Construction system and method of variable-section steel truss beam bridge

Abstract

The invention provides a construction system and a construction method for a variable-section steel truss beam bridge, and relates to the technical field of bridge engineering. A gantry crane construction system, a side pier beam adjustment system, a main pier beam adjustment system, a cantilever end temporary pier beam adjustment system, and a steel truss beam assembly temporary support system are provided; by providing a steel truss beam assembly temporary support system, a front guide beam is welded before installing the front section of a gantry crane triangular track beam, and a cross-river section is constructed through a reverse wheel box moving device, so that the track beam construction speed is fast and the construction process is safe and reliable; by providing a main pier and a cantilever end temporary pier beam adjustment system, the steel truss beam is adjusted in the transverse, longitudinal and vertical directions to ensure that the bridge line does not have a large deviation; by providing a steel truss beam assembly temporary support and a river pier anti-collision pier system, the steel truss beam splicing is stable, the construction speed is fast, and the effect is good.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge engineering, and in particular to a construction system and a construction method for a variable-section steel truss beam bridge. Background Art

[0002] With the rapid development of social economy, the dense intersection of highway network and railway network, the number of highway-railway and railway-railway cross-line bridges has increased, which has further promoted the continuous development of cross-line construction technology. The construction level of bridge engineering is a true display of the country's comprehensive strength and scientific and technological strength, and is the country's new business card. Steel truss beam bridges are often a hybrid structure of bolted and welded large integral node chords and integral steel bridge decks. The rod hole group is large and numerous, requiring both accurate hole positions and guaranteed linear shapes, and trial assembly of various parts of the steel truss beams. Therefore, the workload of manufacturing and installation is large and the precision requirements are high. It is often restricted by engineering conditions. The installation of gantry crane track beams is difficult, and the installation accuracy of underground piers and the level of closing construction technology are required to be high. There are high requirements for the strength, stiffness and stability of the overall bridge steel truss assembly.

[0003] In view of this, in view of the shortcomings of previous steel truss beam bridge construction, such as slow track beam construction speed, unstable support system and easy deviation of bridge linearity, a new variable-section steel truss beam bridge construction system and construction method is urgently needed to improve construction efficiency, improve construction quality and ensure safe and reliable construction quality. Summary of the invention

[0004] The purpose of the present invention is to provide a variable-section steel truss beam bridge construction system and construction method, aiming to solve the technical problems of slow track beam construction speed, unstable support system and easy deviation of bridge linearity in the existing steel truss beam bridge construction.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0006] The construction system of the variable-section steel truss girder bridge includes the gantry crane construction system, the side pier beam adjustment system, the main pier beam adjustment system, the cantilever end temporary pier beam adjustment system and the steel truss girder assembly temporary support system;

[0007] The gantry crane construction system comprises a track beam, a triangular track beam, a triangular front guide beam, a front guide beam anti-supporting wheel box moving device, an I-rail and a gantry crane; the triangular front guide beam is fixedly arranged at the front end of the triangular track beam; the I-rail is fixed at the top of the triangular track beam, so as to make the top of the I-rail and the upper surface of the track beam at the overlapped part be on the same horizontal line; the front guide beam anti-supporting wheel box moving device is positioned under the triangular track beam; the block of the gantry crane is arranged on the main bridge, and moves on the track beam through the driving mechanism;

[0008] The side pier beam adjustment system includes a beam adjustment mechanism 1; the beam adjustment mechanism 1 is positioned and installed between the side pier and the beam body of the main bridge;

[0009] The main pier beam adjustment system comprises a beam adjustment mechanism 2, embedded parts and a construction platform; the beam adjustment mechanism 2 is positioned and installed between the main pier and the beam body of the main bridge; the embedded parts are embedded in the circumferential outer side of the main pier; the construction platforms are respectively arranged on both sides of the width direction of the main pier and are fixedly connected to the embedded parts;

[0010] The cantilever end temporary pier beam adjustment system includes a beam adjustment mechanism three; the beam adjustment mechanism three is arranged between the triangular front guide beam and the temporary pier;

[0011] The temporary support system for assembling steel trusses includes a support, a support foundation and a support pipe; the support is fixed to the ground through the support foundation to support the beam body; the support pipe is installed on the top of the support to support the bridge end.

