Demolition construction method for existing river channel-crossing prestressed concrete bridge

Abstract

The invention discloses a demolition construction method of an existing over-crossing river channel prestressed concrete bridge, and the demolition construction method of the existing over-crossing river channel prestressed concrete bridge can ensure the safety and effectiveness of demolition work by performing windowing inspection on the existing bridge and evaluating the arrangement and failure conditions of internal steel strands. According to the demolition construction method for the existing overpass river channel prestressed concrete bridge, potential risk points can be recognized, accurate data support is provided for subsequent demolition work, an accurate demolition construction scheme is formulated through detailed stress calculation and analysis, in this way, the safety of the demolition work is improved, and the demolition efficiency of the existing overpass river channel prestressed concrete bridge is improved. According to the dismantling construction method of the existing overpass river channel prestressed concrete bridge, island construction and cofferdam construction are conducted on the two sides of the bridge, a stable construction platform is formed, a water area is effectively isolated, the river channel environment is protected, and meanwhile a guarantee is provided for safe operation of large mechanical equipment.

Description

Technical Field

[0001] The invention relates to the technical field of bridge demolition, and in particular to a demolition construction method for an existing prestressed concrete bridge that crosses a river channel. Background Art

[0002] With the rapid development of my country's infrastructure in recent decades, the functions of some completed bridges can no longer meet existing needs and need to be demolished or rebuilt on the original basis. Some of the large-span highway and river bridges are multi-span prestressed concrete continuous rigid frame bridges, which are cast by cantilever using a hanging basket during construction. When dismantling and reconstructing this type of bridge, the main construction method currently used is: set up a bracket under the beam to be cut to support the beam, then cut the bridge into sections, and finally use a crane to lift the cut beam blocks; when rebuilding, use the original bracket to cast concrete in situ, or directly use a crane to assemble the prefabricated beams.

[0003] The main difficulties and challenges in the demolition of some existing bridges are as follows:

[0004] (1) Bridge demolition has high safety risks. Some existing bridges have been built for a long time. Due to historical or environmental factors, the bridges have been damaged. It is impossible to determine the extent of the damage to the bridge structure. During the demolition period, the bridge may become unstable.

[0005] (2) Large-scale mechanical construction has high safety risks. Large-scale mechanical equipment is used during the dismantling of the beams, and the dismantling equipment operates on a floating bridge, which poses a high safety risk.

[0006] (3) The risk of environmental and water conservation is high. The existing bridge crosses the canal. During the demolition of the bridge, some of the concrete removed will fall into the water. The river needs to be cleaned in time. During the construction process, it is strictly forbidden to pollute the water source with oil stains, concrete blocks, and debris.

[0007] Therefore, a demolition method that can ensure structural safety, environmental protection and construction efficiency is needed. Summary of the invention

[0008] The object of the present invention is to provide a method for dismantling an existing prestressed concrete bridge across a river, so as to solve the problems existing in the prior art mentioned in the above background technology.

[0009] To achieve the above object, the present invention provides the following technical solution, a method for dismantling an existing prestressed concrete bridge across a river, comprising the following steps:

[0010] S1. Preparation before construction

[0011] Conduct window inspections on existing bridges to assess the placement and failure of internal steel strands;

[0012] S2. Force analysis and design

[0013] Carry out force calculation and analysis of bridge structures, draw three-dimensional diagrams of bridges, and formulate detailed demolition construction plans;

[0014] S3. Island cofferdam construction

[0015] Build island cofferdams on both sides of the bridge to form a construction platform and ensure its stability;

[0016] S4. Preparation of large machinery and equipment

[0017] Select and inspect suitable demolition equipment, including a 65t Liebherr 964 large hydraulic hammer;

[0018] S5. Demolition of bridge beams

[0019] Use hydraulic hammers to break bridge beams in sections and monitor the stress conditions of the bridge in real time;

[0020] S6. Lifting of concrete blocks

[0021] Use ship lifting equipment to lift the broken concrete blocks away from the construction site and transport them to a designated location for processing;

[0022] S7. River cleaning and environmental protection measures

[0023] During the demolition process and after completion, the river channel will be cleaned and an environmental and water protection team will be set up to prevent water pollution.

[0024] Preferably, the pre-construction preparation in step S1 specifically includes the following steps:

[0025] S11. Conduct on-site surveys of existing bridges and record the basic conditions and damage conditions of the bridges, especially the structural stress conditions;

[0026] S12. Open the bridge for inspection, cut the surface of the bridge to expose the internal steel strands, and assess their arrangement and degree of damage;

[0027] S13. Collect the design drawings and historical maintenance records of the bridge;

[0028] S14. Evaluate the current stability of the bridge and identify possible danger points and key monitoring areas;

[0029] S15. Coordinate with relevant government departments and owners to ensure that construction permit and environmental protection requirements are met;

[0030] S16. Arrange on-site monitoring equipment to monitor in real time the dynamic stress changes of the bridge during the demolition process.

[0031] Preferably, the force analysis and scheme design in step S2 includes the following specific steps:

[0032] S21. Based on the window inspection results, a detailed mechanical analysis of the internal steel strands and concrete structure of the bridge is conducted;

[0033] S22. Use advanced computing software to simulate the three-dimensional stress of the bridge structure and evaluate the stress changes that may occur during the demolition process;

[0034] S23. Develop a bridge demolition plan, including the specific steps for segmental demolition and force calculation for each segment;

[0035] S24. Draw a three-dimensional diagram of the bridge and clarify the operation steps and safety measures at each stage of demolition;

[0036] S25. Develop a detailed construction plan, including the selection and operation of demolition equipment, as well as safety measures;

[0037] S26. Conduct multiple discussions and drills with structural engineers and construction teams to ensure that each step is fully verified and optimized;

[0038] S27. Determine the maximum load-bearing weight and force limit of each section during the demolition process to ensure safety during the demolition process.

