A method for demolishing a deck beam of a viaduct reserved superstructure type pier column
By employing cap beam protection technology and pier column semi-circular partition top cutting technology, combined with anti-overturning hoisting and jacking structures, the problem of dismantling viaduct cap beams under space constraints was solved, achieving a stable and safe dismantling process, and improving construction efficiency and environmental friendliness.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ZHEJIANG COMM CONSTR GRP CO LTD
- Filing Date
- 2023-09-04
- Publication Date
- 2026-05-19
AI Technical Summary
In the reinforcement and renovation of urban elevated bridges, there are situations where the piers are located in spaces that are limited and not suitable for blasting, making it impossible to effectively remove the cap beams.
By employing cap beam protection technology, pier column semi-circular sectional top cutting technology, and cap beam segmented cutting technology, and through anti-overturning hoisting devices, limit protection devices, and jacking structures, the pier columns and cap beams are gradually dismantled to ensure construction stability and safety.
While ensuring the integrity of the bridge's superstructure, the demolition process improved stability and safety, reduced the impact on the surrounding environment, saved material consumption, shortened the time to restore traffic, and achieved social and environmental benefits.
Smart Images
Figure CN117107680B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of bridge construction technology, specifically to a method for removing the cap beams of piers with retained superstructure on viaducts. Background Technology
[0002] In the reinforcement and renovation of urban viaducts, it is common to encounter situations where piers need to be replaced in situ. When the working space is limited, large-scale mechanical in-situ demolition cannot be used. Furthermore, blasting demolition also has significant limitations due to structural and environmental safety considerations. Therefore, it is necessary to study in-situ demolition methods for viaduct piers and cap beams.
[0003] For example, the left span of the fourth section of the Jingshui Road No. 1 Viaduct of the Hangzhou-Shaoxing-Taizhou Expressway is located south of the intersection of Jingshui South Road and Yangshao Highway in Keqiao District, Shaoxing City. The superstructure (bridge deck) consists of 5×30m prestressed concrete T-beams connected by wet joints, with three spans per beam and a single span width of 16.25m. The substructure consists of bored pile foundations + column piers (pier columns) + prestressed cap beams (cap beams). Pier #04 is a double-column structure located at the mid-span, with a column spacing of 9m, a column height of 8m, and a column diameter of 1.6m. The cap beam is 1.6m high and 2.0m wide. Because pier #04 of the left span of the Jingshui Road No. 1 Viaduct is located on the river side, there is a deep layer of silt and soft soil. During the operation of the bridge, external factors caused lateral displacement of the soil between the piles, resulting in tilting of the pile foundation and pier column, slippage of the superstructure, and damage to the cap beam on top of pier #04. After investigation and assessment, it was determined that the bridge superstructure was intact, and its functionality could be restored simply by dismantling and rebuilding the piers and cap beams in situ. However, because pier #04 is located at the mid-span, with a 9m distance from surrounding piers and an 8m clearance under the bridge, large machinery could not be accessed. Furthermore, due to its proximity to a residential area, blasting was not feasible. The above scenario of dismantling and rebuilding the cap beams exemplifies the situation where space constraints made blasting unsuitable. Summary of the Invention
[0004] This invention aims to provide a method for removing cap beams of elevated bridges with retained superstructure piers in situations where space is limited and blasting is not suitable, thus solving the problem of cap beam removal in such situations.
