A kind of viaduct disassembly support system and disassembly method

Abstract

The invention relates to a disassembly support system and a disassembly method for an elevated bridge, comprising a support unit; a support row group is arranged under each span of the cast-in-place box girder in the extension direction of the cast-in-place box girder; each support row group comprises a plurality of support units arranged at intervals in a transverse direction; a first cross bar is fixed to the upper part of each support row group, a second cross bar is fixed to the upper part of each support unit of the support row group close to a pier column, and two first cross bars and two second cross bars form an upper rectangular frame; a first vertical scissors brace is fixed to the left side surface of the leftmost support unit of each support row group and the right side surface of the rightmost support unit, a second vertical scissors brace is fixed to the side of the support row group close to the pier column facing the pier column, the first vertical scissors brace is fixedly connected to the first cross bar and the third cross bar respectively; the second vertical scissors brace is fixedly connected to the second cross bar and the fourth cross bar respectively; the support stability of the cast-in-place box girder is increased.

Description

Technical Field

[0001] The invention belongs to the field related to urban municipal engineering demolition, and in particular relates to a viaduct dismantling support system and a dismantling method. Background Art

[0002] A viaduct is a bridge that is built on a series of narrow reinforced concrete or masonry arches and has high supporting towers or pillars, spanning valleys, rivers, roads or other low obstacles. After urban development, traffic is congested, buildings are densely packed, and streets are difficult to widen. The use of such bridges can disperse traffic density and improve transportation efficiency. In addition, in order to avoid horizontal intersections with other lines and save land, viaducts can also be used on inter-city highways or railways.

[0003] With the renovation and upgrading of viaducts across railways, the middle approach bridge of viaducts across railways also needs to be demolished and rebuilt. The traditional method is to crush the bridge with a crusher on site, but the traditional bridge demolition method has the following disadvantages: (1) The traditional bridge demolition method has a long construction period, slow progress, many machines and high cost; (2) The on-site demolition operation generates a lot of dust and the noise disturbs the public, which is not conducive to construction near the city; (3) After demolition, the amount of steel bars and concrete transported out is large, the cleaning work is arduous, and the original ground road is greatly disturbed and damaged. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide a viaduct disassembly support system and disassembly method to solve the problems of long construction period, slow progress, large dust and noise disturbance caused by on-site demolition operations during viaduct disassembly in the prior art.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by a viaduct disassembly support system of the present invention is:

[0006] A viaduct disassembly support system, comprising:

[0007] Support unit: The bottom of the support unit is supported on the leveling layer, and the top of the support unit is supported on the bottom of the cast-in-place box girder of the viaduct;

[0008] In the extension direction of the cast-in-place box girder, a plurality of support row groups are arranged under each span of the cast-in-place box girder, and two adjacent support row groups are arranged at intervals in the extension direction of the cast-in-place box girder. Each support row group includes a plurality of support units arranged at intervals in the transverse direction of the cast-in-place box girder, and each support row group is located at the longitudinal center of each cast-in-place box girder;

[0009] A first crossbar is fixed to the upper part of the left side surface of the leftmost support unit of each support row group and the upper part of the right side surface of the rightmost support unit, and a second crossbar is fixed to the upper part of the side facing the pier column of each support unit of the support row group close to the pier column, two first crossbars are provided, and two second crossbars are provided, and the two first crossbars and the two second crossbars form an upper rectangular frame;

[0010] A third cross bar is fixed to the lower part of the left side surface of the leftmost support unit of each support row group and the lower part of the right side surface of the rightmost support unit, and a fourth cross bar is fixed to the lower part of the side facing the pier column of each support unit of the support row group close to the pier column, two third cross bars are provided, and two fourth cross bars are provided, and the two third cross bars and the two fourth cross bars form a lower rectangular frame;

[0011] A first vertical scissors strut is fixed to the left side surface of the leftmost support unit of each support row group and the right side surface of the rightmost support unit, and a second vertical scissors strut is fixed to the side of the support row group close to the pier facing the pier, and the first vertical scissors strut is fixedly connected to the first cross bar and the third cross bar, respectively; the second vertical scissors strut is fixedly connected to the second cross bar and the fourth cross bar, respectively.