[0039] Preferably, the island cofferdam construction in step S3 includes the following specific steps:

[0040] S31. Determine the specific location and size of the island cofferdams on both sides of the bridge to ensure that the cofferdams can form a stable construction platform;

[0041] S32. Use excavation equipment to excavate the cofferdam foundation to ensure that the foundation is stable and the excavation depth is not less than 5 meters;

[0042] S33. Install the cofferdam slabs and support structures to ensure that the cofferdam will not collapse during construction;

[0043] S34. Use a pump boat to remove the water inside the cofferdam to ensure that the construction area is dry;

[0044] S35. Lay tarpaulins and reinforcement materials inside the cofferdam to further enhance the stability of the cofferdam;

[0045] S36. Regularly inspect and maintain the cofferdam structure to ensure it remains stable throughout the demolition process;

[0046] S37. Ensure that the cofferdam height is not less than 2 meters to meet the operating requirements of construction equipment and personnel.

[0047] Preferably, the preparation of large-scale mechanical equipment in step S4 includes the following specific steps:

[0048] S41. According to the bridge demolition plan, select appropriate demolition equipment, including 65t Liebherr 964 large hydraulic hammer and other auxiliary equipment;

[0049] S42. Conduct detailed safety inspections and performance tests on all demolition equipment to ensure that they operate normally during the demolition process;

[0050] S43. Train equipment operators to make them familiar with the equipment operation methods and safety regulations;

[0051] S44. Develop a safety manual for equipment operation, clearly specifying the operating steps and precautions for each device;

[0052] S45. Arrange spare equipment and emergency maintenance tools to ensure timely handling when equipment fails;

[0053] S46. Regularly maintain and service the equipment to ensure that it remains in optimal condition throughout the demolition process;

[0054] S47. Ensure that the lifting capacity of the equipment meets the maximum weight requirements of each section of the bridge to ensure safety during the demolition process.

[0055] Preferably, the bridge beam breaking in step S5 includes the following specific steps:

[0056] S51. Under the premise of ensuring safety, use hydraulic hammer to break the bridge beams in sections to avoid overall structural instability;

[0057] S52. Before each demolition, a detailed stress analysis of the bridge section is conducted to ensure the safety of the demolition process;

[0058] S53. Use sensors and monitoring equipment to monitor the stress of the bridge structure in real time, record the data and analyze it;

[0059] S54. Clean up the broken concrete blocks in time to prevent them from causing harm to the surrounding environment and construction workers;

[0060] S55. Keep detailed records of the demolition process of each section to ensure that each step complies with the requirements of the demolition plan;

[0061] S56. Regularly evaluate and summarize the demolition process and adjust the demolition plan and operation methods in a timely manner;

[0062] S57. Ensure that the weight of each section of the beam to be removed does not exceed the maximum lifting capacity of the equipment and the length of each section does not exceed 10 meters.

[0063] Preferably, the concrete block lifting in step S6 comprises the following specific steps:

[0064] S61. Use floating cranes and other ship-lifting equipment to lift the broken concrete blocks away from the construction site;

[0065] S62. Ensure the stability and safety of the lifting equipment to prevent concrete blocks from falling during the lifting process;

[0066] S63. Transport the lifted concrete blocks to a designated processing site for crushing and reuse;

[0067] S64. During transportation, measures should be taken to prevent concrete blocks from polluting the river and surrounding environment;

[0068] S65. Keep detailed records of the lifting and transportation process to ensure that each step meets environmental protection requirements;

[0069] S66. Regularly inspect and maintain lifting equipment to ensure it remains in good condition throughout the demolition process;

[0070] S67. Ensure that the weight of concrete blocks hoisted each time does not exceed 5 tons and the transportation distance does not exceed 1 kilometer.

[0071] Preferably, the river cleaning and environmental protection measures in step S7 include the following specific steps:

[0072] S71. During the demolition process, a special environmental and water conservation team will be set up to monitor the construction area 24 hours a day;

[0073] S72. Clean up the river and surrounding construction waste in a timely manner to prevent water pollution;

[0074] S73. Use environmentally friendly equipment and materials to ensure that the entire construction process complies with environmental standards;

[0075] S74. After the demolition is completed, conduct a comprehensive inspection and cleanup of the construction area to ensure that the construction site is restored to its original state;

[0076] S75. All garbage and pollutants shall be sorted and processed to ensure that they will not cause secondary pollution to the environment;

[0077] S76. Regularly report the construction progress and environmental protection measures to the environmental protection department to ensure that all steps meet environmental protection requirements;

[0078] S77. Ensure that water quality indicators in the construction area meet national and local environmental protection standards, especially the suspended matter concentration does not exceed 50mg / L.

[0079] Preferably, the real-time monitoring of the stress condition of the bridge structure and the maximum load-bearing weight and stress limit of each section during the demolition process in step S53 specifically includes the following specific steps:

[0080] S531. Install force sensors at key locations of the bridge to monitor the force changes of the bridge in real time;

[0081] S532. Use data acquisition equipment to record and analyze the stress data of various parts of the bridge during the demolition process;

[0082] S533. Based on the monitoring data, evaluate the stability of each section of the bridge during the demolition process to ensure that instability or collapse will not occur;

[0083] S534. Conduct real-time analysis of force data during the demolition process and adjust the demolition plan and operation methods in a timely manner;

[0084] S535. Regularly report monitoring results to ensure the transparency and controllability of the demolition process;

[0085] S536. Develop detailed safety measures based on monitoring data to ensure the safety of construction personnel and equipment;

[0086] S537. Ensure that the maximum load-bearing weight of each section of the bridge during the demolition process does not exceed the design limit, the maximum load-bearing weight of each section of the beam does not exceed 20 tons, and the maximum force does not exceed 2000kN.

