Device for dismantling upper-layer support of double-layer bridge

Abstract

The utility model discloses a device for dismantling an upper-layer support of a double-layer bridge. The device is composed of a continuous jack, a jack base, a steel strand, a bearing beam, an anchorage device, a bearing beam, a steel bar, a nut, a safety preformed hole, a falling frame preformed hole and a transverse moving track. A continuous jack, a jack base, a steel strand, a bearing beam, a bearing beam and an anchorage device jointly form a lowering system, the upper structure of a support such as a truss and a bottom die distribution beam is integrally lowered to a lower-layer beam body, and the bearing beam, a steel bar and a nut are arranged before lowering to form a safety system so as to prevent the upper structure of the support from falling off when a support foundation is dismantled. And a transverse moving track is arranged on the lower-layer beam body to transversely move and drag the support truss and the bottom die distribution beam out of the projection range of the upper-layer beam body, and then a crane is used for disassembly. The device is simple in stress, convenient to disassemble and rapid to install, the working efficiency is further improved, the construction progress can be effectively accelerated, the construction quality is guaranteed, and the construction cost is saved.

Description

Technical Field

[0001] This utility model relates to the field of bridge construction, and in particular to a device for dismantling the upper support of a double-layer bridge. Background Technology

[0002] To minimize the use of bridge site resources, land resources, and project investment, various types of combined road-rail bridges have emerged. These bridges typically feature a road bridge and a railway bridge arranged in two layers, forming a single, double-deck structure. The upper and lower beams of these bridges are usually constructed from bottom to top using ground-supported scaffolding. After the upper beams are completed, the lower beams are laid beneath the scaffolding. However, when dismantling the scaffolding, the space constraints of the upper and lower beams prevent the crane from lifting, dismantling, and transporting the upper beam scaffolding. This presents certain shortcomings in terms of construction feasibility, safety, and cost. Summary of the Invention

[0003] The purpose of this utility model is to provide a device for dismantling the upper support of a double-layer bridge. It is simple to apply force, easy to disassemble, and quick to install, which further improves work efficiency, effectively speeds up construction progress, ensures construction quality, and saves construction costs.

[0004] The purpose of this utility model is achieved as follows:

[0005] A device for dismantling the upper support of a double-layer bridge, characterized by comprising: continuous jacks, jack bases, steel strands, load-bearing beams, anchorages, pad beams, steel bars, nuts, safety pre-drilled holes, lowering pre-drilled holes, and transverse tracks, wherein:

[0006] Each pier is supported by a support structure consisting of a support foundation, transverse distribution beams, steel unloading blocks, trusses, and bottom formwork distribution beams. Support foundations are located on the side walls of each pier and support structure. The top of the support foundations is fixed to the pier by horizontal tie rods. A transverse distribution beam is located at the top of the support foundation. A steel unloading block is located above the transverse distribution beam. A truss is located between the steel unloading blocks of two adjacent transverse distribution beams. A bottom formwork distribution beam and an upper beam are located sequentially from bottom to top on the truss. Each upper beam has a safety reserved hole and a frame-dropping reserved hole that run through the entire upper beam. A jack base is located above each frame-dropping reserved hole of the upper beam. A continuous jack is located above the jack base. At the bottom of each frame-dropping reserved hole of the upper beam, a load-bearing beam, a pad beam with a round hole, and an anchor are located sequentially from top to bottom.

[0007] A steel strand is inserted into the continuous jack. The steel strand passes through the center of the jack base, the pre-reserved hole for the upper beam, the truss, the load-bearing beam, and the round hole of the pad beam at the bottom of the load-bearing beam in sequence from top to bottom, and then into the anchor, so that the lower end of the steel strand is anchored to the pad beam at the bottom of the load-bearing beam.

[0008] A pad beam is provided above each safety reserved hole in the upper beam and at the bottom of the transverse distribution beam. The steel bar passes through the round hole of the pad beam above the safety reserved hole in the upper beam, the safety reserved hole in the upper beam, the through hole on the bottom formwork distribution beam, the through hole on the truss, the through hole on the transverse distribution beam, and the round hole of the pad beam at the bottom of the transverse distribution beam in sequence from top to bottom. Then, two nuts are screwed on each end of the steel bar to anchor the steel bar to the upper beam and the transverse distribution beam, forming a safety system.