[0012] Beneficial effect: The viaduct disassembly unit support system of the present invention comprises a plurality of support units, a plurality of support row groups are arranged under each span of cast-in-place box girder, each support row group is used to support the cutting block respectively, each support row group as a whole supports a span of cast-in-place box girder between two adjacent piers that have not been cut, an upper rectangular frame is fixedly arranged on the upper outer side of the outer ring support unit, the upper rectangular frame fixes the upper part of the outer support unit, a lower rectangular frame is fixedly arranged on the lower outer side of the outer ring support unit, the lower rectangular frame fixes the lower part of the outer support unit, and a left side or right side support unit of the leftmost support unit of each support row group is fixedly arranged on the left side or right side support unit of the leftmost support unit of each support row group. A first vertical scissors brace is fixed to the right side surface of the support unit, and the first vertical scissors brace is fixedly connected to the first cross bar and the third cross bar of the rectangular frame respectively. A second vertical scissors brace is fixed to the side of the support row group facing the pier close to the pier, and the second vertical scissors brace is fixedly connected to the second cross bar and the fourth cross bar of the rectangular frame respectively. Therefore, the outer ring support unit below the cast-in-place box girder between two adjacent piers is connected through the upper rectangular frame, the lower rectangular frame, the first vertical scissors brace and the second vertical scissors brace, so that the support unit below the cast-in-place box girder between two adjacent piers forms a stable support system, thereby increasing the support stability of the cast-in-place box girder.

[0013] Furthermore, a fifth cross bar is fixed to the middle of the left side surface of the leftmost support unit of each support row group and the middle of the right side surface of the rightmost support unit, and a sixth cross bar is fixed to the middle of the side facing the pier of each support unit of the support row group close to the pier. Two fifth cross bars are provided and two sixth cross bars are provided. The two fifth cross bars and the two sixth cross bars form a middle rectangular frame. The first vertical scissors strut is fixedly connected to the fifth cross bar, and the second vertical scissors strut is fixedly connected to the sixth cross bar.

[0014] Beneficial effect: The setting of the middle rectangular frame further increases the connection strength between the support units under the cast-in-place box girder, ensuring that the support units under the cast-in-place box girder located between two adjacent piers form a stable support system, thereby increasing the support stability of the cast-in-place box girder.

[0015] Furthermore, the support units of the support row group close to the pier are fixedly connected to the pier via connecting rods, and three connecting rods are arranged at intervals in the up and down directions.

[0016] Beneficial effect: The support units of the support row group close to the pier are fixedly connected to the pier through connecting rods, so that the support system under the cast-in-place box girder between the two piers is more stable.

[0017] The support unit includes a bottom support placed on the leveling layer, a plurality of lattice columns fixed on the bottom support, a top support fixed directly above the top lattice column, and a screw jack fixed above the top support, wherein the top of the screw jack is supported on the bottom of the cast-in-place box girder.

[0018] Beneficial effects: The structural composition of the support unit ensures that the support unit has a relatively stable support strength. The setting of the screw jack can be adaptively adjusted according to the distance from the bottom of the cast-in-place box girder, so that the screw jack can effectively support the bottom of the cast-in-place box girder. In addition, the support unit includes a number of lattice columns, which can speed up the support of the support unit and ensure the erection efficiency of the support unit.

[0019] Furthermore, connecting angle steels are vertically welded on the lattice columns, steel pipes are welded on the connecting angle steels, and the rectangular frame and the vertical scissor braces are detachably connected to the steel pipes via fasteners.

[0020] Beneficial effects: The setting of the connecting angle steel facilitates the welding and fixing of the steel pipe and the lattice column, the setting of the steel pipe facilitates the fixed connection between the rectangular frame and the lattice column, and also facilitates the detachable connection between the vertical scissors brace and the lattice column.

[0021] To achieve the above object, a technical solution adopted by a viaduct disassembly construction method of the present invention is:

[0022] A viaduct disassembly construction method comprises the following steps:

[0023] S1: The auxiliary structures of the bridge deck are removed, and the anti-collision guardrail is removed by rope saw, cut into pieces and transported to the designated site;

[0024] S2: Erection of disassembly support system. Before erection, the base of the support system shall be hardened as the leveling layer of the disassembly support system;

[0025] S3: Cast-in-place box beams are cut in blocks, with the top and bottom plates cut horizontally from top to bottom. The cuts should be slightly inclined outwards to ensure that the beams do not fall when the beams are cut;

[0026] S4: Lifting and transportation of cast-in-place box beams. The truck crane drives into the cast-in-place box beam area to lift and transport the cut beams. Steel wire ropes are installed on the cut beams, which are then lifted slowly and evenly by the crane and then hoisted to the beam transport vehicle for transportation.

[0027] S5: Pier column removal and transportation. Pier columns should be cut off and hoisted in sections from top to bottom. The length of each section of pier column should be determined according to the site conditions. Pier columns should be piled up in time after removal. Pier columns should be removed to ensure that they are 0.5m below the ground line.

[0028] S6: Dismantling and transportation of the foundation;

[0029] The support system is the above-mentioned viaduct disassembly support system.

