Splicing construction method for main beam of half-through basket arch bridge

Abstract

The invention relates to the technical field of arch bridge construction, in particular to a girder assembly construction method for a half-through basket arch bridge. The construction method comprises the steps that after the arch frame is erected, the main beam sections are assembled in an original temporary assembling factory on the south shore; a supporting structure is constructed on the north shore, the main beam section of the north shore arch outer main beam is transported to the north shore and installed, and then the main beam section of the south shore arch outer main beam is transported to the north shore and placed on the north shore arch outer main beam; a supporting structure outside the operation influence range of the original shipping platform is constructed on the south shore, and the main beam sections of the in-arch main beam are sequentially installed from the two ends to the middle; the shipping platform is dismantled, the remaining supporting structure is constructed on the south shore, and the main beam section of the south shore arch outer main beam is transported back to the south shore and is installed; wherein the conveying operation from the temporary assembly plant to the position under the bearing main cable of the cable crane along the shipping platform is completed by the rail flat car group, and other conveying operations are completed by the cable crane.

Description

Technical Field

[0001] The present invention relates to the technical field of arch bridge construction, and in particular to a method for assembling and constructing the main girder of a half-through basket arch bridge. Background Art

[0002] During the installation and construction of an arch bridge, generally, large temporary facilities such as a temporary assembly plant near the bridge site and a transportation road leading to the bridge position are first built, then the arch frame is erected, and finally the main girder is assembled. The assembly construction of the main girder makes full use of the existing large temporary facilities. Among them, a part of the main girder of the arch bridge is located below the arch frame and a part is outside the area of the arch frame. And the transfer transportation during the assembly of the main girder below the arch frame is more difficult. There are currently two transfer transportation methods: one is to first build a temporary road below the main girder of the arch bridge and directly transport the main girder segments to be installed to the hoisting position by a large transport vehicle; the other is to newly build a dock nearby or use an existing dock nearby, transport the main girder segments to be installed to the dock by the river by a large transport vehicle and load them onto a ship, and then use a barge to transport them to the hoisting position under the arch frame.

[0003] However, for the first method, due to the construction of the temporary road, it is greatly restricted by geographical conditions and is difficult to be widely applied or applied at low cost; for the second method, since the barge occupies a large area of the waterway during operation, it affects the passage of ships in the waterway, and is easily affected by the water level and cannot be continuously constructed, which greatly delays the construction progress and increases the construction cost. Summary of the Invention

[0004] The present invention aims to solve the technical problems existing in the related art. For this purpose, the present invention provides a method for assembling and constructing the main girder of a half-through basket arch bridge to solve the problems that the assembly operation of the main girder is easily restricted by geographical conditions, easily affected by the water level, and difficult to be continuously constructed.

[0005] The present invention provides a method for assembling and constructing the main girder of a half-through basket arch bridge. The half-through basket arch bridge includes: an arch frame base, an arch frame, piers and abutments, and a main girder assembled from main girder segments; the middle part of the main girder is located below the arch frame and is the main girder inside the arch; the two ends of the main girder are located behind and above the arch frame and are the main girder outside the arch on the south bank and the main girder outside the arch on the north bank respectively; The construction method is as follows: S1. After the arch frame is erected, assemble the main girder segments at the original temporary assembly plant on the south bank; S2. Build a support structure on the north bank, transport the main girder segments of the main girder outside the arch on the north bank to the north bank and install them, and then transport the main girder segments of the main girder outside the arch on the south bank to the north bank and place them on the main girder outside the arch on the north bank; S3. Build a support structure outside the influence range of the original shipping platform operation on the south bank, and install the main girder segments of the main girder inside the arch in the order from both ends to the middle; S4. Demolish the shipping platform, construct the remaining support structure on the south bank, transport the main girder segments of the main girder outside the south bank arch back to the south bank and complete the installation. Among them, the transportation operation from the temporary assembly plant along the shipping platform to the position directly below the main load-bearing cable of the cable crane is completed by the rail flatcar group, and other transportation operations are completed by the cable crane.