[0005] The above technical problems are solved by the following technical solution: A method for dismantling a viaduct with retained superstructure piers and cap beams, wherein each end of the cap beam is supported by a pier, and the bridge deck is supported on the cap beam. The method includes: A) Lifting the bridge deck: The bridge deck supported on the cap beam to be dismantled is supported by an upper lifting structure so that the bridge deck remains in place during cap beam dismantling; B) Installing an anti-overturning hoisting device: An anti-overturning hoisting device is installed to prevent the cap beam from overturning during descent; C) Installing a cap beam limit protection device: A cap beam limit protection device is installed to prevent horizontal displacement during cap beam dismantling; D) Separating the piers from the cap beam; cutting the cap beam. The connection between the beam and the supporting cap beam; E. Pier cutting and demolition: The pier is divided into two halves distributed along the transverse direction of the bridge and demolished alternately from top to bottom. The half facing the center of the transverse direction of the bridge is called the inner semi-circular column of the pier, and the other half is called the outer semi-circular column of the pier. The pier cutting and demolition specifically includes the following steps: E1. First cutting and demolition of the inner semi-circular column of the pier: Cut off the inner section of the inner semi-circular column of the pier by a set length and remove the inner section. At this time, the cap beam is supported by the outer semi-circular column of the pier. The inner jack is supported on the inner semi-circular column of the pier to support the cap beam; E2. First cutting and demolition of the outer semi-circular column of the pier: Cut off the inner section of the outer semi-circular column of the pier by a set length and remove the inner section. At this time, the cap beam is supported by the outer semi-circular column of the pier. The inner jack is supported on the inner semi-circular column of the pier to support the cap beam; Cut off the outer section of the predetermined length and remove it. Support the outer jack on the outer semi-cylinder, so that the anti-overturning lifting device loses its function of limiting the descent of the cap beam. Lower the inner jack so that the cap beam is supported by the outer jack, and the anti-overturning lifting device re-limits the vertical position of the cap beam. E3. Cut and remove the inner semi-cylinder of the pier again: Remove the inner jack, cut off the inner removal section of the predetermined length at the top of the inner semi-cylinder of the pier and remove it. Support the inner jack on the inner semi-cylinder of the pier, so that the anti-overturning lifting device loses its function of limiting the descent of the cap beam. Lower the outer jack so that the cap beam is supported by the inner jack, and the anti-overturning lifting device re-limits the vertical position of the cap beam. Re-limit the vertical position of the cap beam; E4, cut and remove the outer semi-circular column of the pier again: remove the outer jack, cut off the outer removal section of the set length at the top of the outer semi-circular column of the pier and remove it, support the outer jack on the outer semi-circular column of the pier, so that the anti-overturning hoisting device loses its function of limiting the descent of the cap beam, so that the inner jack descends and the cap beam is supported by the outer jack, so that the anti-overturning hoisting device re-limits the vertical position of the cap beam, repeat E3 and E4 until the pier is cut to the remaining set length; F, cut the cap beam into blocks: cut the cap beam into blocks and transfer them away so that new piers and new cap beams can be built on the original site to support the bridge deck again.
[0006] As a preferred method, in step F, a load-bearing support column is set up to support the cap beam. During cutting, the cap beam is divided and dismantled from both ends toward the middle. Before cutting, an excavator is used to suspend the steel wire rope holding the cap beam piece to be cut off, so that when the cap beam piece is completely cut off from the cap beam, the steel wire rope holds the cap beam piece, and the excavator transfers the cap beam piece away. This can improve the efficiency of cap beam division.
[0007] Preferably, the cuts in steps D, E, and F are all performed using a wire saw static cutting machine. This minimizes interference.
[0008] Preferably, the upper lifting structure includes a foundation built on the ground and two support frames distributed longitudinally along both sides of the cap beam, with the lower end supported on the foundation. Each support frame comprises two rows of steel pipes distributed longitudinally, with the pipes in the same row distributed transversely. The upper ends of all the pipes in the row are supported below a distribution beam extending transversely. Several lifting jacks are installed above the distribution beam for lifting the bridge deck. This provides reliable support and facilitates easy installation for lifting the bridge deck.
[0009] Preferably, the foundation includes two rows of piles and a concrete base plate cast on the piles. The concrete base plate has two clearance holes for piers, and two piers pass through these holes. The lower end of the steel pipe is supported on the concrete base plate. This provides reliable support and a robust structure.
[0010] Preferably, the steel pipe is assembled from several pipe sections connected together by flanges.