[0012] As a further improvement of the present invention, a river pier anti-collision system is also provided; the river pier anti-collision system includes steel sheet piles and steel pipe supports; the steel sheet piles are driven into the soil on the water side of the temporary pier, and steel pipe supports are arranged at the corners on both sides of the steel sheet piles to achieve reinforcement and fixed support for the steel sheet piles.

[0013] As a further improvement of the present invention, the main bridge includes side piers, main piers, auxiliary piers, a beam body and temporary piers; the side piers, main piers and auxiliary piers are all positioned under the beam body; the main piers and auxiliary piers are arranged on both sides of the beam body in the width direction.

[0014] As a further improvement of the present invention, a support frame, a column and a step platform are also provided; one section of the support frame is welded to the lower part of the construction platform, and one section is fixed on the main pier, for supporting the construction platform; the column is installed between the main pier and the auxiliary pier, and a support frame is arranged in the middle for reinforcement; the step platform is erected on the column, and both ends are fixed on the embedded parts of the main pier and the auxiliary pier.

[0015] As a further improvement of the present invention, a temporary support system for assembling steel trusses is simultaneously constructed on the side piers, the main piers and the temporary piers.

[0016] As a further improvement of the present invention, the anti-roller box of the front guide beam moving device is installed on the temporary pier and moves along the length direction of the track beam.

[0017] As a further improvement of the present invention, the beam adjusting mechanism 1, the beam adjusting mechanism 2 and the beam adjusting mechanism 3 all include a top pad, a fixing frame, a vertical jack, a positioning clamp, a lower pad, a polytetrafluoroethylene plate, a horizontal jack and a reaction seat;

[0018] The top pad, fixing frame, vertical jack, positioning card plate and lower pad are positioned and connected in sequence from top to bottom; the vertical jack is positioned in the positioning card plate; the two horizontal jacks are respectively arranged corresponding to the adjacent two sides of the positioning card plate through reaction seats.

[0019] A variable-section steel truss beam bridge and a construction method thereof, comprising the following steps:

[0020] S1. Construction preparation: According to the construction requirements, the construction machinery and tools are inspected before construction to ensure their normal use; at the same time, the materials required for construction are prepared, technical explanations are given to relevant technical personnel, and construction machinery is gradually brought into the site;

[0021] S2. Support construction: Install support foundations on the ground line and on the side piers and main piers according to the layout position, and construct temporary piers and their upper supports. Install an anti-collision system on the water side of the temporary piers, drive steel sheet piles into the soil, and install steel pipe supports to reinforce them. Install support pipes at the bridge end supports, and install track beams on the top of the supports;

[0022] S3, gantry crane track construction: Use the truck crane to install the track beam and triangular track beam, fix the triangular front guide beam at the front end of the triangular track beam across the river, install the I-rail on the top of the triangular track beam, install the anti-support wheel box at the bottom of the triangular track beam, and move it to the designated position to contact the track beams at both ends to form a whole;

[0023] S4. Lifting, transportation and assembly of steel trusses: Use floating boats to transport steel trusses in the river channel. After the floating boats transport the rods to the middle of the river, use gantry cranes to lift and transport them. Assemble the steel trusses according to the final design line shape. Use gantry cranes to install steel trusses symmetrically from the side spans on both sides to the middle of the span. Use large gantry cranes to lift and complete the installation of all steel trusses at both ends of the bridge. When the steel trusses are installed at the main pier position, adjust and position the steel trusses once with the main pier and the side pier as reference points.

[0024] S5. Remove the supporting pipes at both ends of the bridge to complete the emptying: continue to assemble the steel trusses until the final closing section is reached. After the two ends of the bridge are assembled, use jacks to remove the supporting pipes at both ends of the bridge, and the steel trusses at both ends are empty and freed from constraints.