[0006] According to a main girder assembly construction method for a half-through basket arch bridge provided by the present invention, the main girder is arranged as a plurality of main girder segments along its length direction. The step S2 specifically includes: constructing a support structure for installing the main girder outside the north bank arch on the north bank, numbering each main girder segment of the main girder outside the north bank arch, and then transporting and installing them on the support structure on the north bank in the numbered order by the cable crane. Then, assemble the main girder segments for forming the main girder outside the south bank arch in the temporary assembly plant, number each main girder segment, and then transport them to the north bank in the numbered order by the cable crane and place them on the main girder outside the north bank arch.

[0007] According to a main girder assembly construction method for a half-through basket arch bridge provided by the present invention, the step S3 specifically includes: Set small pier columns for fixing the main girder on the cross beam at the intersection position of the main girder and the arch frame. When installing the main girder inside the arch, install the first main girder segment on the small pier column, and then gradually assemble towards the middle and complete the closure in the middle.

[0008] According to a main girder assembly construction method for a half-through basket arch bridge provided by the present invention, when constructing with an arch frame on the south bank, the shipping platform is equipped with a rail flatcar group and is located below the main girder outside the south bank arch. The rail flatcar group extends from the shipping platform into the temporary assembly plant, and a gantry is provided in the temporary assembly plant. Assemble the main girder segments in the temporary assembly plant, then place the main girder segments on the rail flatcar group through the gantry, and then transport them along the shipping platform to the position directly below the main load-bearing cable of the cable crane.

[0009] According to a main girder assembly construction method for a half-through basket arch bridge provided by the present invention, construct a dock below the arch frame on the south bank. The dock is provided with a lifting device for assisting in hoisting and splicing the main girder inside the arch.

[0010] According to a main girder assembly construction method for a half-through basket arch bridge provided by the present invention, the cable crane includes three groups of main load-bearing cables distributed in parallel. The middle main load-bearing cable and the central axis of the main girder in the length direction are located in the same vertical plane, and the two side main load-bearing cables are respectively offset and arranged upstream and downstream of the main girder. The main beam in the arch is hoisted and installed by the load-bearing main cables on both sides; The south bank arch outer main beam and the north bank arch outer main beam are hoisted and installed through the middle load-bearing main cable.

[0011] According to a main beam assembly construction method for a mid-through basket arch bridge provided by the present invention, the main beam in the arch is hoisted and installed by load-bearing main cables on both sides, specifically comprising: The rail flat car group transports the main beam segment to the delivery platform position just below the load-bearing main cable offset upstream of the main beam, and then lifts the main beam segment from the rail flat car group to a position higher than the top of the arch frame, and then moves from the south bank to the north bank along the extension direction of the load-bearing main cable; When the vertical projection edge line of the main beam segment can avoid the arch frame, the main beam segment is lowered to the side and lower part of the main beam, and then transported to the lifting device on the dock; The lifting device moves the main beam segment laterally to just below the main beam, and the load-bearing main cables on both sides then lift the lifting device equipped with the main beam segment and move it along the length direction of the main beam to the position to be installed for assembly.

[0012] According to a main beam assembly construction method for a mid-through basket arch bridge provided by the present invention, the south bank arch outer main beam and the north bank arch outer main beam are hoisted and installed through the middle load-bearing main cable, which specifically includes: The rail flat car group transports the main beam segment to the shipping platform position just below the middle load-bearing main cable, and then the middle load-bearing main cable extends the lifting cable downward to lift the main beam segment from the rail flat car group to above the top of the arch frame, and then moves from the south bank to the north bank along the extension direction of the load-bearing main cable. After reaching just above the installation position on the north bank, the main beam segment is lowered to the supporting structure or the main beam outside the north bank arch.

[0013] According to a main beam assembly construction method for a mid-through basket arch bridge provided by the present invention, the construction of a support structure on the south bank, transporting the main beam outside the south bank arch back to the south bank and completing the installation specifically include: After the installation of the main beam inside the arch is completed, the shipping platform is dismantled and a supporting structure for installing the main beam outside the arch on the south bank is built. The middle load-bearing main cable extends downward through the lifting cable to lift the main beam segment for assembling the main beam outside the arch on the north bank, and then lift the main beam segment to a level above the top of the arch frame, and then move it from the north bank to the south bank along the extension direction of the load-bearing main cable. After reaching the top of the installation position on the south bank, the main beam segment is lowered to the supporting structure to complete the assembly of the main beam outside the arch on the south bank.