[0087] Preferably, the use of environmentally friendly equipment and materials in step S73 to ensure that the entire construction process complies with environmental protection standards specifically includes the following specific steps:

[0088] S731. Before construction, select equipment and materials that meet environmental standards to ensure they will not pollute the environment;

[0089] S732. During the construction process, use environmental protection equipment to monitor the construction area in real time to ensure that all environmental protection indicators meet the standards;

[0090] S733. During the demolition process, measures shall be taken to prevent the impact of dust, noise and waste on the surrounding environment;

[0091] S734. Classify and dispose of waste generated during the construction process to ensure that it does not cause secondary pollution to the environment;

[0092] S735. Clean the construction area regularly to ensure the site is clean and environmentally friendly;

[0093] S736. Develop a detailed environmental protection plan to ensure that every step of the construction process meets environmental protection standards;

[0094] S737. After the construction is completed, the construction area shall be comprehensively inspected and cleaned to ensure that the construction site is restored to its original state, that the treatment of waste during the construction process complies with environmental protection standards, that the centralized waste treatment rate reaches more than 95%, that noise is controlled within 85 decibels, and that dust concentration is controlled within 30% of the national standard.

[0095] Compared with the prior art, the present invention has the following beneficial effects:

[0096] 1. The demolition construction method of the existing prestressed concrete bridge over the river can ensure the safety and effectiveness of the demolition work by opening windows to inspect the existing bridge and evaluating the layout and failure of the internal steel strands, which helps to identify potential risk points and provide accurate data support for subsequent demolition work;

[0097] 2. The demolition construction method of the existing prestressed concrete bridge over the river channel has formulated an accurate demolition construction plan through detailed force calculation and analysis, which not only improves the safety of the demolition work, but also ensures the efficiency of the construction process;

[0098] 3. The demolition construction method of the existing prestressed concrete bridge across the river is to build island cofferdams on both sides of the bridge to form a stable construction platform, effectively isolate the water area, protect the river environment, and also provide guarantee for the safe operation of large machinery and equipment;

[0099] 4. The demolition construction method of the existing prestressed concrete bridge over the river channel ensures the safety and reliability of the mechanical equipment during the demolition process by selecting appropriate demolition equipment and conducting strict safety inspections and performance tests. The segmented demolition method is adopted to reduce the damage to the bridge structure and the impact on the surrounding environment.

[0100] 5. The demolition construction method of the existing prestressed concrete bridge across the river channel uses ship lifting equipment to safely lift the broken concrete blocks, effectively avoiding the pollution of the river channel and surrounding environment by the concrete blocks. During the demolition process and after completion, the river channel was cleaned, and an environmental and water protection team was set up to effectively prevent water pollution and protect the aquatic ecological environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0101] Figure 1 It is a flow chart of a method for dismantling an existing prestressed concrete bridge across a river according to the present invention;

[0102] Figure 2 A specific flow chart prepared before construction of the present invention;

[0103] Figure 3 A specific flow chart of the present invention for conducting window inspection on a bridge and evaluating the arrangement and failure of internal steel strands;

[0104] Figure 4 A specific flow chart for the force analysis and scheme design of the present invention;

[0105] Figure 5 A specific flow chart of the island cofferdam construction of the present invention;

[0106] Figure 6 A specific flow chart prepared for the large-scale mechanical equipment of the present invention;

[0107] Figure 7 A specific flow chart of the present invention for ensuring that the lifting capacity of the equipment meets the maximum weight requirements of each section of the bridge;

[0108] Figure 8 A specific flow chart of breaking the bridge beam of the present invention;

[0109] Fig. 9 A specific flow chart of the present invention for real-time monitoring of the stress condition of the bridge structure and the maximum load-bearing weight and stress limit of each section during the demolition process;

[0110] Fig.10 A specific flow chart of the concrete block lifting of the present invention;

[0111] Fig.11 A specific flow chart of the river cleaning and environmental protection measures of the present invention;

[0112] Fig.12 A specific flow chart for the use of environmentally friendly equipment and materials in the present invention to ensure that the entire construction process complies with environmental protection standards;

[0113] Fig.13 The present invention is a specific flow chart for taking measures to prevent oil stains, concrete blocks, debris, etc. from polluting water sources and ensuring environmental protection requirements during the demolition process. DETAILED DESCRIPTION

[0114] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0115] In the description of the invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "two ends", "one end", "the other end" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0116] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0117] See also Figure 1-13 The present invention provides a technical solution: a method for dismantling an existing prestressed concrete bridge across a river, comprising the following steps:

[0118] S1. Preparation before construction

[0119] Conduct window inspections on existing bridges to assess the placement and failure of internal steel strands;

[0120] S2. Force analysis and design

[0121] Carry out force calculation and analysis of bridge structures, draw three-dimensional diagrams of bridges, and formulate detailed demolition construction plans;

[0122] S3. Island cofferdam construction

[0123] Build island cofferdams on both sides of the bridge to form a construction platform and ensure its stability;

[0124] S4. Preparation of large machinery and equipment

[0125] Select and inspect suitable demolition equipment, including a 65t Liebherr 964 large hydraulic hammer;

[0126] S5. Demolition of bridge beams

[0127] Use hydraulic hammers to break bridge beams in sections and monitor the stress conditions of the bridge in real time;

[0128] S6. Lifting of concrete blocks

[0129] Use ship lifting equipment to lift the broken concrete blocks away from the construction site and transport them to a designated location for processing;

[0130] S7. River cleaning and environmental protection measures

[0131] During the demolition process and after completion, the river channel will be cleaned and an environmental and water protection team will be set up to prevent water pollution.

