Construction method for bridge demolition construction and crushing apparatus

Abstract

The application discloses a kind of bridge demolition construction construction method and its crushing equipment, construction method includes the following steps: preparation construction machinery and material, segmented division to bridge, erect protective support frame, build construction access 3, remove guardrail, remove flange plate, break beam double room roof, remove beam web, remove beam double room bottom plate, remove middle beam support body, remove pier top beam section, according to actual situation on site, comply with bridge demolition relevant specification, check whether beam body is stable and whether the disease or disease aggravation condition appears in bridge lower structure, ensure the overall stability of bridge, check if there is no bridge safety problem, the next span of bridge can continue to be removed;The construction method guarantees the stability of bridge overall structure in the process of removal, protects the safety of bridge lower structure, and the crushing equipment can remove concrete safely, quickly, with high quality and without pollution, efficiently and labor-saving.

Description

Technical Field

[0001] This invention relates to the field of bridge demolition construction technology, specifically a bridge demolition construction method and its crushing equipment. Background Technology

[0002] Continuous box girder bridges are a common and technologically mature bridge type. They primarily utilize a continuous structural load distribution and employ a box-shaped cross-section to provide efficient strength and stiffness. The core design concepts of continuous box girder bridges are continuity and the box-shaped cross-section. Continuity allows the bridge to distribute loads across multiple supports, rather than supporting each span independently. This reduces deck deflection and is suitable for long-span bridges. The box-shaped cross-section, through its closed shape, provides efficient bending, shear, and torsional resistance. This design not only improves material efficiency but also enables the bridge to withstand greater loads and adverse environmental impacts.

[0003] Over time, continuous box girder bridges will gradually develop various problems such as cracks, corrosion, or settlement displacement, requiring maintenance or demolition and reconstruction. The difficulties in demolishing continuous box girder bridges mainly stem from their continuous structure, the materials used, the bridge's scale, and its geographical location. Common demolition methods include blasting, mechanical demolition, and cutting demolition. However, for continuous box girder curved bridges where the superstructure must be demolished and rebuilt while protecting the substructure, common demolition methods may cause beam overturning or pier settlement during the demolition process. This not only fails to meet the corresponding construction requirements but also poses certain hazards to the surrounding environment and people. Summary of the Invention

[0004] The purpose of this invention is to address the aforementioned problems and deficiencies by providing a construction method and crushing equipment for bridge demolition, thereby improving overall work efficiency.

[0005] The technical problem solved by this invention is:

[0006] The continuous structural design of a continuous box girder bridge means that demolition will have unpredictable effects on the overall structure. For continuous box girder bridges that require demolition and reconstruction of the superstructure and maintenance of the substructure, common demolition methods may cause hazards such as overturning of the girder or settlement of the piers during the demolition process. This not only fails to meet the corresponding construction requirements, but also poses certain hazards to the surrounding environment and people.

[0007] The objective of this invention can be achieved through the following technical solution: a construction method for bridge demolition, comprising the following steps:

[0008] Step S1: Divide the bridge into spans and sections, mark the abutments and piers, erect protective support frames under the main beams, and build construction access roads.

[0009] Step S2: Demolish the main beam in layers and sections. Use a concrete crusher to break up the concrete on the guardrail, flange plate, double-cell top plate of the beam, web plate of the beam, double-cell bottom plate of the beam, and the middle beam support, and hoist away the top beam section of the pier.

[0010] Step S3: Check the stability and defects of the bridge. If there are no problems, repeat step S2 to continue dismantling the next span of the bridge.

[0011] As a further aspect of the invention, in step S1, the entire bridge is divided into five spans based on the locations of the piers and abutments. Each span is 24 meters long, and each span is further divided into eight segments in the longitudinal direction of the bridge, with each segment being 3 meters long. During demolition, the bridge is dismantled sequentially from the fourth and fifth segments in the middle of the span towards both ends.

[0012] As a further aspect of the invention, the step S1 of erecting a protective support frame includes the following steps:

[0013] S121: Construct a protective and anti-overturning support for the bridge piers and abutments. The support includes columns, horizontal bracing and diagonal bracing, and foundation. The columns are made of 429*10mm steel pipe, the horizontal bracing and diagonal bracing are made of 140*16mm angle steel, and the foundation is made of C30 concrete.

[0014] S122: Three steel pipes are installed on both sides of each pier and under the main beam. First, steel plates are welded to the top of the steel pipes and the steel plates are bolted to the bottom plate of the double-cell beam. Then, pads are added to the bottom of each steel pipe and the pads are welded firmly to the steel pipes. Finally, the pads are fixedly connected to the foundation.

[0015] S123: When erecting protective and anti-overturning supports for bridge abutments, steel supports are inserted in the middle of the supports between the bridge abutment and the main beam as an anti-overturning measure for the bridge abutment. The steel supports are made of SUS429 steel pipes welded together, and the abutment blocks are fixed to the connected beams by bolted steel plates.

[0016] S124. Pier-beam consolidation: After completing the above steps, lock the supports between the pier and the main beam, as well as between the abutment and the main beam, and protect the support frame to start supporting the main beam, thus serving as a temporary pier-beam consolidation device.

[0017] As a further aspect of the invention, the boundary line is determined according to the design, and an excavator is used to level and compact the original ground within the boundary line. When encountering a riverbank, the construction access road is backfilled and compacted with nearby sand and gravel. Within a 10-meter width of the bridge piers or abutments near the water, round logs are laid longitudinally and covered with wooden planks to facilitate water passage and prevent concrete blocks from falling into the water and causing pollution. The construction access road is 6 meters wide and 4 meters below the bridge projection line.