[0014] According to a main beam assembly construction method for a mid-through basket arch bridge provided by the present invention, the support structure includes abutments, large piers, small piers, and a temporary tower; The abutment is arranged at the docking position between the main beam and the tunnel and is used for fixedly supporting the end of the main beam. The large pier column is arranged on the arch support base. The small pier column is arranged on the cross beam at the intersection position of the main beam and the arch support. The temporary tower is arranged between the arch support base and the pier platform or the large pier column and is used for supporting the splicing ends of the main beam outside the south bank arch and the splicing ends of the main beam outside the north bank arch.

[0015] One or more of the above technical solutions in the present invention have at least one of the following technical effects: It replaces the method of positioning and lifting the main beam segments by barge, eliminates the factors restricting the splicing and assembly operation of the main beam such as geographical conditions and water levels, reduces the construction cost, speeds up the construction progress, and avoids geographical restrictions.

[0016] In addition to the technical problems solved by the present invention, the technical features of the technical solutions constituted, and the advantages brought by these technical features of the technical solutions described above, the other technical features of the present invention and the advantages brought by these technical features will be further described in conjunction with the drawings or understood through the practice of the present invention. Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the following will briefly introduce the drawings required for use in the description of the embodiments or related technologies. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 It is a front view schematic diagram of the construction facility layout for assembling the main beam provided by the embodiment of the present invention.

[0019] Figure 2 It is a schematic diagram before the installation of the main beam provided by the embodiment of the present invention.

[0020] Figure 3 It is a schematic diagram of the completion of the assembly of the main beam outside the north bank arch provided by the embodiment of the present invention.

[0021] Figure 4 It is a schematic diagram of hoisting the main beam segment from the narrowest part in the middle of the arch support to the side lower part of the main beam when assembling the main beam inside the arch provided by the embodiment of the present invention.

[0022] Figure 5 It is a schematic diagram of hoisting the main beam segment onto the hoisting device when assembling the main beam inside the arch provided by the embodiment of the present invention.

[0023] Figure 6 Schematic diagram of closing in the middle when assembling the main girder inside the arch provided by an embodiment of the present invention.

[0024] Figure 7 Schematic diagram of the state when the main girder inside the arch is assembled as provided by an embodiment of the present invention.

[0025] Figure 8 Top view schematic diagram of the construction facility layout for assembling the main girder provided by an embodiment of the present invention.

[0026] Figure 9 Top view schematic diagram of hoisting the main girder segment by the load-bearing main cable in the middle of the cable crane provided by an embodiment of the present invention.

[0027] Figure 10 Side view schematic diagram of hoisting the main girder segment by the load-bearing main cable in the middle of the cable crane provided by an embodiment of the present invention.

[0028] Figure 11 Top view schematic diagram of hoisting the main girder segment by the load-bearing main cable on the upstream side of the cable crane provided by an embodiment of the present invention.

[0029] Figure 12 Side view schematic diagram of hoisting the main girder segment by the load-bearing main cable on the upstream side of the cable crane provided by an embodiment of the present invention.

[0030] Figure 13 Side view schematic diagram of the main girder segment being horizontally moved by the lifting device to directly below the main girder provided by an embodiment of the present invention.

[0031] Figure 14 Side view schematic diagram of hoisting the lifting device carrying the main girder segment by the load-bearing main cables on both sides provided by an embodiment of the present invention.

[0032] Reference numerals: 1. Arch frame base; 2. Arch frame; 21. Small pier column; 3. Main girder; 31. Main girder inside the arch; 32. Main girder outside the arch on the south bank; 33. Main girder outside the arch on the north bank; 4. Cable crane; 41. Load-bearing main cable; 5. Support structure; 51. Abutment; 52. Large pier column; 53. Temporary tower; 6. Temporary assembly plant; 61. Gantry; 7. Shipping platform; 71. Rail flat car group; 8. Wharf; 81. Lifting device. Detailed implementation manners

[0033] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the present invention will be clearly described below in conjunction with the accompanying drawings in the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0034] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the embodiments of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0035] In the description of the embodiments of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "connected" and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific situations.

