A method for installing the main girder of a steel bridge

Abstract

The present invention discloses a method for installing a steel bridge main girder, which comprises the following steps: Step A, fabricating and processing the steel bridge main girder in sections; Step B, constructing the bridge piers; Step C, assembling the roadbed boxes; Step D, erecting temporary supports; Step E, fixing secondary beams between two parallel cross beams; Step F, inserting the connecting columns of the cross beams into steel pipes; Step G, hoisting the steel bridge main girder in sections; Step H, recycling the steel structures. The present invention can be used for detachable connection between steel components for supporting the steel bridge, reducing the welding process, so that the support frames and cross beams of the steel components of the present invention can be recycled, meeting the concept of energy conservation and environmental protection.

Description

Technical Field

[0001] The present invention belongs to the technical field of bridge construction, and particularly relates to a method for installing the main girder of a steel bridge. Background Art

[0002] In recent years, with the rapid economic growth, the country has increased its investment in expressways and urban roads, and the scale of urban development has gradually increased. To meet the needs of urban development layouts and according to the different development strategic requirements of each city, a large number of steel structure bridges have been newly built. The main girder of a steel structure bridge generally has a large span. Due to restrictions on processing, transportation, installation, etc., its main girder usually needs to be installed in sections, so a temporary support system needs to be erected at the section to serve as the temporary support for the sectional main girder.

[0003] In the traditional temporary support system, a cross beam is provided at the top of the support frame, and the cross beam and the support frame are usually fixedly connected by welding. When the temporary support system is demolished after the installation of the main girder of the steel bridge is completed, the cross beam needs to be demolished by cutting, which has a large workload and causes certain damage to the columns and cross beams, and is not conducive to secondary use. Summary of the Invention

[0004] The purpose of the present invention is to solve the above technical problems existing in the prior art, and provide a method for installing the main girder of a steel bridge, which can make the steel components used for supporting the main girder of the steel bridge be detachably connected, reduce the welding process, and thus enable the steel components to be recycled.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A method for installing the main girder of a steel bridge, characterized by including the following steps:

[0007] Step A: Fabricate and process the main girder of the steel bridge in sections, and process the main girder of the steel bridge with the required dimensions and shapes according to the construction drawings.

[0008] Step B: Construct the bridge pier, and construct the height of the bridge pier according to the construction drawings.

[0009] Step C: Assemble the roadbed box:

[0010] (1) Process the steel sections according to the drawings, and process fixing holes and grouting holes at the flange plates of each steel section.

[0011] (2) Place the embedded sleeve into the fixing hole and fix the embedded sleeve in the fixing hole, mainly by welding the ring of the embedded sleeve to the flange plate.

[0012] (3) Position and fix the steel sections so that the flange plates of two adjacent steel sections are in contact, and then weld and fix the contact parts of the flange plates of the steel sections.

[0013] (4) Weld the second sealing plate to the side of the outermost section steel, and then weld the first sealing plate between the section steel and the second sealing plate. At this time, a first cavity is formed between the first sealing plate and the section steel, and a second cavity is formed among the first sealing plate, the second sealing plate and the section steel. The first cavity is communicated with the grouting hole, and at the same time, the second cavity is also communicated with the grouting hole.

[0014] (5) Insert steel bars into the through holes of the first sealing plate, and arrange the upper steel bars and the lower steel bars staggeredly up and down. The steel bars extend into the first cavity and the second cavity, and then pour concrete into the first cavity and the second cavity through the grouting hole.

[0015] (6) Cut the part of the steel bar protruding from the first sealing plate, and then weld the first ear plate to the top surface of the flange plate of the section steel to obtain the roadbed box.

[0016] (7) Transport the assembled roadbed box to the construction site, and then use a crane to lift and place the roadbed box to the designated place at the construction site through the first ear plate.

[0017] Step D: Erect temporary supports:

[0018] (1) Assemble the support frame and then weld the base at the bottom of the support frame.

[0019] (2) Fix the connecting component on the support frame. The connecting component includes a bottom plate, a steel pipe and the first tension bolt. Among them, the bottom plate is fixed on the support frame, the steel pipe is fixed on the bottom plate, and the steel pipe is provided with a second through hole.

[0020] (3) Lift the support frame onto the roadbed box, then set the embedded bolt in the through hole of the base, screw the embedded bolt into the threaded hole of the embedded sleeve, then screw the nut onto the embedded bolt and tighten the nut.

[0021] Step E: Fix the secondary beam between two parallel cross beams to form an integral structure, improve the stress capacity of the cross beam, and meet the support of the cross beam for the main beam of the steel bridge with a large span. Then fix the connecting column on the cross beam. The connecting column is provided with a first through hole. At the same time, fix the adjusting support on the top of the cross beam. The adjusting support is used for adjusting its own height.

[0022] Step F: Insert the connecting column of the cross beam into the steel pipe, and then pass the first tension bolt through the first through hole and the second through hole.

[0023] Step G: Hoist the main beam of the steel bridge in sections:

[0024] (1) Install a jack on the cross beam, then hoist the first section of the main beam of the steel bridge into place, use the jack to lift the main beam of the steel bridge to a set height, then adjust the height of the adjusting support so that the top of the adjusting support supports the first section of the steel bridge, then return the jack to the initial position, remove the jack, and then fixedly connect the first section of the steel bridge to the corresponding bridge pier.

