A segmental erection method for a multi-span continuous steel truss bridge built on both road and rail

Abstract

The present invention discloses a method for erecting segments of a multi-span continuous steel truss bridge constructed jointly by road and rail. The method comprises sequentially arranging a trestle, temporary piers, a crawler crane, and a fully revolving crane assembly platform. Two fully revolving cranes are respectively assembled and arranged on the long-distance side and the short-distance side. The method adopts a construction scheme of temporary pier-assisted semi-cantilever installation. Four temporary piers are pre-arranged between two adjacent main piers of the approach section on one side, and one temporary pier is pre-arranged between the remaining main piers. The crawler crane on the trestle is then used to install four inter-segment steel trusses on the main pier and the four temporary piers. The upper chord of the temporary pier serves as a starting platform for cantilever assembly. Two fully revolving beam erection cranes are then assembled on the starting platform to symmetrically install the remaining inter-segment steel beams on the short-distance side and the long-distance side. The present invention adopts cantilever assembly of steel trusses, realizing cantilever assembly of multi-span steel trusses and synchronous lifting and lowering control of large-span steel trusses. It does not require the erection of a large number of assembly supports, and only requires one set of temporary piers, thereby improving construction efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge construction, and in particular to a method for erecting segments of a multi-span continuous steel truss bridge constructed jointly by road and rail. Background Art

[0002] A river-crossing bridge is a large-span steel truss bridge, typically in single- or double-deck structures. Trusses are typically erected using methods such as large floating cranes for whole-span hoisting, cantilever installation, and jacking construction. Floating crane whole-span hoisting is often suitable for deep water and areas where large equipment can enter and exit; cantilever assembly is often suitable for multi-span continuous standard-section steel trusses; and jacking construction is often suitable for straight standard-section steel trusses. Traditional methods for simply supported steel trusses often involve erecting double-sided trestles to install gantry cranes across piers or using large floating cranes for whole-piece hoisting. These methods require large material inputs and a long construction period, making them unsuitable for shallow water and other areas where large equipment cannot enter. Traditional cantilever assembly erection methods are more suitable for single-unit, multi-span continuous steel trusses. However, for multi-unit construction, the initial section of each unit can only be erected using the scaffolding method, which increases construction time and material costs, prevents continuous operation, and reduces overall construction efficiency. Summary of the Invention

[0003] In order to solve the defects of the above-mentioned technology, the present invention provides a method for erecting sections of a multi-span continuous steel truss bridge built jointly by road and rail.

[0004] The technical solution adopted by the present invention to achieve the above technical effects is:

[0005] A method for erecting segments of a multi-span continuous steel truss bridge constructed jointly by road and rail, comprising the following steps:

[0006] S1. Arrange a trestle. Set up a trestle on the downstream side of the bridge line to provide a construction platform and material transportation channel for water operations;

[0007] S2. Arrange temporary buttresses: Set up four temporary buttresses between two adjacent main piers on one side of the approach section, and set up one temporary buttress between the remaining main piers, with the center of each temporary buttress corresponding to the centerline of the main girder;

[0008] S3. Arrange crawler cranes. Arrange crawler crane No. 1 on the widened area of ​​the trestle to the right of the two adjacent main piers in step S2 to assemble the intersegmental steel beams and two full-slewing cranes on the four temporary supporting piers. Arrange crawler crane No. 2 on the main pier position close to the long mileage side and at least four main piers away from the main pier in step S2 as a steel beam lifting station, and set up a lifting station platform at this location to facilitate the entry and exit of transport ships.

[0009] S4. Arrange a platform for assembling a fully revolving crane. Use the four temporary buttresses described in step S2 and the main piers located at both ends of the four temporary buttresses, one close to the shorter mileage side, as support foundations. Use a crawler crane No. 1 installed on the trestle to assemble four bays, which serve as an assembly platform for the fully revolving crane.

[0010] S5. Arrange the full-revolving cranes and synchronously erect the steel truss bridge segments in two directions. At the side of the four segments close to the short mileage side in step S4, use the segment upper chord as the assembly platform for the No. 1 full-revolving crane. After the No. 1 full-revolving crane is assembled, it is cantilevered toward the short mileage side to assemble and erect the steel truss bridge segment and move forward toward the short mileage side. Then, at the side of the four segments close to the long mileage side, use the segment upper chord as the assembly platform for the No. 2 full-revolving crane. Use the segment upper chord as the assembly platform for the No. 2 full-revolving crane to complete the assembly of the No. 2 full-revolving crane, and use the No. 2 full-revolving crane to cantilever and assemble the steel truss bridge segment toward the long mileage side.

[0011] S6. After the entire bridge is erected, the upper deck concrete precast slabs are erected;

[0012] S7. After the concrete is erected, pour wet joints starting from the middle span, with each span as the unit. First pour the wet joints at the middle of each span, then pour the wet joints at the piers. When pouring the wet joints at the piers, lift the steel beam to a certain height.

[0013] Preferably, in the above-mentioned method for erecting multi-span continuous steel truss bridge segments for road and rail co-construction, the trestle adopts a structural form of a steel pipe column foundation plus a Bailey beam, a double-jointed I-56 steel is used as a pile top distribution beam on the pile cap, a Bailey beam is used as the main beam of the trestle, a 25# I-beam is set on the Bailey beam as a transverse bridge distribution beam, and the bridge deck uses a 12.6# I-beam and a steel plate with a thickness of 10 mm as a longitudinal bridge distribution beam and bridge deck respectively.

[0014] Preferably, in the above-mentioned method for erecting segments of multi-span continuous steel truss bridges jointly built by road and rail, the trestle is constructed using the fishing method, and brake piers are arranged according to the linear direction of the main bridge. A brake segment is arranged every 3-5 spans of the curved section so that the trestle matches the linear direction of the main bridge, and a brake pier is arranged every 6 spans of the straight section.

[0015] Preferably, in the above-mentioned method for erecting a multi-span continuous steel truss bridge segment for road and rail co-construction, a temporary support and a fine-adjustment device area are set on the top of the temporary pier, and a manual fine-adjustment operation area is reserved in the middle of the top. The space between the columns is connected by a truss, and vertical jacks and horizontal limit jacks are arranged on the pier top and the temporary pier for use in adjusting the position and elevation of the steel truss.