[0132] Specifically, the demolition construction method provided by the present invention realizes the safe demolition of a prestressed concrete bridge across a river by comprehensively considering structural safety, environmental protection and construction efficiency. The method is particularly suitable for bridges located in sensitive environments, such as bridges across rivers or other important water bodies, where environmental protection is an important consideration in the demolition process. Through steps such as building island cofferdams, breaking beams with hydraulic hammers and ship lifting, the method can effectively control the pollution generated during the demolition process while ensuring the safety and efficiency of the demolition operation. In addition, the method also takes into account various risks that may arise during the demolition process, such as structural instability and environmental pollution, and therefore a number of preventive measures are taken during the design to ensure that the entire demolition process is both safe and environmentally friendly.

[0133] The pre-construction preparation of step S1 specifically includes the following steps:

[0134] S11. Conduct on-site surveys of existing bridges and record the basic conditions and damage conditions of the bridges, especially the structural stress conditions;

[0135] S12. Open the bridge for inspection, cut the surface of the bridge to expose the internal steel strands, and assess their arrangement and degree of damage;

[0136] S13. Collect the design drawings and historical maintenance records of the bridge;

[0137] S14. Evaluate the current stability of the bridge and identify possible danger points and key monitoring areas;

[0138] S15. Coordinate with relevant government departments and owners to ensure that construction permit and environmental protection requirements are met;

[0139] S16. Arrange on-site monitoring equipment to monitor in real time the dynamic stress changes of the bridge during the demolition process.

[0140] Specifically, by performing window inspections on existing bridges, the present invention can accurately evaluate the layout and failure status of internal steel strands, providing important data support for subsequent demolition work. This step helps to identify potential risk points and ensure the safety and effectiveness of the demolition work. In addition, this step also helps to optimize the demolition plan, reduce unnecessary demolition work, and save cost and time.

[0141] Specifically, in step S12, the window inspection of the bridge and the evaluation of the arrangement and failure of the internal steel strands include the following specific steps:

[0142] S121. Select appropriate window locations at key locations of the bridge to avoid damage to the overall structure of the bridge;

[0143] S122. Use cutting equipment to carefully cut open the bridge surface to expose the internal steel strands;

[0144] S123. Record the arrangement of the steel strands, including the number, location, diameter and anchorage of the steel strands;

[0145] S124. Check the physical condition of the steel strands and assess whether they have any problems such as corrosion, breakage or looseness;

[0146] S125. Test the strength of the steel strands to assess their current load-bearing capacity;

[0147] S126. Record the inspection results and compare them with the design drawings to assess the actual condition of the bridge;

[0148] S127. Adjust the demolition plan based on the inspection results to ensure the safety and effectiveness of the demolition process.

[0149] Specifically, checking the layout and failure of the steel strands inside the bridge will help assess the current state of the bridge and the risk of demolition. This step is especially important for bridges with a long history or that have been damaged. Through detailed inspection of the internal structure of the bridge, potential risk points can be discovered, so that corresponding reinforcement measures can be taken before demolition to ensure the safety of the demolition work.

[0150] Among them, the force analysis and scheme design of step S2 includes the following specific steps:

[0151] S21. Based on the window inspection results, a detailed mechanical analysis of the internal steel strands and concrete structure of the bridge is conducted;

[0152] S22. Use advanced computing software to simulate the three-dimensional stress of the bridge structure and evaluate the stress changes that may occur during the demolition process;

[0153] S23. Develop a bridge demolition plan, including the specific steps for segmental demolition and force calculation for each segment;

[0154] S24. Draw a three-dimensional diagram of the bridge and clarify the operation steps and safety measures at each stage of demolition;

[0155] S25. Develop a detailed construction plan, including the selection and operation of demolition equipment, as well as safety measures;

[0156] S26. Conduct multiple discussions and drills with structural engineers and construction teams to ensure that each step is fully verified and optimized;

[0157] S27. Determine the maximum load-bearing weight and force limit of each section during the demolition process to ensure safety during the demolition process.

[0158] Specifically, in step S2, an accurate demolition construction plan was developed through force calculation and analysis. This not only improves the safety of the demolition work, but also ensures the efficiency of the construction process. The detailed force analysis helps to predict and avoid possible structural instability and ensure the safety of construction personnel and equipment.

[0159] The island cofferdam construction in step S3 includes the following specific steps:

[0160] S31. Determine the specific location and size of the island cofferdams on both sides of the bridge to ensure that the cofferdams can form a stable construction platform;

[0161] S32. Use excavation equipment to excavate the cofferdam foundation to ensure that the foundation is stable and the excavation depth is not less than 5 meters;

[0162] S33. Install the cofferdam slabs and support structures to ensure that the cofferdam will not collapse during construction;

[0163] S34. Use a pump boat to remove the water inside the cofferdam to ensure that the construction area is dry;

[0164] S35. Lay tarpaulins and reinforcement materials inside the cofferdam to further enhance the stability of the cofferdam;

[0165] S36. Regularly inspect and maintain the cofferdam structure to ensure it remains stable throughout the demolition process;

[0166] S37. Ensure that the cofferdam height is not less than 2 meters to meet the operating requirements of construction equipment and personnel.

[0167] Specifically, by building islands and cofferdams on both sides of the bridge, a stable construction platform is formed, which effectively isolates the water area and protects the river environment, while also providing guarantees for the safe operation of large machinery and equipment. The establishment of cofferdams helps control the water level at the construction site and prevent construction risks caused by water level changes.