[0025] (2) Repeat step (1) to fixedly connect the remaining main girders of the steel bridge and the corresponding bridge piers.

[0026] Step H: After the construction of the steel bridge is completed, lower the self-height of the adjusting support so that there is a certain distance between the adjusting support and the steel bridge. Then remove the first tension bolt, then move the connecting column upward in the steel pipe and remove the cross beam from the support frame as a whole. Then unscrew the embedded bolts and nuts, remove the support frame from the roadbed box, and then recycle the roadbed box.

[0027] Furthermore, the steel pipe includes a first connecting section and a second connecting section. The first connecting section is fixed between the bottom plate and the second connecting section. The first connecting section is provided with a first mounting hole which is cylindrical in shape. The second connecting section is provided with a second mounting hole which is frustum-shaped, and the cross-sectional area of the second mounting hole gradually increases from bottom to top. The first mounting hole and the second mounting hole are communicated. This makes the diameter of the top of the second mounting hole larger, facilitating the quick insertion of the connecting column into the second mounting hole and the first mounting hole, and facilitating the positioning of the connecting column in the steel pipe.

[0028] Furthermore, the support frame is fixed with a first connecting plate, and the bottom plate and the first connecting plate are fixed by bolts, making the connection between the connecting component and the support frame detachable. When the connecting component is damaged or rusted during long-term use, a new connecting component can be replaced in time to ensure the normal connection between the support frame and the cross beam.

[0029] Furthermore, in step E, a reinforcing plate is fixed between the secondary beam and the cross beam. The reinforcing plate is fixedly welded to the cross beam, and the reinforcing plate and the secondary beam are fixed by bolts, making the connection between the secondary beam and the cross beam detachable and facilitating the separate storage of the cross beam and the secondary beam.

[0030] Furthermore, the adjusting support includes two seat bodies and a connecting member distributed vertically. By changing the distribution position of the two seat bodies through the connecting member, the height of the adjusting support is adjusted.

[0031] The upper seat body is fixed with a mounting column, and the end of the mounting column is fixed with a contact plate which is used to support the main girder of the steel bridge. The lower seat body is fixed on the cross beam. The contact plate closely adheres to the bottom surface of the bridge to play a supporting role.

[0032] The seat body includes a first panel, a second panel and a side plate. The first panel is obliquely fixed at one end of the side plate, and the second panel is horizontally fixed at the other end of the side plate. A partition is fixed between the first panel, the second panel and the side plate. The partition is provided with a first long circular hole, and the first panel is provided with a second long circular hole. When the two seat bodies are stacked vertically, the first panels of the upper seat body and the lower seat body are closely adhered to each other. The connecting member uses a second tension bolt, and the second tension bolt passes through the first long circular hole and the second long circular hole. When the second tension bolt is loosened, the upper seat body can slide obliquely on the lower seat body. After the adjustment is completed, lock the second tension bolt to change the distribution position of the two seat bodies, and then adjust the height of the adjusting support.

[0033] Further, considering that the support frame is relatively long in height and it is difficult to disassemble the entire support frame, to solve this technical problem, the support frame of the present invention includes support units distributed up and down. The height of the support unit is relatively short. A second connecting plate is fixed to the support unit. The second connecting plates between two adjacent support units up and down are fixed by bolts, so that two adjacent support units up and down can be detachably connected, and the support units can be installed or removed one by one, reducing the installation difficulty of the relatively long support frame.

[0034] The support unit includes four support rods. Second connecting plates are welded to the top and bottom of the support rods, and connecting rods are welded between two adjacent support rods, increasing the strength of the support unit and improving the load-bearing capacity of the support frame.

[0035] Further, considering that when the profiled steel is horizontally spliced, the contact part of the lower flange plate cannot be welded. Technicians first weld the contact part of the upper flange plate, and then turn the welded profiled steel by 180°. Since the overall structure of the profiled steel after welding has a relatively large weight, during the turning process, the welded part between the flange plates is prone to cracking, and the turning process is relatively difficult. To solve this technical problem, the present invention makes an improved design on the welding method of the contact part of the flange plate of the profiled steel.

[0036] In step (3) of step C, the step is completed in the workshop, specifically:

[0037] 1) Install two groups of limiting structures on the support base. The limiting structure includes two limiting plates distributed up and down. The limiting plates are detachably connected to the support base in the horizontal direction. There is a set distance between the two limiting plates, and this distance is greater than the height of the profiled steel. The upper limiting plate is provided with fixing bolts, and the distance between adjacent fixing bolts is designed according to the width of the flange plate of the profiled steel. The lower limiting plate is fixed with a backing plate, and the backing plate is provided with a groove. The distance between adjacent grooves is designed according to the width of the flange plate of the profiled steel.

[0038] 2) Place the profiled steels into the space between the two limiting plates one by one, and place the innermost profiled steel at the designated position on the backing plate. The flange plates of two adjacent profiled steels are in contact. At this time, one fixing bolt corresponds to one profiled steel, and the contact part of the flange plates of two profiled steels is located at the center position of the groove of the backing plate, so that the contact part of the flange plates is exposed. Then turn the fixing bolts to tighten the top surface of the profiled steel with the fixing bolts. At this time, the profiled steel is fixed between the fixing bolts and the backing plate, and several profiled steels are distributed in the horizontal direction.