[0025] S6. Assemble the beam adjustment system: place the vertical jack in the positioning card plate, the lower pad is placed at the bottom of the positioning card plate, the lower part of the vertical jack, the positioning card plate fixes the vertical jack, the polytetrafluoroethylene plate is placed under the positioning card plate, the top pad is welded and fixed to the top of the vertical jack through the lower fixing frame, one end of the horizontal jack is fixed on the reaction seat, and is placed on the adjacent two sides of the positioning card plate, which can be adjusted horizontally;

[0026] S7. Use the beam adjustment system to adjust the main pier: embedded parts are embedded around the main pier, one end of the construction platform is connected to the embedded parts and fixed on both sides of the main pier, one section of the support frame is welded to the lower part of the construction platform, and one section is fixed on the main pier to support the construction platform. The second beam adjustment mechanism is installed on the main pier, and a column is installed between the main pier and the auxiliary pier. A support frame is set in the middle for reinforcement. A step platform is set on the column, and both ends are installed and fixed on the embedded parts of the main pier and the auxiliary pier;

[0027] S8. Construction of the beam adjustment system of the temporary pier at the cantilever end: The beam adjustment mechanism 3 is installed on the temporary pier, and the anti-support wheel box can move on the track beam of the temporary pier;

[0028] S9. Dismantle the gantry crane track beam and brackets: adjust the linearity and use the truck crane to dismantle the gantry crane, track beams and brackets. The construction of the entire bridge is completed and enters the system conversion.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] This application sets up a temporary support system for assembling steel trusses, welds the leading guide beam before installing the front section of the gantry crane triangular track beam, and constructs the river-crossing section through the anti-support wheel box moving device. The track beam construction speed is fast and the construction process is safe and reliable. By setting up a temporary pier adjustment system for the main pier and the cantilever end, the steel trusses are adjusted in the horizontal, longitudinal and vertical directions to ensure that the bridge line does not have a large deviation. By setting up temporary supports for assembling steel trusses and a collision-proof pier system for the pier in the river, the steel trusses are stably spliced, the construction speed is fast, and the effect is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. It is obvious that the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 This is a schematic diagram of the overall construction structure of the present invention.

[0033] Figure 2 This is the side view of the main pier beam adjustment system

[0034] Figure 3 This is the front view of the main pier beam adjustment system

[0035] Figure 4 This is the front view of the temporary pier beam adjustment system

[0036] Figure 5 This is the front view of the beam adjustment system

[0037] Figure 6Top view of the beam adjustment system

[0038] Figure 7 This is the schematic diagram of the installation and connection structure of the anti-support wheel box

[0039] Figure 8 This is a schematic diagram of the crash barrier system structure.

[0040] Fig. 9 It is a schematic diagram of the horizontal structure of the present invention;

[0041] Fig.10 It is a schematic diagram of the structure of the track beam and the triangular track beam of the present invention;

[0042] Fig.11 It is a schematic diagram of the overall construction structure of the present invention;

[0043] Fig.12 This is a final schematic diagram of the bridge body of the present invention;

[0044] Description of the numbers in the figure:

[0045] 1. Gantry crane construction system; 11. Track beam; 12. Triangular track beam; 13. Triangular front guide beam; 14. Front guide beam anti-roller box moving device; 141. Anti-roller box; 15. I-beam; 16. Gantry crane; 2. Side pier beam adjustment system; 21. Beam adjustment mechanism 1; 201. Top pad; 202. Fixed frame; 203. Vertical jack; 204. Positioning card; 205. Lower pad; 206. Polytetrafluoroethylene plate; 207. Horizontal jack; 208. Reaction seat; 3. Main pier beam adjustment system; 31. Beam adjustment mechanism 2; 3 2. Embedded parts; 33. Construction platform; 34. Support frame; 35. Column; 36. Step platform; 4. Temporary pier beam adjustment system for cantilever end; 41. Beam adjustment mechanism three; 5. Temporary support system for steel truss assembly; 51. Support; 52. Support foundation; 53. Support pipe; 6. Anti-collision system for piers in the river; 61 steel sheet piles, 62. Steel pipe support; 7. Main bridge; 71. Side pier; 72. Main pier; 73. Auxiliary pier; 74. Beam body; 75. Temporary pier; 8. River surface; 9. Ground line; 10. Steel truss; 101. Closing section; 20. Floating boat. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] Combined with Figures 1 to 12The present invention provides a construction system and a construction method for a variable-section steel truss beam bridge, aiming to solve the technical problems of slow track beam construction speed, unstable support system and easy deviation of bridge linearity in the existing steel truss beam bridge construction.