[0018] As a further aspect of the invention, step S2, which involves dismantling the main beam in layers and segments, includes the following steps:

[0019] S211: Removal of guardrail: Move the concrete crusher to the corresponding positions on both sides of the span to be removed, and use the concrete crusher to demolish the guardrail synchronously and symmetrically from the middle of the span to both sides, demolishing one segment at a certain distance; when crushing, do not crush to the bottom of the guardrail all at once, first crush the upper half of the segment gradually, and then crush the lower half after completion;

[0020] S212: Flange plate removal: After the guardrail is removed, use a concrete crusher to remove the flange plates symmetrically and gradually from the middle of the span to both sides in one segment; when removing the flange plates, do not remove them all at once, first remove the concrete within a certain width on the outside, and then remove the concrete within a certain width on the inside.

[0021] S213: Removal of the double-cell roof slab of the beam: After the flange plates are removed, use a concrete crusher to simultaneously and symmetrically remove the double-cell roof slab of the beam from the middle of the span to both sides, so that all the concrete of the double-cell roof slab of the beam is broken.

[0022] S214: Removal of beam web: Use a concrete crusher to remove the beam web segmentally and symmetrically from the mid-span to both sides. Do not crush to the bottom all at once. Crush the upper half first, and then crush the lower half. After removal, use hydraulic shears to cut the steel bars of the removed parts from both ends and lift them away from the site.

[0023] S215: Demolition of the double-cell bottom slab of the beam: Using a concrete crusher, the double-cell bottom slab of the beam is demolished synchronously and symmetrically from the mid-span to both sides, segment by segment.

[0024] S216: Demolition of the central beam support structure: Use a concrete crusher to demolish the central beam support structure symmetrically and gradually from the middle of the span to both sides. During the demolition process, use a water truck to spray and reduce dust. The central beam support structure is also removed layer by layer from top to bottom. The top chamfered plate, the middle chamfered plate and the bottom chamfered plate are crushed concrete and the steel bars are cleaned in sequence.

[0025] S217: Removal of Pier Top Beam Segment: After the demolition is completed, use hydraulic shears to cut and remove the reinforcing bars from both ends, and use a truck crane to remove the remaining pier top beam segment on the pier or abutment.

[0026] A crushing device for bridge demolition construction includes an AGV trolley, a rotating base mounted on the AGV trolley, a lifting scissor lift mounted on the rotating base, a support plate mounted on the top of the lifting scissor lift, a support slide plate and an electrically controlled slide table mounted on the support plate, the support slide plate and the support plate being slidably connected, the electrically controlled slide table driving the support slide plate to slide left and right, and a dust-free demolition mechanism being provided on the support slide plate.

[0027] As a further aspect of the invention, the dust-free demolition mechanism is positioned diagonally above the support plate by means of a diagonal brace. A bag vacuum cleaner is installed on the side of the support plate away from the dust-free demolition mechanism. The bag vacuum cleaner is connected to the dust-free demolition mechanism through a connecting hose. A material dropping bracket is provided on one side of the lifting scissor lift and directly below the dust-free demolition mechanism. The material dropping bracket is connected to the dust-free demolition mechanism through a guide cloth tube. An audio probe is installed on the dust-free demolition mechanism.

[0028] As a further embodiment of the invention, the dust-free demolition mechanism includes a rotating bracket, which is rotatably mounted on the upper end of a diagonal support bracket. A rotary motor is mounted on one side of the diagonal support bracket, and the drive shaft of the rotary motor is fixedly connected to the diagonal support bracket. A support slide rail is fixedly connected to the end of the rotating bracket away from the electrically controlled slide table. A positioning slider is slidably sleeved on the support slide rail, and a hydraulic pick is mounted on the positioning slider. A hydraulic push rod is mounted on the rotating bracket, and the telescopic end of the hydraulic push rod is fixedly connected to the tail end of the hydraulic pick.

[0029] As a further aspect of the invention, a first bracket is installed on one end of the rotating bracket near the support slide rail. Two first brackets are provided and located on both sides of the hydraulic push rod. A second bracket is fixedly connected to the middle of the side of the first bracket away from the hydraulic push rod. The axis of the hydraulic push rod and the hydraulic pick is located on the plane where the two second brackets are located. A baffle plate is rotatably connected to the end of each of the two second brackets away from the hydraulic push rod. The two baffle plates are symmetrical to each other and have a semi-circular structure.

[0030] As a further aspect of the invention, a positioning rod is fixedly connected between two pairs of opposite inflection points on the two baffles. A winding frame is fixedly connected to both sides of the second bracket near the arc edge of the baffle. A deflection frame is provided between the winding frame and the baffle. A dust-proof cloth roll is sleeved on the winding frame, and the winding frame is rotatably connected to the dust-proof cloth roll through an elastic rotating shaft. The cloth roll of the dust-proof cloth on each side passes around the deflection frame and is fixedly connected to the positioning rod on the same side. Under the limitation of the deflection frame, and with magnetic strips embedded on the sides of the dust-proof cloth roll and the two baffles, the dust-proof cloth roll is tightly abutted against the baffle after the deflection frame is deflected. The end of the dust-proof cloth roll located above the hydraulic pick is connected to a connecting hose, and the end of the dust-proof cloth roll located below the hydraulic pick is connected to a guide cloth cylinder.

[0031] The beneficial effects of this invention are:

[0032] (1) This invention follows the idea of ​​"vertical layering, longitudinal segmentation, transverse striping, and balanced symmetry", that is, longitudinal bridge segmentation, transverse bridge striping, upper and lower layering, sequential dismantling, and support frame protection, which ensures the stability of the overall bridge structure during the dismantling process, protects the safety of the bridge substructure, and meets the corresponding construction requirements.