[0036] In the embodiments of the present invention, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may mean that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may mean that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0037] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0038] During the installation and construction process of an arch bridge, usually large temporary facilities such as a temporary assembly plant and a transportation road leading to the bridge site are built near the bridge site first, then the arch frame 2 is erected, and finally the main beam 3 is assembled. The main beam assembly construction makes full use of the existing large temporary facilities. Among them, a part of the main beam 3 of the arch bridge is located under the arch frame and a part is outside the area of the arch frame. And the transfer and transportation during the assembly of the main beam under the arch frame is difficult. There are currently two transfer and transportation methods: one is to build a temporary road under the main beam 3 of the arch bridge first, and directly transport the main beam segments to be installed to the lifting position by a large transport vehicle; the other is to use a cable crane 4 erected on both sides of the arch bridge to lift the main beam segments to be installed onto a barge in the river, and then use the barge to transport them to the lifting position under the arch frame.

[0039] However, for the first method, due to the construction of the temporary road, it is greatly restricted by geographical conditions and is difficult to be widely applicable or applicable at low cost; for the second method, since the barge occupies a large area of the waterway during operation, it affects the passage of ships in the waterway, and is easily affected by the water level and cannot be continuously constructed, which greatly delays the construction progress and increases the construction cost.

[0040] To solve the above problems, in the embodiments of the present invention, a method for assembling the main beam of a half-through basket arch bridge is introduced.

[0041] As Figure 1 shown, the half-through basket arch bridge includes: an arch frame base 1, an arch frame 2, piers, and a main beam 3 assembled from main beam segments, etc. The middle part of the main beam 3 is located under the arch frame 2 and is the main beam 31 inside the arch. The two ends of the main beam 3 are located behind and above the arch frame 2, which are the main beam 32 outside the arch on the south bank and the main beam 33 outside the arch on the north bank respectively.

[0042] Specifically, the steps of the construction method mainly include: First, set up a cable crane 4 spanning both banks, build the arch frame base 1, and erect the arch frame 2 on the arch frame base 1. After the erection of the arch frame 2 is completed, assemble the main beam segments at the original temporary assembly plant 6 on the south bank.

[0043] Secondly, build a support structure 5 on the north bank for fixing the main beam 33 outside the arch on the north bank, transport the main beam segments of the main beam 33 outside the arch on the north bank to the north bank and install them, and then transport the main beam segments of the main beam 32 outside the arch on the south bank to the north bank and place them on the main beam 33 outside the arch on the north bank.

[0044] After that, build a support structure outside the influence range of the original shipping platform 7 on the south bank, assemble the main beam 31 inside the arch, and install it in the order from both ends to the middle.

[0045] Finally, the outhaul platform 7 is demolished, and the remaining support structure 5 is constructed on the south bank. The girder segments of the main girder 32 outside the south bank arch are transported back to the south bank and installed. Among them, the transportation operation from the temporary assembly plant 6 along the outhaul platform to the position directly below the load-bearing main cable 41 of the cable crane 4 is completed by the rail car group 71, and other transportation operations are completed by the cable crane 4.

[0046] In addition, the main girder 3 is arranged as a number of girder segments along its length direction. Preferably, the main girder 3 includes 24 girder segments. The main girder 3 forms an integral bridge structure through the top supports of the small pier columns 21 or the hangers between the main arches. φ22 cylinder head stud bolts are arranged on the top surface of the main girder 3 to form a steel-concrete composite structure with the reinforced concrete bridge deck.

[0047] The arch support 2 adopts a concrete-filled steel tube structure. The arch support 2 is provided with two inward-inclined arch ribs. The cross-section of the arch ribs adopts a four-limb truss type. The width of the arch ribs is 2.5 m. The height of the arch ribs at the top of the arch support 2 is 6 m. The height of the arch ribs at the arch feet of the arch support 2 is 10 m. The steel tube diameter is 1.1 m. The arch ribs are connected by connecting systems such as web members and horizontal bracing members in the transverse and vertical directions to form an integral space truss structure. The two arch ribs of the arch support 2 are arranged as a left-right separated structure, and 15 cross braces are arranged between the two arch ribs.

[0048] In this embodiment, the cable crane 4 is used to hoist the girder segments, and gradually assemble the main girder 33 outside the north bank arch, the main girder 31 inside the arch and the main girder 32 outside the south bank arch, replacing the method of positioning and hoisting the girder segments by barge consignment, eliminating the factors restricting the splicing operation of the main girder 3 such as geographical conditions and water levels, reducing the construction cost and accelerating the construction progress.