[0039] 3) Install the first mounting plate on each group of limiting structures. The first mounting plate is detachably connected to the two limiting plates, and then fix the second mounting plate between the two first mounting plates with screws, increasing the load-bearing capacity of the limiting plates and being used for turning the fixing bolts.

[0040] 4) An ear plate II is fixed at the end of the limit plate. A lifting rope is arranged on the ear plate II, and then the lifting rope is fixed on the hook of the crane. The entire limit structure is lifted by the crane. At the same time, the jack installed on the support base is activated, so that the support base is placed flat on the ground, and the limit plate is arranged vertically. At this time, several steel profiles are distributed in the vertical direction. The jack supports the web of the lowermost steel profile, and the lifting rope does not unhook.

[0041] 5) Weld seams are set at the contact positions of the flange plates of adjacent two steel profiles, and full welding is carried out on both the inner side and the outer side of the flange plates of the steel profiles.

[0042] 6) The entire limit structure is laid down by the crane, and then the fixing bolts are loosened. At the same time, the jack is controlled to return to the initial position. Then, the mounting plate II is removed, and then the mounting plate I is removed. Next, the support base is removed, and the upper limit plate is taken out. At this time, the steel profiles welded into an integral structure are placed on the backing plate.

[0043] In the present invention, fixing bolts and backing plates are used to position and fix the steel profiles, and then the steel profiles are distributed vertically. Considering that the steel profiles have a certain weight, a jack is used to support the lowermost steel profile to prevent the steel profiles from sliding during welding. After the steel profiles are distributed up and down, there is enough welding operation space on both the left and right sides of the steel profiles, so that full welding can be carried out along the entire length at the contact positions of both the inner side and the outer side of the flange plates of the steel profiles, and the contact positions of the upper flange and the lower flange of the steel profiles can be welded simultaneously. During the welding process, the steel profiles are accurately positioned at the set positions, ensuring the welding quality, improving the firmness of the welding between the steel profiles, and at the same time, the welding points can be fully cooled, improving the safety and ensuring the integrity between the steel profiles.

[0044] Furthermore, a peripheral plate is welded on the support base, and a reinforcing plate is welded on the inner side of the peripheral plate. Then, the reinforcing plate and the support base are fixed by bolts. The limit plate is fixed in the slot of the peripheral plate by screws, so that the limit plate is detachably connected to the support base, and the support base has sufficient strength.

[0045] Furthermore, weld seams are first set at the contact positions on the outer side of the flange plates of the steel profiles, and then weld seams are set at the contact positions on the inner side of the flange plates of the steel profiles. The weld seams are set from bottom to top to avoid missed welding.

[0046] Furthermore, after step 4) is completed, a stable support is fixed on the mounting plate II by screws. The bottom of the stable support supports on the ground and is fixed to the ground by bolts, increasing the stability of the entire limit structure, preventing the steel profiles from shaking left and right during welding, and improving the welding quality. After step 5) is completed, the bolts at the bottom of the stable support are screwed out, and then the screws between the mounting plate II and the stable support are screwed out, and the stable support is removed.

[0047] Further, after step 6) is completed, the profiled steel welded into an integral structure is lifted out from the backing plate, then a convex block is inserted into the groove of the backing plate, and then the profiled steel welded into an integral structure is placed entirely on the convex block, so that there is a gap between the profiled steel and the backing plate. Then, a second sealing plate is welded to the side of the outermost profiled steel, and the U-shaped second sealing plate can be welded to the flange plate of the profiled steel.

[0048] Due to the adoption of the above technical solution, the present invention has the following beneficial effects:

[0049] (1) In the present invention, the detachable design is adopted between the roadbed box and the support frame: embedded bolts are arranged at the bottom of the support frame, and the embedded bolts are screwed into the threaded holes of the embedded sleeves of the profiled steel, and then nuts are screwed onto the embedded bolts. The detachable design is adopted between the support frame and the cross beam: the connecting column of the cross beam is inserted into the steel pipe of the support frame, and then the first tension bolt is passed through the first through hole and the second through hole.

[0050] After the construction of the steel bridge is completed, first reduce the self-height of the adjusting support so that there is a certain distance between the adjusting support and the steel bridge. Then, remove the first tension bolt. Next, move the connecting column upward in the steel pipe, and the cross beam can be removed from the support frame as a whole. Then, the entire support frame is removed from the base, and the support frame, the cross beam and the roadbed box can be used again later. The present invention can be used for the detachable connection between the steel components supporting the steel bridge, reducing the welding process, so that the support frame and the cross beam of the steel components of the present invention can be recycled, meeting the concept of energy conservation and environmental protection.

[0051] (2) The roadbed box of the present invention is welded into a framework through the flange plates of the steel beams, and then assembled into an integral structure with sealing performance through profiled steel, the first sealing plate and the second sealing plate. Then, steel bars and concrete are arranged in the cavity, so that the roadbed box has sufficient strength to avoid deformation of the roadbed box and meet the bearing capacity requirements of the support frame and the cross beam.