[0030] Beneficial effect: When the present invention is used to dismantle an elevated bridge with a cast-in-place box girder, a support system is set up at the bottom of the cast-in-place box girder, and then the cast-in-place box girder is cut into blocks, so that the bottom of each cut cast-in-place box girder is supported by a support row group, thereby ensuring that the support row group provides stable support for the cut cast-in-place box girder, and then the cast-in-place box girder is cut into blocks, and the cut cast-in-place box girder is supported on the support row group, and then hoisted and transported to a beam transport vehicle for transportation, and then the piers are dismantled and transported, and finally the cap is dismantled and transported. The method for dismantling the cast-in-place box girder of the present invention not only has strong safety, but also has high dismantling efficiency, and generates as little dust pollution and noise pollution as possible during dismantling.

[0031] Furthermore, in S2, measurement and positioning are first performed to determine the position of the support unit; then, each support unit is erected, and in the extension direction of the cast-in-place box girder, a plurality of support row groups are arranged under each span of the cast-in-place box girder, and two adjacent support row groups are arranged at intervals in the extension direction of the cast-in-place box girder, and each support row group includes a plurality of support units arranged at intervals in the transverse direction of the cast-in-place box girder, and each support row group is located at the longitudinal center of each cast-in-place box girder, and then an upper rectangular frame, a lower rectangular frame, a first vertical scissors brace, and a second vertical scissors brace are respectively fixed on the support units.

[0032] Beneficial effect: While determining the precise positioning of each support unit, the support row group is located exactly at the longitudinal center line of each cut cast-in-place box girder, so that after the cast-in-place box girder is cut, the support row group can be stably supported underneath it, ensuring that the cast-in-place box girder has greater stability before and after cutting, and ensuring the safety of construction.

[0033] Furthermore, when the support unit is erected, a bottom support is placed on the leveling layer, and then the lattice column is placed on the bottom support accordingly, and the lattice column and the bottom support, as well as the lattice column and the lattice column are fixedly connected respectively, and then connecting angle steels are welded at positions corresponding to the rectangular frames on the lattice columns and at positions corresponding to the vertical scissors braces, and steel pipes are welded on the connecting angle steels. After the upper rectangular frame, the lower rectangular frame, the first vertical scissors brace, and the second vertical scissors brace are fixed; fix the top support on the lattice column at the top of the support unit, and finally install the top jack on the top support.

[0034] Beneficial effects: The erection process of each support unit is simple and easy to operate, ensuring that the support unit has a high erection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a structural schematic diagram of a disassembly support system of a middle approach bridge section according to a first specific embodiment of the present invention;

[0036] Figure 2 yes Figure 1 Another side view of the dismantling support system of the middle approach bridge section;

[0037] Figure 3 yes Figure 1 A partial enlarged view of the dismantling support system of the middle approach bridge section;

[0038] Figure 4 yes Figure 3 A structural schematic diagram of a cross section of a solid section of a dismantling support system of a middle approach bridge section;

[0039] Figure 5 yes Figure 3 A schematic structural diagram of a cross section of a hollow section of a dismantling support system of a middle approach bridge section;

[0040] Figure 6 yes Figure 3 A top perspective view of the dismantling support system of the middle approach bridge section;

[0041] Figure 7 yes Figure 3 A schematic diagram of the structure of the lattice columns in the dismantling support system of the middle approach bridge section;

[0042] Figure 8 yes Figure 3A schematic diagram of the structure of the top support in the dismantling support system of the middle approach bridge section;

[0043] Fig. 9 yes Figure 3 A schematic diagram of the structure of the connection between the lattice columns and the top bearings in the dismantling support system of the middle approach bridge section;

[0044] Fig.10 yes Figure 3 A structural schematic diagram of a lattice column with connecting angle steel and steel pipe in the dismantling support system of the middle approach bridge section;

[0045] Fig.11 yes Figure 1 Process flow chart for dismantling cast-in-place box girder of the middle approach bridge section;

[0046] Fig.12 yes Figure 1 Installation and erection process flow chart of the middle support unit;

[0047] Fig.13 It is a structural schematic diagram of the disassembly support system of the viaduct EN ramp 05 joint in the specific embodiment 2 of the present invention;

[0048] Fig.14 yes Fig.13 A schematic structural diagram of a cross section of a solid section of a disassembly support system of a mid-ramp;

[0049] Fig.15 yes Fig.13 A schematic structural diagram of a cross section of a hollow section of a disassembly support system of a mid-ramp;

[0050] Fig.16 yes Fig.13 Structural diagram of cast-in-place box girder support unit + disc bracket erection in the disassembly support system of the middle ramp

[0051] Fig.17 yes Fig.13 Top perspective view of the dismantling support system for the mid-ramp.