[0016] Preferably, in the above-mentioned method for erecting a multi-span continuous steel truss bridge segment for road and rail co-construction, in step S2, the four temporary piers arranged between two adjacent main piers of the approach section on one side include three double-column temporary piers close to the small mileage side and four-column temporary piers close to the large mileage side, and one temporary pier between the remaining main piers is a four-column temporary pier. The double-column temporary pier is supported by double-tube columns, and longitudinal and transverse steel pipe connection systems are arranged between the columns, so that the three double-column temporary piers form an integral structure, and the four-column temporary pier is supported by four-tube columns.

[0017] Preferably, in the above-mentioned method for erecting multi-span continuous steel truss bridge segments for road and rail co-construction, during the cantilever assembly process, the upper chord and the lower chord between two adjacent sections of the approach bridge are respectively connected into one body to meet the forward support of the fully rotating crane. After the erection is completed, the overall chord is cut and separated at the bridge position to complete the conversion of the steel truss from a continuous to a simply supported force system.

[0018] Preferably, in the above-mentioned method for erecting segments of multi-span continuous steel truss bridges jointly built by road and rail, temporary piers for assembling steel beams are set at the nodes of the lower chords of the steel trusses, and the temporary piers are used to assist the semi-cantilever method for installation. When the steel trusses begin to be erected, all the pier top supports are first put in place but not installed. When the steel beams are erected, the main chord nodes are all installed on the temporary supports on the pier tops. After all the steel beams are assembled, the longitudinal and transverse adjustment devices on the pier tops are used to perform precise longitudinal and transverse adjustments. Finally, the main beams are lifted with jacks and permanent supports are installed.

[0019] Preferably, in the above-mentioned method for erecting segments of multi-span continuous steel truss bridges built jointly by road and rail, when the steel trusses are erected to the position where permanent supports are provided on the pier top, the assembly of the inter-segment rods is completed first to make it a stable integral structure, and the steel trusses are temporarily not assembled. After all the high-strength bolts of the assembled structure are finally set in place, the permanent supports are installed. When installing the permanent supports, the steel beams are jacked up, and the jacking height is controlled at 2-3 cm to provide construction space for installing the permanent supports of the bridge. After the permanent supports are installed in place, the cantilevered steel truss members are erected forward.

[0020] Preferably, in the above-mentioned method for erecting segments of multi-span continuous steel truss bridges jointly built by road and rail, the steel trusses are assembled by cantilever, and only the inter-segment rods and the railway bridge deck system bridge panels are assembled. After the assembly of the rods and the railway bridge deck system bridge panels of the highway bridge deck system is completed, the highway bridge deck system bridge panels are installed in reverse using a full-rotating crane. When installing the precast slabs of the highway bridge deck system, the wet joints are weighted with equal weights. When the wet joints are subsequently poured with concrete, the pre-stressed counterweights are simultaneously unloaded.

[0021] Preferably, in the above-mentioned method for erecting segments of a multi-span continuous steel truss bridge constructed by road and rail, the order for tightening the high-strength bolts after the segment hoisting is completed is:

[0022] 1) First tighten the high-strength bolts between the lower chords and the upper chords. After the bolts between the upper chords are initially tightened, weld the butt welds between the top plates of the upper chords, and then finally tighten the high-strength bolts.

[0023] 2) Unscrew the high-strength bolts between the chord and the web;

[0024] 3) Tighten the high bolts between the lower chord and the lower railway bridge deck block. After the initial tightening, weld the weld between the lower chord and the lower bridge deck block first, and then tighten the high-strength bolts;

[0025] 4) Tighten the high bolts between the upper chord and the upper beam, weld the butt weld between the upper chord and the beam top plate after the initial tightening, and then finally tighten the high-strength bolts;

[0026] 5) Tighten the high bolts between the upper chord and the cantilever arm. After the initial tightening, weld the butt weld between the upper chord and the cantilever arm top plate, and then finally tighten the high-strength bolts.

[0027] 6) Tighten the high bolts between the small longitudinal beams of the lower deck blocks, weld the butt welds between the lower deck blocks after the initial tightening, and then finally tighten the high-strength bolts.

[0028] The beneficial effects of the present invention are as follows: the present invention adopts cantilever assembly of steel trusses, and only the inter-segment rods and the railway bridge deck system bridge panels are assembled. After the assembly of the rods and the railway bridge deck system bridge panels of the highway bridge deck is completed, the full-rotation crane is used to install them in reverse, thereby realizing the cantilever assembly of multi-span steel trusses and the synchronous lifting and lowering control of large-span steel trusses. There is no need to set up a large number of assembly brackets, and only one set of temporary piers is needed, thereby improving construction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is an elevation view of a river-spanning bridge according to an embodiment of the present invention;

[0030] Figure 2 These are the four temporary supporting piers between the main piers S12 and S11 in the embodiment of the present invention;

[0031] Figure 3 This is the assembly platform for the full-rotation crane No. 1 according to the embodiment of the present invention;

[0032] Figure 4 This is the assembly platform for the second full-rotation crane according to the embodiment of the present invention;

[0033] Figure 5 This is a diagram showing the dynamic changes of assembling a portion of the full-rotation crane assembly platform according to an embodiment of the present invention;

[0034] Figure 6 This is a dynamic diagram of the assembly of two parts of a full-rotation crane assembly platform according to an embodiment of the present invention;

[0035] Figure 7 This is a dynamic diagram of the assembly of three parts of a full-rotation crane assembly platform according to an embodiment of the present invention;

[0036] Figure 8 This is a dynamic change diagram of the four-part assembly of the full-rotation crane assembly platform according to an embodiment of the present invention;

[0037] Figure 9 This is a dynamic change diagram of the four-part assembly of the full-rotation crane assembly platform according to an embodiment of the present invention;

[0038] Figure 10 This is a diagram showing the dynamic changes in the assembly of a portion of the cantilevered long-distance side steel derivative beam according to an embodiment of the present invention;

[0039] Figure 11 This is a diagram showing the dynamic changes in the assembly of two parts of a cantilevered long-distance side steel derivative beam according to an embodiment of the present invention;

