Railway hole connection length existing bridge and culvert wing wall demolition protection method

Abstract

This application discloses a method for protecting the wing walls of existing bridges and culverts during railway extension projects. The method includes the following steps: S1, installing multiple reinforced concrete bored piles between the existing wing wall and the roadbed; S2, connecting the multiple reinforced concrete bored piles with a capping beam; S3, demolishing the portion of the existing wing wall that interferes with the new frame structure; S4, constructing the extended bridge and culvert, connecting it to the existing culvert. During the process of extending and demolishing the existing wing wall, a portal-type pile structure formed by a capping beam and reinforced concrete bored piles is constructed on the back of the existing wing wall, effectively supporting the roadbed and controlling lateral displacement within millimeters. Furthermore, during the demolition of the existing wing wall, only the portion interfering with the construction of the new frame structure is removed; the remaining existing wing wall structure and the portal-type pile structure protect the roadbed, effectively improving the overall rigidity of the roadbed protection structure.

Description

Technical Field

[0001] This application relates to the field of wing wall demolition and protection technology, and in particular to a method for demolishing and protecting the wing walls of existing bridges and culverts that are connected by railway spans. Background Technology

[0002] In the reconstruction and expansion of high-speed railways, the expansion of the line or the addition of new tracks leads to a significant increase in the width of the roadbed, which drastically reduces the cross-sectional area or clearance of the original bridges and culverts, creating bottlenecks that block waterways or traffic. If the bridges and culverts are directly abandoned and demolished and rebuilt, not only will the long-term interruption of their existing functions induce water damage or roadbed instability, but the large-scale excavation and disturbance will also directly endanger the safety of mainline traffic. Therefore, extending bridges and culverts has become the optimal solution that maximizes the use of existing structures, minimizes costs, and is the fastest while ensuring uninterrupted railway operation.

[0003] The extension construction of bridges and culverts requires the demolition of the wing walls and other ancillary structures of existing culverts. The demolition section is located at the slope of the roadbed near the bridge abutment, which has a significant impact on the stability of the roadbed slope. Large-diameter culverts have thick foundation slabs and abutments, resulting in deep excavation pits and large excavation areas. If the existing roadbed is not reinforced, traffic safety will be directly endangered.

[0004] Therefore, it is necessary to propose a method for the removal and protection of the wing walls of existing bridges and culverts for railway extension to ensure traffic safety, which has become an important technical problem that urgently needs to be solved. Summary of the Invention

[0005] This application provides a method for protecting the wing walls of existing bridges and culverts during railway extension projects. The aim is to address the problem in existing technologies where bridge and culvert extension construction requires the removal of the wing walls and other ancillary structures of existing culverts, with the removal area located precisely at the abutment and roadbed slope, significantly impacting the stability of the roadbed slope. Large-diameter culverts have thick foundation slabs and abutments, resulting in deep and extensive excavation pits. Without reinforcement of the existing railway roadbed, this directly jeopardizes traffic safety.

[0006] To achieve the above objectives, this application proposes a method for protecting the demolition of the wing wall of an existing bridge or culvert for railway extension. The protection method specifically includes the following steps: S1, setting multiple reinforced concrete bored piles between the existing wing wall and the roadbed; S2, connecting the multiple reinforced concrete bored piles with a cap beam; S3, demolishing the part of the existing wing wall that interferes with the newly built frame structure; S4, constructing an extension bridge or culvert and connecting the extension bridge or culvert with the existing bridge or culvert.

[0007] In some embodiments, S1 further includes the following steps: S11, filling the pile foundation operation platform; S12, disassembling and hoisting each component of the full-rotation drilling rig, using an 80-ton truck crane to hoist it to the operation platform for assembly, and then moving it to the predetermined drilling pile position for drilling operations; S13, hoisting the steel cage section by section; S14, pouring concrete to form a reinforced concrete bored pile.