[0052] Figure markings: 1- pier; 2- supporting unit; 3- cutting block; 4- bottom support; 5- lattice column; 6- top support; 7- screw jack; 8- upper rectangular frame; 9- middle rectangular frame; 10- lower rectangular frame; 11- first vertical scissors brace; 12- second vertical scissors brace; 13- solid section; 14- hollow section; 15- intersecting angle steel; 16- connecting angle steel; 17- steel pipe; 18- cutting block; 19- supporting unit; 20- solid section; 21- screw jack; 22- hollow section; 23- disc bracket. DETAILED DESCRIPTION

[0053] The following is a further detailed description of a viaduct disassembly support system and disassembly method of the present invention in conjunction with the accompanying drawings and specific embodiments:

[0054] Specific embodiment 1, the disassembly support system and disassembly method of the middle approach bridge section; Figure 1-Figure 6 As shown, the south and north sides of the cast-in-place box girder of the middle approach bridge are 304m in total. The structural form is based on the old bridge drawings and actual on-site measurements. The maximum clearance is 10.06m, the beam structure height is 1m, the standard width of the top plate is 8.5m, and the bottom plate width is 6.4m. The cast-in-place box girder is cut into 2m blocks, and the support units 2 are calculated and arranged. The cast-in-place box girder between adjacent piers 1 is called a span, and each span is arranged with 8 rows of support groups. The cast-in-place box girder cut block 3 close to the pier 1 is a solid section 13, and the solid section 13 is arranged with 3 support units 2 at intervals in the horizontal direction. The middle cast-in-place box girder cut block 3 is a hollow section 14, and the hollow section 14 is arranged with 2 support units 2 at intervals in the horizontal direction. In this embodiment, the extension direction of the cast-in-place box girder is the longitudinal direction, which is also the front-back direction, and the direction perpendicular to the extension direction of the cast-in-place box girder is the transverse direction, which is also the left-right direction.

[0055] The disassembly support system of the middle approach bridge section includes a support unit 2, the bottom of the support unit 2 is supported on the leveling layer, the top of the support unit 2 is supported on the bottom of the cast-in-place box girder of the middle approach bridge of the viaduct, and in the extension direction of the cast-in-place box girder, a number of support row groups are arranged under each span of the cast-in-place box girder. In this embodiment, a total of 8 rows of support row groups are arranged in each span, and two adjacent support row groups are arranged at intervals in the extension direction of the cast-in-place beam. Each support row group includes a number of support units 2 arranged at intervals in the transverse direction of the cast-in-place box girder. In this embodiment, the support row group under the solid section 13 of the middle approach bridge section includes three support units 2 arranged at intervals in the transverse direction, and the support row group under the hollow section 14 of the middle approach bridge section includes two support units 2 arranged at intervals in the transverse direction. Each support row group is located at the longitudinal center position of each cast-in-place box girder cutting block 3, so as to ensure that the support row group is located at the center position of the cutting block 3 in the longitudinal direction, and ensure that the support row group can stably support the cutting block 3.

[0056] A first cross bar is fixed to the upper part of the left side surface of the leftmost support unit 2 of each support row group and the upper part of the right side surface of the rightmost support unit 2, and a second cross bar is fixed to the upper part of the side facing the pier 1 of each support unit 2 of the support row group close to the pier 1. Two first cross bars are provided, and two second cross bars are provided. The two first cross bars and the two second cross bars form an upper rectangular frame 8.

[0057] A fifth cross bar is fixed to the middle of the left side surface of the leftmost support unit 2 of each support row group and the middle of the right side surface of the rightmost support unit 2, and a sixth cross bar is fixed to the middle of the side facing the pier 1 of each support unit 2 of the support row group close to the pier 1. Two fifth cross bars are provided and two sixth cross bars are provided. The two fifth cross bars and the two sixth cross bars form a middle rectangular frame 9.

[0058] A third cross bar is fixed to the lower part of the left side surface of the leftmost support unit 2 of each support row group and the lower part of the right side surface of the rightmost support unit 2, and a fourth cross bar is fixed to the lower part of the side facing the pier 1 of each support unit 2 of the support row group close to the pier 1. Two third cross bars are provided and two fourth cross bars are provided. The two third cross bars and the two fourth cross bars form a lower rectangular frame 10.

[0059] The left side of the leftmost support unit 2 of each support row group and the right side of the rightmost support unit 2 are respectively fixed with a first vertical scissors brace 11, and the angle of the first vertical scissors brace 11 is set at 45°-60°; the side of the support row group close to the pier 1 facing the pier 1 is fixed with a second vertical scissors brace 12, and the angle of the second vertical scissors brace 12 is set at 45°-60°. The first vertical scissors brace 11 is respectively fixedly connected to the first crossbar of the upper rectangular frame 8, the fifth crossbar of the middle rectangular frame 9, and the third crossbar of the lower rectangular frame 10. The second vertical scissors brace 12 is respectively fixedly connected to the second crossbar of the upper rectangular frame 8, the sixth crossbar of the middle rectangular frame 9, and the fourth crossbar of the lower rectangular frame 10, so that each support unit 2, the upper rectangular frame 8, the middle rectangular frame 9, the lower rectangular frame 10, the first vertical scissors brace 11, and the second vertical scissors brace 12 form a stable support system, so that the support system can stably support the cast-in-place box girder between the two piers 1.