[0033] (2) When using a concrete crusher to break up the concrete on the bridge to expose the reinforcing steel, the outer surface of each segment is first divided into areas. Each symmetrical area is then paired with several pairs of concrete crushers. When starting the concrete crusher, the crushers on both sides are started simultaneously in pairs, allowing for synchronous crushing of the areas on both sides of each segment in relative directions. During crushing, the height of the dust-free demolition mechanism is adjusted using the lifting scissor lift, the horizontal position is adjusted using the electrically controlled slide and support plate, and the angle between the axis of the dust-free demolition mechanism and the outer surface of the bridge is adjusted using the rotating base and inclined support. This ensures that the dust-free demolition mechanism can efficiently crush the divided areas. This allows the concrete crushers to gradually converge from both sides towards the center, ensuring a balanced crushing process on both sides. The movement speed and efficiency of the crushers are adjusted so that the convergence point of each pair is directly below the fitted line of the center of gravity of each bridge segment. This maintains the balance of each segment during demolition, preventing the bridge from tilting to one side, especially avoiding the tilting of curved bridges due to their shape and weight distribution. Furthermore, under the monitoring of an audio probe, the impact of the dust-free demolition mechanism on the reinforcing steel is detected. Upon detecting the sound of the steel being struck, the dust-free demolition mechanism is immediately moved horizontally via an electrically controlled slide, preventing damage to the mechanism and increasing the proportion of time the concrete is impacted, thus improving the efficiency of concrete removal.

[0034] (3) During operation, the hydraulic push rod pushes the hydraulic pick head to impact, break, and demolish the concrete on the outer side of the bridge. The angle between the hydraulic pick head and the outer side of the bridge is adjusted by the rotary motor to maintain the best breaking effect. When the hydraulic pick head is impacting, the straight edge of the shield plate abuts against the outer side of the bridge. The shield plate adapts to different inclination angles of the outer side of the bridge by rotating at the end of the second bracket, ensuring that the straight edge of the shield plate always remains in contact. The elastic expansion and contraction of the dustproof cloth roll extended on the winding frame adapts to the shield plate's movement. The rotation angle is the same in the same state, and the side of the dustproof cloth roll and the side of the baffle plate are magnetically abutted to maintain an elastic seal. This can not only shield the crushed stone and dust generated, preventing the stone and dust from splashing and interfering with the hydraulic pick, but also guide the dust to the bag vacuum cleaner for collection through the connecting hose. The crushed stone is guided downward through the guide cloth tube, and the lower bag opening is opened by the material drop bracket to facilitate the loading and transfer of the transport vehicle. This reduces dust pollution in the construction environment and classifies and collects the construction waste for centralized treatment. Attached Figure Description

[0035] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0036] Figure 1This is a plan view of the bridge demolition sequence in a bridge demolition construction method according to the present invention;

[0037] Figure 2 This is a plan view of the removal of guardrails in a bridge demolition construction method according to the present invention;

[0038] Figure 3 This is a cross-sectional schematic diagram of the removal of guardrails in a bridge demolition construction method according to the present invention;

[0039] Figure 4 This is a plan view of the removal of the flange plate in a bridge demolition construction method according to the present invention;

[0040] Figure 5 This is a schematic cross-sectional view of the removal of the flange plate in a bridge demolition construction method according to the present invention;

[0041] Figure 6 This is a plan view of the top slab breaking in a bridge demolition construction method according to the present invention;

[0042] Figure 7 This is a schematic cross-sectional view of the top slab being broken in a bridge demolition construction method according to the present invention;

[0043] Figure 8 This is a plan view of the removal of the beam web in a bridge demolition construction method according to the present invention;

[0044] Figure 9 This is a schematic cross-sectional view of the beam web being removed in a bridge demolition construction method according to the present invention;

[0045] Figure 10 This is a plan view of the double-cell bottom slab of a beam in a bridge demolition construction method according to the present invention;

[0046] Figure 11 This is a schematic cross-sectional view of the double-cell bottom slab of a bridge demolition construction method according to the present invention.

[0047] Figure 12 This is a plan view of the dismantling of the middle beam support in a bridge demolition construction method according to the present invention;

[0048] Figure 13 This is a schematic cross-sectional view of the dismantling of the middle beam support in a bridge demolition construction method according to the present invention;

[0049] Figure 14 This is a plan view of the removal of the pier top beam segment in a bridge demolition construction method according to the present invention;

[0050] Figure 15 This is a plan view of the bridge demolition construction method of the present invention, showing the demolition of the next span;

[0051] Figure 16This is a front view of the overall structure of the concrete crusher of the present invention;

[0052] Figure 17 This is a top view of the overall structure of the concrete crusher of the present invention;

[0053] Figure 18 This is a side view of the overall structure of the dust-free demolition mechanism of the present invention;

[0054] In the diagram: 1. Main beam; 2. Protective support frame; 3. Construction access road; 4. Concrete crusher; 5. Water truck; 6. Truck crane; 101. Pier; 102. Abutment; 103. Guardrail; 104. Flange plate; 105. Double-cell top slab of beam; 106. Beam web; 107. Double-cell bottom slab of beam; 108. Middle beam support; 109. Pier top beam segment; 401. AGV trolley; 402. Rotating base; 403. Lifting scissor lift; 404. Support plate; 405. Support slide plate; 406. Electric... 407. Control table; 408. Dust-free dismantling mechanism; 409. Diagonal brace; 410. Baghouse vacuum cleaner; 411. Connecting hose; 412. Material drop support; 413. Guide cloth tube; 701. Rotating support; 702. Support rail; 703. Rotary motor; 704. Hydraulic push rod; 705. Hydraulic pick; 706. First support; 707. Second support; 708. Baffle plate; 709. Rewinding frame; 710. Deflecting frame; 711. Dustproof cloth roll; 712. Positioning rod; 713. Positioning slider. Detailed Implementation

[0055] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0056] Please see Figure 1-18 The following is a construction method for bridge demolition, comprising the following steps:

[0057] Step S1, Construction Preparation: Prepare construction machinery and materials, divide the bridge into sections, erect protective support frames, and build temporary construction roads.