[0040] Figure 12 This is a diagram showing the dynamic changes in the assembly of a portion of the cantilevered steel beam on the short-distance side according to an embodiment of the present invention;

[0041] Figure 13 This is a dynamic change diagram of the two-part assembly of the cantilevered small-mileage side steel derivative beam according to an embodiment of the present invention;

[0042] Figure 14 This is a diagram showing the dynamic changes in the assembly of the main pier S14 when the main pier S14 is cantilevered in accordance with an embodiment of the present invention;

[0043] Figure 15 This is a diagram showing the dynamic changes of a portion of two adjacent steel beams assembled by cantilever spanning according to an embodiment of the present invention;

[0044] Figure 16 This is a two-part dynamic change diagram of the cantilever span assembly of two adjacent steel beams according to an embodiment of the present invention;

[0045] Figure 17 Schematic diagram of the integrated cantilever assembly of two adjacent connecting rods. DETAILED DESCRIPTION

[0046] In order to further understand the present invention, the present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0047] In the description of the present invention, it should be noted that the terms "vertical," "upper," "lower," and "horizontal," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0048] It should also be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0049] A method for erecting segments of a multi-span continuous steel truss bridge constructed jointly by road and rail, comprising the following steps:

[0050] S1. Arrange a trestle. Set up a trestle on the downstream side of the bridge line to provide a construction platform and material transportation channel for water operations;

[0051] S2. Arrange temporary buttresses: Set up four temporary buttresses between two adjacent main piers on one side of the approach section, and set up one temporary buttress between the remaining main piers, with the center of each temporary buttress corresponding to the centerline of the main girder;

[0052] S3. Arrange crawler cranes. Arrange crawler crane No. 1 on the widened area of ​​the trestle to the right of the two adjacent main piers in step S2 to assemble the intersegmental steel beams and two full-slewing cranes on the four temporary supporting piers. Arrange crawler crane No. 2 on the main pier position close to the long mileage side and at least four main piers away from the main pier in step S2 as a steel beam lifting station, and set up a lifting station platform at this location to facilitate the entry and exit of transport ships.

[0053] S4. Arrange a platform for assembling a fully revolving crane. Use the four temporary buttresses described in step S2 and the main piers located at both ends of the four temporary buttresses, one close to the shorter mileage side, as support foundations. Use a crawler crane No. 1 installed on the trestle to assemble four bays, which serve as an assembly platform for the fully revolving crane.

[0054] S5. Arrange the full-revolving cranes and synchronously erect the steel truss bridge segments in two directions. On the side of the four segments close to the short mileage side in step S4, use the segment upper chord as the assembly platform for the No. 1 full-revolving crane. After the No. 1 full-revolving crane is assembled, the steel truss bridge segment is assembled and erected by cantilevering toward the short mileage side and moving forward toward the short mileage side. Then, on the side of the four segments close to the long mileage side, use the segment upper chord as the assembly platform for the No. 2 full-revolving crane. Use the segment upper chord as the assembly platform for the No. 2 full-revolving crane to complete the assembly of the No. 2 full-revolving crane, and use the No. 2 full-revolving crane to cantilever and assemble the steel truss bridge segment toward the long mileage side.

[0055] S6. After the entire bridge is erected, the upper deck concrete precast slabs are erected;

[0056] S7. After the concrete is erected, pour wet joints starting from the middle span, with each span as the unit. First pour the wet joints at the middle of each span, then pour the wet joints at the piers. When pouring the wet joints at the piers, lift the steel beam to a certain height.

[0057] In some embodiments, the trestle adopts a steel pipe column foundation plus Bailey beam structure, double-jointed 56-type steel is used as the pile top distribution beam on the pile cap, the Bailey beam is used as the main beam of the trestle, 25# I-beam is set on the Bailey beam as the transverse bridge distribution beam, and the bridge deck uses 12.6# I-beam and 10mm thick steel plate as the longitudinal bridge distribution beam and bridge deck respectively. The trestle provides a construction platform and material transportation channel for the construction of the pile foundation and substructure of the main bridge project. After the construction of the main foundation and substructure of the bridge is completed, the trestle will continue to be used as a construction platform and transportation channel for the assembly of temporary piers and steel beams. Specifically, the trestle is constructed using the fishing method, and brake piers are arranged according to the linear direction of the main bridge. A brake section is set every 3-5 spans of the curved section so that the trestle matches the linear direction of the main bridge, and a brake pier is set every 6 spans of the straight section.

[0058] In some embodiments, a temporary support and fine-tuning device area is provided at the top of the temporary pier, with a manual fine-tuning operation area reserved in the middle of the top. The spaces between the columns are connected by trusses, and vertical jacks and horizontal limit jacks are arranged on the pier top and temporary piers for adjusting the position and elevation of the steel trusses. The steel trusses are assembled using the semi-cantilever method assisted by temporary piers. The temporary piers consist of three parts: steel pipe piles, distribution beams, and temporary pads. The center of the temporary pier for the main bridge is located at the center of the steel truss node, providing temporary support during the steel beam assembly stage.

[0059] Specifically, in step S2, the four temporary piers arranged between two adjacent main piers of the approach bridge section on one side include three double-column temporary piers close to the small mileage side and four-column temporary piers close to the large mileage side, and one temporary pier between the remaining main piers is a four-column temporary pier. Among them, the double-column temporary piers are supported by double-tube columns, and longitudinal and transverse steel pipe connection systems are set between the columns so that the three double-column temporary piers form an integral structure, and the four-column temporary piers are supported by four-tube columns. In an embodiment of the present invention, the temporary pier foundation adopts a driven steel pipe pile foundation, and the pier structure adopts steel pipe columns. For the convenience of explanation, S represents the main pier, and the number after S represents the main pier number, and L represents the temporary pier, and the number after L represents the temporary pier number, such as Figure 1 and Figure 2As shown, four temporary buttresses (L1-L4) were installed between main piers S12# and S13# to support the initial assembly of the four interspan steel trusses, allowing for the installation of a fully revolving girder erection crane on the upper chord. Given the long distances between the main piers, a temporary buttress was installed between each of the remaining main piers to serve as mid-span support during the cantilevered assembly of the steel trusses by the fully revolving crane. Each temporary buttress L1-L3 is supported by a double-tube column, known as the double-column temporary buttress. Specifically, the columns of the temporary buttresses L1-L3 are 820mm Φ tubular piles, with longitudinal and transverse steel pipe connections installed between the columns, forming a single, integrated structure. Temporary buttress L4 is supported by four tube columns, known as the four-column temporary buttress. Specifically, 820mm Φ tubular piles are used, with longitudinal and transverse steel pipe connections installed between the columns, forming a separate braking system. The structure of the temporary buttresses at the remaining main piers is similar to that of L4. The centers of the temporary piers correspond to the center lines of the main trusses. The locations of the temporary piers L5-L13 are at the center lines of the main nodes of the corresponding main trusses near the middle of the main pier span.