[0048] Specifically, the construction system of the variable-section steel truss beam bridge includes a gantry crane construction system 1, a side pier beam adjustment system 2, a main pier beam adjustment system 3, a cantilever end temporary pier beam adjustment system 4 and a steel truss beam assembly temporary support system 5;

[0049] The gantry crane construction system 1 comprises a track beam 11, a triangular track beam 12, a triangular front guide beam 13, a front guide beam anti-roller box moving device 14, an I-rail 15 and a gantry crane 16; the triangular front guide beam 13 is fixedly arranged at the front end of the triangular track beam 12; the I-rail 15 is fixed at the top of the triangular track beam 12, so as to make the top of the I-rail 15 and the upper surface of the track beam 7 at the overlapped part be on the same horizontal line; the front guide beam anti-roller box moving device 14 is positioned under the triangular track beam 12; the block of the gantry crane 16 is arranged on the main bridge 7, and moves on the track beam 7 through a driving mechanism;

[0050] The side pier beam adjustment system 2 includes a beam adjustment mechanism 21; the beam adjustment mechanism 21 is positioned and installed between the side pier 71 and the beam body 74 of the main bridge 7;

[0051] The main pier beam adjustment system 3 includes a beam adjustment mechanism 31, an embedded part 32 and a construction platform 33; the beam adjustment mechanism 31 is positioned and installed between the main pier 72 and the beam body 74 of the main bridge 7; the embedded part 32 is embedded in the circumferential outer side of the main pier 72; the construction platform 33 is respectively arranged on both sides of the main pier 72 in the width direction and is fixedly connected to the embedded part 32;

[0052] The cantilevered temporary pier beam adjustment system 4 includes a beam adjustment mechanism 3 41; the beam adjustment mechanism 3 41 is arranged between the triangular front guide beam 13 and the temporary pier 75;

[0053] The temporary support system 5 for assembling steel trusses includes a support 51, a support foundation 52 and a support pipe 53; the support 51 is fixed to the ground through the support foundation 52 to support the beam body 74; the support pipe 53 is installed on the top of the support 51 to support the bridge end.

[0054] Furthermore, a river pier anti-collision system 6 is provided; the river pier anti-collision system 6 includes steel sheet piles 61 and steel pipe supports 62; the steel sheet piles 61 are driven into the soil on the water side of the temporary pier 75, and steel pipe supports 62 are provided at the corners on both sides of the steel sheet piles 61, for achieving reinforcement and fixed support for the steel sheet piles 61.

[0055] Furthermore, the main bridge 7 includes side piers 71, main piers 72, auxiliary piers 73, a beam body 74 and temporary piers 75; the side piers 71, main piers 72 and auxiliary piers 73 are all positioned under the beam body 74; the main piers 72 and auxiliary piers 73 are arranged on both sides of the beam body 74 in the width direction; the variable-section steel truss beam bridge of the present application spans the river surface 8, and two temporary piers are located on both sides of the river.

[0056] Furthermore, a support frame 34 , a column 35 and a step platform 36 are provided; one section of the support frame 34 is welded to the lower part of the construction platform 33 , and one section is fixed to the main pier 72 , for supporting the construction platform 33 .

[0057] Furthermore, the column 35 is installed between the main pier 72 and the auxiliary pier 73, and a support frame 34 is arranged in the middle for reinforcement.

[0058] Furthermore, the step platform 36 is erected on the column 35, and both ends are fixed on the embedded parts 32 of the main pier 72 and the auxiliary pier 73, so as to facilitate the personnel to operate and construct thereon.

[0059] Furthermore, a temporary support system 5 for assembling steel trusses is simultaneously constructed on the side pier 71, the main pier 72 and the temporary pier 75, so as to facilitate the installation of the platform and the gantry crane track.