[0058] Specifically, the bridge includes a main girder 1, which has an arc-shaped structure. Abutments 102 are provided at both ends of the main girder 1. Several piers 101 are provided on the lower side of the main girder 1, evenly distributed in a fan-shaped array. The arc of the array of piers 101 coincides with the arc of the main girder 1. Flange plates 104 and guardrails 103 are provided sequentially from the inside to the outside on both sides of the upper part of the main girder 1. The guardrails 103 are located at the upper edge of the flange plates 104. The main girder 1 includes a central beam support 108, which has an I-shaped structure. The interior of the central beam support 108, from top to bottom... The structure includes a top chamfer plate 1081, a middle chamfer plate 1082, and a bottom chamfer plate 1083. The top chamfer plate 1081 of the middle beam support 108 is fixedly connected to a double-cell top plate 105 on both sides. The middle chamfer plate 1082 has empty cavities on both sides. The bottom chamfer plate 1083 is fixedly connected to a double-cell bottom plate 107 on both sides. A beam web 106 is fixedly connected between the double-cell top plate 105 and the double-cell bottom plate 107 near the flange plate 104. The part of the main beam 1 located at the top of the pier 101 or abutment 102 is designated as the pier top beam segment 109.

[0059] Specifically, in this embodiment, for the segmentation in step S1, the entire bridge is divided into five spans based on the locations of the piers 101 and abutments 102. Each span is 24 meters long, and each span is divided into eight segments in the longitudinal direction of the bridge, with each segment marked in 3-meter increments. Before demolition, the segments are marked. During demolition, the fourth and fifth segments in the middle of the span are broken off sequentially towards both ends. When the concrete crusher 4 breaks the concrete to the segment marking line, the commander confirms that the segment has been broken before proceeding to the next segment.

[0060] Specifically, in this embodiment, the erection of the protective support frame 2 in step S1 includes the following steps:

[0061] S121: Construct a protective and anti-overturning support for pier 101 and abutment 102. The support includes columns, horizontal bracing and diagonal bracing, and foundation. The columns are made of 429*10mm steel pipe, the horizontal bracing and diagonal bracing are made of 140*16mm angle steel, and the foundation is made of C30 concrete.

[0062] S122: Three steel pipes are installed on both sides of each pier 101 and under the main beam 1. First, steel plates are welded to the top of the steel pipes and the steel plates are bolted to the bottom plate 107 of the double-cell beam. Then, pads are added to the bottom of each steel pipe and the pads are welded firmly to the steel pipes. Then, the pads are fixedly connected to the foundation.

[0063] Specifically, the protective support frame 2 can be used during bridge demolition and its service life can be extended until the subsequent construction of a new bridge using the undemolished piers 101 and abutments 102 is completed. Due to the extended service life, the protective support frame 2 is shared with the cast-in-place support used during bridge construction. The foundation center must be 1.5m from the pier top centerline. The design dimensions of the support are 10*2m, and the steel reinforcement used in the support is arranged in a double-layer 0.2m*0.2m steel mesh pattern. The top surface of the protective support frame 2 foundation is the top surface of the pier cap, and the bottom is determined based on the site excavation conditions. An excavator is used to clear the bedrock to the top surface and then excavate downwards to a depth of 0.3m before pouring C30 concrete. The foundation height must not be less than 1m. According to the site conditions and original drawings, the steel pipe columns of the protective support frame 2 are all located on the pier cap. During bridge demolition, the support frame foundation is excavated to the pier cap, using the pier cap as the bottom foundation. The pier cap concrete must not be damaged. The cast-in-place support used during bridge construction is extended and wrapped according to the dimensions, which will not be elaborated upon here.

[0064] S123: When erecting a protective and anti-overturning support for abutment 102, a steel support is inserted in the middle of the support between abutment 102 and main beam 1 as an anti-overturning measure for abutment 102. The steel support is made of SUS429 steel pipe welded together, and the stop block of abutment 102 is fixed to the connected beam body by bolted steel plates.

[0065] S124. Pier-beam consolidation: After completing the above steps, the supports between pier 101 and main beam 1 and between abutment 102 and main beam 1 are locked, and the protective support frame 2 begins to support the main beam 1, thus serving as a temporary pier-beam consolidation device.

[0066] Specifically, in this embodiment, for the construction of the temporary access road 3 in step S1, a temporary access road 3 is constructed outward on both sides of the bridge for bridge demolition. During construction, a site survey is conducted, and the boundary line is determined according to the design. An excavator is used to level and compact the original ground within the boundary line. When encountering a riverbank, the access road 3 is backfilled and compacted with nearby sand and gravel. Within a 10-meter width range from the pier 101 or abutment 102 near the water, round logs are laid longitudinally and covered with wooden planks to facilitate water passage and prevent the demolished concrete blocks from falling into the water and causing pollution. The access road 3 is 6m wide and 4m below the bridge projection line. The area within 4m of the bridge projection line is designated as a safety warning zone, and no personnel or machinery are allowed to enter during demolition operations.

[0067] Please see Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Figure 9 , Figure 10 , Figure 11 , Figure 12 , Figure 13 , Figure 14 As shown, step S2, the layered and segmented removal of main beam 1, includes the following steps:

[0068] Specifically, in this embodiment, please refer to Figure 2 Figure 3 The removal of guardrail 103 in step S2 includes the following steps:

[0069] S211: Remove guardrail 103: Move the concrete crusher 4 to the corresponding positions on both sides of one of the spans, and use the concrete crusher 4 to demolish the guardrail 103 in a synchronous and symmetrical manner from the middle of the main beam 1 of that span to both sides, and demolish it in 3m segments; when crushing, do not crush to the bottom of the guardrail 103 at once, first crush the upper half of the 3m segment gradually, and then crush the lower half after completion.