[0060] Due to the large reaction forces at the fulcrums, a robust distribution beam system was required at the top of the steel pipe column piers to evenly distribute the immense concentrated force to each column. The distribution beams were designed with a box-shaped cross-section. To adjust the node elevations during steel beam erection, jack positions were reserved under each girders on the piers. These jacks could be used to adjust the heights based on the calculated forces, and once adjusted, the pads were securely placed.

[0061] Specifically, the joints of the temporary pier columns are welded with a 45° groove, and each joint is reinforced by welding with 8 200×14×150mm stiffening plates. The pier top adopts a circular pier cap, and the pier cap is provided with a "well"-shaped stiffening plate, and a slot is set at the top of the column according to the size of the stiffening plate, so that the pier cap can be inserted into the column for welding. The pier top distribution beam adopts two forms of double H-shaped steel and steel box beam, which are selected according to the location of the temporary pier. The main beam material of the H-shaped steel beam is 2 HM588 steels, and vertical stiffening plates are set on the inner side of its cross section, and top and bottom panels are set on the upper and lower surfaces to form a box-shaped whole to increase its overall rigidity; the box-shaped distribution volume is composed of four steel plates welded and assembled, and vertical stiffening plates are set in its box to increase its overall rigidity.

[0062] In some embodiments, during the cantilever assembly process, the upper and lower chords of the two adjacent sections of the approach bridge are connected into one piece to meet the forward support of the full-slewing crane. After the erection is completed, the integral chords are cut and separated at the bridge location to complete the transformation of the steel truss from a continuous to a simply supported load system. Specifically, Figure 1 and Figure 17As shown, the upper chords and lower chords of the fourth and fifth joints (S14# pier) and the fifth and sixth joints (S16# pier) need to be connected into one piece to meet the needs of the 55t slewing crane to move forward and complete the cantilever assembly of the fifth and sixth joints. That is, the cantilever assembly of the fifth and sixth joints is completed by adopting the method of first continuous support and then simple support.

[0063] exist Figure 1 Among them, the S14# pier is equipped with a 800-type unitized multi-directional bridge expansion joint, with a spacing of 500mm between the steel beams on both sides. The S16# pier is equipped with a 240-type unitized multi-directional bridge expansion joint, with a spacing of 200mm between the steel beams on both sides. Considering the spacing and structural form of the rods on both sides, it is proposed to make the upper and lower chords on both sides of the expansion joint into integral rods. After the erection is completed, the integral chords will be cut, separated, polished, and painted at the bridge position to complete the transformation of the steel truss from a continuous to a simply supported force system. Specifically, Figure 17 As shown, the upper chords and lower chords of the fifth and sixth piers (S16# pier) are connected into one piece and then cut after the erection is completed.

[0064] In some embodiments, temporary piers for assembling steel beams are set at the nodes of the lower chords of the steel trusses, and the temporary piers are used to assist the semi-cantilever method for installation. When the steel trusses begin to be erected, all the pier top supports are first placed in place but not installed. When the steel beams are erected, the main chord nodes are all installed on the temporary supports on the pier tops. After all the steel beams are assembled, the longitudinal and transverse adjustment devices on the pier tops are used to accurately adjust the longitudinal and transverse directions of the bridge. Finally, the main beams are lifted by jacks and permanent supports are installed. When the steel trusses are erected to the position where the permanent supports are set on the pier tops, the assembly of the inter-section rods is completed first to make it a stable overall structure. The steel trusses are not assembled forward for the time being. After all the high-strength bolts of the assembled structure are finally set in place, the permanent supports are installed. When installing the permanent supports, the steel beams are lifted, and the lifting height is controlled at 2-3 cm to provide construction space for installing the permanent supports of the bridge. After the permanent supports are installed in place, the cantilever erection of the steel truss steel members is continued forward.

[0065] The steel trusses are assembled by cantilever, and only the inter-segment members and the railway bridge deck system bridge panels are assembled. After the members and the railway bridge deck system bridge panels are assembled, the highway bridge deck system bridge panels are installed in reverse using a full-revolving crane. When installing the precast slabs of the highway bridge deck system, the wet joints are weighted with equal weights. When the wet joints are subsequently poured with concrete, the pre-stressed counterweights are simultaneously unloaded.

[0066] After the inter-section hoisting is completed, the tightening order of high-strength bolts is as follows:

[0067] 1) First tighten the high-strength bolts between the lower chords and the upper chords. After the bolts between the upper chords are initially tightened, weld the butt welds between the top plates of the upper chords, and then finally tighten the high-strength bolts.

[0068] 2) Unscrew the high-strength bolts between the chord and the web;

[0069] 3) Tighten the high bolts between the lower chord and the lower railway bridge deck block. After the initial tightening, weld the weld between the lower chord and the lower bridge deck block, and then finally tighten the high-strength bolts.

[0070] 4) Tighten the high bolts between the upper chord and the upper beam, weld the butt weld between the upper chord and the beam top plate after the initial tightening, and then finally tighten the high-strength bolts;

[0071] 5) Tighten the high bolts between the upper chord and the boom, weld the butt weld between the upper chord and the boom top plate after the initial tightening, and then finally tighten the high-strength bolts;

[0072] 6) Tighten the high bolts between the small longitudinal beams of the lower deck blocks, weld the butt welds between the lower deck blocks after the initial tightening, and then finally tighten the high-strength bolts.