[0060] Furthermore, the anti-roller box 141 of the front guide beam anti-roller box moving device 14 is installed on the temporary pier 75 and moves along the length direction of the track beam 11.

[0061] Further, the beam adjusting mechanism 1 21, the beam adjusting mechanism 2 31 and the beam adjusting mechanism 3 41 all include a top pad 201, a fixing frame 202, a vertical jack 203, a positioning clamping plate 204, a lower pad 205, a polytetrafluoroethylene plate 206, a horizontal jack 207 and a reaction seat 208;

[0062] The top pad 201, the fixing frame 202, the vertical jack 203, the positioning card plate 204 and the lower pad 205 are positioned and connected in sequence from top to bottom; the vertical jack 203 is positioned in the positioning card plate 204; the two horizontal jacks 207 are respectively arranged corresponding to the adjacent two side edges of the positioning card plate 204 through the reaction seats 208.

[0063] Preferably, the lower pad 205 is fixed to the bottom of the positioning card plate 204, the vertical jack 203 is placed on the lower pad 205 in the positioning card plate 204, the positioning card plate 204 fixes and positions it, the polytetrafluoroethylene plate 206 is placed under the positioning card plate 204, the top pad 201 is fixed to the top of the vertical jack 203 through the lower fixing frame 202, one end of the horizontal jack 207 is fixed on the reaction seat 208, and is placed on two adjacent sides of the positioning card plate 204.

[0064] A variable-section steel truss beam bridge and a construction method thereof, comprising the following steps:

[0065] S1. Construction preparation: According to the construction requirements, the construction machinery and tools are inspected before construction to ensure their normal use; at the same time, the materials required for construction are prepared, technical explanations are given to relevant technical personnel, and construction machinery is gradually brought into the site;

[0066] S2, construction of support 51: install support foundation 52 on ground line 9 and side pier 71 and main pier 72 according to the layout position, and construct temporary pier 75 and its upper support 51, install anti-collision system on the water side of temporary pier 75, drive steel sheet pile 61 into the soil, and install steel pipe support 62 to reinforce it, install support pipe 53 at the bridge end support 51, and install track beam on the top of support 51;

[0067] S3, gantry crane track construction: Use a truck crane to install the track beam 11 and the triangular track beam 12, fix the triangular front guide beam 13 at the front end of the triangular track beam 12 across the river, install the I-rail 15 on the top of the triangular track beam 12, and install the anti-supporting wheel box 43 at the bottom of the triangular track beam 12, and move it to the designated position to contact the track beams 11 at both ends to form a whole;

[0068] S4, hoisting, transporting and assembling the steel trusses: transport the steel trusses 10 on the river surface 8 by using the floating boat 20. After the floating boat 20 transports the rods to the middle of the river, it is hoisted and transported by using the gantry crane. The steel trusses 10 are assembled according to the final design line shape. The steel trusses 10 are installed by using the gantry crane and assembled symmetrically from the side spans on both sides to the middle of the span. The steel trusses 10 at both ends of the bridge are hoisted by using the large gantry crane. When the steel trusses 10 are installed at the main pier 72, the steel trusses are adjusted and positioned once with the main pier 72 and the side pier 71 as reference points.

[0069] S5. Remove the supporting pipes at both ends of the bridge to complete the emptying: continue to assemble the steel trusses 10, and stop assembling at the final closing section 101. After the two ends of the bridge are assembled, use jacks to remove the supporting pipes 53 at both ends of the bridge, and the steel trusses at both ends are completely empty and freed from constraints;

[0070] S6. Assemble the beam adjustment system: place the vertical jack 203 in the positioning card plate 204, the lower pad 205 is placed at the bottom of the positioning card plate 204, the lower part of the vertical jack 203, the positioning card plate 204 fixes the vertical jack 203, the polytetrafluoroethylene plate 206 is placed under the positioning card plate 204, the top pad 201 is welded and fixed to the top of the vertical jack 203 through the lower fixing frame 202, one end of the horizontal jack 207 is fixed on the reaction seat 208, and is placed on the adjacent two sides of the positioning card plate 204, which can be adjusted horizontally;