[0009] A lower beam is erected between the left and right piers. A transverse track is placed on the left and right sides of the lower beam. The two transverse tracks are placed on the left and right sides of the lower beam, in the area between the safety reserved hole and the drop-off reserved hole of the upper beam in the longitudinal direction of the bridge.

[0010] Furthermore, both the safety reserve holes and the unloading reserve holes are pre-embedded holes that penetrate the entire upper beam. There are a total of 6 safety reserve holes, arranged in two rows in a 3:3 symmetrical pattern along the longitudinal bridge centerline of the upper beam, with each row located 3m from the end of the upper beam. The three safety reserve holes in each row are located 1.8m from the ends of the flange plates on both sides of the upper beam and at the center of the cross section. There are a total of 8 unloading reserve holes, arranged in two rows in a 4:4 symmetrical pattern along the longitudinal bridge centerline of the upper beam, with each row located 5m from the end of the upper beam. The four unloading reserve holes in each row are located 1.8m from the ends of the flange plates on both sides of the upper beam and 4m from the centerline on both sides of the cross section.

[0011] Furthermore, the continuous jacks are the commonly available 50t-100t hydraulic continuous jacks, equipped with a synchronous control system; the jack base is welded from two sections of double-jointed I-beams, long plates, and stiffening plates; the load-bearing beams are welded from double-jointed H-beams and flat plates; the number of steel strands is determined based on the weight of the support, with five steel strands arranged on each continuous jack, and 10-hole anchors are used according to the specifications and number of steel strands; the pad beams are welded from two [14a channel steels, partitions, upper limit plates, and lower limit plates, with the channel steels welded back-to-back by partitions, an upper limit plate with a round hole welded directly above the middle of the channel steel, and a lower limit plate with a round hole welded directly below the middle of the channel steel; the transverse track is an I-beam structure.

[0012] Furthermore, the lifting capacity of each continuous jack shall not be less than 1.3 times the standard value of the support load at the corresponding lifting point.

[0013] Furthermore, the jack base is 1m long and 0.85m wide, with a designed load capacity of 50t. Six stiffening plates are welded between the upper and lower flanges of each set of I-beams on the jack base, directly below the continuous jack installation position. The gap between the two sets of I-beams on the jack base is not less than 120mm, and four long plates are arranged at intervals of 250mm, 320mm, and 250mm and welded perpendicularly to the two sets of I-beams.

[0014] Furthermore, the length of the load-bearing beam is equal to the length of the transverse distribution beam of the support; the distance between the edges of the two sets of H-beams of the load-bearing beam is not less than 140mm, and the upper and lower surfaces of both ends of the two sets of H-beams are vertically welded to the two sets of H-beams using flat plates.

[0015] Furthermore, the pad beam is 0.8m long and 0.216m wide. The two channel steels of the pad beam are arranged back to back, with a distance of not less than 100mm between the edges. Six partitions are then symmetrically arranged at intervals of 60mm, 110mm, and 200mm, centered on the transverse axis perpendicular to the length of the pad beam, and welded and fixed between the two channel steels. An upper limit plate is welded at the center of the upper surface of the pad beam. The upper limit plate is a 120mm×206mm steel plate with a 100mm diameter hole in the center. A lower limit plate is welded at the center of the lower surface of the pad beam. The lower limit plate is a 180mm×206mm steel plate with a 100mm diameter hole in the center.

[0016] Furthermore, the steel bars are made of Φ40mm precision rolled threaded steel, and the length of a single steel bar is not less than "0.5m + 2 pad beam heights + 2 nut heights + upper beam height + truss height + bottom formwork distribution beam height"; the length of a single steel strand is not less than the distance from the upper beam to the lower beam + the height of the continuous jack + 2m; in order to ensure smooth connection of the steel strands, the head of the steel strand should be processed into a 10mm long conical head with a conical angle of 30°; the end of the steel strand extends beyond the anchor by not less than 3cm.

[0017] Furthermore, the length of the transverse track is such that both ends extend 3m beyond the projection range of the upper beam.

[0018] Furthermore, the safety hole and the drop-off hole are both pre-embedded using φ120mm PVC pipes.