[0073] In an embodiment of the present invention, after trial assembly at Jiangsu Bridge Heavy Industry, the steel beams are shipped to the bridge site hoisting station. An 180t crawler crane is used to unload the shipped beams onto the hoisting station platform. At the unloading dock, the beams to be installed are pre-assembled and then loaded onto a beam transport flatbed truck using an 180t crawler crane. The beams are then transported to the lifting position via the main trestle for assembly. The crawler crane arrangement is as follows: a 180t crawler crane is deployed at the main pier S17# as a steel beam hoisting station. The steel beams are shipped from the Jiangsu Heavy Industry base to the bridge site hoisting station. An 180t crawler crane is used to lift the beam segments to be assembled onto the hoisting platform. After pre-assembly, the beams are transported to the lifting position via the trestle. A full-revolving crane on the upper chord of the steel truss is then used to lift the beams for installation. The location of the hoisting station platform takes into account the waterway depth and the draft of the transport vessel, ensuring smooth entry and exit of the transport vessel. A 180t crawler crane is arranged on the widened trestle on the right side of the main pier S12#-S13# to assemble the E10-E13 inter-section steel beams and two 55t fully rotary beam erection cranes.

[0074] like Figure 3 and Figure 4 As shown in the figure, the layout of the full-slewing crane assembly platform is as follows: After the construction of temporary piers L1-L4 is completed, the four intersegments E14-E10 are assembled using the main pier S12# and temporary piers L1-L4. The four intersegments are assembled in two stages, providing a platform for the assembly of the 55t full-slewing crane. During the first assembly of intersegments E10-E14 of temporary piers L1-L4, the assembled A13-A11 main truss intersegment upper chord serves as the assembly platform for the first 55t full-slewing crane. After the first 55t full-slewing crane is assembled, it is used to assemble the E14-E15 and A14-A15 intersegments. Once the assembled steel trusses form a complete framework, the first beam-erecting crane is moved forward to the A14-A15 upper chord, and the second 55t full-slewing crane is assembled on the A11-A12 upper chord.

[0075] The following describes in detail the overall steel beam erection scheme of the present invention in conjunction with specific construction steps:

[0076] 1) First, use the main pier S12# to assemble the single node E14 and its beam connection system. Limit marks must be made on the pier top to ensure that the first assembled lower chord member is in the correct position and axial direction;

[0077] 2) Use a 180t crawler crane to lift the single nodes E13, E14 and the lower chord to the temporary pier L1, and then connect the transverse connecting rods of the single node E13 to form a horizontal frame with the lower chords on the left and right sides. Figure 5 middle Figure 5 (a)

[0078] 3) The railway bridge deck between the single nodes E13 and E14 is then assembled. The paved railway bridge deck not only increases the overall stability of the assembled members on both the upstream and downstream sides, but also increases the weight of the assembled members, ensuring the safety of the subsequent cantilever assembly.

[0079] 4) Continue to use the 180t crawler crane to assemble the lower chords of the single nodes E12 and E13 on the temporary piers L1 and L2, and connect the transverse connecting rods of the single node E13, and then assemble the railway bridge deck between the single nodes E12 and E13. The process is as follows: Figure 5 middle Figure 5 (b)

[0080] 5) Next, install the diagonal bars between the single nodes E13, E14 and A14. The process is as follows: Figure 5 middle Figure 5 (c) and then install the diagonal bars between the single nodes E12, E13 and A13. Figure 5 middle Figure 5 (d)

[0081] 6) Then install the upper chord between A13 and A14, so that the assembled single node E12-E13 internode members form an overall frame of the facade. The process is as follows Figure 5 middle Figure 5 (e)

[0082] 7) Continue to hoist the lower chord members of the single nodes E11 and E12 and connect them with the assembled single nodes E12 and E13 to form a whole. The process is as follows Figure 6 middle Figure 6 (a); then hoist the transverse connecting rods of the single node E11 and the railway bridge deck between the single nodes E11 and E12;

[0083] 8) Then assemble the diagonal bars between the single nodes E12, E11 and A12. The process is as follows Figure 6 middle Figure 6 (b)

[0084] 9) Then assemble the upper chord between A12 and A13, so that the assembled rods and the assembled steel truss interspaces are connected as a whole. The process is as follows: Figure 6 middle Figure 6 (c)

[0085] 10) Use temporary piers L3 and L4 to install the lower chord between the single nodes E10 and E11. The process is as follows: Figure 7 middle Figure 7 (a)

[0086] 11) Install the transverse connecting rod at the single node E10 and the railway bridge deck panel between the single nodes E10 and E11;

[0087] 12) Then install the diagonal bars between the single nodes E11, E10 and A11. The process is as follows Figure 7 middle Figure 7 (b)

[0088] 13) Continue to install the upper chord between A11 and A12 to form an integral frame of the assembled cantilever structure. The process is as follows: Figure 7 middle Figure 7 (c)

[0089] 14) Using the 180t crawler crane on the steel truss upper chord at A12-A13, assemble the first 55t full-slewing crane, namely the aforementioned No. 1 full-slewing crane. Because the A13 and A14 sections are not closed to form a whole frame, the front outrigger position of the No. 1 full-slewing crane does not exceed the A13 node. The process is as follows Figure 8 middle Figure 8 (a)

[0090] 15) Use the assembled No. 1 full-slewing crane to assemble the single node A14. The process is as follows: Figure 8 middle Figure 8 (b)

[0091] 16) The No. 1 fully revolving crane moves to the upper chord of the steel truss beam on A13 and A14, first hoists the single node E15, and then hoists the lower chords at E14 and E15. The process is as follows: Figure 9 middle Figure 9 (a)

[0092] 17) Install the transverse connecting rod at the single node E15 and the railway bridge deck panel between E14 and E15;

[0093] 18) Assemble the diagonal bars between the single nodes E14, E15 and A15. The process is as follows: Figure 9 middle Figure 9 (b)

[0094] 19) Then install the upper chord between A14 and A15 to form an integral frame. The process is as follows: Figure 9 middle Figure 9 (c)

[0095] 20) As the length of the full-slewing crane is longer than the single steel beam inter-section, in order to ensure the assembly platform of the second full-slewing beam erection crane (the aforementioned No. 2 full-slewing crane), the No. 1 full-slewing crane is moved to the inter-section side of A14 and A15. The process is as follows: Figure 4 As shown;

[0096] 21) The 180t crawler crane assembles the second fully rotating crane on the upper chord members between the A11 and A12 sections. The two fully rotating cranes are installed in place to facilitate the subsequent cantilevering of the main bridge steel truss members in the long mileage side and the short mileage side. The process is as follows: Figure 4 shown.