[0011] Preferably, the support frame further includes a reinforcing frame, which comprises two uprights located on both sides of the two rows of steel pipes and several pairs of clamping rods. The two ends of each pair of clamping rods are connected to the two uprights in a one-to-one correspondence. The two uprights clamp the two rows of steel pipes, and each steel pipe is clamped by at least one pair of clamping rods. Each pair of clamping rods simultaneously clamps one steel pipe from each of the two rows of steel pipes. This design offers good structural strength and ease of manufacture.
[0012] Preferably, the support frame includes a plurality of horizontal steel bars distributed in the vertical direction, the horizontal steel bars extending in the transverse direction, and adjacent horizontal steel bars are connected together by a plurality of diagonal steel bar pairs distributed in the transverse direction, the diagonal steel bar pairs including two diagonal steel bars that are cross-connected.
[0013] Preferably, the clamping rod is connected to the horizontal steel rod.
[0014] Preferably, the number of clamping rod pairs clamped on the same steel pipe is the same as the number of horizontal steel rods in the same upright.
[0015] Preferably, the clamping rod is a steel rod, and the clamping rod is welded together with the horizontal steel rod.
[0016] Preferably, the horizontal steel bar is welded together with the diagonal steel bar.
[0017] Preferably, the lower end of the steel pipe is provided with a connecting flange plate and several reinforcing steel ribs distributed along the circumference of the steel pipe. The lower ends of the reinforcing steel ribs are welded to the connecting flange plate and to the steel pipe. The upper surfaces of all the reinforcing steel ribs are on the same plane. The lowermost horizontal steel bar supports the upper end of the reinforcing steel ribs. The connecting flange plate is fixed to the concrete base plate by anchor bolts. This design provides convenient connection and reliable support.
[0018] Preferably, the anti-overturning hoisting device includes two anti-overturning frames distributed along the transverse direction of the bridge. Each anti-overturning frame includes a steel support beam and two vertical threaded rods. The steel support beam extends along the longitudinal direction of the bridge, and the lower ends of the two vertical threaded rods pass through both ends of the steel support beam. A supporting nut is threadedly connected to the lower end of each vertical threaded rod, supporting the steel support beam. The upper end of the vertical threaded rod is suspended on the bridge deck. The two vertical threaded rods are distributed along the longitudinal direction of the bridge on both sides of the cap beam. The steel support beam is located below the cap beam and is used to restrict the descent of the cap beam. This can prevent the cap beam from descending during the pier removal process, improving the reliability of the cap beam descent.
[0019] Preferably, the anti-overturning suspension device further includes two upper pad beams placed flat on the bridge deck, with the upper ends of the vertical threaded steel bars suspended from the upper pad beams. Each upper pad beam suspends only two of the vertical threaded steel bars. This avoids damage to the bridge deck during suspension and improves the reliability of the suspension.
[0020] Preferably, the upper support beam extends along the transverse direction of the bridge. This improves the connection reliability of the anti-tipping hoisting device.
[0021] Preferably, the structure of the upper support beam is the same as that of the steel support beam. This makes it easy to manufacture.
[0022] Preferably, the steel support beam includes double-section I-beams and two pairs of pads. Each pair of pads includes an upper pad and a lower pad, which clamp the double-section I-beams vertically. A vertically threaded steel rod passes between the two I-beams constituting the double-section I-beam, with the lower ends of the two vertically threaded steel rods correspondingly inserted into the two pairs of pads. The supporting nut supports the double-section I-beams through the lower pad. This design prevents the double-section I-beams from separating.
[0023] Preferably, the upper pad has downward extending upper blocks at both ends along the transverse direction of the bridge, and the two upper blocks block the double-I-beam on both sides. The lower pad has upward extending lower blocks at both ends along the transverse direction of the bridge, and the two lower blocks block the double-I-beam on both sides.
[0024] Preferably, the cap beam limiting protection device includes two rigid limiting rings, which are correspondingly fitted onto the two piers. When the piers are cut, the rigid limiting rings are located below the cut portion of the pier. Each rigid limiting ring is connected to two rigid vertical limiting rods, which are distributed along the longitudinal direction of the bridge on both sides of the cap beam. The rigid vertical limiting rods restrict the longitudinal movement of the cap beam. The rigid limiting rings are suspended from the cap beam by a suspension structure. This effectively limits longitudinal movement of the cap beam during the cutting process.