[0019] This utility model employs a lowering system composed of continuous jacks, jack bases, steel strands, load-bearing beams, pad beams, and anchors to lower the upper structure of supports such as trusses and bottom formwork distribution beams onto the lower beam. Before lowering, a safety system consisting of pad beams, steel bars, and nuts is installed to prevent the upper structure of the supports from falling when the support foundation is dismantled. A transverse track is set on the lower beam to move the truss and bottom formwork distribution beams laterally out of the projection range of the upper beam, and then a crane is used for dismantling.

[0020] The beneficial effects of this utility model are as follows:

[0021] 1. By adopting a continuous jacking cyclic lowering method, the construction problem of disassembling and transporting the support frame under limited space conditions was solved;

[0022] 2. The system is equipped with continuous jacks and steel strands as the main lowering system, which provides higher load capacity and can withstand higher support loads. It is also equipped with safety devices such as steel bars, pad beams and nuts, which greatly improves safety and construction efficiency.

[0023] 3. The force distribution is clear, making installation and disassembly convenient, which further improves work efficiency, effectively speeds up construction progress, ensures construction quality, and saves construction costs.

[0024] 4. It has a simple structure, is easy to operate, is safe and reliable, and is highly economical. Attached Figure Description

[0025] Figure 1 This is a schematic cross-sectional view of the upper beam in an embodiment of the present invention;

[0026] Figure 2 for Figure 1 Top view;

[0027] Figure 3 This is a side view of an embodiment of the present utility model;

[0028] Figure 4 for Figure 3 End section view;

[0029] Figure 5 for Figure 3 Mid-span cross-section;

[0030] Figure 6 This is a schematic diagram of the dismounted state in an embodiment of the present invention;

[0031] Figure 7 This is a schematic diagram showing the completion of the lowering of the frame in this embodiment of the invention;

[0032] Figure 8 for Figure 7 Cross-sectional view;

[0033] Figure 9 This is a schematic diagram showing the lateral movement of the truss after the lowering of the frame is completed according to an embodiment of this novel invention;

[0034] Figure 10 This is a front view of the jack base according to an embodiment of the present utility model;

[0035] Figure 11 for Figure 10 Side view;

[0036] Figure 12 for Figure 10 Floor plan;

[0037] Figure 13 This is a schematic diagram of the cross-section of the load-bearing beam according to an embodiment of the present utility model;

[0038] Figure 14 for Figure 13 Floor plan;

[0039] Figure 15 This is a side view of the pad beam according to an embodiment of the present utility model;

[0040] Figure 16 for Figure 15 Plan view of the upper surface;

[0041] Figure 17 for Figure 15 The lower surface plan view.

[0042] Figure 18 This is a schematic diagram of the steel strand end processing according to an embodiment of the present utility model;

[0043] Attached reference numerals: 1. Continuous jack; 2. Jack base; 21. I-beam; 22. Long plate; 23. Stiffening plate; 3. Steel strand; 4. Load-bearing beam; 41. H-beam; 42. Flat plate; 5. Anchor; 6. Pad beam; 61. Channel steel; 62. Partition plate; 63. Upper limit plate; 64. Lower limit plate; 65. Round hole; 7. Steel bar; 8. Nut; 9. Safety hole; 10. Lowering hole; 11. Lateral track; 12. Upper beam; 13. Lower beam; 14. Support; 141. Support foundation; 142. Lateral distribution beam; 143. Steel unloading block; 144. Truss; 145. Bottom formwork distribution beam. Detailed Implementation

[0044] The present invention will now be described in further detail with reference to the accompanying drawings and implementation examples.