[0070] Specifically, in this embodiment, please refer to Figure 4 Figure 5 The removal of flange 104 in step S2 includes the following steps:

[0071] S212: Removal of flange plate 104: After the guardrail 103 is removed, use concrete crusher 4 to remove the flange plate 104 symmetrically and gradually from the middle of the span to both sides in 3-meter segments; when removing the flange plate 104, do not remove it all at once, first remove the concrete within the outer 1-meter width, and then remove the concrete within the inner 1-meter width; during the removal process, safety officers on both sides are on duty throughout, and at the same time, the surveyors need to observe the condition of the adjacent span beams. After removal, the surveyors measure the measurement points of the adjacent spans;

[0072] Specifically, in this embodiment, please refer to Figure 6 Figure 7 For step S2, the removal of the double-cell roof slab 105 of the beam includes the following steps:

[0073] S213: Demolition of the double-cell roof slab 105: After the flange plate 104 is removed, use a concrete crusher 4 to demolish the double-cell roof slab 105 of the beam simultaneously and symmetrically from the middle of the span to both sides, so that all the concrete of the double-cell roof slab 105 of the beam is broken; during the demolition process, safety officers on both sides are on duty throughout the process, and at the same time, the surveyors need to observe the condition of the adjacent span beams. After the demolition, the surveyors measure the measurement points of the adjacent spans.

[0074] Specifically, in this embodiment, please refer to Figure 8 Figure 9 The removal of the beam web 106 in step S2 includes the following steps:

[0075] S214: Removal of beam web 106: Using concrete crusher 4, beam web 106 is removed segmentally and symmetrically from the mid-span to both sides. During crushing, it is not removed all at once to the bottom; the upper half is crushed first, and then the lower half is crushed. After removal, concrete crusher 4 is replaced with hydraulic shears to cut the steel bars of the removed parts from both ends and lift them away from the site. Safety officers on both sides are on duty throughout the removal process, and surveyors need to observe the condition of the adjacent span beams. After removal, surveyors measure the measurement points of the adjacent spans.

[0076] Specifically, in this embodiment, please refer to Figure 10 Figure 11 For step S2, the removal of the double-cell bottom slab 107 of the beam includes the following steps:

[0077] S215: Demolition of the double-cell bottom slab 107 of the beam: Using a concrete crusher 4, the double-cell bottom slab 107 of the beam is demolished symmetrically from the mid-span to both sides in 3m segments. During the demolition process, safety officers on both sides are on duty throughout the process, and at the same time, the surveyors need to observe the condition of the beams in adjacent spans. After the demolition, the surveyors measure the measurement points of the adjacent spans.

[0078] Specifically, in this embodiment, please refer to Figure 12 Figure 13 The removal of the central beam support 108 in step S2 includes the following steps:

[0079] S216: Dismantling of the central beam support 108: Using a concrete crusher 4, the central beam support 108 is dismantled symmetrically and gradually from the middle of the span to both sides. During the dismantling process, a water truck 5 is used to spray water to reduce dust. The central beam support 108 is also removed layer by layer from top to bottom. The top chamfered plate 1081, the middle chamfered plate 1082, and the bottom chamfered plate 1083 are successively crushed and the steel bars are cleaned. Safety officers on both sides are on duty throughout the dismantling process. At the same time, the surveyors need to observe the condition of the adjacent span beams. After the dismantling, the surveyors measure the measurement points of the adjacent spans.

[0080] Specifically, in this embodiment, please refer to Figure 14 For step S2, the removal of the pier top beam segment 109 includes the following steps:

[0081] S217: Removal of pier top beam segment 109: After the main beam 1 of this span is removed, hydraulic shears are used to cut and remove the reinforcing bars. The remaining pier top beam segment 109 on pier 101 or abutment 102 is removed in a timely manner using truck crane 6. Safety officers on both sides are on duty throughout the removal process to determine the location of the broken pier top beam segment in advance, so as not to affect the removal of the next span.

[0082] Please see Figure 15As shown, for step S3, inspecting and dismantling the next span: based on the actual site conditions and in accordance with the relevant bridge dismantling specifications, check whether beam 1 is stable and whether there are any defects or aggravation of defects in the substructure of the bridge to ensure the overall stability of the bridge. If there are no bridge safety issues, step S2 can be repeated to continue dismantling the next span of the bridge.

[0083] Please see Figure 16 A type of crushing equipment for bridge demolition includes a concrete crusher 4, which comprises an AGV trolley 401. A rotating base 402 is mounted on the AGV trolley 401, and a lifting scissor lift 403 is mounted on the rotating base 402. A support plate 404 is mounted on the top of the lifting scissor lift 403, and a support slide plate 405 and an electrically controlled slide table 406 are mounted on the support plate 404. The support slide plate 405 is slidably connected to the support plate 404, and the electrically controlled slide table 406 drives the support slide plate 405 to slide left and right. A dust-free demolition mechanism 407 is provided on the support slide plate 405. 07 is positioned diagonally above the support plate 404 by the inclined support bracket 408. A bag vacuum cleaner 409 is installed on the side of the support plate 404 away from the dust-free demolition mechanism 407. The bag vacuum cleaner 409 is connected to the dust-free demolition mechanism 407 through the connecting hose 410. A material drop bracket 411 is provided on one side of the lifting scissor frame 403 and directly below the dust-free demolition mechanism 407. The material drop bracket 411 is connected to the dust-free demolition mechanism 407 through the guide cloth tube 412. Both the connecting hose 410 and the guide cloth tube 412 are telescopic structures. An audio probe is installed on the dust-free demolition mechanism 407.