[0060] In order to further ensure the support stability of the support system, in this embodiment, the support unit 2 of the support row group close to the pier 1 is fixedly connected to the pier 1 through connecting rods, and three connecting rods are arranged at intervals in the vertical direction.

[0061] In this embodiment, the structures of the supporting units 2 are the same, and they all include a bottom support 4 placed on the leveling layer, a number of lattice columns 5 correspondingly fixed on the bottom support 4, a top support 6 correspondingly fixed directly above the top lattice column 5, and a screw jack 7 fixedly arranged above the top support 6, and the top of the screw jack 7 is supported on the bottom of the cast-in-place box girder.

[0062] The number of lattice columns 5 of each support unit 2 is specifically determined according to the bottom height of the corresponding cast-in-place box beam above the support unit 2. In this embodiment, Figure 7As shown, the lattice column 5 is a standard supporting member, and the lattice column 5 is a rectangular frame with a height of 1.5m, a length of 1.2m, and a width of 1.2m. An obliquely intersecting angle steel 15 is fixed on the top of each lattice column 5. Each lattice column 5, the lattice column 5 and the top support 6, the lattice column 5 and the bottom support 4, and the top support 6 and the screw jack 7 are connected by high-strength bolts to ensure the structural strength between the various components of the support unit 2. The lattice column 5 is installed by a 25-ton crane in combination with manual assembly. After assembly, it is moved to the designated position under the bridge by a 10-ton forklift.

[0063] like Fig.10 As shown, in order to facilitate the connection between the support unit 2 and the upper rectangular frame 8, the middle rectangular frame 9, the lower rectangular frame 10, the first vertical scissors strut 11, and the second vertical scissors strut 12, in this embodiment, a connecting angle steel 16 is vertically welded on the lattice column 5 of the support unit 2, and a steel pipe 17 is welded on the connecting angle steel 16. The upper rectangular frame 8, the middle rectangular frame 9, the lower rectangular frame 10, the first vertical scissors strut 11, and the second vertical scissors strut 12 are respectively detachably connected to the steel pipe 17 through fasteners, thereby realizing the connection between the upper rectangular frame 8, the middle rectangular frame 9, the lower rectangular frame 10, the first vertical scissors strut 11, and the second vertical scissors strut 12 and the lattice column 5 respectively. In this embodiment, before welding the connecting angle steel 16, it is necessary to determine the setting position of the connecting angle steel 16 on the lattice column 5 of each supporting unit 2. In this embodiment, the connecting angle steel 16 is located in the upper rectangular frame 8, the middle rectangular frame 9, the lower rectangular frame 10, the first vertical scissors strut 11, and the second vertical scissors strut 12, which correspond to the lattice column 5 of the supporting unit 2 respectively.

[0064] like Figure 8 and Fig. 9 As shown, the top support 6 and the bottom support 4 of the support unit 2 have the same structure. The top support 6 of the support unit 2 is set to different height specifications according to the actual construction situation, and the height of the top support 6 is less than the height of the lattice column 5. When the distance between the top lattice column 5 and the bottom of the cast-in-place box girder is less than the height of a standard lattice column 5, a top support 6 of a suitable height is selected and fixed on the top lattice column 5, and then the screw jack 7 is fixed on the top support 6, and the height of the screw jack 7 is adjusted so that the screw jack 7 is pressed tightly against the bottom of the cast-in-place box girder.

[0065] In this embodiment, the solid section 13 of the middle approach bridge has three support units 2 arranged at intervals in the horizontal direction, and the screw jacks 7 are placed at the 1 / 4, 1 / 2, and 3 / 4 center of gravity positions, respectively, with a total of six screw jacks 7 placed; the hollow section 14 of the middle approach bridge has two support units 2 arranged at intervals in the horizontal direction, and the screw jacks 7 are placed at the 1 / 4 and 3 / 4 center of gravity positions, respectively, with a total of four screw jacks 7 placed.

[0066] In this embodiment, the screw jack 7 uses a 25-ton screw jack 7, which is placed on the top support 6 of the support unit 2. The top surface of the screw jack 7 is hinged on the top of the screw jack 7 rotating rod, so that the top surface of the screw jack 7 can be adjusted according to the slope of the beam body. In order to ensure that the top surface is tightly pressed against the bottom of the cast-in-place box beam, in this embodiment, a rubber pad is glued and fixed on the top surface.