[0049] On the basis of the above embodiment, in another embodiment of the present invention, a method for assembling and constructing the main girder of a half-through basket-shaped arch bridge is introduced.

[0050] As Figures 2 to 4 shown, a support structure 5 for installing the main girder 33 outside the north bank arch is constructed on the north bank, and each girder segment of the main girder outside the north bank arch is numbered. Then, the cable crane 4 transports and installs them on the support structure 5 on the north bank in the numbered order.

[0051] The girder segments for forming the main girder 32 outside the south bank arch are assembled in the temporary assembly plant 6, and each girder segment is numbered. Then, they are transported to the north bank by the cable crane 4 in the numbered order and placed on the main girder 33 outside the north bank arch.

[0052] As Figure 8As shown in the figure, the facilities for auxiliary construction on the south bank are: temporary assembly plant 6, gantry crane, shipping platform 7 and rail car group 71. In particular, cable-crane 4 has tower frames installed on both banks. The tower frame foundation adopts a group-pile cap foundation. The installation of large steel components of the arch bridge is mainly carried out by cable-crane 4. Cable-crane 4 is arranged with a total of 3 groups of load-bearing main cables 41 with a spacing of 15 m. The horizontal projection of the middle load-bearing main cable 41 coincides with the longitudinal axis of the bridge. Each group of load-bearing main cables 41 is provided with two lifting points, front and back.

[0053] In addition, the temporary assembly plant 6 is located on the riverside side of the road, which is behind and above the side of the arch support 2. The gantry crane is installed in the temporary assembly plant 6. The shipping platform 7 is located between the main arch and the road, connecting the temporary assembly plant 6 and extending all the way to directly below the load-bearing main cable 41 of the cable-crane 4. The rail car group 71 includes 2 rail cars and is used to transfer the main beam segments to directly below the load-bearing main cable 41 of the cable-crane 4.

[0054] A dock 8 is provided below the arch support 2. The dock 8 is built on the shore in front of the arch support base 1. The waterside side of the dock 8 has a retaining wall with a length of 50 m and a height of 8 m. Inside the retaining wall, there is a site with a length of 45 m and a width of 18 m. The surface of the site is poured with a 20-cm-thick concrete surface, on which a lifting device 81 is parked.

[0055] Specifically, as Figure 9 and Figure 10 shown, the main beam segments of the main beam 33 outside the arch on the north bank are transported from the temporary assembly plant 6 to directly below the middle load-bearing main cable 41 of the cable-crane 4 via the shipping platform 7 by rail cars, and then the main beam 3 is directly lifted by the cable-crane 4 to the designed position for installation.

[0056] Since the shipping platform 7 affects the construction of the large pier column 52 that supports the main beam 32 outside the arch on the south bank, the main beam segments to be installed above the shipping platform 7 need to be pre-assembled in the temporary assembly plant 6 first, and then transferred and stored above the main beam 33 outside the arch on the north bank. After the main beam 31 inside the arch is assembled, the shipping platform 7 is removed first, then the large pier column 52 is constructed, and finally the main beam segments are lifted back by the cable-crane 4 to complete the installation of the main beam 32 outside the arch on the south bank.

[0057] On the basis of the above embodiments, in another embodiment of the present invention, a construction method for assembling the main beam of a half-through basket arch bridge is introduced.

[0058] As Figures 5 to 7 shown, small pier columns 21 for fixing the main beam 3 are provided on the cross beams at the intersection positions of the main beam 3 and the arch support 2. When installing the main beam 31 inside the arch, the first main beam segment is installed on the small pier columns 21, and then assembled section by section towards the middle and completed the closure in the middle.

[0059] Specifically, to prevent the main girder segments from forming a "floating" structure during the installation process, the first main girder segment must start from the position of the small pier 21, so as to be fixed to the small pier 21, preventing the assembled main girder segments from swaying under the adverse influence of external factors such as wind before closure, thus affecting the installation accuracy.

[0060] In addition, the cable crane 4 includes three groups of load-bearing main cables 41 distributed in parallel. The middle load-bearing main cable 41 is located in the same vertical plane as the central axis in the length direction of the main girder 3. The two side load-bearing main cables 41 are respectively offset and arranged upstream and downstream of the main girder 3.