[0084] In this embodiment, when the concrete crusher 4 breaks the concrete on various parts of the bridge to expose the reinforcing steel, the outer surface of each segment is first divided into areas. Each symmetrical area on both sides is associated with several pairs of concrete crushers 4. When the concrete crusher 4 is started, the two sides of the crusher 4 are started simultaneously, in pairs, so that the areas on both sides of each segment are broken synchronously in relative directions. During breaking, the height of the dust-free demolition mechanism 407 is adjusted by the lifting scissor lift 403, the horizontal position of the dust-free demolition mechanism 407 is adjusted by the electrically controlled slide 406 and the support slide plate 405, and the angle between the axis of the dust-free demolition mechanism 407 and various parts of the outer surface of the bridge is adjusted by the rotating base 402 and the inclined support bracket 408. This allows the dust-free demolition mechanism 407 to break the divided areas with optimal efficiency, gradually moving from both sides towards the center. The concrete crushers 4 are brought together and the crushing process is carried out in a balanced manner on both sides. The moving speed and working efficiency of the concrete crushers 4 on both sides are adjusted so that the convergence point of each pair of concrete crushers 4 is located directly below the fitting line of the center of gravity of each segment of the bridge. This maintains the balance of each segment of the bridge during the demolition process and prevents the bridge from tilting to one side, especially preventing the tilting of the curved bridge due to its shape and weight distribution. Under the monitoring of the audio probe, the impact of the dust-free demolition mechanism 407 on the steel bars is distinguished. After the sound of the steel bars being hit is detected, the dust-free demolition mechanism 407 is immediately moved by the electric control slide table 406 to avoid damage to the dust-free demolition mechanism 407. At the same time, the proportion of time that the concrete part is hit is increased, which improves the efficiency of concrete removal and facilitates the subsequent removal of steel bars by hydraulic shears. It also facilitates the classification and transportation of concrete and steel bars during bridge demolition and facilitates further decomposition and processing.

[0085] Please see Figure 17-18The dust-free demolition mechanism 407 includes a rotating bracket 701, which is rotatably mounted on the upper end of a diagonal support bracket 408. A rotary motor 703 is mounted on one side of the diagonal support bracket 408, and the drive shaft of the rotary motor 703 is fixedly connected to the diagonal support bracket 408. A support slide rail 702 is fixedly connected to the end of the rotating bracket 701 away from the electrically controlled slide table 406. A positioning slider 713 is slidably sleeved on the support slide rail 702, and a hydraulic pick 705 is mounted on the positioning slider 713. A hydraulic push rod is mounted on the rotating bracket 701. 704, the telescopic end of the hydraulic push rod 704 is fixedly connected to the tail end of the hydraulic pick 705. A first bracket 706 is installed on one end of the rotating bracket 701 near the support slide rail 702. There are two first brackets 706 located on both sides of the hydraulic push rod 704. A second bracket 707 is fixedly connected to the middle of the side of the first bracket 706 away from the hydraulic push rod 704. The axis of the hydraulic push rod 704 and the hydraulic pick 705 is located on the plane where the two second brackets 707 are located. The two second brackets 707 are away from the hydraulic push rod 704. One end of each of the 04 brackets is rotatably connected to a baffle plate 708. The two baffle plates 708 are symmetrical and have a semi-circular structure. A positioning rod 712 is fixedly connected between two pairs of opposite inflection points on the two baffle plates 708. A winding frame 709 is fixedly connected to both sides of the second bracket 707 near the arc edge of the baffle plate 708. A deflection frame 710 is provided between the winding frame 709 and the baffle plate 708. A dust-proof cloth roll 711 is sleeved on the winding frame 709, and the winding frame 709 is rotatably connected to the dust-proof cloth roll 711 through an elastic rotating shaft. Each side is equipped with a dust-proof cloth roll 711. The dust cloth roll 711 is wrapped around the deflector 710 and fixedly connected to the positioning rod 712 on the same side. Under the limit of the deflector 710, and with magnetic strips embedded on the sides of the dust cloth roll 711 and the two baffles 708, the dust cloth roll 711 is tightly abutted against the baffles 708 after the deflector 710 is deflected. The end of the dust cloth roll 711 above the hydraulic pick 705 is connected to the connecting hose 410, and the end of the dust cloth roll 711 below the hydraulic pick 705 is connected to the guide cloth cylinder 412.

[0086] In this embodiment, the hydraulic push rod 704 pushes the hydraulic pick 705 to impact, break, and demolish the concrete on the outer surface of the bridge. The rotary motor 703 adjusts the angle between the hydraulic pick 705 and the outer surface of the bridge to maintain the optimal breaking effect. When the hydraulic pick 705 impacts, the straight edge of the baffle plate 708 abuts against the outer surface of the bridge. The baffle plate 708 rotates at the end of the second bracket 707 to adapt to different inclination angles of the outer surface of the bridge, ensuring that the straight edge of the baffle plate 708 always remains in contact. The elastic extension and retraction of the dustproof cloth roll 711 extending on the winding frame 709 adapts to the rotation angle of the baffle plate 708 in different states, and the dustproof cloth roll 711... The side of the shield 708 is magnetically abutted against to maintain an elastic seal, which can shield the crushed stone and dust generated, preventing the stone and dust from splashing and interfering with the hydraulic pick 705. At the same time, the dust is sucked and guided to the bag vacuum cleaner 409 for collection through the connecting hose 410. The crushed stone is guided downward through the guide cloth cylinder 412 and the lower bag opening is opened by the material drop bracket 411 to facilitate the loading and transfer of the transport vehicle. This reduces dust pollution in the construction environment and classifies and collects the construction waste for centralized treatment. As a result, the construction process is efficient, low-noise, and low-pollution. The whole process can be programmed and intelligently controlled, reducing manpower consumption, extending continuous construction time, and shortening the total construction period.

[0087] When using this invention, workers follow the approach of "vertical layering, longitudinal segmentation, transverse striping, and balanced symmetry," that is, segmenting the bridge longitudinally, stripping the bridge transversely, layering the upper and lower parts, dismantling in sequence, and protecting it with support frames. This ensures the stability of the overall bridge structure during dismantling, protects the safety of the bridge substructure, and meets the corresponding construction requirements.