[0052] (3) In the present invention, a cross beam is installed on the support frame, and secondary beams are fixed between two parallel cross beams to form an integral structure, improving the stress capacity of the cross beam and meeting the support of the cross beam for the main beam of the steel bridge with a large span. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The present invention will be further described below with reference to the accompanying drawings:

[0054] Figure 1 It is a schematic structural diagram of the temporary support system in the present invention;

[0055] Figure 2 It is a schematic structural diagram of the cross beam in the present invention;

[0056] Figure 3 It is a schematic structural diagram of the connection component in the present invention;

[0057] Figure 4 Schematic diagram of the structure where the reinforcement plate and the secondary beam are fixed by bolts in the present invention;

[0058] Figure 5 Schematic diagram of the structure of the adjusting support in the present invention;

[0059] Figure 6 Schematic diagram of the structure of the upper seat body in the present invention;

[0060] Figure 7 Schematic diagram of the structure of the lower seat body in the present invention;

[0061] Figure 8 is Figure 1 Schematic diagram of the structure at position A in;

[0062] Figure 9 Schematic diagram of the structure of the roadbed box in the present invention;

[0063] Figure 10 Schematic diagram of the internal structure of the roadbed box in the present invention;

[0064] Figure 11 Schematic diagram of the connection structure between the embedded sleeve and the profiled steel in the present invention;

[0065] Figure 12 Schematic diagram of the structure of the embedded sleeve in the present invention;

[0066] Figure 13 Schematic diagram of the structure of the support seat in the present invention;

[0067] Figure 14 Schematic diagram of the structure of the present invention when two groups of limiting structures are installed on the support seat;

[0068] Figure 15 Schematic diagram of the structure of the present invention when the profiled steel is fixed between the fixing bolt and the backing plate;

[0069] Figure 16 is Figure 15 front view of;

[0070] Figure 17 Schematic diagram of the structure of the present invention when the first mounting plate and the second mounting plate are installed;

[0071] Figure 18 Schematic diagram of the structure of the first mounting plate in the present invention;

[0072] Figure 19 Schematic diagram of the structure of the second mounting plate in the present invention;

[0073] Figure 20 Schematic diagram of the structure of the present invention when the profiled steel is vertically distributed;

[0074] Figure 21 is Figure 20 front view;

[0075] Figure 22 is a schematic structural view of the present invention when the welding seal plate II is in place;

[0076] Figure 23 is a schematic structural view of the present invention when reinforcing bars are inserted into the through holes of the seal plate I;

[0077] Figure 24 is a schematic structural view of the present invention when the roadbed box assembly is completed;

[0078] Figure 25 is a schematic structural view of the present invention when the main girders of the steel bridge are hoisted in sections;

[0079] Figure 26 is a schematic structural view of the steel bridge in the present invention.

[0080] In the figure, 1 - roadbed box; 2 - support frame; 3 - cross beam; 4 - connecting column; 5 - first through hole; 6 - bottom plate; 7 - first tension bolt; 8 - steel pipe; 9 - first connecting section; 10 - second connecting section; 11 - first connecting plate; 12 - secondary beam; 13 - reinforcement plate; 14 - adjusting support; 15 - seat body; 16 - installation column; 17 - contact plate; 18 - first panel; 19 - side plate; 20 - second panel; 21 - second oblong hole; 22 - partition board; 23 - first oblong hole; 24 - second tension bolt; 25 - support rod; 26 - second connecting plate; 27 - connecting rod; 28 - section steel; 29 - embedded sleeve; 30 - seal plate II; 31 - concrete; 32 - first ear plate; 33 - seal plate I; 34 - flange plate; 35 - ; 36 - ring; 37 - support seat; 38 - jack; 39 - peripheral plate; 40 - notch; 41 - strengthening plate; 42 - limiting plate; 43 - fixing bolt; 44 - backing plate; 45 - groove; 46 - grouting hole; 47 - second installation plate; 48 - stabilizing bracket; 49 - convex block; 50 - reinforcing bar; 51 - main girder of steel bridge; 52 - bridge pier; 53 - second ear plate; 54 - threaded hole; 55 - first installation plate. Specific embodiments

[0081] As Figures 1 to 26 shown, a method for installing the main girder of a steel bridge according to the present invention includes the following steps:

[0082] Step A, fabricating and processing the main girder 51 of the steel bridge in sections, and processing the main girder 51 of the steel bridge with the required dimensions and shapes according to the construction drawings.

[0083] Step B, constructing the bridge pier 52, and constructing the height of the bridge pier 52 according to the construction drawings.

[0084] Step C, assembling the roadbed box 1:

[0085] (1) Process the profiled steel according to the drawing, and process fixing holes and grouting holes 46 at the flange plates 34 of each profiled steel 28. The number and size of the grouting holes 46 can be adjusted according to actual requirements.

[0086] (2) Place the embedded sleeve 29 into the fixing hole and fix the embedded sleeve 29 in the fixing hole. Mainly weld the ring 36 of the embedded sleeve 29 to the flange plate 34.

[0087] (3) Position and fix the profiled steel 28 so that the flange plates 34 of two adjacent profiled steels 28 are in contact, and then weld and fix the contact part of the flange plates 34 of the profiled steel 28.

[0088] (4) Weld the second sealing plate 30 to the side of the outermost profiled steel 28, and then weld the first sealing plate 33 between the profiled steel 28 and the second sealing plate 30. At this time, a first cavity is formed between the first sealing plate 33 and the profiled steel 28, and a second cavity is formed among the first sealing plate 33, the second sealing plate 30 and the profiled steel 28. The first cavity is communicated with the grouting hole 46, and at the same time, the second cavity is communicated with the grouting hole 46.

[0089] (5) Insert the steel bars 50 into the holes of the first sealing plate 33, and the upper steel bars 50 and the lower steel bars 50 are arranged in a staggered manner up and down. The steel bars 50 extend into the first cavity and the second cavity, and then pour the concrete 31 into the first cavity and the second cavity through the grouting hole 46.