[0008] In some embodiments, during the filling process of the above-mentioned pile foundation operation platform, Group B filler is used for filling, the roadbed slope toe is filled outward, and the layers are compacted in layers. The thickness of each layer is not more than 20cm, the compaction degree of the operation platform must meet the compaction requirement of 93%, and the foundation bearing capacity must reach more than 100kpa.

[0009] In some embodiments, the specific construction method of the capping beam in S2 above is as follows: S21, construction preparation and surveying and setting out; S22, trimming the reinforcing bars and pile heads of the reinforced concrete bored piles; S23, leveling the bottom surface; S24, tying the capping beam reinforcing bar skeleton; S25, erecting the capping beam pouring formwork; S26, pouring concrete and curing.

[0010] In some embodiments, in the above S3, the existing wing wall includes a retained portion and a portion to be demolished. The specific demolition method for the portion to be demolished is as follows: S31, first cut off the pier edge of the wing wall to be demolished; S32, then cut off the interfering portion of the wing wall to be demolished in layers; S33, finally cut off the pier below the interfering portion of the wing wall to be demolished.

[0011] In some embodiments, during the layered cutting process described in S32, a hydraulic wire saw is used to cut the interfering portion.

[0012] In some embodiments, in S3 above, the pile foundation operation platform is first dismantled, and then the part of the existing wing wall that interferes with the new frame structure is dismantled.

[0013] In some embodiments, in S3 above, the demolition method further includes the following steps: S34, installing horizontal support walers and steel pipe supports, one end of the steel pipe supports abutting against the retained portion, and the other end of the steel pipe supports abutting against the side wall of the previously constructed central frame structure.

[0014] This application proposes a method for protecting the wing walls of existing bridges and culverts during railway extension and connection. The method includes the following steps: S1, installing multiple reinforced concrete bored piles between the existing wing wall and the roadbed; S2, connecting the multiple reinforced concrete bored piles with a capping beam; S3, demolishing the portion of the existing wing wall that interferes with the new frame structure; S4, constructing the extended bridge and culvert, connecting it to the existing culvert. During the process of extending and demolishing the existing wing wall, a portal-type pile structure formed by a capping beam and reinforced concrete bored piles is constructed on the back of the existing wing wall, effectively supporting the roadbed and controlling lateral displacement within millimeters. Furthermore, during the demolition of the existing wing wall, only the portion interfering with the construction of the new frame structure is removed, while the majority of the existing wing wall structure is retained. The retained existing wing wall structure, along with the capping beam and all the reinforced concrete bored piles, protects the roadbed, effectively improving the overall rigidity of the roadbed protection structure. It also avoided the massive amount of engineering work involved in large-scale demolition, as well as the large amount of concrete waste that would result. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein: Figure 1 This is a technical roadmap of a method for removing and protecting the wing wall of an existing railway bridge with a butt joint, according to one embodiment of this application. Figure 2 This is a plan view of the demolition of the existing wing wall of the frame bridge and the arrangement of the reinforced concrete bored piles in one embodiment of this application; Figure 3 This is a schematic diagram of a filling operation platform in one embodiment of this application; Figure 4 This is another schematic diagram of the filling operation platform in one embodiment of this application; Figure 5 This is a schematic diagram of the positioning and hoisting of a full-rotation drilling rig in one embodiment of this application; Figure 6 This is a structural schematic diagram of a reinforced concrete bored pile and capping beam in one embodiment of this application; Figure 7 This is a schematic diagram illustrating the demolition sequence of an existing wing wall in one embodiment of this application; Figure 8 This is a schematic diagram of the portion of the existing wing wall to be demolished in one embodiment of this application; Figure 9 This is a schematic diagram of the steel pipe support structure in one embodiment of this application.