[0061] The in-arch main girder 31 is hoisted and installed by the two side load-bearing main cables 41. The south-bank out-of-arch main girder 32 and the north-bank out-of-arch main girder 33 are hoisted and installed by the middle load-bearing main cable 41.

[0062] Since there are 15 cross braces arranged between the two arch ribs of the arch frame 2. The main girder segments of the in-arch main girder 31 cannot directly pass through the two arch ribs from directly behind the arch frame 2 to the directly below of the main arch. It is necessary to utilize the structural characteristics of the arch ribs being inclined inwards, wider at the arch feet and narrower at the arch crown to hoist the main arch segments. The lifting cable of the upstream load-bearing main cable 41 is used to hoist the main girder segment from the shipping platform 7 at the side rear of the main arch. It moves forward above the side of the main arch in the air. After the vertical projection edge line of the main girder 3 can avoid the arch frame 2, it descends to the side below of the arch frame 2. Then, it is transported to the lifting device 81 parked at the dock 8. Finally, the lifting device 81 moves the main girder segment from the side below of the main girder 3 to directly below the main girder 3.

[0063] Specifically, as Figures 11 to 14 shown, the main girder segments of the in-arch main girder 31 are transported by the rail flatcar from the temporary assembly plant 6 through the shipping platform 7 to stop directly below the upstream load-bearing main cable 41 of the cable crane 4. The lifting cable of the upstream load-bearing main cable 41 of the cable crane 4 is used to hoist the main girder 3 and move forward above the installed main arch to the middle of the main arch. After avoiding the main arch, it descends to the side below of the main arch. Then, it retreats to the shore dock 8 and is lowered onto the lifting device 81. The lifting device 81 horizontally moves the main girder segment on the support truss of the main girder 3 to directly below the main arch through its own device. Finally, the lifting cables of the upper and lower two bundles of load-bearing main cables 41 of the cable crane 4 are used to lift the lifting device 81 and transport the main girder 3 to the design position for installation.

[0064] Based on the above embodiments, in another embodiment of the present invention, a construction method for assembling the main girder of a half-through basket-shaped arch bridge is introduced.

[0065] When constructing with the arch frame 2 on the south bank, the shipping platform 7 is equipped with a set of rail flatcars 71 and is located below the south-bank out-of-arch main girder 32. The set of rail flatcars 71 extends from the shipping platform 7 into the temporary assembly plant 6. A gantry crane 61 is provided in the temporary assembly plant 6.

[0066] The main girder segments are assembled in the temporary assembly plant 6, and then the main girder segments are placed on the rail flatcar group 71 through the gantry 61, and then transported along the shipping platform 7 to a position directly below the load-bearing main cable 41 of the cable crane.

[0067] Further, a wharf 8 is constructed on the south bank below the arch frame 2. The wharf 8 is provided with a lifting device 81 for assisting in hoisting and splicing the main girder 31 inside the arch.

[0068] Based on the above embodiments, in another embodiment of the present invention, a construction method for assembling the main girder of a half-through basket arch bridge is introduced.

[0069] The hoisting and installation of the main girder 31 inside the arch by the load-bearing main cables 41 on both sides specifically includes: the rail flatcar group 71 transports the main girder segments to a position on the shipping platform directly below the upstream load-bearing main cable 41 or the downstream load-bearing main cable 41. Then, the main girder segments are lifted from the rail flatcar group 71 to a height higher than the top of the arch frame 2, and then moved from the south bank to the north bank along the extension direction of the load-bearing main cable 41.

[0070] When the vertical projection side line of the main girder segment can avoid the arch frame 2, the main girder segment is lowered to the side below the main girder 3, and then transported to the lifting device 81 on the wharf 8.

[0071] The lifting device 81 laterally moves the main girder segment to a position directly below the main girder 3. The load-bearing main cables 41 on both sides then hoist the lifting device 81 equipped with the main girder segment and move it along the length direction of the main girder 3 to the position to be installed for assembly.

[0072] Further, the hoisting and installation of the main girder 32 outside the arch on the south bank and the main girder 33 outside the arch on the north bank by the intermediate load-bearing main cable 41 specifically includes: The rail flatcar group 71 transports the main girder segments to a position on the shipping platform directly below the intermediate load-bearing main cable 41. Then, the intermediate load-bearing main cable 41 extends downward with a lifting cable to lift the main girder segments from the rail flatcar group 71 to a height higher than the top of the arch frame 2. Then, it moves from the south bank to the north bank along the extension direction of the load-bearing main cable 41, and after reaching directly above the installation position on the north bank, the main girder segments are lowered and placed on the support structure 5 or the main girder 33 outside the arch on the north bank.