[0090] (6) Cut the part of the steel bar 50 protruding from the first sealing plate 33, and then weld the first ear plate 32 to the top surface of the flange plate 34 of the profiled steel 28 to obtain the roadbed box 1.

[0091] (7) Transport the assembled roadbed box 1 to the construction site, and then use a crane to lift and place the roadbed box 1 to the designated place at the construction site through the first ear plate 32.

[0092] Step D: Erect temporary supports:

[0093] (1) Assemble the support frame 2, and then weld the base at the bottom of the support frame 2.

[0094] The support frame 2 is fixed with a first connecting plate 11. The bottom plate 6 and the first connecting plate 11 are fixed by bolts, so that the connection assembly and the support frame 2 are detachably connected. When the connection assembly is damaged or rusty after long-term use, the new connection assembly can be replaced in time to ensure the normal connection between the support frame 2 and the cross beam 3.

[0095] Considering that the support frame 2 is relatively long in height and it is difficult to disassemble the entire support frame 2, to address this technical problem, the support frame 2 of the present invention includes support units distributed vertically. The height of the support units is relatively short, and a second connecting plate 26 is fixed to the support units. The second connecting plates 26 on two adjacent support units above and below are fixed by bolts, so that two adjacent support units above and below are detachably connected, and the support units can be installed or removed one by one, reducing the installation difficulty of the relatively long support frame 2.

[0096] The support unit includes four support rods 25. The second connecting plates 26 are welded to the top and bottom of the support rods 25, and connecting rods 27 are welded between two adjacent support rods 25 to increase the strength of the support unit and improve the load-bearing capacity of the support frame 2.

[0097] (2) A connecting component is fixedly connected to the support frame 2. The connecting component includes a bottom plate 6, a steel pipe 8, and a first tension bolt 7. Among them, the bottom plate 6 is fixed to the support frame 2, the steel pipe 8 is fixed to the bottom plate 6, and the steel pipe 8 is provided with a second through hole.

[0098] The steel pipe 8 includes a first connecting section 9 and a second connecting section 10. The first connecting section 9 is fixed between the bottom plate 6 and the second connecting section 10. The first connecting section 9 is provided with a first installation hole, the first installation hole is cylindrical in shape, the second connecting section 10 is provided with a second installation hole, the second installation hole is frustum-shaped, and the cross-sectional area of the second installation hole gradually increases from bottom to top. The first installation hole and the second installation hole are communicated. This makes the diameter of the top of the second installation hole larger, facilitating the quick insertion of the connecting column 4 into the second installation hole and the first installation hole, and facilitating the positioning of the connecting column 4 into the steel pipe 8.

[0099] (3) The support frame 2 is hoisted onto the roadbed box 1, then embedded bolts are arranged in the through holes of the base, and the embedded bolts are screwed into the threaded holes 54 of the embedded sleeve 29. Then nuts are screwed onto the embedded bolts and tightened.

[0100] Step E: A secondary beam 12 is fixed between two parallel cross beams 3 to form an integral structure, improving the stress capacity of the cross beam 3 and meeting the support of the cross beam 3 for the main beam 51 of the steel bridge with a relatively large span. A reinforcing plate 13 is fixed between the secondary beam 12 and the cross beam 3. The reinforcing plate 13 is welded and fixed to the cross beam 3, and the reinforcing plate 13 and the secondary beam 12 are fixed by bolts, so that the secondary beam 12 and the cross beam 3 are detachably connected, facilitating the separate storage of the cross beam 3 and the secondary beam 12.

[0101] Then a connecting column 4 is fixed to the cross beam 3. The connecting column 4 is provided with a first through hole 5. At the same time, an adjusting support 14 is fixed to the top of the cross beam 3, and the adjusting support 14 is used for adjusting its own height.

[0102] The adjusting support 14 includes two seat bodies 15 distributed vertically and a connecting member. By changing the distribution position of the two seat bodies 15 through the connecting member, the height of the adjusting support 14 is adjusted.

[0103] The upper seat body 15 is fixed with a mounting column 16, and a contact plate 17 is fixed at the end of the mounting column 16. The contact plate 17 is used to support the main beam of the steel bridge. The lower seat body 15 is fixed on the cross beam 3. The contact plate 17 is closely attached to the bottom surface of the bridge to play a supporting role.

[0104] The seat body 15 includes a first panel 18, a second panel 20 and a side plate 19. The first panel 18 is inclined and fixed at one end of the side plate 19, and the second panel 20 is horizontally fixed at the other end of the side plate 19. A partition plate 22 is fixed between the first panel 18, the second panel 20 and the side plate 19. The partition plate 22 is provided with a first long circular hole 23, and the first panel 18 is provided with a second long circular hole 21. When two seat bodies 15 are stacked up and down, the first panel 18 of the upper seat body 15 and the first panel 18 of the lower seat body 15 are closely attached to each other. The connecting piece adopts a second tension bolt 24, and the second tension bolt 24 passes through the first long circular hole 23 and the second long circular hole 21. When the second tension bolt 24 is loosened, the upper seat body 15 can slide obliquely on the lower seat body 15. After the adjustment is completed, the second tension bolt 24 is locked to change the distribution position of the two seat bodies 15, and then the height of the adjusting support 14 is adjusted.