[0016] In the diagram: 1. Reinforced concrete bored pile; 2. Existing wing wall; 3. Foundation pipe pile; 4. Wing wall foundation; 5. Part to be demolished; 6. 80-ton truck crane; 7. Full-rotation drilling rig; 8. Isolation fence; 9. Crown beam; 10. Retained part; 11. Steel pipe support. Detailed Implementation

[0017] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0018] See Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 As shown, this application discloses a method for protecting the wing wall of an existing railway bridge / culvert after its extension. The method specifically includes the following steps: S1. Multiple reinforced concrete bored piles 1 are installed between the existing wing wall 2 and the roadbed; reinforced concrete bored piles 1 are installed between the existing wing wall 2 and the roadbed for support, and the roadbed at the edge of the new bridge and culvert pit is protected by the structural combination of reinforced concrete bored piles 1 and existing wing wall 2.

[0019] The cast-in-place piles are 100cm in diameter, spaced 1.2m apart, and 36m long, and were constructed directly behind the existing wing wall 2. They essentially replaced the retaining function of the wing wall. During demolition, the earth pressure was borne by the reinforced concrete bored piles 1.

[0020] S2. Multiple reinforced concrete bored piles 1 are connected by a capping beam 9. The capping beam 9 is 1.2m wide and 1.0m high, connecting the bored piles into a single unit. The main reinforcement of the capping beam 9 is made of continuous Φ20 threaded steel bars spaced 10cm apart, and the stirrups are made of Φ12 threaded steel bars spaced 20cm apart. The capping beam 9 and all the reinforced concrete bored piles 1 are connected to form a portal frame pile structure. The overall structural stiffness of the portal frame pile structure far exceeds the sum of the stiffness of the multiple reinforced concrete bored piles 1, effectively controlling the lateral displacement of the roadbed to the millimeter level. The earth pressure is evenly distributed to all the reinforced concrete bored piles 1 through the capping beam 9, reducing the risk of individual reinforced concrete bored piles 1 being broken one by one, and greatly improving the bearing capacity and reliability of the entire protection system.

[0021] S3. Demolish the portion of the existing wing wall 2 that interferes with the construction of the new frame structure. During the demolition of the existing wing wall 2, only the portion that interferes with the construction of the new frame structure is removed, while the majority of the existing wing wall 2 structure is retained. The retained existing wing wall 2 structure, along with the capping beam 9 and all the reinforced concrete bored piles 1, protects the roadbed, effectively improving the overall rigidity of the roadbed protection structure. This also avoids the enormous workload of large-scale demolition and the resulting large amount of concrete waste removal.

[0022] S4. Construct extended culverts that connect to existing culverts. An extension joint is installed between the extended and existing culverts. Since the foundation compaction and settlement differ between the extended and existing culverts, the extension joint effectively prevents cracking at the junction due to uneven settlement. Water-swellable sealing strips are embedded in the extension joint to meet the sealing requirements of the culvert.

[0023] Specifically, during the extension of the existing bridge and culvert wing walls and the demolition of existing wing wall 2, a portal-type pile structure consisting of a capping beam 9 and reinforced concrete bored piles 1 was constructed on the back of existing wing wall 2. This effectively supported the roadbed and controlled the lateral displacement of the roadbed to the millimeter level. Furthermore, during the demolition of existing wing wall 2, only the portion of existing wing wall 2 structure that interfered with the construction of the new frame structure was removed, while the majority of the existing wing wall 2 structure was retained. The retained existing wing wall 2 structure, along with the capping beam 9 and all the reinforced concrete bored piles 1, protected the roadbed, effectively improving the overall rigidity of the roadbed protection structure. This also avoided the enormous workload and the large amount of concrete waste that would result from large-scale demolition.

[0024] See Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, in some embodiments, the above-mentioned S1 further includes the following steps: S11, Pile Foundation Construction Platform; The construction platform not only provides a construction site for the full-rotation drilling rig 7, but also functions as a gravity retaining structure. When drilling damages part of the slope toe soil, the construction platform, relying on its own weight and strength, provides temporary support reaction force for the roadbed slope, ensuring the stability of the roadbed slope.