[0097] During the assembly process, the members of each span were assembled synchronously and symmetrically along the left and right spans of the transverse bridge. After the members of the same transverse bridge section were assembled, the corresponding transverse bridge connecting members were installed. After the two fully-rotating cranes were assembled, the steel truss main beam components were erected symmetrically in the directions of greater and lesser mileage.

[0098] On the long mileage side, the overall construction plan for cantilever erection is: use a 55t fully revolving crane to cantilever erect steel trusses to temporary pier L5, continue to erect forward to main pier S11#, and continue to erect in sequence to temporary pier L6 → main pier S10# → temporary pier L7 → main pier S9# → temporary pier L8 → main pier S8# → temporary pier L9 → main pier S7#, until the erection of all steel trusses on the long mileage side of the fourth joint is completed.

[0099] The following is a detailed description of the long mileage side cantilever erection plan in combination with specific construction steps:

[0100] 1) First, use the cantilever of the No. 1 full-slewing crane to assemble the lower chord between the single nodes E15 and E16. The process is as follows: Figure 10 middle Figure 10 (a)

[0101] 2) Then, hoist the transverse connecting rod at the single node E16 and the railway bridge deck between E15 and E16;

[0102] 3) Then hoist the diagonal chords between the single nodes E15, E16 and A16. The process is as follows: Figure 10 middle Figure 10 (b)

[0103] 4) Continue to hoist the A15 node rod and the upper chord rod between A15 and A16 to form an integral frame. The process is as follows: Figure 10 middle Figure 10 (c)

[0104] 5) Move the 55t full-slewing crane on the Fuzhou side forward to the upper chord at A15 and A16. The process is as follows: Figure 11 middle Figure 11 As shown in (a), the lower chord between the single nodes E16 and E17 is then hoisted by cantilever. The process is as follows Figure 11 middle Figure 11 (b)

[0105] 6) Then, hoist the transverse connecting rods at the single node E17 and the railway bridge deck between the E16 and E17 intervals;

[0106] 7) Then hoist the diagonal braces between the single nodes E16, E17 and A17. The process is as follows: Figure 11 middle Figure 11 (c)

[0107] 8) Continue to hoist the upper chord between A16 and A17 to form an integral frame. The process is as follows: Figure 11 middle Figure 11 (d)

[0108] 9) Continue erecting the remaining main truss members in this sequence until reaching temporary pier L5. Continue cantilevering toward the greater mileage side to ensure the travel of the No. 1 fully revolving crane on the upper chord. Each span is assembled symmetrically across the bridge. After assembling the members in the same position across the bridge, install the connecting members at the corresponding nodes.

[0109] On the small mileage side, the overall construction plan for cantilever erection is: use the No. 2 full-rotating crane to cantilever erect steel trusses to the main pier S13#, and continue to erect them in sequence to the temporary pier L10 → main pier S14#, completing the erection of all steel trusses on the Changle side of the fourth joint, and continue to cantilever erect steel trusses to the small mileage side.

[0110] The following is a detailed description of the short-mileage side cantilever erection plan based on specific construction steps:

[0111] 1) First, hoist the lower chord between the single nodes E9 and E10. The process is as follows: Figure 12 middle Figure 12 (a)

[0112] 2) Then, the transverse connecting rod at the single node E9 and the railway bridge deck between the E9 and E10 intervals were hoisted;

[0113] 3) Then hoist the diagonal braces between the single nodes E10, E9 and A10. The process is as follows: Figure 12 middle Figure 12 (b)

[0114] 4) Continue to hoist the upper chord between A10 and A11 to form an integral frame. The process is as follows: Figure 12 middle Figure 12 (c)

[0115] 5) Move the No.2 full-slewing crane on the short-distance side forward to the upper chords of A10 and A11, and then cantilever the lower chords between the single nodes E8 and E9. The process is as follows: Figure 13 middle Figure 13 (a)

[0116] 6) Then, hoist the transverse connecting rod at the E8 node and the railway bridge deck between the E8 and E9 intervals;

[0117] 7) Continue to hoist the diagonal braces between E9, E8 and A9. The process is as follows: Figure 13 middle Figure 13 (b)

[0118] 8) Then hoist the upper chord between A9 and A10 to make the assembled E7 and E8 internodes into an integral frame. The process is as follows: Figure 13 middle Figure 13 (c)

[0119] 9) Erect the remaining main truss members sequentially to the main pier S13#, and continue to cantilever toward the lower mileage side to ensure the travel of the No. 2 fully revolving crane on the upper chord. Assemble the members of each interval symmetrically in the transverse direction of the bridge. After the members in the same position in the transverse direction are assembled, install the transverse connecting members.

[0120] 10) When the cantilever is erected to the main pier S14#, the fourth steel truss is erected. After the upper chord between A2 and A3 is erected, the lower chord between the single nodes E0 and E1 is hoisted. The process is as follows: Figure 14 middle Figure 14 (a)

[0121] 11) Next, hoist the transverse connecting rod at the single node E0 and the railway bridge deck between E0 and E1;

[0122] 12) Next, install the diagonal bars between E1, E0 and A1 in sequence. The process is as follows: Figure 14 middle Figure 14 (b)

[0123] 13) Continue to hoist the upper chord between A1 and A2 to form a stable overall structure. The process is as follows: Figure 14 middle Figure 14 (c)

[0124] 14) Then hoist the vertical rod between the single node E0 and A0. The process is as follows Figure 14 middle Figure 14 (d)

[0125] 15) Finally, hoist the upper chord between A0 and A1. The process is as follows: Figure 14 middle Figure 14 As shown in (e), the fourth steel truss main truss is now completed.