[0045] A device for dismantling the upper support of a double-layer bridge comprises a continuous jack 1, a jack base 2, steel strands 3, a load-bearing beam 4, an anchor 5, a pad beam 6, a steel bar 7, a nut 8, a safety reserved hole 9, a lowering reserved hole 10, and a transverse track 11, wherein:

[0046] A pier body 16 is provided on each pier cap 15. The support 14 is composed of a support foundation 141, a transverse distribution beam 142, steel unloading blocks 143, a truss 144, and a bottom formwork distribution beam 145. A support foundation 141 is provided on the side wall of each pier cap 15 and pier body 16. The top of the support foundation 141 is fixed to the pier body 16 by a horizontal tie rod 17. A transverse distribution beam 142 is provided at the top of the support foundation 141. A steel unloading block 143 is provided on the top of the transverse distribution beam 142. A truss 144 is provided on the steel unloading blocks 143 of two adjacent transverse distribution beams 142. A bottom formwork distribution beam 145 and an upper beam body 12 are provided sequentially from bottom to top on the truss 144. Each upper beam 12 is provided with a safety reserved hole 9 and a lowering reserved hole 10 that run through the entire upper beam 12. A jack base 2 is provided above each lowering reserved hole 10 of the upper beam 12. A continuous jack 1 is provided above the jack base 2. At the bottom of each lowering reserved hole 10 of the upper beam 12, a load-bearing beam 4, a pad beam 6 with a round hole 65 and an anchor 5 are provided from top to bottom.

[0047] A steel strand 3 is inserted into the continuous jack 1. The steel strand 3 passes through the center of the jack base 2, the pre-reserved hole 10 of the upper beam 12, the truss 144, the load-bearing beam 4, and the round hole 65 of the pad beam 6 at the bottom of the load-bearing beam 4 from top to bottom, and then enters the anchor 5 so that the lower end of the steel strand 3 is anchored to the pad beam 6 at the bottom of the load-bearing beam 4.

[0048] A pad beam 6 is provided above each safety reserved hole 9 of the upper beam 12 and at the bottom of the transverse distribution beam 142. The steel bar 7 passes through the round hole 65 of the pad beam 6 above the safety reserved hole 9 of the upper beam 12, the safety reserved hole 9 of the upper beam 12, the through hole on the bottom formwork distribution beam 145, the through hole on the truss 144, the through hole on the transverse distribution beam 142, and the round hole 65 of the pad beam 6 at the bottom of the transverse distribution beam 142 in sequence from top to bottom. Then, two nuts 8 are screwed on each end of the steel bar 7 to anchor the steel bar 7 to the upper beam 12 and the transverse distribution beam 142, forming a safety system.

[0049] A lower beam 13 is erected between the two left and right piers 16. A transverse track 11 is placed on the left and right sides of the lower beam 13. The two transverse tracks 11 are placed on the left and right sides of the lower beam 13, in the area between the safety reserved hole 9 and the drop reserved hole 10 of the upper beam 12 in the longitudinal direction of the bridge.

[0050] Furthermore, both the safety reserved hole 9 and the dismounting reserved hole 10 are pre-embedded holes that penetrate the entire upper beam 12. There are a total of 6 safety reserved holes 9, arranged in two rows in a three-by-three symmetrical pattern along the longitudinal bridge centerline of the upper beam 12, with each row located 3m from the end of the upper beam 12. The three safety reserved holes in each row are located 1.8m from the ends of the flange plates on both sides of the upper beam 12 and at the center of the cross section. There are a total of 8 dismounting reserved holes 10, arranged in two rows in a four-by-four symmetrical pattern along the longitudinal bridge centerline of the upper beam 12, with each row located 5m from the end of the upper beam 12. The four dismounting reserved holes 10 in each row are located 1.8m from the ends of the flange plates on both sides of the upper beam 12 and 4m from the centerline on both sides of the cross section.

[0051] Furthermore, the continuous jack 1 is a common 50t-100t hydraulic continuous jack on the market, equipped with a synchronous control system; the jack base 2 is welded together from two sections of double-jointed I-beams 21, long plates 22 and stiffening plates 23; the load-bearing beam 4 is welded together from double-jointed H-beams 41 and flat plates 42; the number of steel strands 3 is determined according to the weight of the support 14, with five steel strands 3 arranged in each continuous jack 1, and 10-hole anchors 5 are used according to the specifications and number of steel strands 3; the pad beam 6 is welded together from two [14a channel steels 61, partition plates 62, upper limit plates 63 and lower limit plates 64, with the channel steels 61 welded back-to-back through partition plates 62, the upper limit plate 63 with round holes 65 welded directly above the middle of the channel steel 61, and the lower limit plate 64 with round holes 65 welded directly below the middle of the channel steel 61; the transverse track 11 is an I-beam structure.