[0067] The specific steps for dismantling the middle approach bridge section are as follows: Figure 10-11 As shown, the specific steps include:

[0068] S1: The auxiliary structures of the bridge deck are removed, and the anti-collision guardrails are removed by rope saw, cut into pieces and transported to the designated site.

[0069] S2: Erection of disassembly support system. Before erection, the base of the support system shall be hardened as the leveling layer of the disassembly support system. The leveling layer shall be hardened. The lower foundation of the cast-in-place box girder of the existing approach bridge is 20-37cm thick C20 concrete. A 10cm thick C20 concrete leveling layer shall be poured before the erection of the support system.

[0070] Before erecting the support system, measurement and positioning are carried out first to determine the position of each support unit 2; then each support unit 2 is erected, and attention is paid to the extension direction of the cast-in-place box girder, so that 8 support row groups are arranged under each span of the cast-in-place box girder, and two adjacent support row groups are arranged at intervals in the extension direction of the cast-in-place box girder. The corresponding support row group under the solid section 13 includes 3 support units 2 arranged at intervals laterally, and the corresponding support row group under the hollow section 14 includes 2 support units 2 arranged at intervals laterally.

[0071] When the top lattice column 5 is installed in each support unit 2, the upper rectangular frame 8, the middle rectangular frame 9, the lower rectangular frame 10, the first vertical scissors brace 11, and the second vertical scissors brace 12 are fixed on the support unit 2 respectively; specifically, the connecting angle steel 16 perpendicular to the side of the lattice column 5 is welded on the top lattice column 5, and then the steel pipe 17 is welded on the connecting angle steel 16, and the connecting angle steel 16 is located at the position corresponding to the upper rectangular frame 8 and the top lattice column 5. Then, the connecting angle steel 16 and the steel pipe 17 are welded on the middle lattice column 5 and the bottom lattice column 5 in turn, and finally, the connecting angle steel 16 and the steel pipe 17 are welded on the lattice column 5 corresponding to the first vertical scissors brace 11 and the second vertical scissors brace 12.

[0072] Then, the upper rectangular frame 8, the middle rectangular frame 9, the lower rectangular frame 10, the first vertical scissors brace 11, and the second vertical scissors brace 12 are fixed to the steel pipe 17 of the corresponding lattice column 5 on the support system by fasteners, thereby forming a stable support system.

[0073] After the upper rectangular frame 8, the middle rectangular frame 9, the lower rectangular frame 10, the first vertical scissors brace 11 and the second vertical scissors brace 12 are fixed, the top support 6 is fixed on the lattice column 5 at the top of the support unit 2, and finally the screw jack 7 is installed on the top support 6, and the screw jack 7 is adjusted so that the top surface of the screw jack 7 is in contact with and tightened against the bottom of the cast-in-place box girder.

[0074] S3: The cast-in-place box girder is cut into 8 blocks. The top plate and bottom plate of the cast-in-place box girder are cut horizontally from top to bottom. The cut seam should be slightly inclined outward to ensure that the beam does not fall when the beam body is cut off; 4 lifting holes are set on the top of each cast-in-place box girder cutting block 3.

[0075] S4: Lifting and transportation of cast-in-place box beams. A truck crane enters the cast-in-place box beam area to lift and transport the cut beam body. The lifting adopts steel wire rope, fine-rolled threaded steel and steel lifting equipment. The fine-rolled threaded steel is PSB830 type with a diameter of 32 + pad + single-end double nut connected with the cast-in-place box beam cut block 3. The pad thickness is 2 cm. The lifting equipment is used to slowly and evenly lift the beam by the crane and then lift it to the beam transport vehicle for transportation. In this embodiment, the lifting equipment is the prior art and will not be described in detail here.

[0076] During the dismantling of cast-in-place box girders, the pier 1 and the support system should be observed throughout the process to prevent abnormalities in the pier 1 and the support system. Dismantle each span of cast-in-place box girders in turn according to the above steps.

[0077] S5: Pier 1 shall be removed and transported. Pier 1 shall be cut off and hoisted in sections from top to bottom. The length of each section of Pier 1 shall be determined according to the site conditions. Pier 1 shall be piled up in time after being removed. Pier 1 shall be removed to ensure that it is 0.5m below the ground line. Bored piles shall not be removed in this section.

[0078] S6: Dismantling and transportation of the foundation.