[0168] Specifically, island cofferdams can not only effectively isolate waters and protect the river environment, but also provide a stable platform for demolition operations. Island cofferdams are particularly suitable for rivers with fast currents or large water level changes. They can ensure that the equipment will not become unstable or the demolished objects will not fall into the water due to the influence of water flow during the demolition process. The establishment of cofferdams can also help control noise and dust during the demolition process, thereby reducing the impact on the surrounding environment and residents. In addition, water level control inside the cofferdam is also the key to ensuring demolition safety. It can prevent demolition accidents caused by sudden floods or other unexpected situations.

[0169] Among them, the preparation of large-scale mechanical equipment in step S4 includes the following specific steps:

[0170] S41. According to the bridge demolition plan, select appropriate demolition equipment, including 65t Liebherr 964 large hydraulic hammer and other auxiliary equipment;

[0171] S42. Conduct detailed safety inspections and performance tests on all demolition equipment to ensure that they operate normally during the demolition process;

[0172] S43. Train equipment operators to make them familiar with the equipment operation methods and safety regulations;

[0173] S44. Develop a safety manual for equipment operation, clearly specifying the operating steps and precautions for each device;

[0174] S45. Arrange spare equipment and emergency maintenance tools to ensure timely handling when equipment fails;

[0175] S46. Regularly maintain and service the equipment to ensure that it remains in optimal condition throughout the demolition process;

[0176] S47. Ensure that the lifting capacity of the equipment meets the maximum weight requirements of each section of the bridge to ensure safety during the demolition process.

[0177] Specifically, by selecting appropriate demolition equipment and conducting strict safety inspections and performance tests, the present invention ensures that the mechanical equipment during the demolition process is safe and reliable. This step helps to improve demolition efficiency and reduce construction delays caused by equipment failures.

[0178] Specifically, the step of using a hydraulic hammer to break the beam allows for precise control of the demolition process, which is particularly important for prestressed concrete bridges, because of their complex structures and special stress conditions. The hydraulic hammer can accurately break the designated area to avoid unnecessary damage to other parts of the bridge. This precisely controlled demolition method not only improves the safety of demolition, but also helps reduce the generation of waste, thereby reducing demolition costs and reducing environmental impact.

[0179] Among them, in step S47, ensuring that the lifting capacity of the equipment meets the maximum weight requirements of each section of the bridge includes the following specific steps:

[0180] S471. Evaluate the weight and stress of each section of the bridge during demolition and develop a detailed weight distribution plan;

[0181] S472. Select lifting equipment that meets the weight requirements, such as the 65t Liebherr 964 large hydraulic hammer, and ensure the operating capacity of the equipment;

[0182] S473. Conduct detailed inspection and maintenance of lifting equipment to ensure that it can work normally during the demolition process;

[0183] S474. Before each lifting, check the stability and load capacity of the equipment to ensure it can be operated safely;

[0184] S475. Arrange experienced operators to operate the equipment to ensure that every step of the operation meets safety standards;

[0185] S476. During the hoisting process, monitor the stress of the equipment in real time to ensure that it works within a safe range;

[0186] S477. Keep detailed records and evaluations of equipment operations to ensure that the weight of each lift does not exceed the maximum lifting capacity of the equipment (for example, the maximum lifting weight is 65 tons, the lifting height does not exceed 30 meters, and the operating radius does not exceed 15 meters).

[0187] Specifically, by evaluating the weight and stress conditions of each section of the bridge during the demolition process, lifting equipment that meets the weight requirements, such as the 65t Liebherr 964 large hydraulic hammer, can be selected, and the operating capacity of the equipment can be ensured. Such measures can not only improve the safety of the demolition operation, but also improve the efficiency of the operation, because it allows the construction team to adjust the demolition plan according to the actual situation. In addition, detailed records and evaluations of equipment operations can ensure that the weight of each lifting does not exceed the maximum lifting capacity of the equipment, thereby avoiding equipment overload and potential safety risks.

[0188] Among them, the bridge beam demolition in step S5 includes the following specific steps:

[0189] S51. Under the premise of ensuring safety, use hydraulic hammer to break the bridge beams in sections to avoid overall structural instability;

[0190] S52. Before each demolition, a detailed stress analysis of the bridge section is conducted to ensure the safety of the demolition process;

[0191] S53. Use sensors and monitoring equipment to monitor the stress of the bridge structure in real time, record the data and analyze it;

[0192] S54. Clean up the broken concrete blocks in time to prevent them from causing harm to the surrounding environment and construction workers;

[0193] S55. Keep detailed records of the demolition process of each section to ensure that each step complies with the requirements of the demolition plan;

[0194] S56. Regularly evaluate and summarize the demolition process and adjust the demolition plan and operation methods in a timely manner;

[0195] S57. Ensure that the weight of each section of the beam to be removed does not exceed the maximum lifting capacity of the equipment and the length of each section does not exceed 10 meters.

[0196] Specifically, by adopting the method of segmented demolition, the damage to the bridge structure is reduced, and the impact on the surrounding environment is also reduced. Segmented demolition helps control dust and noise during the demolition process and reduce interference with surrounding residents and the environment.

[0197] Specifically, the force calculation and analysis steps ensure the structural safety of the entire demolition process, which is particularly important for the demolition of prestressed concrete bridges. Through accurate force analysis, various risks that may occur during the demolition process, such as structural instability and local damage, can be predicted, so that corresponding preventive measures can be taken. This method not only improves the safety of demolition operations, but also helps to optimize demolition plans, reduce unnecessary demolition work, and save costs and time.