[0052] Furthermore, the lifting capacity of each continuous jack 1 is not less than 1.3 times the standard load value of the support 14 at the corresponding lifting point.

[0053] Furthermore, the jack base 2 is 1m long and 0.85m wide, with a designed load capacity of 50t; directly below the installation position of the continuous jack 1, between the upper and lower flanges of each set of I-beams 21 of the jack base 2, 6 stiffening plates 23 are welded, the gap between the two sets of I-beams 21 of the jack base 2 is not less than 120mm, and 4 long plates 22 are arranged at intervals of 250mm, 320mm, and 250mm and vertically welded to the two sets of I-beams 21.

[0054] Furthermore, the length of the load-bearing beam 4 is equal to that of the transverse distribution beam 142 of the support 14; the distance between the edges of the two sets of H-beams 41 of the load-bearing beam 4 is not less than 140mm, and the upper and lower surfaces of the two sets of H-beams 41 are vertically welded to the two sets of H-beams 41 using flat plates 42.

[0055] Furthermore, the pad beam 6 is 0.8m long and 0.216m wide. The two channel steels 61 of the pad beam 6 are arranged back to back, with a distance of not less than 100mm between the edges. Six partition plates 62 are then arranged symmetrically at intervals of 60mm, 110mm, and 200mm, centered on the transverse axis perpendicular to the length of the pad beam 6, and welded and fixed between the two channel steels 61. An upper limit plate 63 is welded at the center of the upper surface of the pad beam 6. The upper limit plate 63 is a 120mm×206mm steel plate with a 100mm diameter circular hole 65 in the center. A lower limit plate 64 is welded at the center of the lower surface of the pad beam 6. The lower limit plate 64 is a 180mm×206mm steel plate with a 100mm diameter circular hole 65 in the center.

[0056] Furthermore, the steel bar 7 is made of Φ40mm precision rolled threaded steel, and the length of a single steel bar 7 is not less than "0.5m + 2 pad beams 6m high + 2 nuts 8m high + upper beam 12m high + truss 144m high + bottom formwork distribution beam 145m high"; the length of a single steel strand 3 is not less than the distance from the upper beam 12 to the lower beam 13 + the height of the continuous jack 1 + 2m; in order to ensure smooth connection of the steel strand 3, the head of the steel strand 3 should be processed into a cone with a length of 10mm and a cone angle of 30°; the end of the steel strand 3 extends beyond the anchor 5 by not less than 3cm.

[0057] Furthermore, the length of the transverse track 11 is such that both ends extend 3m beyond the projection range of the upper beam 12.

[0058] Furthermore, both the safety reserved hole 9 and the drop-off reserved hole 10 are pre-embedded using φ120mm PVC pipes.

[0059] Specific implementation process:

[0060] A. Before installing the device, the steel unloading block 143 needs to be used to unload the truss 144 and the bottom formwork distribution beam 145, lowering it by 5cm.

[0061] B. During the construction of the upper beam 12, reserve safety holes 9 and scaffolding removal holes 10 in advance; before the scaffolding 14 is removed, first use steel unloading blocks 143 to unload the truss 144 and bottom formwork distribution beam 145, and lower it by 5cm.

[0062] C. Insert steel rod 7 through the safety reserved hole 9 until it reaches the transverse distribution beam 142. Insert steel rod 7 through the hole on the transverse distribution beam 142. Install pad beam 6 at the point where steel rod 7 enters the upper beam 12 and at the point where steel rod 7 exits the transverse distribution beam 142, and tighten nut 8 to anchor.

[0063] D. Install jack base 2 and continuous jack 1 in sequence on the pre-reserved hole 10 of the lowering frame, and thread the steel strand 3 through the continuous jack 1 and jack base 12 to the bottom of the truss 144; a load-bearing beam 4 is installed below the truss 144, thread the steel strand 3 through the load-bearing beam 4, and install pad beam 6 and anchor 5 at the bottom of the load-bearing beam 4 to anchor the steel strand 3 to the load-bearing beam 4;

[0064] E. Arrange two transverse tracks 11 on the lower beam 13;

[0065] F. After the device is installed, a trial lift must be performed. After the steel strand 3 is installed, use the continuous jack 1 to tighten the steel strand 3 so that each steel strand 3 is under stress. Slightly loosen the nut 8 on the steel bar 7. At this time, increase the load on the continuous jack 1 by 30%, 50%, and 100% at a time, driving the entire truss 144 and the bottom formwork distribution beam 145 to rise by 5cm and stop the lift. Then tighten the nut 8 on the steel bar 7 again to ensure that the steel strand 3 and the steel bar 7 are both under stress.