[0073] Based on the above embodiments, in another embodiment of the present invention, a construction method for assembling the main girder of a half-through basket arch bridge is introduced.

[0074] Since the shipping platform 7 affects the construction of the large pier column 52 supporting the main girder 32 outside the south bank arch, the main girder segments to be installed above the shipping platform 7 need to be pre-assembled in the temporary assembly plant 6 first, and then transferred and stored above the main girder 33 outside the north bank arch. After the main girder 31 inside the arch is assembled, the shipping platform 7 is removed first, then the large pier column 52 is constructed, and finally the main girder segments are lifted back by the cable crane 4 to complete the installation of the main girder 32 outside the south bank arch.

[0075] Specifically, after the main girder 31 inside the arch is installed, the shipping platform 7 is removed. Then, a support structure 5 for installing the main girder 32 outside the south bank arch is constructed. After that, the middle load-bearing main cable 41 extends downward to extend the lifting cable to lift and transport the main girder segments for assembling the main girder 32 outside the south bank arch placed on the main girder 33 outside the north bank arch, lift the main girder segments above the top of the arch frame 2, and then move from the north bank to the south bank along the extension direction of the load-bearing main cable 41. After reaching directly above the installation position on the south bank, lower the main girder segments to the support structure 5 to complete the assembly of the main girder 32 outside the south bank arch.

[0076] Among them, the support structure 5 includes a bridge abutment 51, a large pier column 52, and a temporary tower 53. The bridge abutment 51 is arranged at the butt joint of the main girder 3 and the roadbed and is used to fixedly support the end of the main girder 3. The large pier column 52 is arranged on the arch frame base 1. The temporary tower 53 is arranged between the arch frame base 1 and the bridge abutment 51 and is used to support the splicing ends of the main girder 32 outside the south bank arch and the main girder 33 outside the north bank arch.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0078] The above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for assembling and constructing the main beam of a half-through basket arch bridge, characterized in that The half-through basket arch bridge includes: arch support bases, arch supports, piers and abutments, and a main girder assembled from main girder segments, etc.; the middle part of the main girder is located below the arch support and is the main girder inside the arch; the two ends of the main girder are located behind and above the arch support, and are respectively the main girder outside the arch on the south bank and the main girder outside the arch on the north bank; The construction method is as follows: S1. After the arch support is erected, assemble the main girder segments at the original temporary assembly plant on the south bank; S2. Construct a support structure on the north bank, transport the main girder segments of the main girder outside the arch on the north bank to the north bank and install them, and then transport the main girder segments of the main girder outside the arch on the south bank to the north bank and place them on the main girder outside the arch on the north bank; S3. Construct a support structure outside the influence range of the original outhaul platform on the south bank, and install the main girder segments of the main girder inside the arch in the order from both ends to the middle; S4. Demolish the outhaul platform, construct the remaining support structure on the south bank, transport the main girder segments of the main girder outside the arch on the south bank back to the south bank and complete the installation; Among them, the transportation operation from the temporary assembly plant along the outhaul platform to the position directly below the load-bearing main cable of the cable crane is completed by the track flatcar group, and other transportation operations are completed by the cable crane; 2. The main girder erection construction method for the through basket arch bridge according to claim 1, characterized in that, The main girder is arranged as several main girder segments along its length direction; The specific steps of S2 include: construct a support structure for installing the main girder outside the arch on the north bank, number each main girder segment of the main girder outside the arch on the north bank, and then transport and install them on the support structure on the north bank in the numbered order by the cable crane; Then, assemble the main girder segments for forming the main girder outside the arch on the south bank at the temporary assembly plant, number each main girder segment, and then transport them to the north bank in the numbered order by the cable crane and place them on the main girder outside the arch on the north bank; 3. The main girder erection construction method for the half-through basket arch bridge according to claim 2, characterized in that The specific steps of S3 include: Set small pier columns for fixing the main girder on the cross beam at the intersection position of the main girder and the arch support. When installing the main girder inside the arch, install the first main girder segment on the small pier columns, and then assemble them section by section towards the middle and complete the closure in the middle; 4. The main girder erection construction method for a half-through basket arch bridge according to claim 2 or 3, characterized in that When constructing using the arch support on the south bank, the outhaul platform is equipped with a track flatcar group and is located below the main girder outside the arch on the south bank. The track flatcar group extends from the outhaul platform to the inside of the temporary assembly plant, and a gantry crane is provided inside the temporary assembly plant; Assemble the main girder segments inside the temporary assembly plant, and then place the main girder segments on the track flatcar group through the gantry crane, and then transport them along the outhaul platform to the position directly below the load-bearing main cable of the cable crane; 5. The main girder erection construction method for the through basket arch bridge according to claim 4, characterized in that, Construct a dock below the arch support on the south bank. The dock is provided with a lifting device for assisting in hoisting and splicing the main girder inside the arch; 6. The main girder erection construction method for a half-through basket arch bridge according to claim 5, characterized in that The cable crane includes three groups of load-bearing main cables distributed in parallel. The middle load-bearing main cable and the central axis of the main girder in the length direction are located in the same vertical plane, and the load-bearing main cables on both sides are respectively offset and arranged upstream and downstream of the main girder; The main girder inside the arch is hoisted and installed by the load-bearing main cables on both sides; The main girder outside the arch on the south bank and the main girder outside the arch on the north bank are hoisted and installed by the middle load-bearing main cable; 7. The method for assembling and constructing the main beam of the half-through basket arch bridge according to claim 6, characterized in that, The specific process of hoisting and installing the main girder inside the arch by the load-bearing main cables on both sides includes: The rail flat car group transports the main beam segment to the delivery platform position just below the load-bearing main cable offset upstream of the main beam, and then lifts the main beam segment from the rail flat car group to a position higher than the top of the arch frame, and then moves from the south bank to the north bank along the extension direction of the load-bearing main cable; When the vertical projection edge line of the main beam segment can avoid the arch frame, the main beam segment is lowered to the side and lower part of the main beam, and then transported to the lifting device on the dock; The lifting device moves the main beam segment laterally to just below the main beam, and the load-bearing main cables on both sides then lift the lifting device equipped with the main beam segment and move it along the length direction of the main beam to the position to be installed for assembly.