[0105] Step F: Insert the connecting column 4 of the cross beam 3 into the steel pipe 8, and then pass the first tension bolt 7 through the first through hole 5 and the second through hole.

[0106] Step G: Hoist the main beam 51 of the steel bridge in sections:

[0107] (1) Install a jack on the cross beam 3, and then hoist the first section of the main beam 51 of the steel bridge into place. Use the jack to raise the main beam 51 of the steel bridge to a set height, and then adjust the height of the adjusting support 14 so that the top of the adjusting support 14 supports the first section of the steel bridge. Then return the jack to the initial position, remove the jack, and then fixedly connect the first section of the steel bridge and the corresponding bridge pier 52.

[0108] (2) Repeat step (1) to fixedly connect the remaining main beam 51 of the steel bridge and the corresponding bridge pier 52.

[0109] Step H: After the construction of the steel bridge is completed, reduce the self-height of the adjusting support 14 so that there is a certain distance between the adjusting support 14 and the steel bridge. Then remove the first tension bolt 7, then move the connecting column 4 upward in the steel pipe 8, remove the cross beam 3 from the support frame 2 as a whole, then screw out the embedded bolts and nuts, remove the support frame 2 from the roadbed box 1, and then recycle the roadbed box 1.

[0110] Considering that when the profiled steel 28 is horizontally spliced, the contact part of the lower flange plate 34 cannot be welded. The technician first welds the contact part of the upper flange plate 34, and then flips the welded profiled steel 28 by 180°. Since the overall structure of the profiled steel 28 after welding has a large weight, during the flipping process, the welded part between the flange plates 34 is prone to cracking, and the flipping process is rather difficult. To address this technical problem, the present invention makes an improved design for the welding method at the contact part of the flange plates 34 of the profiled steel 28.

[0111] In step (3) of step C, the step is completed in the workshop, specifically as follows:

[0112] 1) Install two sets of limiting structures on the support base 37. The limiting structure includes two limiting plates 42 distributed vertically. The limiting plates 42 are detachably connected to the support base 37 in the horizontal direction: Weld the peripheral plate 39 on the support base 37, then weld the reinforcing plate 41 inside the peripheral plate 39, and then fix the reinforcing plate 41 and the support base 37 with bolts. The limiting plate 42 is fixed in the notch 40 of the peripheral plate 39 with screws, so that the limiting plate 42 is detachably connected to the support base 37, and the support base 37 has sufficient strength. There is a set distance between the two limiting plates 42, and this distance is greater than the height of the profiled steel 28. The upper limiting plate 42 is provided with fixing bolts 43, and the distance between adjacent fixing bolts 43 is designed according to the width of the flange plate 34 of the profiled steel 28. The lower limiting plate 42 is fixed with a backing plate 44, and the backing plate 44 is provided with a groove 45. The distance between adjacent grooves 45 is designed according to the width of the flange plate 34 of the profiled steel 28.

[0113] 2) Place the profiled steel 28 one by one between the two limiting plates 42, and place the innermost profiled steel 28 at the designated position of the backing plate 44. The flange plates 34 of adjacent profiled steels 28 are in contact. At this time, one fixing bolt 43 corresponds to one profiled steel 28, and the contact part of the flange plates 34 of the two profiled steels 28 is located at the center position of the groove 45 of the backing plate 44, so that the contact part of the flange plates 34 is exposed. Then turn the fixing bolt 43 to tighten the top surface of the profiled steel 28. At this time, the profiled steel 28 is fixed between the fixing bolt 43 and the backing plate 44, and several profiled steels 28 are distributed horizontally.

[0114] 3) Install the first mounting plate 55 on each set of limiting structures. The first mounting plate 55 is detachably connected to the two limiting plates 42, and then fix the second mounting plate 47 between the two first mounting plates 55 with screws to increase the bearing capacity of the limiting plate 42, which can be used for turning the fixing bolt 43.

[0115] 4) An ear plate two 53 is fixed at the end of the limit plate 42. A lifting rope is arranged on the ear plate two 53, and then the lifting rope is fixed on the hook of the crane. The whole limit structure is lifted by the crane. At the same time, the jack 38 installed on the support seat 37 is started, so that the support seat 37 is placed flat on the ground. At the same time, the limit plate 42 is arranged vertically. At this time, several profiled steels 28 are distributed in the vertical direction. The jack 38 abuts against the web of the lowermost profiled steel 28 to prevent the profiled steel 28 from sliding, and the lifting rope does not unhook, improving safety.

[0116] After step 4) is completed, the stable support 48 is fixed to the mounting plate two 47 with screws. The bottom of the stable support 48 supports on the ground and is fixed to the ground with bolts, increasing the stability of the whole limit structure, preventing the profiled steel 28 from shaking left and right during welding, and improving the welding quality.

[0117] 5) Weld seams are set at the contact positions of the flange plates 34 of two adjacent profiled steels 28. Full welding is carried out on both the inner side and the outer side of the flange plates 34 of the profiled steel 28. First, weld seams are set at the contact positions on the outer side of the flange plates 34 of the profiled steel 28, and then weld seams are set at the contact positions on the inner side of the flange plates 34 of the profiled steel 28. The weld seams are set from bottom to top to avoid missed welding.

[0118] After step 5) is completed, the bolts at the bottom of the stable support 48 are screwed out, and then the screws between the mounting plate two 47 and the stable support 48 are screwed out, and the stable support 48 is removed.