[0088] When using concrete crusher 4 to break up the concrete on various parts of the bridge to expose the reinforcing steel, the outer surface of each segment is first divided into areas. Each symmetrical area is then associated with several pairs of concrete crushers 4. When concrete crusher 4 is started, the two pairs of crushers 4 are started simultaneously, allowing for synchronous breaking of the areas on both sides of each segment in relative directions. During breaking, the height of the dust-free demolition mechanism 407 is adjusted using the lifting scissor lift 403, the horizontal position of the dust-free demolition mechanism 407 is adjusted using the electrically controlled slide 406 and the support slide plate 405, and the angle between the axis of the dust-free demolition mechanism 407 and various points on the outer surface of the bridge is adjusted using the rotating base 402 and the diagonal brace 408. This ensures that the dust-free demolition mechanism 407 can efficiently break up the divided areas. The system advances by crushing the entire surface, gradually converging the pairs of concrete crushers 4 from both sides towards the center, ensuring the crushing process is balanced on both sides. The movement speed and efficiency of the concrete crushers 4 on both sides are adjusted so that the convergence point of each pair of concrete crushers 4 is directly below the fitted line of the center of gravity of each segment of the bridge. This maintains the balance of each segment of the bridge during the demolition process, preventing the bridge from tilting to one side, especially avoiding the tilting of curved bridges due to their shape and weight distribution. Furthermore, under the monitoring of an audio probe, the impact of the dust-free demolition mechanism 407 on the reinforcing steel is detected. Upon detecting the sound of the reinforcing steel being struck, the dust-free demolition mechanism 407 is immediately moved horizontally via the electrically controlled slide table 406, thus preventing damage to the dust-free demolition mechanism 407 and increasing the proportion of time the concrete is impacted, thereby improving the efficiency of concrete removal.

[0089] During operation, the hydraulic push rod 704 pushes the hydraulic pick 705 to impact, break, and demolish the concrete on the outer surface of the bridge. The rotary motor 703 adjusts the angle between the hydraulic pick 705 and the outer surface of the bridge to maintain the optimal breaking effect. When the hydraulic pick 705 strikes, the straight edge of the baffle plate 708 abuts against the outer surface of the bridge. The baffle plate 708 adapts to different inclination angles of the outer surface of the bridge by rotating at the end of the second bracket 707, ensuring that the straight edge of the baffle plate 708 always remains in contact. The elastic extension and retraction of the dustproof cloth roll 711 extending on the winding frame 709 adapts to the shielding. The rotation angle of plate 708 in different states, and the magnetic contact between the side of dustproof cloth roll 711 and the side of shield plate 708 maintain an elastic seal, can not only shield the crushed stone and dust generated, preventing the stone and dust from splashing and interfering with the hydraulic pick 705, but also guide the dust to the bag vacuum cleaner 409 for collection through the connecting hose 410. The crushed stone is guided downward through the guide cloth cylinder 412 and the lower bag opening is opened by the material drop bracket 411 to facilitate the loading and transfer of transport vehicles, thereby reducing dust pollution in the construction environment, and classifying and collecting the construction waste for centralized treatment.

[0090] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A construction method for bridge demolition, characterized in that, Includes the following steps: Step S1: Divide the bridge into spans and sections, mark the abutments (102) and piers (101), erect a protective support frame (2) under the main beam (1), and build a construction access road (3). Step S2: Demolish the main beam (1) in layers and sections. Use a concrete crusher (4) to break the concrete on the guardrail (103), flange plate (104), double-cell top plate (105), web plate (106), double-cell bottom plate (107), and middle beam support (108), and hoist away the pier top beam section (109). Step S3: Check the stability and defects of the bridge. If there are no problems, repeat step S2 to continue dismantling the next span of the bridge. The concrete crusher (4) includes an AGV trolley (401), a rotating base (402) is installed on the AGV trolley (401), a lifting scissor lift (403) is installed on the rotating base (402), a support plate (404) is installed on the top of the lifting scissor lift (403), a support slide plate (405) and an electric control slide table (406) are installed on the support plate (404), the support slide plate (405) is slidably connected to the support plate (404), the electric control slide table (406) drives the support slide plate (405) to slide left and right, and a dust-free demolition mechanism (407) is provided on the support slide plate (405). The dust-free demolition mechanism (407) includes a rotating bracket (701), which is rotatably mounted on the upper end of the inclined support bracket (408). A rotary motor (703) is installed on one side of the inclined support bracket (408). The drive shaft of the rotary motor (703) is fixedly connected to the inclined support bracket (408). A support slide rail (702) is fixedly connected to the end of the rotating bracket (701) away from the electric control slide table (406). A positioning slider (713) is slidably sleeved on the support slide rail (702). A hydraulic pick (705) is installed on the positioning slider (713). A hydraulic push rod (704) is installed on the rotating bracket (701). The telescopic end of the hydraulic push rod (704) is fixedly connected to the tail end of the hydraulic pick (705). The rotating bracket (701) is equipped with a first bracket (706) at one end near the support slide rail (702). There are two first brackets (706) located on both sides of the hydraulic push rod (704). A second bracket (707) is fixedly connected to the middle of the side of the first bracket (706) away from the hydraulic push rod (704). The axis of the hydraulic push rod (704) and the hydraulic pick (705) is located on the plane where the two second brackets (707) are located. A baffle plate (708) is rotatably connected to the end of the two second brackets (707) away from the hydraulic push rod (704). The two baffle plates (708) are symmetrical to each other and have a semi-circular structure. Positioning rods (712) are fixedly connected between two pairs of opposite inflection points on the two baffles (708). A winding frame (709) is fixedly connected to both sides of the second bracket (707) near the arc edge of the baffle (708). A deflector frame (710) is provided between the winding frame (709) and the baffle (708). A dust-proof cloth roll (711) is sleeved on the winding frame (709), and the winding frame (709) is rotatably connected to the dust-proof cloth roll (711) via an elastic pivot. The cloth roll of the dust-proof cloth roll (711) on each side passes around the deflector frame (710). And it is fixedly connected to the positioning rod (712) on the same side. Under the limit of the deflection frame (710), and the dustproof cloth roll (711) and the two baffles (708) are all embedded with magnetic strips that attract each other, so that the dustproof cloth roll (711) is tightly abutted against the baffle (708) after the deflection frame (710) is deflected. The end of the dustproof cloth roll (711) above the hydraulic pick (705) is connected to the connecting hose (410), and the end of the dustproof cloth roll (711) below the hydraulic pick (705) is connected to the guide cloth cylinder (412).