8. The method for assembling the main beam of a half-through basket arch bridge according to claim 7, characterized in that The installation of the south bank arch outer main beam and the north bank arch outer main beam by hoisting through the middle load-bearing main cable specifically includes: The rail flat car group transports the main beam segment to the shipping platform position just below the middle load-bearing main cable, and then the middle load-bearing main cable extends the lifting cable downward to lift the main beam segment from the rail flat car group to above the top of the arch frame, and then moves from the south bank to the north bank along the extension direction of the load-bearing main cable. After reaching just above the installation position on the north bank, the main beam segment is lowered to the supporting structure or the main beam outside the north bank arch.

9. The method for assembling the main girder of the half-through basket arch bridge according to claim 8, characterized in that, The construction of the support structure on the south bank, transporting the south bank arch outer main beam back to the south bank and completing the installation specifically includes: After the installation of the main beam inside the arch is completed, the shipping platform is dismantled and a supporting structure for installing the main beam outside the arch on the south bank is built. The middle load-bearing main cable extends downward through the lifting cable to lift the main beam segment for assembling the main beam outside the arch on the north bank, and then lift the main beam segment to a level above the top of the arch frame, and then move it from the north bank to the south bank along the extension direction of the load-bearing main cable. After reaching the top of the installation position on the south bank, the main beam segment is lowered to the supporting structure to complete the assembly of the main beam outside the arch on the south bank.

10. The method for assembling the main beam of a half-through basket arch bridge according to any one of claims 1-3, characterized in that, The supporting structure includes abutments, large piers, small piers, and temporary towers; Abutments are provided at the joint between the main beam and the tunnel and are used to fix and support the ends of the main beam; A large pier column is arranged on the arch frame base; A small pier column is arranged on the cross beam at the intersection of the main beam and the arch frame; A temporary tower is arranged between the arch frame base and the pier or the large pier column, and is used to support the spliced ends of the arch outer main beam on the south bank and the arch outer main beam on the north bank.

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