[0079] Specific embodiment 2, the disassembly support system and disassembly method of the viaduct EN ramp 05, the structural form of the support unit 19, the structure of the support system are the same as those of the specific embodiment 1, and the disassembly method is also the same as the disassembly steps of the specific embodiment 1, and the difference from the specific embodiment 1 is: Figure 13-15 , Fig.17As shown, after consulting the old bridge drawings and actual on-site measurements, the maximum clearance of the structure is 7.14m, the height of the beam structure is 2m, the standard width of the top plate is 8.5m, the width of the bottom plate is 3.6m, the solid section 20 of the cast-in-place box beam is cut at 1.2m per block, and the hollow section 22 is cut at 2m per block, and the support units 19 are calculated and arranged. The cast-in-place box beam between adjacent piers is called a span, and each span is arranged with 15 rows of support row groups. The cast-in-place box beam cut block 18 close to the pier is a solid section 20, and two support units 19 are arranged at intervals in the horizontal direction of the solid section 20. The middle cast-in-place box beam cut block 18 is a hollow section 22, and two support units 19 are arranged at intervals in the horizontal direction of the hollow section 22. In this embodiment, the extension direction of the cast-in-place box beam is the longitudinal direction, which is also the front-back direction, and the direction perpendicular to the extension direction of the cast-in-place box beam is the transverse direction, which is also the left-right direction.

[0080] In this embodiment, Fig.14 As shown, the solid section 20 of the cast-in-place box girder has two support units 19 placed transversely, with a transverse spacing of 0.4m between the support units 19 and a remaining 0.2m on each side. Four screw jacks 21 are placed in each row, and the solid section 20 of the cast-in-place box girder has four lifting holes.

[0081] like Fig.15 As shown, two support units 19 are placed horizontally in the hollow section 22 of the cast-in-place box girder, and the horizontal spacing of the support units 19 is 0.4m, with 0.2m remaining on each side. Two screw jacks 21 are placed in each row, and a total of four screw jacks 21 are placed. Four lifting holes are set in the hollow section 22 of the cast-in-place box girder.

[0082] like Fig.16 As shown, since the first two spans of the ramp have a transverse slope, a buckle bracket 23 is used on the inner side of the superelevation to support and maintain stability. The buckle bracket 23 adopts a 60-type heavy-duty buckle bracket 23 with a longitudinal and transverse spacing of 90 cm and a step distance of 1.5 m. A longitudinal double row of steel pipes is set on the top support to tighten against the bottom of the ramp flange plate.

[0083] In the above embodiments, a fifth cross bar is fixed in the middle of the left side surface of the leftmost support unit of each support row group and in the middle of the right side surface of the rightmost support unit, and a sixth cross bar is fixed in the middle of the side facing the pier of each support unit of the support row group close to the pier. Two fifth cross bars are provided and two sixth cross bars are provided. The two fifth cross bars and the two sixth cross bars form a middle rectangular frame. The first vertical scissors strut is fixedly connected to the fifth cross bar, and the second vertical scissors strut is fixedly connected to the sixth cross bar. In other embodiments, the middle rectangular frame may not be provided.

[0084] In the above embodiment, the support units of the support row group close to the pier are fixedly connected to the pier by connecting rods, and three connecting rods are arranged at intervals in the vertical direction; in other embodiments, no connecting rods may be arranged between the support units of the support row group close to the pier and the pier, or four connecting rods may be arranged at intervals in the vertical direction.

[0085] In the above embodiment, the support unit includes a bottom support placed on the leveling layer, a plurality of lattice columns fixed on the bottom support, a top support fixed directly above the top lattice column, and a screw jack fixedly arranged above the top support, and the top of the screw jack is supported on the bottom of the cast-in-place box girder; in other embodiments, the support unit may also include a plurality of lattice columns placed on the ground, a top support fixed directly above the top lattice column, and a screw jack fixedly arranged above the top support.

[0086] In the above embodiment, connecting angle steels are vertically welded on the lattice columns, steel pipes are welded on the connecting angle steels, and the rectangular frame and the vertical scissors brace are detachably connected to the steel pipes via fasteners respectively; in other embodiments, the connecting angle steels and steel pipes on the lattice columns may not be provided, in which case the rectangular frame and the vertical scissors brace are respectively fixed to the lattice columns via binding ropes.