[0025] Preferably, the rigid limiting ring is provided with a plurality of supporting rollers distributed along the circumference of the pier, and the rigid limiting ring is supported on the pier by the supporting rollers. This ensures good reliability when descending together with the rigid limiting ring.
[0026] Preferably, the suspension structure includes a rod with its lower end connected to a rigid limiting ring and a lifting ring connected to the upper end of the rod. The lifting ring is sleeved on the vertical threaded rod and suspended from the supporting nut. The cap beam limiting device can descend synchronously with the cap beam below the anti-tipping hoisting device, making connection convenient.
[0027] As another preferred embodiment, the suspension structure includes a sling with one end connected to the same rigid vertical limiting rod, and the other end of the sling passing over the top of the cap beam and connected to another rigid vertical limiting rod.
[0028] Preferably, the rigid vertical limiting rod is provided with a rope hole. The end of the sling passes through the rope hole, bends upward to suspend the rigid vertical limiting rod, and then bends downward to form a folded part. The folded part is inserted into a "U"-shaped connector. Both ends of the connector are simultaneously inserted into the compression block. Each end of the connector is threaded with a pressing nut. The pressing nuts on the two ends of the connector compress the compression block, causing the compression block to clamp the folded part in conjunction with the connector. The connection between the sling and the rigid vertical limiting rod is reliable and easy to disassemble.
[0029] The beneficial effects of this invention are as follows: By employing a combination of cap beam protection technology, pier semi-circular partition top cutting technology, and cap beam segmented cutting technology, the invention solves the difficult problem of dismantling bridge piers and cap beams under conditions of preserving the bridge superstructure intact and having limited construction space. This greatly improves the stability of the bridge pier dismantling process and ensures construction safety. The dismantling of bridge piers and cap beams results in minimal construction vibration, significantly reducing the impact on the surrounding environment and gaining support from local residents, resulting in significant social benefits. Furthermore, it allows for the reuse of the original bridge superstructure, saving material consumption for superstructure reconstruction, shortening the time required to restore traffic, and demonstrating significant environmental benefits. Attached Figure Description
[0030] Figure 1 This is a process flow diagram of the present invention;
[0031] Figure 2 This is a schematic diagram of the front elevation of the upper lifting structure;
[0032] Figure 3 This is a schematic diagram of the side elevation of the upper lifting structure;
[0033] Figure 4 This is a top view of the concrete substrate.
[0034] Figure 5 This is a frontal elevation view of the anti-tipping hoisting device and the cap beam limiting device. The upper lifting structure is not shown in the figure.
[0035] Figure 6 A side elevation diagram of the anti-tipping hoisting device;
[0036] Figure 7 This is an enlarged schematic diagram of the steel support beam;
[0037] Figure 8 This is a schematic diagram of step E1 during the demolition process. The anti-tipping hoisting device, the upper lifting structure, and the cap beam limiting device are not shown in the diagram.
[0038] Figure 9 This is a schematic diagram of step E2 during the demolition process. The anti-tipping hoisting device, the upper lifting structure, and the cap beam limiting device are not shown in the diagram.
[0039] Figure 10 This is a schematic diagram of step E3 during the demolition process. The anti-tipping hoisting device, the upper lifting structure, and the cap beam limiting device are not shown in the diagram.
[0040] Figure 11 This is a front elevation view of the cap beam limiting device in Embodiment 2;
[0041] Figure 12 for Figure 11 A magnified view of a portion of point A;
[0042] Figure 13 A cross-sectional view of the knotted and secured point of the sling.