2. The construction method for bridge demolition according to claim 1, characterized in that, In step S1, the entire bridge is divided into five spans based on the locations of the piers (101) and abutments (102). Each span is 24 meters long and is further divided into eight segments in the longitudinal direction of the bridge, with each segment being 3 meters long. During demolition, the bridge is dismantled sequentially from the fourth and fifth segments in the middle of the span towards both ends.

3. The construction method for bridge demolition according to claim 1, characterized in that, The step S1 of erecting the protective support frame (2) includes the following steps: S121: Construct protective and anti-overturning supports for the piers (101) and abutments (102). The supports include columns, horizontal bracing, diagonal bracing, and foundations. The columns are made of 429 steel. 10mm steel pipe, horizontal bracing and diagonal bracing use 140 16mm angle steel, C30 concrete for the foundation; S122: Three steel pipes are installed on both sides of each pier (101) and under the main beam (1). First, a steel plate is welded to the top of the steel pipe and the steel plate is bolted to the bottom plate (107) of the double-cell beam. Then, a pad is added to the bottom of each steel pipe and the pad is welded firmly to the steel pipe. Then the pad is fixedly connected to the foundation. S123: When erecting a protective and anti-overturning support on the abutment (102), a steel support is inserted in the middle of the support between the abutment (102) and the main beam (1) as an anti-overturning measure for the abutment (102). The steel support is made of SUS429 steel pipe welded together, and the block of the abutment (102) is fixed to the connected beam body by bolted steel plates. S124. Pier-beam consolidation: After completing the above steps, lock the supports between the pier (101) and the main beam (1) and between the abutment (102) and the main beam (1), and protect the support frame (2) to start supporting the main beam (1), thus serving as a temporary pier-beam consolidation device.

4. The construction method for bridge demolition according to claim 1, characterized in that, According to the design, the boundary line is determined, and the original ground inside the boundary line is leveled and compacted by an excavator. When encountering the riverbank, the construction access road (3) is backfilled and compacted with nearby sand and gravel. Within a 10-meter width of the bridge pier (101) or abutment (102) near the water, round logs are laid longitudinally and covered with wooden boards for water passage and to prevent the demolition of concrete blocks from falling into the water and causing pollution. The construction access road (3) is 6m wide and 4m below the bridge projection line.

5. The construction method for bridge demolition according to claim 1, characterized in that, The step S2, dismantling the main beam (1) in layers and sections, includes the following steps: S211: Remove the guardrail (103): Move the concrete crusher (4) to the corresponding positions on both sides of the span to be removed, and use the concrete crusher (4) to gradually and symmetrically remove the guardrail from the middle of the span to both sides, removing it one segment at a certain distance; when crushing, do not crush to the bottom of the guardrail (103) at once, first crush the upper half of the segment gradually, and then crush the lower half after completion; S212: Remove flange plate (104): After the guardrail (103) is removed, use a concrete crusher (4) to remove the flange plate (104) symmetrically from the middle of the span to both sides in one segment. When removing the flange plate (104), do not remove it all at once. First remove the concrete within a certain width on the outside, and then remove the concrete within a certain width on the inside. S213: Demolish the double-cell roof slab of the beam (105): After the flange plate (104) is removed, use a concrete crusher (4) to simultaneously and symmetrically demolish the double-cell roof slab of the beam (105) from the middle of the span to both sides, so that all the concrete of the double-cell roof slab of the beam (105) is broken. S214: Removal of beam web (106): Using a concrete crusher (4), the beam web (106) is removed from the middle of the span to both sides in a synchronous and symmetrical manner, segment by segment. When crushing, it is not to crush to the bottom all at once, but to crush the upper half first, and then crush the lower half after completion. After removal, hydraulic shears are used to cut the steel bars of the removed parts from both ends and lift them away from the site. S215: Demolition of the double-cell bottom slab of the beam (107): Using a concrete crusher (4), the double-cell bottom slab of the beam (107) is demolished symmetrically from the middle of the span to both sides in one segment at a time; S216: Dismantle the central beam support (108): Use a concrete crusher (4) to dismantle the beam symmetrically from the middle of the span to both sides. During the dismantling process, use a water truck (5) to spray and reduce dust. The central beam support (108) is removed layer by layer from top to bottom. The top chamfer plate (1081), the middle chamfer plate (1082), and the bottom chamfer plate (1083) are then crushed and the reinforcing steel is removed. S217: Removal of the pier top beam segment (109): After the demolition is completed, use hydraulic shears to cut the steel bars from both ends and remove them. Use a truck crane (6) to remove the remaining pier top beam segment (109) on the pier (101) or abutment (102).

6. The construction method for bridge demolition according to claim 5, characterized in that, The dust-free demolition mechanism (407) is positioned diagonally above the support plate (404) by a diagonal brace (408). A bag vacuum cleaner (409) is installed on the side of the support plate (404) away from the dust-free demolition mechanism (407). The bag vacuum cleaner (409) is connected to the dust-free demolition mechanism (407) through a connecting hose (410). A material drop bracket (411) is provided on one side of the lifting scissor lift (403) and directly below the dust-free demolition mechanism (407). The material drop bracket (411) is connected to the dust-free demolition mechanism (407) through a guide cloth tube (412). An audio probe is installed on the dust-free demolition mechanism (407).

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