Claims

1. A viaduct dismantling construction method, characterized in that: A viaduct disassembly support system comprises: Support unit: The bottom of the support unit is supported on the leveling layer, and the top of the support unit is supported on the bottom of the cast-in-place box girder of the viaduct; In the extension direction of the cast-in-place box girder, a plurality of support row groups are arranged under each span of the cast-in-place box girder, and two adjacent support row groups are arranged at intervals in the extension direction of the cast-in-place box girder. Each support row group includes a plurality of support units arranged at intervals in the transverse direction of the cast-in-place box girder, and each support row group is located at the longitudinal center of each cast-in-place box girder; A first crossbar is fixed to the upper part of the left side surface of the leftmost support unit of each support row group and the upper part of the right side surface of the rightmost support unit, and a second crossbar is fixed to the upper part of the side facing the pier column of each support unit of the support row group close to the pier column, two first crossbars are provided, and two second crossbars are provided, and the two first crossbars and the two second crossbars form an upper rectangular frame; A third cross bar is fixed to the lower part of the left side surface of the leftmost support unit of each support row group and the lower part of the right side surface of the rightmost support unit, and a fourth cross bar is fixed to the lower part of the side facing the pier column of each support unit of the support row group close to the pier column, two third cross bars are provided, and two fourth cross bars are provided, and the two third cross bars and the two fourth cross bars form a lower rectangular frame; The left side surface of the leftmost support unit of each support row group and the right side surface of the rightmost support unit are respectively fixed with a first vertical scissors brace, and the side of the support row group close to the pier column facing the pier column is fixed with a second vertical scissors brace, the first vertical scissors brace is respectively fixedly connected to the first cross bar and the third cross bar; the second vertical scissors brace is respectively fixedly connected to the second cross bar and the fourth cross bar; The viaduct dismantling construction method includes the following steps: S1: The auxiliary structures of the bridge deck are removed, and the anti-collision guardrail is removed by rope saw, cut into pieces and transported to the designated site; S2: Erection of disassembly support system. Before erection, the base of the support system shall be hardened as the leveling layer of the disassembly support system; S3: Cast-in-place box beams are cut in blocks, with the top and bottom plates cut horizontally from top to bottom. The cuts should be slightly inclined outwards to ensure that the beams do not fall when the beams are cut; S4: Lifting and transportation of cast-in-place box beams. The truck crane drives into the cast-in-place box beam area to lift and transport the cut beams. Steel wire ropes are installed on the cut beams, which are then lifted slowly and evenly by the crane and then hoisted to the beam transport vehicle for transportation. S5: Pier column removal and transportation. Pier columns should be cut off and hoisted in sections from top to bottom. The length of each section of pier column should be determined according to the site conditions. Pier columns should be piled up in time after removal. Pier columns should be removed to ensure that they are 0.5m below the ground line. S6: Dismantling and transportation of the foundation.

2. A viaduct dismantling construction method according to claim 1, characterized in that: A fifth cross bar is fixed to the middle of the left side surface of the leftmost support unit of each support row group and the middle of the right side surface of the rightmost support unit, and a sixth cross bar is fixed to the middle of the side facing the pier of each support unit of the support row group close to the pier. Two fifth cross bars are provided and two sixth cross bars are provided. The two fifth cross bars and the two sixth cross bars form a central rectangular frame. The first vertical scissors strut is fixedly connected to the fifth cross bar, and the second vertical scissors strut is fixedly connected to the sixth cross bar.

3. A viaduct dismantling construction method according to claim 2, characterized in that: The support units of the support row group close to the pier are fixedly connected to the pier via connecting rods, and three connecting rods are arranged at intervals in the up and down directions.

4. A viaduct dismantling construction method according to any one of claims 1 to 3, characterized in that: The support unit includes a bottom support placed on the leveling layer, a plurality of lattice columns fixed on the bottom support, a top support fixed directly above the top lattice column, and a screw jack fixed above the top support, wherein the top of the screw jack is supported on the bottom of the cast-in-place box girder.

5. A viaduct dismantling construction method according to claim 4, characterized in that: A connecting angle steel is vertically welded on the lattice column, a steel pipe is welded on the connecting angle steel, and the rectangular frame and the vertical scissors brace are detachably connected to the steel pipe through fasteners.

6. A method for dismantling a viaduct according to claim 4, characterized in that In S2, measurement and positioning are first performed to determine the position of the support unit; then, each support unit is erected, and in the extension direction of the cast-in-place box girder, a plurality of support row groups are arranged under each span of the cast-in-place box girder, and two adjacent support row groups are arranged at intervals in the extension direction of the cast-in-place box girder. Each support row group includes a plurality of support units arranged at intervals in the transverse direction of the cast-in-place box girder, and each support row group is located at the longitudinal center of each cast-in-place box girder. Then, an upper rectangular frame, a lower rectangular frame, a first vertical scissors brace, and a second vertical scissors brace are respectively fixed on the support units.

7. A viaduct dismantling construction method according to claim 6, characterized in that: When the support unit is erected, the bottom support is placed on the leveling layer, and then the lattice column is placed on the bottom support accordingly, and the lattice column and the bottom support, as well as the lattice column and the lattice column are fixedly connected respectively, and then the connecting angle steel is welded at the position of the corresponding rectangular frame on the lattice column and the position of the corresponding vertical scissors brace, and the steel pipe is welded on the connecting angle steel. After the upper rectangular frame, the lower rectangular frame, the first vertical scissors brace and the second vertical scissors brace are fixed, the top support is fixed on the lattice column at the top of the support unit, and finally the screw jack is installed on the top support.

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