[0066] G. Manually dismantle the support foundation 141. After dismantling, start the continuous jack 1 to bear the force, loosen the nuts 8 of the steel rods 7 on the upper beam 12, and use the continuous jack 1 to cyclically lower the truss 144, steel unloading block 143, transverse distribution beam 142 and bottom formwork distribution beam 145 until the truss 144 falls onto the transverse track 11 of the lower beam 13.

[0067] H. Loosen the end nut 8 under the steel bar 7, and use the crane to unload the transverse distribution beam 142 and steel unloading block 143 onto the lower beam 143.

[0068] I. Continue to start the continuous jack 1, lower the load-bearing beam 4 to the lower beam 143, and remove the steel strand 3, the continuous jack 1, the jack base 2, the pad beam 6, and the steel bar 7 on the upper beam 12.

[0069] J. Using a chain conveyor system, the truss 144 and the bottom formwork distribution beam 145 are moved laterally to outside the projection range of the upper beam 12 for transport and hoisting. Finally, the remaining steel unloading blocks 143, the transverse distribution beam 142, the load-bearing beam 4, and the pad beam 6 are transported to the ground.

[0070] The entire construction process ensures safety while maintaining an aesthetically pleasing appearance, convenient and quick operation, and saving time and manpower.

[0071] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. All equivalent structural changes made based on the description and drawings of this utility model are included within the scope of this utility model.

Claims

1. A device for dismantling the upper support of a double-layer bridge, characterized in that: It consists of continuous jacks, jack bases, steel strands, load-bearing beams, anchors, pad beams, steel bars, nuts, safety pre-drilled holes, lowering pre-drilled holes, and transverse tracks, wherein: Each pier is supported by a support structure consisting of a support foundation, transverse distribution beams, steel unloading blocks, trusses, and bottom formwork distribution beams. Support foundations are located on the side walls of each pier and support structure. The top of the support foundations is fixed to the pier by horizontal tie rods. A transverse distribution beam is located at the top of the support foundation. A steel unloading block is located above the transverse distribution beam. A truss is located between the steel unloading blocks of two adjacent transverse distribution beams. A bottom formwork distribution beam and an upper beam are located sequentially from bottom to top on the truss. Each upper beam has a safety reserved hole and a frame-dropping reserved hole that run through the entire upper beam. A jack base is located above each frame-dropping reserved hole of the upper beam. A continuous jack is located above the jack base. At the bottom of each frame-dropping reserved hole of the upper beam, a load-bearing beam, a pad beam with a round hole, and an anchor are located sequentially from top to bottom. A steel strand is inserted into the continuous jack. The steel strand passes through the center of the jack base, the pre-reserved hole for the upper beam, the truss, the load-bearing beam, and the round hole of the pad beam at the bottom of the load-bearing beam in sequence from top to bottom, and then into the anchor, so that the lower end of the steel strand is anchored to the pad beam at the bottom of the load-bearing beam. A pad beam is provided above each safety reserved hole in the upper beam and at the bottom of the transverse distribution beam. The steel bar passes through the round hole of the pad beam above the safety reserved hole in the upper beam, the safety reserved hole in the upper beam, the through hole on the bottom formwork distribution beam, the through hole on the truss, the through hole on the transverse distribution beam, and the round hole of the pad beam at the bottom of the transverse distribution beam in sequence from top to bottom. Then, two nuts are screwed on each end of the steel bar to anchor the steel bar to the upper beam and the transverse distribution beam, forming a safety system. A lower beam is erected between the left and right piers. A transverse track is placed on the left and right sides of the lower beam. The two transverse tracks are placed on the left and right sides of the lower beam, in the area between the safety reserved hole and the drop-off reserved hole of the upper beam in the longitudinal direction of the bridge.