[0198] The real-time monitoring of the stress condition of the bridge structure and the maximum load-bearing weight and stress limit of each section during the demolition process in step S53 specifically includes the following specific steps:

[0199] S531. Install force sensors at key locations of the bridge to monitor the force changes of the bridge in real time;

[0200] S532. Use data acquisition equipment to record and analyze the stress data of various parts of the bridge during the demolition process;

[0201] S533. Based on the monitoring data, evaluate the stability of each section of the bridge during the demolition process to ensure that instability or collapse will not occur;

[0202] S534. Conduct real-time analysis of force data during the demolition process and adjust the demolition plan and operation methods in a timely manner;

[0203] S535. Regularly report monitoring results to ensure the transparency and controllability of the demolition process;

[0204] S536. Develop detailed safety measures based on monitoring data to ensure the safety of construction personnel and equipment;

[0205] S537. Ensure that the maximum load-bearing weight of each section of the bridge during the demolition process does not exceed the design limit, the maximum load-bearing weight of each section of the beam does not exceed 20 tons, and the maximum force does not exceed 2000kN.

[0206] Specifically, real-time monitoring of the stress conditions of the bridge structure and the maximum load-bearing weight and stress limits of each section during the demolition process is the key to ensuring demolition safety. By installing force sensors at key locations on the bridge, the stress changes of the bridge can be monitored in real time, thereby promptly identifying potential structural problems. This monitoring can not only prevent accidents such as bridge instability or collapse, but also improve the efficiency of the demolition process because it allows the construction team to adjust the demolition plan and operating methods based on real-time data. In addition, regular reporting of monitoring results and the formulation of detailed safety measures can ensure the transparency and controllability of the demolition process, thereby enhancing the trust of the public and relevant stakeholders.

[0207] The concrete block lifting in step S6 includes the following specific steps:

[0208] S61. Use floating cranes and other ship-lifting equipment to lift the broken concrete blocks away from the construction site;

[0209] S62. Ensure the stability and safety of the lifting equipment to prevent concrete blocks from falling during the lifting process;

[0210] S63. Transport the lifted concrete blocks to a designated processing site for crushing and reuse;

[0211] S64. During transportation, measures should be taken to prevent concrete blocks from polluting the river and surrounding environment;

[0212] S65. Keep detailed records of the lifting and transportation process to ensure that each step meets environmental protection requirements;

[0213] S66. Regularly inspect and maintain lifting equipment to ensure it remains in good condition throughout the demolition process;

[0214] S67. Ensure that the weight of concrete blocks hoisted each time does not exceed 5 tons and the transportation distance does not exceed 1 kilometer.

[0215] Specifically, the broken concrete blocks are safely lifted away using ship lifting equipment, effectively preventing the concrete blocks from polluting the river and surrounding environment, thereby helping to quickly clean up the construction site and keep the river clean, while also reducing the impact on the aquatic ecology.

[0216] Specifically, the use of ship lifting can safely transfer the destroyed bridge structure components, which is particularly important for the demolition of cross-river bridges. Through professional ship lifting equipment, heavy bridge components can be safely lifted and transported to the designated location. In addition, ship lifting can also improve the efficiency of demolition operations, shorten the demolition period, and thus reduce the overall demolition cost.

[0217] Among them, the river cleaning and environmental protection measures in step S7 include the following specific steps:

[0218] S71. During the demolition process, a special environmental and water conservation team will be set up to monitor the construction area 24 hours a day;

[0219] S72. Clean up the river and surrounding construction waste in a timely manner to prevent water pollution;

[0220] S73. Use environmentally friendly equipment and materials to ensure that the entire construction process complies with environmental standards;

[0221] S74. After the demolition is completed, conduct a comprehensive inspection and cleanup of the construction area to ensure that the construction site is restored to its original state;

[0222] S75. All garbage and pollutants shall be sorted and processed to ensure that they will not cause secondary pollution to the environment;

[0223] S76. Regularly report the construction progress and environmental protection measures to the environmental protection department to ensure that all steps meet environmental protection requirements;

[0224] S77. Ensure that water quality indicators in the construction area meet national and local environmental protection standards, especially the suspended matter concentration does not exceed 50mg / L.

[0225] Specifically, the present invention cleans the river channel during and after the demolition process, and sets up an environmental and water conservation team, which effectively prevents water pollution, protects the aquatic ecological environment, helps ensure environmental protection and soil and water conservation at the construction site, and complies with environmental protection laws and regulations. By timely cleaning up the waste generated during the demolition process, pollutants can be effectively prevented from entering the water body and protecting water quality. In addition, river channel cleaning also helps to restore the natural state of the river channel and provide a healthy living environment for aquatic organisms.

[0226] Among them, the use of environmentally friendly equipment and materials in step S73 to ensure that the entire construction process complies with environmental protection standards specifically includes the following specific steps:

[0227] S731. Before construction, select equipment and materials that meet environmental standards to ensure they will not pollute the environment;

[0228] S732. During the construction process, use environmental protection equipment to monitor the construction area in real time to ensure that all environmental protection indicators meet the standards;

[0229] S733. During the demolition process, measures shall be taken to prevent the impact of dust, noise and waste on the surrounding environment;

[0230] S734. Classify and dispose of waste generated during the construction process to ensure that it does not cause secondary pollution to the environment;

[0231] S735. Clean the construction area regularly to ensure the site is clean and environmentally friendly;

[0232] S736. Develop a detailed environmental protection plan to ensure that every step of the construction process meets environmental protection standards;

[0233] S737. After the construction is completed, the construction area shall be comprehensively inspected and cleaned to ensure that the construction site is restored to its original state, that the treatment of waste during the construction process complies with environmental protection standards, that the centralized waste treatment rate reaches more than 95%, that noise is controlled within 85 decibels, and that dust concentration is controlled within 30% of the national standard.