[0025] S12. Disassemble and hoist the various components of the full-rotation drilling rig 7 to the work platform using an 8080-ton truck crane 6, then move it to the designated drilling pile position for drilling operations. During maintenance windows, the full-rotation drilling rig 7, weighing 18 tons, is disassembled and hoisted to the work platform using an 8080-ton truck crane 6, then moved to the designated pile position and the frame is adjusted to a vertical position before drilling operations begin. Because the work platform is suspended on three sides and attached to the existing structure on one side, there is no ramp for heavy machinery to drive through. Forcibly constructing a temporary access road would be a massive undertaking and would severely damage the stability of the existing slope. Using the 8080-ton truck crane 6 effectively reduces the workload. S13. Hoist the reinforcing cage section by section; S14. Pour concrete to form the reinforced concrete bored pile 1. The forming process of the drilled and reinforced concrete bored pile 1 is as follows: full-circuit drilling rig 7 is positioned and the casing is installed; reverse circulation drilling rig is positioned and mud circulation is used to remove drilling cuttings; hole formation inspection; hole cleaning; reinforcement cage fabrication and installation; guide pipe installation; secondary hole cleaning; concrete pouring; and pile foundation curing. Full casing installation effectively reduces the disturbance of drilling to the roadbed slope and prevents borehole collapse and mud seepage into the roadbed soil. During the section-by-section hoisting of the reinforcement cage, the frame of the low-profile reverse circulation drilling rig is used for hoisting.

[0026] See Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, in some embodiments, during the filling process of the aforementioned pile foundation working platform, Group B fill material is used for filling. Filling proceeds outward from the toe of the roadbed slope, with layered compaction. Each layer is no more than 20cm thick, and the compaction degree of the working platform must meet the requirement of 93% compaction, with the foundation bearing capacity reaching over 100kPa. The pile foundation working platform provides a stable working surface for the roadbed protective pile drilling rig and ensures the temporary stability of the roadbed slope. The filling material requirements are as follows: Group B fill material (generally sandy soil, gravelly soil, etc., with good permeability and stability) must be strictly used. The use of poor fill materials such as silt and humus is strictly prohibited to prevent softening or settlement. The specific filling method is as follows: filling proceeds outward from the toe of the roadbed slope, with layered compaction. Each layer is no more than 20cm thick; a small rammer is used for layered filling and compaction. The platform width must meet the requirements for operation of the full-rotation drilling rig and casing stacking; the working platform must be no less than 8 meters wide. The top surface of the work platform should form a 2% outward drainage slope. The acceptance requirements for the work platform are as follows: the platform compaction degree must meet the requirement of 93%, the foundation bearing capacity must reach more than 100 kPa, and the next step of the operation can only be carried out after passing the test.

[0027] See Figure 4 and Figure 6 As shown, in some embodiments, the specific construction method of the cap beam 9 in S2 above is as follows: S21. Construction preparation and surveying: The axis, edge lines and elevation control lines of the cap beam 9 are accurately laid out using a total station.

[0028] S22. Trim the reinforcing bars and pile head of reinforced concrete bored pile 1; use the circumferential cutting method to precisely break the pile head of reinforced concrete bored pile 1 to the design elevation, and strictly prohibit direct splitting to ensure that the pile head concrete is intact, dense, and free of loose interlayers. Straighten the main reinforcing bars of reinforced concrete bored pile 1 as designed, and remove surface laitance and rust. According to design requirements, it may be necessary to bend the main reinforcing bars to the designed anchorage angle and anchor them into the capping beam 9.

[0029] S23. Leveling the bottom surface: Pour a 50mm thick C15 or C20 fine stone concrete cushion layer on the prepared soil between the reinforced concrete bored piles 1, as the bottom formwork of the cap beam 9, to ensure that the bottom surface is flat and the stress is uniform.

[0030] S24. Bind the 9-bar reinforcement cage for the capping beam; strictly follow the binding procedure for the 9-bar reinforcement cage for the capping beam. The location of the main reinforcement joints and the setting of the stirrup reinforcement zone must comply with the specifications.

