing bridge structure in a stable suspended state throughout the dismantling process, while also preventing environmental pollution caused by the indiscriminate falling of construction waste.

[0027] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0028] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for the reconstruction and demolition of a rigid frame bridge into a steel truss bridge, characterized in that, Includes the following steps: S1: Information gathering and investigation; S2: Determination of construction plan; S3: Carry out construction in accordance with the construction plan and engineering construction requirements; In step S2, the construction plan includes the following steps: A1: Demolish the old bridge flanges and build new bridge pile foundations and piers; use the old bridge as a construction access road, precisely cut off the old bridge flanges at the location of the main pier of the proposed new bridge, and then build a steel platform on the water to carry out the construction work of the new bridge pile foundations and piers. A2: Drive steel pipe piles and assemble temporary supports; accurately drive steel pipe piles on both sides of the old bridge and strictly construct temporary supports for the steel truss bridge in accordance with construction requirements; A3: Erection and assembly of steel truss girders; Taking advantage of the good load-bearing capacity of the old bridge deck, appropriate hoisting equipment is used to carry out the hoisting and assembly of steel truss girders; A4: Remove the old bridge deck crash barriers, pavement, and precast bridge panels; use professional cutting equipment and tools to carefully cut and remove the old bridge deck crash barriers, pavement, and precast bridge panels; A5: Install lifting rings and suspension points; install lifting rings at appropriate locations on the old bridge, and at the same time install corresponding suspension points on the tie beams of the new bridge deck; A6: Load transfer; The old bridge is securely suspended from the grid beam of the new bridge using high-strength steel wire ropes or prestressed tendons, and the load is gradually applied to smoothly transfer the load of the old bridge to the grid beam of the new bridge. A7: Demolition of the old bridge frame; strictly follow the principle of left-right symmetry to demolish the longitudinal beams and connecting cross beams of the old bridge frame one by one, cut them and use professional lifting equipment to lower them to the water surface, and then transport them away by boat; A8: Installation of the new bridge deck system: Install the new bridge deck system in an orderly manner to complete the bridge construction.

2. The method for demolition and reconstruction of a rigid frame bridge into a steel truss bridge according to claim 1, characterized in that: In step S1, the as-built drawings and bridge inspection reports of the old bridge are collected in a comprehensive manner, and the structure of the old bridge is investigated in depth to understand in detail the structural form, material properties, and defects of the old bridge, so as to provide an accurate basis for the formulation of subsequent construction plans.

3. The method for demolition and reconstruction of a rigid frame bridge into a steel truss bridge according to claim 1, characterized in that: In step S2, a construction plan is determined based on the accurate information obtained in step S1 and the actual landform characteristics.

4. The method for demolition and reconstruction of a rigid frame bridge into a steel truss bridge according to claim 1, characterized in that: The engineering requirements of the construction plan include:

1. In step A1, when cutting the flange, professional cutting equipment must be used to ensure that the cut surface is flat and does not affect the stability of the remaining structure of the old bridge; when erecting the steel platform on the water, factors such as water flow and water level must be fully considered to ensure the stability and safety of the platform.

2. In step A2, the spacing, height and other parameters of the temporary supports need to be calculated and determined based on the size and weight of the steel truss beam to ensure that they can stably support the assembly operation of the steel truss beam.

3. In step A3, during the hoisting process, the load-bearing capacity of the old bridge deck must be verified, and the hoisting points should be arranged reasonably to ensure a safe and stable hoisting process.

4. In step A4, care should be taken to protect the main structure of the old bridge during the demolition process to avoid causing unnecessary damage; 5. In step A5, the lifting force is calculated. Based on the accurate force calculation results, the material and specifications of the lifting rings and suspension points must meet the design force requirements, and the installation process must ensure that it is firm and reliable.

6. In step A6, during the application of force, the deformation of the old bridge and the new bridge should be monitored in real time to ensure structural safety; 7. In step A7, the demolition process should follow the order of secondary structures first and then main structures to ensure the stability of the demolition process; 8. In step A8, after the bridge construction is completed, check whether each indicator meets the bridge design requirements.

5. The method for demolition and reconstruction of a rigid frame bridge into a steel truss bridge according to claim 4, characterized in that: During the construction of the new bridge's pile foundations and piers, as well as the assembly of the steel truss, the old bridge structure was monitored in real time. The monitoring included structural deformation and stress changes. Based on the monitoring data, the construction parameters were adjusted in a timely manner to ensure the safety and stability of the old bridge during the construction process.

Images