[0126] 16) During the span installation, a temporary connection device was used between the fourth and fifth spans to temporarily connect the two spans of steel beams together, allowing the No. 2 fully revolving crane to cantilever the fifth and sixth spans of steel trusses toward the shorter mileage side. The erection sequence was as follows: Using the temporary connection device, connect the fifth span assembly members to the fourth span members. The No. 2 fully revolving crane then cantilevered the steel trusses to temporary support pier L11. The cantilevered steel trusses were then cantilevered to main pier S15#, and then to temporary support pier L12, then main pier S16#, completing the erection of all the steel trusses for the fifth span. Similarly, the sixth to eighth spans of steel beams were cantilevered using the same method and sequence.

[0127] The fourth and fifth steel trusses are connected at Pier S14#. For ease of description, the fourth steel truss member number is marked with 4, and the fifth steel truss member number is marked with 5. The specific steps are as follows:

[0128] 1) Assemble the 5E0 member with 5E0 and 5A0 into a whole member, then hoist it into place using the No. 2 full-slewing crane, and use the temporary connector of the fourth and fifth steel truss bridges to connect it with the fourth steel truss beam that has been erected to form a whole. The process is as follows: Figure 15 middle Figure 15 (a)

[0129] 2) Hoist the horizontal connecting rod at 5E0;

[0130] 3) Use the No. 2 full-slewing crane to hoist the lower chord between 5E0 and 5E1. The process is as follows: Figure 15 middle Figure 15 (b)

[0131] 4) Then, hoist the transverse connecting rod at the 5E1 node and the railway bridge deck panels between the 5E0 and 5E1 sections;

[0132] 5) Continue to install the diagonal brace between 5E0, 5E1 and 5A1. The process is as follows: Figure 15 middle Figure 15 (c)

[0133] 6) Hoist the upper chord between 5A0 and 5A1 to form a stable overall frame. Figure 15 middle Figure 15 (d)

[0134] 7) Move the No.2 full-slewing crane to the 4A1 and 5A1 intersections. The process is as follows: Figure 16 middle Figure 16 (a)

[0135] 8) Continue to hoist the lower chord between 5E1 and 5E2. The process is as follows Figure 16 middle Figure 16 (b)

[0136] 9) Hoist the transverse connecting rod at the 5E2 node and the railway bridge deck panels between the 5E1 and 5E2 sections;

[0137] 10) Then hoist the diagonal braces between 5E1, 5E2 and 5A2. The process is as follows: Figure 16 middle Figure 16 (c)

[0138] 11) Then hoist the upper chord between 5A1 and 5A2 to form an integral frame. The process is as follows: Figure 16 middle Figure 16 (d)

[0139] 12) Following this hoisting sequence, cantilever the fifth steel truss toward the Changle side to temporary pier L10. Continue assembly toward the short-distance mileage side to main pier S16#, completing the fifth steel truss assembly. Continue erecting the sixth steel truss toward the short-distance mileage side in this sequence. The members of each span are assembled symmetrically across the bridge. After assembling the members in the same position across the bridge, install the connecting members.

[0140] After the steel truss members were assembled, the pier-top transverse positioning device was used to precisely adjust the transverse position of the steel beams to meet the design alignment requirements. Once all the steel beams were assembled and transversely adjusted, the two fully revolving cranes reversed and began erecting the highway bridge deck panels on the upper chords of the steel trusses. Both cranes reversed to main pier S12#. When assembling the precast slabs, care was taken to balance the wet joints. When the cranes reversed to main pier S12#, they were removed using an 180t crawler crane hoisting station. First, the No. 1 fully revolving crane on the long-distance side was removed. Once the No. 2 fully revolving crane on the short-distance side reversed to main pier S12#, it was used to assemble the remaining highway bridge deck panels. The 180t crawler crane then removed the remaining panels and assembled the remaining highway bridge deck panels, completing the assembly of the steel truss bridge. After the steel truss components are assembled, the concrete slabs of the fourth section, except for the five precast concrete slabs at the top of piers S08#-S13#, are not bonded to the main beams. The concrete slabs of the remaining sections are bonded to the main beams and wet joint concrete is poured. In the fifth section, except for the five precast concrete slabs at the top of pier S15#, wet joint concrete is poured. The entire sixth section is poured with wet joint concrete. Once the strength and elastic modulus of the newly poured concrete reach 100% and the age is greater than 7 days, the main trusses of piers S08# and S15# are lifted to their respective inverted heights, and wet joint concrete is poured for the five sections thereon. Once the strength and elastic modulus of the newly poured concrete reach 100% and the age is greater than 7 days, the steel beams are simultaneously lowered to the design elevation. The aforementioned lifting, concrete construction and curing, and beam lowering steps are repeated to complete the wet joint concrete construction of piers S09#-S13#. When the steel truss beam is erected to the location of the permanent support at the top of the pier, first complete the assembly of the intersegmental members as quickly as possible to form a stable integral structure. Do not continue assembling the steel truss until all high-strength bolts in the assembled structure have finally set in place before installing the permanent support. When installing the permanent support, the steel beam needs to be jacked up to a height of 2-3 cm to provide space for the permanent bridge support. Once the permanent support is in place, continue cantilevering the steel truss beam.