[0031] S25. Construct the formwork for the capping beam 9; use high-strength film-coated plywood or standardized combined steel formwork to ensure tight joints and a flat surface. Use square steel or double steel pipes as secondary ribs vertically and double-jointed steel pipes as primary ribs horizontally, and secure them with high-strength tie rods.

[0032] S26. Concrete Pouring and Curing. Pouring operations must be strictly controlled and completed within the maintenance window, allowing sufficient time for initial setting. Concrete is transported to the formwork using a truck pump or chute. Pouring is done in layers, each layer ≤500mm thick, using an immersion vibrator with quick insertion and slow withdrawal. Around the pile heads, meticulous vibration is required until the surface is smooth and no air bubbles overflow. Immediately after final setting, cover with geotextile and water for moisture retention. Curing time should not be less than 14 days. During curing, vibratory work is strictly prohibited near the cap beam 9, and the joints between new and old concrete should be regularly checked for shrinkage cracks. When the concrete strength reaches 25% or more of the design strength, remove the non-load-bearing side formwork. After removal, promptly check for air holes, honeycombing, and pitting.

[0033] See Figure 7 and Figure 8 As shown, in some embodiments, in the above S3, the existing wing wall 2 includes a retained portion 10 and a portion 5 to be demolished. The specific demolition method of the portion 5 to be demolished is as follows: S31. First, cut off the edge of the foundation of the fifth wing wall to be demolished; the edge of the foundation is... Figure 7 For the part marked ①, first cut off the edge of the foundation to sever the existing wing wall 2 foundation to create a free stress release boundary, reducing the probability of saw jamming or uncontrollable structural collapse due to local constraints during the main cut.

[0034] S32. Further layer-by-layer removal of the interfering portion of the 5th wing wall to be demolished; the interfering portion is... Figure 7 Section ② was cut in layers, breaking down the tall wing wall into smaller, segmented pieces. This method eliminated the risk of sudden impact and uncontrollable collapse associated with a single, complete demolition or chiseling operation, ensuring the safety of workers and existing equipment. The weight of each cut component was also controlled, making hoisting and removal easier.

[0035] S33. Finally, cut off the foundation below the interfering section of the fifth wing wall to be demolished. The foundation below the interfering section is... Figure 7 For section ③, the foundation is connected to the foundation pipe pile 3. After all the upper loads are removed, the bottom foundation is left with only its own weight and the connection force between the old and new concrete. At this time, the cutting is safe and the deformation is minimal.

[0036] In some embodiments, during S32 described above, a hydraulic wire saw is used to cut the interfering parts during layered removal. The hydraulic wire saw is vibration-free and can achieve precise cuts of large thicknesses and volumes. For a 1.5-meter-thick wing wall foundation, other demolition methods cannot achieve such precise and safe separation. The straight cutting line of the hydraulic wire saw also creates excellent conditions for subsequent connections between the old and new structures if needed.

[0037] In some embodiments, in step S3 above, the pile foundation work platform is first dismantled, and then the portion of the existing wing wall 2 that interferes with the newly constructed frame structure is dismantled. After the protective piles and capping beam 9 are constructed and reach their strength, the reinforced concrete bored piles 1 and capping beam 9 form a portal-type pile structure with extremely high rigidity, capable of independently resisting the soil pressure of the roadbed behind them. At this point, the work platform can be safely removed, preventing it from hindering the progress of subsequent procedures.

[0038] See Figure 8 and Figure 9 As shown, in some embodiments, in the above S3, the demolition method further includes the following steps: S34, installing horizontal support walers and steel pipe supports 11, one end of the steel pipe supports 11 abutting against the retained portion 10, and the other end of the steel pipe supports 11 abutting against the previously constructed middle frame sidewall. The retained portion 10 and the portal frame pile structure behind it are components of the support structure for the bridge and culvert foundation pit excavation. When demolishing the portion to be demolished 5 and excavating the foundation pit, the construction of protective piles for the roadbed behind the wing wall must be completed. According to the bridge and culvert construction sequence, the portion to be demolished 5 is cut first, and horizontal support walers and steel pipe supports 11 are installed on the retained portion 10. The steel pipe cross braces are used to support the retained portion 10 and the previously constructed middle frame sidewall. Then, the bridge and culvert foundation pit is excavated to the base, and the wire mesh shotcrete and steel sheet pile support structure for the excavated slope below the wing wall foundation pit is implemented simultaneously.