[0043] In the diagram: 1. Cap beam; 2. Pier column; 3. Bridge deck; 4. Outer semi-circular column of pier column; 5. Inner jack; 6. Outer jack; 7. Support frame; 8. Foundation pile; 9. Concrete base plate; 10. Pier column clearance hole; 11. Steel pipe; 12. Distribution beam; 13. Lifting jack; 14. Pipe section; 15. Flange; 16. Connecting flange plate; 17. Reinforcing steel rib plate; 18. Anchor bolt; 19. Horizontal steel bar; 20. Diagonal steel bar; 19. Clamping rod; 20. Steel support. 21. Beam, 22. Vertical threaded rod, 23. Support nut, 24. Upper pad beam, 25. I-beam, 26. Upper pad plate, 27. Lower pad plate, 28. Upper stop block, 29. Lower stop block, 30. Rigid limiting ring, 31. Rigid vertical limiting rod, 32. Suspension structure, 33. Support roller, 34. Rod, 35. Lifting ring, 36. Sling, 37. Folding part, 38. Connector, 39. Pressing block, 40. Pressing nut, 42. Inner semi-cylinder of pier column. Detailed Implementation
[0044] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0045] See Figures 1 to 10A method for dismantling a viaduct with retained superstructure piers and cap beams, wherein each end of the cap beam 1 is supported by a pier 2, and the bridge deck 3 is supported on the cap beam, including: A) Lifting the bridge deck: The bridge deck supported on the cap beam to be dismantled is supported by an upper lifting structure so that the bridge deck remains in place during the dismantling of the cap beam; B) Installing an anti-overturning hoisting device: Installing an anti-overturning hoisting device to prevent the cap beam from overturning during descent; C) Installing a cap beam limit protection device: Installing a cap beam limit protection device to prevent horizontal displacement during the dismantling of the cap beam; D) Separating the piers from the cap beam: Cutting the connection between the cap beam and the piers supporting the cap beam. E. Pier Cutting and Demolition: The pier is divided into two halves distributed along the transverse direction of the bridge and demolished alternately from top to bottom. The half facing the center of the transverse direction of the bridge is called the inner semi-circular column of the pier, and the other half is called the outer semi-circular column of the pier. The pier cutting and demolition specifically includes the following steps: E1. First cutting and demolition of the inner semi-circular column 42: Cut off the inner section of the inner semi-circular column of the pier by a set length and remove the inner section. At this time, the cap beam is supported by the outer semi-circular column 4. The inner jack 5 is supported on the inner semi-circular column of the pier to support the cap beam; E2. First cutting and demolition of the outer semi-circular column: Cut off the inner section of the outer semi-circular column of the pier by a set length. Remove the outer section of the first segment of the length, and support the outer jack 6 on the outer semi-circular column. This causes the anti-overturning lifting device to lose its function of limiting the descent of the cap beam, allowing the inner jack to descend and the cap beam to be supported by the outer jack. This allows the anti-overturning lifting device to re-limit the vertical position of the cap beam. E3. Cut and remove the inner semi-circular column of the pier again: Remove the inner jack, cut off the inner removal section of the set length at the top of the inner semi-circular column of the pier and remove it. Support the inner jack on the inner semi-circular column of the pier, causing the anti-overturning lifting device to lose its function of limiting the descent of the cap beam. This causes the outer jack to descend and the cap beam to be supported by the inner jack. This allows the anti-overturning lifting device to re-limit the vertical position of the cap beam. E4. Cut and remove the outer semi-circular column of the pier again: Remove the outer jacks, cut off the outer removal section of the set length at the top of the outer semi-circular column of the pier and remove it, support the outer jacks on the outer semi-circular column of the pier, so that the anti-overturning hoisting device loses its function of limiting the descent of the cap beam, so that the inner jacks descend and the cap beam is supported by the outer jacks, so that the anti-overturning hoisting device can once again limit the vertical movement of the cap beam, repeat E3 and E4 until the pier is cut to the remaining set length; F. Cut the cap beam into blocks: Cut the cap beam into blocks and move them away so that new piers and new cap beams can be built on the original site to support the bridge deck again. In step F, load-bearing supports are set up to support the cap beam. During cutting, the cap beam is divided and dismantled from both ends toward the middle. Before cutting, an excavator is used to suspend the steel wire rope that holds the cap beam piece to be cut off, so that when the cap beam piece is completely cut off from the cap beam, the steel wire rope holds the cap beam piece, and the excavator is used to transfer the cap beam piece away.The cuts in steps D, E, and F are all made using a wire saw static cutting machine.