[0141] The basic principles, main features and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only illustrate the principles of the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements fall within the scope of the present invention as claimed, and the scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for erecting a multi-span continuous steel truss bridge segment for road and rail co-construction, characterized in that: Including steps: S1. Arrange a trestle. Set up a trestle on the downstream side of the bridge line to provide a construction platform and material transportation channel for water operations; S2. Arrange temporary buttresses: Set up four temporary buttresses between two adjacent main piers on one side of the approach section, and set up one temporary buttress between the remaining main piers, with the center of each temporary buttress corresponding to the centerline of the main girder; S3. Arrange crawler cranes. Deploy crawler crane No. 1 on the widened area of ​​the trestle to the right of the two adjacent main piers in step S2 to assemble the intersegmental steel beams and two full-slewing cranes on the four temporary piers. Deploy crawler crane No. 2 on the side with the longest mileage as a steel beam lifting station, and set up a lifting station platform there to facilitate the entry and exit of transport ships. S4. Arrange a platform for assembling a fully revolving crane. Use the four temporary buttresses described in step S2 and the main piers located at both ends of the four temporary buttresses, one close to the shorter mileage side, as support foundations. Use a crawler crane No. 1 installed on the trestle to assemble four bays, which serve as an assembly platform for the fully revolving crane. S5. Arrange the full-revolving cranes and synchronously erect the steel truss bridge segments in two directions. On the side of the four segments close to the short mileage side in step S4, use the segment upper chord as the assembly platform for the No. 1 full-revolving crane. After the No. 1 full-revolving crane is assembled, the steel truss bridge segment is assembled and erected by cantilevering toward the short mileage side and moving forward toward the short mileage side. Then, on the side of the four segments close to the long mileage side, use the segment upper chord as the assembly platform for the No. 2 full-revolving crane. Use the segment upper chord as the assembly platform for the No. 2 full-revolving crane to complete the assembly of the No. 2 full-revolving crane, and use the No. 2 full-revolving crane to cantilever and assemble the steel truss bridge segment toward the long mileage side. During the cantilever assembly process, the upper and lower chords between the two adjacent sections of the approach bridge are connected into one piece to meet the forward support of the full-slewing crane. After the erection is completed, the integral chords are cut and separated at the bridge location to complete the transformation of the steel truss from a continuous to a simply supported load system. S6. After the entire bridge is erected, the upper deck concrete precast slabs are erected; S7. After the concrete is set, pour the wet joints starting from the middle span, one span at a time. First, pour the wet joints at the middle of each span, then pour the wet joints at the piers. When pouring the wet joints at the piers, lift the steel beam to a certain height. Among them, the steel trusses are assembled by cantilever, and only the inter-segmental members and the railway bridge deck system bridge panels are assembled. After the members and the railway bridge deck system bridge panels are assembled, the highway bridge deck system bridge panels are installed in reverse using a full-rotating crane. When installing the precast slabs of the highway bridge deck system, the wet joints are weighted with equal weights. When the wet joints are subsequently poured with concrete, the pre-stressed counterweights are unloaded simultaneously.

2. The method for erecting a multi-span continuous steel truss bridge segment for road and rail co-construction according to claim 1 is characterized in that: The trestle adopts a steel pipe column foundation plus Bailey beam structure, double-jointed 56-type steel is used as the pile top distribution beam on the pile cap, the Bailey beam is used as the main beam of the trestle, 25# I-beam is set on the Bailey beam as the transverse bridge distribution beam, and the bridge deck uses 12.6# I-beam and 10mm thick steel plate as the longitudinal bridge distribution beam and bridge deck respectively.

3. The method for erecting a multi-span continuous steel truss bridge segment for road and rail construction according to claim 1 or 2, characterized in that: The trestle is constructed using the fishing method, and brake piers are arranged according to the line shape of the main bridge. A brake section is set every 3-5 spans in the curved section so that the trestle matches the line shape of the main bridge, and a brake pier is set every 6 spans in the straight section.

4. The method for erecting a multi-span continuous steel truss bridge segment for road and rail co-construction according to claim 1 is characterized in that: A temporary support and fine-tuning device area are set on the top of the temporary pier, and a manual fine-tuning operation area is reserved in the middle of the top. The space between the columns is connected by trusses, and vertical jacks and horizontal limit jacks are arranged on the pier top and the temporary pier for use in adjusting the position and elevation of the steel truss.

5. The method for erecting a multi-span continuous steel truss bridge segment for road and rail co-construction according to claim 1 is characterized in that: In step S2, the four temporary piers arranged between two adjacent main piers of the approach bridge section on one side include three double-column temporary piers close to the short mileage side and four-column temporary piers close to the long mileage side. One temporary pier between the remaining main piers is a four-column temporary pier. The double-column temporary pier is supported by double-tube columns, and longitudinal and transverse steel pipe connection systems are arranged between the columns so that the three double-column temporary piers form an integral structure. The four-column temporary pier is supported by four-tube columns.

6. The method for erecting a multi-span continuous steel truss bridge segment for road and rail co-construction according to claim 1, characterized in that: Temporary piers for assembling steel beams are set at the nodes of the lower chords of the steel trusses, and the temporary piers are used to assist the semi-cantilever method for installation. When the steel trusses begin to be erected, all the pier top supports are first placed in place but not installed. When the steel beams are erected, the main chord nodes are all installed on the temporary supports on the pier tops. After all the steel beams are assembled, the longitudinal and transverse adjustment devices on the pier tops are used to perform precise longitudinal and transverse adjustments. Finally, the main beams are lifted with jacks and permanent supports are installed.

7. The method for erecting a multi-span continuous steel truss bridge segment for road and rail co-construction according to claim 1, characterized in that: When the steel truss is erected to the position where the permanent support is set on the pier top, complete the assembly of the inter-section rods first to make it a stable overall structure, and do not continue to assemble the steel truss. After all the high-strength bolts of the assembled structure are finally set in place, install the permanent support. When installing the permanent support, jack up the steel beam, and the jacking height is controlled at 2-3cm to provide construction space for installing the permanent support of the bridge. After the permanent support is installed in place, continue to cantilever the steel truss steel parts forward.

8. The method for erecting a multi-span continuous steel truss bridge segment for road and rail co-construction according to claim 1, characterized in that: After the inter-section hoisting is completed, the tightening order of high-strength bolts is as follows: 1) First tighten the high-strength bolts between the lower chords and the upper chords. After the bolts between the upper chords are initially tightened, weld the butt welds between the top plates of the upper chords, and then finally tighten the high-strength bolts. 2) Unscrew the high-strength bolts between the chord and the web; 3) Tighten the high bolts between the lower chord and the lower railway bridge deck block. After the initial tightening, weld the weld between the lower chord and the lower bridge deck block first, and then tighten the high-strength bolts; 4) Tighten the high bolts between the upper chord and the upper beam, weld the butt weld between the upper chord and the beam top plate after the initial tightening, and then finally tighten the high-strength bolts; 5) Tighten the high bolts between the upper chord and the cantilever arm. After the initial tightening, weld the butt weld between the upper chord and the cantilever arm top plate, and then finally tighten the high-strength bolts. 6) Tighten the high bolts between the small longitudinal beams of the lower deck blocks, weld the butt welds between the lower deck blocks after the initial tightening, and then finally tighten the high-strength bolts.

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