[0119] 6) The whole limit structure is laid down by the crane. Then the fixing bolts 43 are loosened. At the same time, the jack 38 is controlled to return to the initial position. Then the mounting plate two 47 is removed, and then the mounting plate one 55 is removed. Then the support seat 37 is removed, and the upper limit plate 42 is taken out. At this time, the profiled steels 28 welded into an integral structure are placed on the backing plate 44.

[0120] After step 6) is completed, the profiled steels 28 welded into an integral structure are lifted out from the backing plate 44. Then the convex blocks 49 are embedded into the grooves 45 of the backing plate 44. Then the profiled steels 28 welded into an integral structure are placed on the convex blocks 49 as a whole, so that there is a gap between the profiled steels 28 and the backing plate 44. Then the closing plate two 30 is welded on the side of the outermost profiled steel 28, and the U-shaped closing plate two 30 can be welded on the flange plates 34 of the profiled steel 28.

[0121] In the present invention, the steel section 28 is positioned and fixed by the fixing bolts 43 and the backing plates 44. Then, the steel sections 28 are vertically distributed. Considering that the steel sections 28 have a certain weight, the jack 38 is used to support the lowermost steel section 28 to prevent the steel section 28 from sliding during welding. After the steel sections 28 are vertically distributed, there is sufficient welding operation space on both the left and right sides of the steel section 28, enabling full-length fillet welding at the contact areas on both the inner and outer sides of the flange plate 34 of the steel section 28. Moreover, the contact areas of the upper flange and the lower flange of the steel section 28 can be welded simultaneously. During the welding process, the steel section 28 is accurately positioned at the set position, ensuring the welding quality, improving the firmness of the welding between the steel sections 28, and at the same time, fully cooling the welding area, enhancing safety and ensuring the integrity between the steel sections 28.

[0122] The above are only specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on the present invention to solve substantially the same technical problems and achieve substantially the same technical effects are all covered by the protection scope of the present invention.

Claims

1. A method for installing the main girder of a steel bridge, characterized in that, It includes the following steps: Step A: Fabricate and process the steel bridge main girder in segments; Step B: Construct the bridge pier; Step C: Assemble the roadbed box: (1) Process the profiled steel according to the drawings, and process fixing holes and grouting holes at the flange plates of each profiled steel; (2) Place the embedded sleeve into the fixing hole and fix the embedded sleeve in the fixing hole; (3) Position and fix the profiled steel so that the flange plates of two adjacent profiled steels are in contact, and then weld and fix the contact part of the flange plates of the profiled steel; (4) Weld the second sealing plate on the side of the outermost profiled steel, and then weld the first sealing plate between the profiled steel and the second sealing plate. At this time, a first cavity is formed between the first sealing plate and the profiled steel, a second cavity is formed among the first sealing plate, the second sealing plate and the profiled steel, the first cavity is communicated with the grouting hole, and at the same time the second cavity is communicated with the grouting hole; (5) Insert steel bars into the holes of the first sealing plate. The steel bars extend into the first cavity and the second cavity, and then pour concrete into the first cavity and the second cavity through the grouting hole; (6) Cut the part of the steel bar extending out of the first sealing plate, and then weld the first ear plate on the top surface of the flange plate of the profiled steel; (7) Transport the assembled roadbed box to the construction site, and then use a crane to lift and place the roadbed box to the designated place at the construction site through the first ear plate; Step D: Erect temporary supports: (1) Assemble the support frame and then weld the base at the bottom of the support frame; (2) Fix the connecting component on the support frame. The connecting component includes a bottom plate, a steel pipe and a first tension bolt. Among them, the bottom plate is fixed on the support frame, the steel pipe is fixed on the bottom plate, and the steel pipe is provided with a second through hole; (3) Lift the support frame onto the roadbed box, then set the embedded bolt in the through hole of the base, screw the embedded bolt into the threaded hole of the embedded sleeve, then screw a nut onto the embedded bolt and tighten the nut; Step E: Fix the secondary beam between two parallel cross beams to form an integral structure, and then fix the connecting column on the cross beam. The connecting column is provided with a first through hole. At the same time, fix the adjusting support on the top of the cross beam. The adjusting support is used for adjusting its own height; Step F: Insert the connecting column of the cross beam into the steel pipe, and then pass the first tension bolt through the first through hole and the second through hole; Step G: Hoist the steel bridge main girder in segments: (1) Install a jack on the cross beam, then hoist the first segment of the steel bridge main girder into place, use the jack to lift the steel bridge main girder to a set height, then adjust the height of the adjusting support so that the top of the adjusting support supports the first segment of the steel bridge, then return the jack to the initial position, take out the jack, and then fixedly connect the first segment of the steel bridge and the corresponding bridge pier; (2) Repeat step (1) to fixedly connect the remaining steel bridge main girders and the corresponding bridge piers; Step H: When the steel bridge construction is completed, lower the self-height of the adjusting support so that there is a certain distance between the adjusting support and the steel bridge, then remove the first tension bolt, then move the connecting column upward in the steel pipe, remove the cross beam from the support frame as a whole, then unscrew the embedded bolt and the nut, remove the support frame from the roadbed box, and then recycle the roadbed box.