[0046] The superstructure includes a foundation 6 built on the ground and two support frames 7, distributed longitudinally along both sides of the cap beam and supported on the foundation. The foundation includes two rows of piles 41 (a total of six piles) and a concrete base plate 8 cast on the piles. Two pier clearance holes 9 are provided on the concrete base plate, and two piers pass through these holes. The support frames include two rows of steel pipes 10 distributed longitudinally along the bridge. The steel pipes in the same row are distributed transversely along the bridge. The upper ends of all the steel pipes in the row are supported below a distribution beam 11 extending transversely. Several lifting jacks 12 are installed above the distribution beam for lifting the bridge deck. The steel pipes are assembled from several pipe sections 13 connected together by flanges 14. The lower end of the steel pipe is supported on a concrete substrate. Specifically, the lower end of the steel pipe is provided with a connecting flange plate 15 and several reinforcing steel ribs 16 distributed circumferentially along the steel pipe. The lower ends of the reinforcing steel ribs are welded to the connecting flange plate and to the steel pipe. The upper surfaces of all the reinforcing steel ribs are on the same plane. The connecting flange plate is fixed to the concrete substrate by anchor bolts 17. The support frame also includes a reinforcing frame, which includes two uprights located on both sides of the two rows of steel pipes and several pairs of clamping rods. The two ends of the clamping rod pairs are connected to the two uprights one-to-one. The two uprights clamp the two rows of steel pipes. Each steel pipe is clamped by at least one pair of clamping rods. One pair of clamping rods clamps one steel pipe in each of the two rows of steel pipes simultaneously. The uprights include several horizontal steel bars 18 distributed vertically. The horizontal steel bars extend in the transverse direction. Adjacent horizontal steel bars are connected by several pairs of diagonal steel bars distributed in the transverse direction. Each pair of diagonal steel bars includes two diagonal steel bars 19 that are cross-connected. Clamping rod 20 is connected to the horizontal steel rod. The number of clamping rod pairs clamping the same steel pipe is the same as the number of horizontal steel rods in the same upright. The clamping rod is a steel rod, and the clamping rod is welded to the horizontal steel rod. The horizontal steel rod is welded to the diagonal steel rod. The lowermost horizontal steel rod is supported on the upper end of the reinforcing steel rib plate.
[0047] The anti-overturning suspension device includes two anti-overturning frames distributed along the transverse direction of the bridge. Each anti-overturning frame includes a steel support beam 21 and two vertical threaded rods 22. The steel support beam extends along the longitudinal direction of the bridge. The lower ends of the two vertical threaded rods pass through both ends of the steel support beam, and the lower ends of the vertical threaded rods are threadedly connected to supporting nuts 23, which support the steel support beam. The upper ends of the vertical threaded rods are suspended on the bridge deck. The two vertical threaded rods are distributed along the longitudinal direction on both sides of the cap beam. The steel support beam is located below the cap beam and is used to limit the descent of the cap beam. The anti-overturning suspension device also includes two upper pad beams 24 placed horizontally on the bridge deck. The upper ends of the vertical threaded steel rods are suspended on the upper pad beams, and each upper pad beam suspends only two of the aforementioned vertical threaded rods. The upper pad beams extend along the transverse direction of the bridge. The structure of the upper pad beams is the same as that of the steel support beams. The steel support beam includes double-section I-beams 25 and two pairs of pads. Each pair of pads includes an upper pad 26 and a lower pad 27. The upper and lower pads clamp the double-section I-beams vertically. A vertical threaded steel rod passes between the two I-beams constituting the double-section I-beam, with the lower ends of the two vertical threaded steel rods correspondingly inserted into the two pairs of pads. A supporting nut supports the double-section I-beams through the lower pad. The upper pad has downward-extending upper blocks 28 at both ends along the transverse direction, blocking the double-section I-beams on both sides. The lower pad has upward-extending lower blocks 29 at both ends along the transverse direction, blocking the double-section I-beams on both sides. When the beam needs to be lowered, the supporting nut is loosened to lower the steel support beam, or the suspension nut on the upper section of the vertical threaded rod is loosened to lower the steel support beam.