[0234] Specifically, the use of environmentally friendly equipment and materials and ensuring that the entire construction process meets environmental standards are essential to maintaining the ecological balance of the construction site and the surrounding environment. By selecting equipment and materials that meet environmental standards before construction, the pollution to the environment during the construction process can be significantly reduced. Taking measures during the demolition process to prevent the impact of dust, noise and waste on the surrounding environment will help protect the health of local residents. In addition, the classification and regular cleaning of waste generated during the construction process can ensure the cleanliness and environmental protection of the construction site, while promoting the recycling of resources.

[0235] Specifically, measures are taken during the demolition process to prevent oil stains, concrete blocks, debris, etc. from polluting water sources, and to ensure environmental protection requirements include the following specific steps:

[0236] SP1. Set up special pollution prevention and control facilities at the construction site to prevent oil stains and debris from entering the water source;

[0237] SP2. Regularly inspect and maintain construction equipment to ensure that it does not leak oil stains and other pollutants;

[0238] SP3. During the construction process, clean up fallen concrete blocks and other construction waste in a timely manner to prevent them from entering the water body;

[0239] SP4. Use environmentally friendly materials and equipment to ensure that waste generated during the demolition process does not pollute the environment;

[0240] SP5. Regularly test the water source at the construction site to ensure that its water quality meets environmental protection standards;

[0241] SP6. After the demolition is completed, the construction site shall be thoroughly cleaned and disinfected to ensure that the water source is not polluted.

[0242] Specifically, taking measures to prevent oil stains, concrete blocks, debris, etc. from polluting water sources during the demolition process is an important measure to ensure environmental protection requirements. By setting up special pollution prevention and control facilities at the construction site, oil stains and debris can be effectively prevented from entering the water source, thereby protecting water quality and aquatic ecosystems. Regularly inspecting and maintaining construction equipment to ensure that it does not leak oil stains and other pollutants will help prevent environmental pollution. In addition, comprehensive cleaning and disinfection of the construction site after demolition is completed can ensure that the water source is not polluted and protect public health and safety.

[0243] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for dismantling an existing prestressed concrete bridge across a river, characterized in that: The following steps are involved: S1. Preparation before construction Conduct window inspections on existing bridges to assess the placement and failure of internal steel strands; S2. Force analysis and design Carry out force calculation and analysis of bridge structures, draw three-dimensional diagrams of bridges, and formulate detailed demolition construction plans; S3. Island cofferdam construction Build island cofferdams on both sides of the bridge to form a construction platform and ensure its stability; S4. Preparation of large machinery and equipment Select and inspect suitable demolition equipment, including a 65t Liebherr 964 large hydraulic hammer; S5. Demolition of bridge beams Use hydraulic hammers to break bridge beams in sections and monitor the stress conditions of the bridge in real time; S6. Lifting of concrete blocks Use ship lifting equipment to lift the broken concrete blocks away from the construction site and transport them to a designated location for processing; S7. River cleaning and environmental protection measures During the demolition process and after completion, the river channel will be cleaned and an environmental and water protection team will be set up to prevent water pollution.

2. A method for dismantling an existing prestressed concrete bridge across a river according to claim 1, It is characterized in that in, The pre-construction preparation of step S1 specifically includes the following steps: S11. Conduct on-site surveys of existing bridges and record the basic conditions and damage conditions of the bridges, especially the structural stress conditions; S12. Open the bridge for inspection, cut the surface of the bridge to expose the internal steel strands, and assess their arrangement and degree of damage; S13. Collect the design drawings and historical maintenance records of the bridge; S14. Evaluate the current stability of the bridge and identify possible danger points and key monitoring areas; S15. Coordinate with relevant government departments and owners to ensure that construction permit and environmental protection requirements are met; S16. Arrange on-site monitoring equipment to monitor in real time the dynamic stress changes of the bridge during the demolition process.

3. A method for dismantling an existing prestressed concrete bridge across a river according to claim 1, It is characterized in that in, The stress analysis and scheme design of step S2 includes the following specific steps: S21. Based on the window inspection results, a detailed mechanical analysis of the internal steel strands and concrete structure of the bridge is conducted; S22. Use advanced computing software to simulate the three-dimensional stress of the bridge structure and evaluate the stress changes that may occur during the demolition process; S23. Develop a bridge demolition plan, including the specific steps for segmental demolition and force calculation for each segment; S24. Draw a three-dimensional diagram of the bridge and clarify the operation steps and safety measures at each stage of demolition; S25. Develop a detailed construction plan, including the selection and operation of demolition equipment, as well as safety measures; S26. Conduct multiple discussions and drills with structural engineers and construction teams to ensure that each step is fully verified and optimized; S27. Determine the maximum load-bearing weight and force limit of each section during the demolition process to ensure safety during the demolition process.

4. The method for dismantling an existing prestressed concrete bridge across a river according to claim 1, characterized in that: in, The island cofferdam construction in step S3 includes the following specific steps: S31. Determine the specific location and size of the island cofferdams on both sides of the bridge to ensure that the cofferdams can form a stable construction platform; S32. Use excavation equipment to excavate the cofferdam foundation to ensure that the foundation is stable and the excavation depth is not less than 5 meters; S33. Install the cofferdam slabs and support structures to ensure that the cofferdam will not collapse during construction; S34. Use a pump boat to remove the water inside the cofferdam to ensure that the construction area is dry; S35. Lay tarpaulins and reinforcement materials inside the cofferdam to further enhance the stability of the cofferdam; S36. Regularly inspect and maintain the cofferdam structure to ensure it remains stable throughout the demolition process; S37. Ensure that the cofferdam height is not less than 2 meters to meet the operating requirements of construction equipment and personnel.