[0039] The above description is only a part or preferred embodiment of this application. Neither the text nor the drawings should limit the scope of protection of this application. All equivalent structural transformations made using the content of this application's specification and drawings under the overall concept of this application, or direct / indirect applications in other related technical fields, are included within the scope of protection of this application.

Claims

1. A method for protecting the wing wall of an existing railway bridge / culvert after its extension, characterized in that, The protection method specifically includes the following steps: S1. Install multiple reinforced concrete bored piles between the existing wing wall and the roadbed; S2. Connect multiple reinforced concrete bored piles through a capping beam; S3. Demolish the parts of the existing wing wall that interfere with the new frame structure; S4. Construct extended bridges and culverts, connecting them to existing bridges and culverts.

2. The method for protecting the demolition of the wing wall of an existing railway bridge / culvert with a span extension, as described in claim 1, is characterized in that... The above-mentioned S1 also includes the following steps: S11, Pile foundation filling operation platform; S12. Disassemble and hoist each component of the full-rotation drilling rig, use an 80-ton truck crane to hoist it to the work platform for assembly, and then move it to the predetermined drilling pile position for drilling operations; S13. Hoist the steel cage section by section; S14. Concrete pouring to form reinforced concrete bored piles.

3. A method for protecting the demolition of wing walls of existing bridges and culverts with spandrel extensions according to claim 2, characterized in that, During the filling process of the above-mentioned pile foundation operation platform, Group B fill material is used for filling. The roadbed slope toe is filled outwards, and the layers are compacted in layers. The thickness of each layer is no more than 20cm. The compaction degree of the operation platform must meet the compaction requirement of 93%, and the bearing capacity of the foundation must reach more than 100kpa.

4. A method for protecting the demolition of wing walls of existing railway bridges and culverts as described in claim 1, characterized in that, The specific construction method for the capping beam in S2 above is as follows: S21. Construction preparation and surveying / layout; S22. Trim the reinforcing bars and pile head of the reinforced concrete bored pile; S23. Leveling the bottom surface; S24. Binding the steel reinforcement cage for the capping beam; S25. Erect the formwork for the capping beam pouring; S26. Pour concrete and cure it.

5. A method for protecting the demolition of wing walls of existing bridges and culverts with spandrel extensions according to claim 4, characterized in that, In S3 above, the existing wing wall includes the retained portion and the portion to be demolished. The specific demolition method for the portion to be demolished is as follows: S31. First, cut off the edge of the foundation of the wing wall to be demolished; S32. Further cut away the interfering parts of the wing wall to be demolished in layers; S33. Finally, cut off the foundation below the interfering part of the wing wall to be demolished.

6. A method for protecting the demolition of wing walls of existing railway bridges and culverts as described in claim 5, characterized in that, In S32 above, a hydraulic wire saw is used to cut the interfering part during layered cutting.

7. A method for protecting the demolition of wing walls of existing railway bridges and culverts as described in claim 2, characterized in that, In S3 above, the pile foundation operation platform is first demolished, and then the parts of the existing wing wall that interfere with the newly built frame structure are demolished.

8. A method for protecting the demolition of wing walls of existing bridges and culverts with spandrel extensions according to claim 1, characterized in that, In S3 above, the demolition method also includes the following steps: S34. Install horizontal support walers and steel pipe supports. One end of the steel pipe support abuts against the reserved portion, and the other end of the steel pipe support abuts against the side wall of the central frame structure constructed earlier.

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