2. The method for installing the main girder of a steel bridge according to claim 1, wherein: The steel pipe adopted includes a first connecting section and a second connecting section. The first connecting section is fixed between the bottom plate and the second connecting section. The first connecting section is provided with a first mounting hole which is cylindrical in shape. The second connecting section is provided with a second mounting hole which is frustum-shaped. The cross-sectional area of the second mounting hole gradually increases from bottom to top. The first mounting hole and the second mounting hole are communicated with each other.

3. The method for installing the main girder of a steel bridge according to claim 1, wherein: In step E, a reinforcing plate is fixed between the secondary beam and the cross beam. The reinforcing plate and the cross beam are welded and fixed, and then bolts are screwed between the reinforcing plate and the secondary beam.

4. A method for installing the main girder of a steel bridge according to claim 1, characterized in that: The adjusting support includes two seat bodies and a connecting member which are distributed up and down. The distribution position of the two seat bodies is changed through the connecting member, so as to adjust the height of the adjusting support. The seat body includes a first panel, a second panel and a side plate. The first panel is obliquely fixed at one end of the side plate, and the second panel is horizontally fixed at the other end of the side plate. A partition plate is fixed between the first panel, the second panel and the side plate. The partition plate is provided with a first long circular hole, and the first panel is provided with a second long circular hole. When the two seat bodies are stacked up and down, the first panels of the upper seat body and the lower seat body are in close contact with each other. The connecting member adopts a second tension bolt, and the second tension bolt passes through the first long circular hole and the second long circular hole.

5. A method for installing the main girder of a steel bridge according to claim 1, characterized in that: The support frame includes support units which are distributed up and down. The support unit includes four support rods. Mounting plates are welded at the top and bottom of the support rods. The mounting plates on the upper and lower adjacent support units are fixed by bolts. Connecting rods are welded between adjacent two support rods.

6. A method for installing the main girder of a steel bridge according to claim 1, characterized in that: In step (3) of step C, the step is completed in the workshop, specifically: 1) Two sets of limiting structures are installed on the support seat. The limiting structure includes two limiting plates which are distributed up and down. The limiting plates are detachably connected to the support seat in the horizontal direction. There is a set distance between the two limiting plates, and this distance is greater than the height of the profiled steel. The upper limiting plate is provided with fixing bolts. The distance between adjacent fixing bolts is designed according to the width of the flange plate of the profiled steel. The lower limiting plate is fixed with a backing plate, and the backing plate is provided with a groove. The distance between adjacent grooves is designed according to the width of the flange plate of the profiled steel. 2) The profiled steels are placed one by one between the two limiting plates, and the innermost profiled steel is placed at the designated position of the backing plate. The flange plates of adjacent two profiled steels are in contact with each other. At this time, one fixing bolt corresponds to one profiled steel. The contact position of the flange plates of the two profiled steels is located at the center position of the groove of the backing plate. Then the fixing bolts are screwed to tighten the top surface of the profiled steel. At this time, the profiled steel is fixed between the fixing bolts and the backing plate. A plurality of profiled steels are distributed in the horizontal direction. 3) A first mounting plate is installed on each set of limiting structures. The first mounting plate is detachably connected to the two limiting plates, and then a second mounting plate is fixed between the two first mounting plates by screws. 4) An ear plate II is fixed at the end of the limit plate. A lifting rope is arranged on the ear plate II, and then the lifting rope is fixed on the hook of the crane. The whole limit structure is lifted by the crane. At the same time, the jack installed on the support seat is activated, so that the support seat is placed flat on the ground, and the limit plate is set vertically. At this time, several steel profiles are distributed in the vertical direction. The jack abuts against the web of the lowermost steel profile, and the lifting rope does not unhook. 5) Weld seams are set at the contact positions of the flange plates of two adjacent steel profiles, and full welding is carried out on both the inner and outer sides of the flange plates of the steel profiles. 6) The whole limit structure is laid down by the crane. Then the fixing bolts are loosened, and at the same time, the jack is controlled to return to the initial position. Then the mounting plate II is removed, and then the mounting plate I is removed. Then the support seat is removed, and the upper limit plate is taken out. At this time, the steel profiles welded into an integral structure are placed on the backing plate.

7. A method for installing the main girder of a steel bridge according to claim 6, characterized in that: The peripheral plate is welded on the support seat, and the reinforcing plate is welded on the inner side of the peripheral plate. Then the reinforcing plate and the support seat are fixed by bolts, and the limit plate is fixed in the groove of the peripheral plate by screws.

8. A method for installing the main girder of a steel bridge according to claim 6, characterized in that: First, weld seams are set at the contact positions on the outer side of the flange plate of the steel profile, and then weld seams are set at the contact positions on the inner side of the flange plate of the steel profile. The weld seams are set from bottom to top.

9. The installation method of a steel bridge main girder according to claim 6, characterized in that: After step 4) is completed, the stable support is fixed on the mounting plate II by screws. The bottom of the stable support abuts against the ground and is fixed on the ground by bolts. After step 5) is completed, the bolts at the bottom of the stable support are screwed out, and then the screws between the mounting plate II and the stable support are screwed out, and the stable support is removed.

10. A method for installing the main girder of a steel bridge according to claim 6, characterized in that: After step 6) is completed, the steel profiles welded into an integral structure are lifted out from the backing plate. Then the bumps are embedded in the grooves of the backing plate. Then the steel profiles welded into an integral structure are placed on the bumps as a whole, so that there is a gap between the steel profiles and the backing plate. Then the closing plate II is welded on the side of the outermost steel profile.

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