[0048] The cap beam limiting protection device includes two rigid limiting rings 30, which are fitted one-to-one onto the two piers. When the piers are cut, the rigid limiting rings are located below the cut portion of the pier. The rigid limiting rings are connected to two rigid vertical limiting rods 31, which are distributed along the longitudinal direction of the bridge on both sides of the cap beam. The rigid vertical limiting rods restrict the movement of the cap beam along the longitudinal direction. The rigid limiting rings are suspended from the cap beam by a suspension structure 32. The rigid limiting rings contain several supporting rollers 33 distributed circumferentially along the pier, supporting the piers. The suspension structure includes a hanging rod 34 connected at its lower end to the rigid limiting ring and a lifting ring 35 connected at its upper end. The lifting ring is fitted onto the vertical threaded hanging rod and suspended from a supporting nut.
[0049] Example 2 differs from the examples above in that:
[0050] See Figure 11 and Figure 13The suspension structure includes a sling 36, one end of which is connected to a rigid vertical limiting rod. The other end of the sling passes over the top of the cap beam and is connected to another rigid vertical limiting rod. The specific connection method between the sling and the rigid vertical limiting rod is as follows: the rigid vertical limiting rod has a rope hole. The end of the sling passes through the hole, bends upward to suspend the rigid vertical limiting rod, and then bends downward to form a folded part 37. The folded part is inserted into a "U"-shaped connector 38. Both ends of the connector are inserted into a pressing block 39. Both ends of the connector are threaded with a pressing nut 40. The pressing nuts on both ends of the connector press the pressing block, causing the pressing block to clamp the folded part in conjunction with the connector.
Claims
1. A method for dismantling a viaduct with retained superstructure piers and cap beams, wherein each end of the cap beam is supported by a pier, and the bridge deck is supported on the cap beam, characterized in that... This includes: A) Lifting the bridge deck: using an upper lifting structure to support the bridge deck resting on the cap beam to be dismantled, ensuring the bridge deck remains in place during dismantling; B) Installing an anti-overturning hoisting device: installing an anti-overturning hoisting device to prevent the cap beam from overturning during descent; C) Installing a cap beam limit protection device: installing a cap beam limit protection device to prevent horizontal displacement during dismantling; D) Separating the pier from the cap beam: cutting the connection between the cap beam and the supporting pier. E. Pier Cutting and Removal: The pier is divided into two halves distributed along the transverse direction of the bridge and removed alternately from top to bottom. The half facing the center of the transverse direction is called the inner semi-circular column of the pier, and the other half is called the outer semi-circular column of the pier. The pier cutting and removal specifically includes the following steps: E1. First Cutting and Removal of the Inner Semi-Circular Column of the Pier: Cut off the inner section of the pier's inner semi-circular column by a predetermined length and remove the inner section. At this time, the cap beam is supported by the outer semi-circular column of the pier. The inner jacks are supported on the inner semi-circular column of the pier to support the cap beam; E2. First Cutting and Removal of the Outer Semi-Circular Column of the Pier: Cut off the outer section of the pier's outer semi-circular column by a predetermined length and remove the outer section. The outer jacks are supported on the outer semi-circular column, so that the anti-overturning hoisting device loses its lowering limit function for the cap beam, causing the inner jacks to descend and the cap beam to be supported by the outer jacks, allowing the anti-overturning hoisting device to re-position... E3. Cut and remove the inner semi-circular column of the pier again: Remove the inner jacks, cut off the inner removal section of the set length at the top of the inner semi-circular column of the pier and remove it, support the inner jacks on the inner semi-circular column of the pier, so that the anti-overturning hoisting device loses its function of limiting the descent of the cap beam, so that the outer jacks descend and the cap beam is supported by the inner jacks, so that the anti-overturning hoisting device can once again limit the vertical descent of the cap beam; E4. Cut again Cutting and removing the outer semi-circular column of the pier: Remove the outer jack, cut off the outer removal section of the set length at the top of the outer semi-circular column of the pier and remove it, support the outer jack on the outer semi-circular column of the pier, so that the anti-overturning hoisting device loses its function of limiting the descent of the cap beam, so that the inner jack descends and the cap beam is supported by the outer jack, so that the anti-overturning hoisting device can once again limit the vertical movement of the cap beam. Repeat E3 and E4 until the pier is cut to the remaining set length. F. Segmented Cap Beam Cutting: The cap beam is cut into segments and moved away so that new piers and new cap beams can be built on the original site to support the bridge deck again.