2. The device for dismantling the upper support of a double-layer bridge according to claim 1, characterized in that: Both the safety and dismounting holes are pre-embedded holes that penetrate the entire upper beam. There are a total of 6 safety holes, arranged in two rows in a 3:3 symmetrical pattern along the longitudinal centerline of the upper beam, with each row located 3m from the end of the upper beam. The three safety holes in each row are located 1.8m from the ends of the flange plates on both sides of the upper beam and at the center of the cross section. There are a total of 8 dismounting holes, arranged in two rows in a 4:4 symmetrical pattern along the longitudinal centerline of the upper beam, with each row located 5m from the end of the upper beam. The four dismounting holes in each row are located 1.8m from the ends of the flange plates on both sides of the upper beam and 4m from the centerline of the cross section on both sides.

3. The device for dismantling the upper support of a double-layer bridge according to claim 1, characterized in that: The continuous jacks are common 50t-100t hydraulic continuous jacks on the market, equipped with a synchronous control system; the jack base is welded from two sections of double-jointed I-beams, long plates, and stiffening plates; the load-bearing beams are welded from double-jointed H-beams and flat plates; the number of steel strands is determined based on the weight of the support, with five steel strands per continuous jack, and 10-hole anchors are used according to the specifications and number of steel strands; the pad beams are welded from two [14a channel steels, partitions, upper limit plates, and lower limit plates, with the channel steels welded back-to-back by partitions, an upper limit plate with a round hole welded directly above the middle of the channel steel, and a lower limit plate with a round hole welded directly below the middle of the channel steel; the transverse track is an I-beam structure.

4. The device for dismantling the upper support of a double-layer bridge according to claim 1, characterized in that: The lifting capacity of each continuous jack shall not be less than 1.3 times the standard value of the support load at the corresponding lifting point.

5. The device for dismantling the upper support of a double-layer bridge according to claim 1, characterized in that: The jack base is 1m long and 0.85m wide, with a designed load capacity of 50t. Six stiffening plates are welded between the upper and lower flanges of each set of I-beams on the jack base, directly below the continuous jack installation position. The gap between the two sets of I-beams on the jack base is not less than 120mm, and four long plates are arranged at intervals of 250mm, 320mm, and 250mm and welded perpendicularly to the two sets of I-beams.

6. The device for dismantling the upper support of a double-layer bridge according to claim 1, characterized in that: The length of the load-bearing beam is the same as the transverse distribution beam of the support; the distance between the edges of the two sets of H-beams of the load-bearing beam is not less than 140mm, and the upper and lower surfaces of the two sets of H-beams at both ends are welded vertically to the two sets of H-beams using flat plates.

7. The device for dismantling the upper support of a double-layer bridge according to claim 1, characterized in that: The pad beam is 0.8m long and 0.216m wide. The two channel steels of the pad beam are arranged back to back, with a distance of not less than 100mm between the edges. Six partitions are then welded and fixed between the two channel steels at symmetrical intervals of 60mm, 110mm, and 200mm, centered on the transverse axis perpendicular to the length of the pad beam. An upper limit plate is welded at the center of the upper surface of the pad beam. The upper limit plate is a 120mm×206mm steel plate with a 100mm diameter hole in the center. A lower limit plate is welded at the center of the lower surface of the pad beam. The lower limit plate is a 180mm×206mm steel plate with a 100mm diameter hole in the center.

8. The device for dismantling the upper support of a double-layer bridge according to claim 1, characterized in that: The steel bars are made of Φ40mm precision rolled threaded steel. The length of a single steel bar is not less than "0.5m + 2 pad beam heights + 2 nut heights + upper beam height + truss height + bottom formwork distribution beam height"; the length of a single steel strand is not less than the distance from the upper beam to the lower beam + the height of the continuous jack + 2m; in order to ensure smooth connection of the steel strands, the head of the steel strand should be processed into a 10mm long conical head with a conical angle of 30°; the end of the steel strand extends beyond the anchorage by not less than 3cm.

9. The device for dismantling the upper support of a double-layer bridge according to claim 1, characterized in that: The length of the transverse track is such that both ends extend 3m beyond the projection range of the upper beam.

10. The device for dismantling the upper support of a double-layer bridge according to claim 1, characterized in that: The safety hole and the drop-off hole are both pre-embedded using φ120mm PVC pipes.

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