5. The method for dismantling an existing prestressed concrete bridge across a river according to claim 1, characterized in that: in, The preparation of large mechanical equipment in step S4 includes the following specific steps: S41. According to the bridge demolition plan, select appropriate demolition equipment, including 65t Liebherr 964 large hydraulic hammer and other auxiliary equipment; S42. Conduct detailed safety inspections and performance tests on all demolition equipment to ensure that they operate normally during the demolition process; S43. Train equipment operators to make them familiar with the equipment operation methods and safety regulations; S44. Develop a safety manual for equipment operation, clearly specifying the operating steps and precautions for each device; S45. Arrange spare equipment and emergency maintenance tools to ensure timely handling when equipment fails; S46. Regularly maintain and service the equipment to ensure that it remains in optimal condition throughout the demolition process; S47. Ensure that the lifting capacity of the equipment meets the maximum weight requirements of each section of the bridge to ensure safety during the demolition process.

6. The method for dismantling an existing prestressed concrete bridge across a river according to claim 1, characterized in that: in, The bridge beam demolition in step S5 includes the following specific steps: S51. Under the premise of ensuring safety, use hydraulic hammer to break the bridge beams in sections to avoid overall structural instability; S52. Before each demolition, a detailed stress analysis of the bridge section is conducted to ensure the safety of the demolition process; S53. Use sensors and monitoring equipment to monitor the stress of the bridge structure in real time, record the data and analyze it; S54. Clean up the broken concrete blocks in time to prevent them from causing harm to the surrounding environment and construction workers; S55. Keep detailed records of the demolition process of each section to ensure that each step complies with the requirements of the demolition plan; S56. Regularly evaluate and summarize the demolition process and adjust the demolition plan and operation methods in a timely manner; S57. Ensure that the weight of each section of the beam to be removed does not exceed the maximum lifting capacity of the equipment and the length of each section does not exceed 10 meters.

7. The method for dismantling an existing prestressed concrete bridge across a river according to claim 1, It is characterized in that in, The concrete block lifting in step S6 includes the following specific steps: S61. Use floating cranes and other ship-lifting equipment to lift the broken concrete blocks away from the construction site; S62. Ensure the stability and safety of the lifting equipment to prevent concrete blocks from falling during the lifting process; S63. Transport the lifted concrete blocks to a designated processing site for crushing and reuse; S64. During transportation, measures should be taken to prevent concrete blocks from polluting the river and surrounding environment; S65. Keep detailed records of the lifting and transportation process to ensure that each step meets environmental protection requirements; S66. Regularly inspect and maintain lifting equipment to ensure it remains in good condition throughout the demolition process; S67. Ensure that the weight of concrete blocks hoisted each time does not exceed 5 tons and the transportation distance does not exceed 1 kilometer.

8. The method for dismantling an existing prestressed concrete bridge across a river according to claim 1, characterized in that: in, The river cleaning and environmental protection measures in step S7 include the following specific steps: S71. During the demolition process, a special environmental and water conservation team will be set up to monitor the construction area 24 hours a day; S72. Clean up the river and surrounding construction waste in a timely manner to prevent water pollution; S73. Use environmentally friendly equipment and materials to ensure that the entire construction process complies with environmental standards; S74. After the demolition is completed, conduct a comprehensive inspection and cleanup of the construction area to ensure that the construction site is restored to its original state; S75. All garbage and pollutants shall be sorted and processed to ensure that they will not cause secondary pollution to the environment; S76. Regularly report construction progress and environmental protection measures to the environmental protection department to ensure that all steps meet environmental protection requirements; S77. Ensure that water quality indicators in the construction area meet national and local environmental protection standards, especially the suspended matter concentration does not exceed 50mg / L.

9. The method for dismantling an existing prestressed concrete bridge across a river according to claim 1, characterized in that: in, The real-time monitoring of the stress condition of the bridge structure and the maximum load-bearing weight and stress limit of each section during the demolition process in step S53 specifically includes the following specific steps: S531. Install force sensors at key locations of the bridge to monitor the force changes of the bridge in real time; S532. Use data acquisition equipment to record and analyze the stress data of various parts of the bridge during the demolition process; S533. Based on the monitoring data, evaluate the stability of each section of the bridge during the demolition process to ensure that instability or collapse will not occur; S534. Conduct real-time analysis of force data during the demolition process and adjust the demolition plan and operation methods in a timely manner; S535. Regularly report monitoring results to ensure the transparency and controllability of the demolition process; S536. Develop detailed safety measures based on monitoring data to ensure the safety of construction personnel and equipment; S537. Ensure that the maximum load-bearing weight of each section of the bridge during the demolition process does not exceed the design limit, the maximum load-bearing weight of each section of the beam does not exceed 20 tons, and the maximum force does not exceed 2000kN.

10. The method for dismantling an existing prestressed concrete bridge across a river according to claim 1, characterized in that: in, The use of environmentally friendly equipment and materials in step S73 ensures that the entire construction process complies with environmental protection standards. The specific steps include the following: S731. Before construction, select equipment and materials that meet environmental standards to ensure they will not pollute the environment; S732. During the construction process, use environmental protection equipment to monitor the construction area in real time to ensure that all environmental protection indicators meet the standards; S733. During the demolition process, measures shall be taken to prevent the impact of dust, noise and waste on the surrounding environment; S734. Classify and dispose of waste generated during the construction process to ensure that it does not cause secondary pollution to the environment; S735. Clean the construction area regularly to ensure the site is clean and environmentally friendly; S736. Develop a detailed environmental protection plan to ensure that every step of the construction process meets environmental protection standards; S737. After the construction is completed, the construction area shall be comprehensively inspected and cleaned to ensure that the construction site is restored to its original state, that the treatment of waste during the construction process complies with environmental protection standards, that the centralized waste treatment rate reaches more than 95%, that noise is controlled within 85 decibels, and that dust concentration is controlled within 30% of the national standard.

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