2. The method for removing the superstructure piers and cap beams of an elevated bridge according to claim 1, characterized in that, In step F, load-bearing supports are set up to support the cap beam. During cutting, the cap beam is divided and dismantled from both ends toward the middle. Before cutting, an excavator is used to suspend the steel wire rope that holds the cap beam piece to be cut off, so that when the cap beam piece is completely cut off from the cap beam, the steel wire rope holds the cap beam piece, and the excavator is used to transfer the cap beam piece away.
3. A method for removing the superstructure piers and cap beams of an elevated bridge according to claim 1 or 2, characterized in that, The cuts in steps D, E, and F are all made using a wire saw static cutting machine.
4. The method for removing the superstructure piers and cap beams of an elevated bridge according to claim 1, characterized in that, The upper lifting structure includes a foundation built on the ground and two support frames distributed along the longitudinal direction of the bridge on both sides of the cap beam, which are supported on the foundation. The support frames include two rows of steel pipes distributed along the longitudinal direction of the bridge. The steel pipes in the same row are distributed along the transverse direction of the bridge. The upper ends of all the steel pipes in the row are supported under the same distribution beam extending in the transverse direction of the bridge. Several lifting jacks are provided above the distribution beam. The lifting jacks are used to lift the bridge deck.
5. A method for removing the superstructure piers and cap beams of an elevated bridge according to claim 4, characterized in that, The foundation includes two rows of foundation piles and a concrete base plate cast on the foundation piles. The concrete base plate is provided with two pier clearance holes, and the two piers are inserted into the two pier clearance holes. The lower end of the steel pipe is supported on the concrete base plate.
6. A method for removing the superstructure pier cap beams of an elevated bridge according to claim 4 or 5, characterized in that, The steel pipe is assembled from several pipe sections connected together by flanges.
7. A method for removing the superstructure piers and cap beams of an elevated bridge according to claim 4 or 5, characterized in that, The support frame also includes a reinforcing frame, which includes two uprights located on both sides of the two rows of steel pipes and several pairs of clamping rods. The two ends of the clamping rod pairs are connected to the two uprights in a one-to-one correspondence. The two uprights clamp the two rows of steel pipes, and each steel pipe is clamped by at least one pair of clamping rods. One pair of clamping rods clamps one steel pipe in each of the two rows of steel pipes at the same time.
8. A method for removing the superstructure piers and cap beams of an elevated bridge according to claim 7, characterized in that, The support frame includes several horizontal steel bars distributed in the vertical direction. The horizontal steel bars extend in the transverse direction of the bridge. Adjacent horizontal steel bars are connected together by several pairs of diagonal steel bars distributed in the transverse direction of the bridge. Each pair of diagonal steel bars includes two diagonal steel bars that are cross-connected.
9. A method for removing the superstructure piers and cap beams of an elevated bridge according to claim 8, characterized in that, The clamping rod is connected to the horizontal steel rod.
10. A method for removing the superstructure piers and cap beams of an elevated bridge according to claim 7, characterized in that, The number of clamping rod pairs clamped on the same steel pipe is the same as the number of horizontal steel bars in the same upright.