[0071] S7. Use the beam adjustment system to adjust the main pier: the embedded parts 32 are embedded around the main pier 72, one end of the construction platform 33 is connected to the embedded parts 32 and fixed on both sides of the main pier 72, one section of the support frame 34 is welded to the lower part of the construction platform 33, and one section is fixed on the main pier 72 to support the construction platform 33, and the beam adjustment mechanism 31 is installed on the main pier 72, and the column 35 is installed between the main pier 72 and the auxiliary pier 73, and the support frame 34 is arranged in the middle for reinforcement, and a step platform 36 is set on the column 35, and both ends are fixed on the embedded parts 32 of the main pier 72 and the auxiliary pier 73, so that personnel can operate and construct on it;

[0072] S8, construction of the beam adjustment system of the temporary pier at the cantilever end: the beam adjustment mechanism 3 41 is installed on the temporary pier 75, and the anti-support wheel box 43 can move on the track beam 11 of the temporary pier 75;

[0073] S9, dismantling the gantry crane track beam 11 and the frame: adjust the linearity, use the truck crane to dismantle the gantry crane, track beam 11 and the bracket 51, the construction of the whole bridge is completed, and enter the system conversion.

[0074] The present application sets up a temporary support system 5 for assembling steel trusses, welds a leading beam before installing the front section of the gantry crane triangular track beam 12, and constructs the river-crossing section through a moving device for an anti-supporting wheel box. The track beam 11 is constructed at a fast speed, and the construction process is safe and reliable. The main pier 72 and the temporary pier beam adjustment system 4 at the cantilever end are set up to adjust the steel trusses in the transverse, longitudinal and vertical directions to ensure that the bridge line does not have a large deviation. The temporary support 51 for assembling steel trusses and the anti-collision pier system for the river pier are set up to ensure that the steel trusses are stably spliced, the construction speed is fast, and the effect is good.

[0075] The process of this application is simple to operate, the construction efficiency and precision are improved, the high-altitude operation time is reduced, and no special equipment is required; less equipment and personnel are required, the labor intensity is low, and the site occupancy is small; the project cost is reduced; this method has achieved good results in the construction of the engineering example bridge project, and has wide promotion and application value under similar conditions, and the economic and social benefits are very obvious.

[0076] It should be noted that some parts not described in detail in the present invention belong to the well-known technology in the art, or can be directly purchased from the market, and those skilled in the art can obtain them without creative work. The specific connection method is extremely widely used in this art or in daily life, and will not be described in detail here.

[0077] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0078] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0079] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0080] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0081] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0082] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A construction method for a variable-section steel truss beam bridge construction system, the construction system comprising a gantry crane construction system, a side pier beam adjustment system, a main pier beam adjustment system, a cantilever end temporary pier beam adjustment system, and a steel truss beam assembly temporary support system; The gantry crane construction system comprises a track beam, a triangular track beam, a triangular front guide beam, a front guide beam anti-supporting wheel box moving device, an I-rail and a gantry crane; the triangular front guide beam is fixedly arranged at the front end of the triangular track beam; the I-rail is fixed at the top of the triangular track beam, so as to make the top of the I-rail and the upper surface of the track beam at the overlapped part be on the same horizontal line; the front guide beam anti-supporting wheel box moving device is positioned under the triangular track beam; the gantry crane is arranged on the main bridge and moves on the track beam through a driving mechanism; The side pier beam adjustment system includes a beam adjustment mechanism 1; the beam adjustment mechanism 1 is positioned and installed between the side pier and the beam body of the main bridge; The main pier beam adjustment system comprises a beam adjustment mechanism 2, embedded parts and a construction platform; the beam adjustment mechanism 2 is positioned and installed between the main pier and the beam body of the main bridge; the embedded parts are embedded in the circumferential outer side of the main pier; the construction platforms are respectively arranged on both sides of the width direction of the main pier and are fixedly connected to the embedded parts; The cantilever end temporary pier beam adjustment system includes a beam adjustment mechanism three; the beam adjustment mechanism three is arranged between the beam body and the temporary pier; The temporary support system for assembling steel trusses includes a support, a support foundation and a support pipe; the support is fixed to the ground through the support foundation to support the beam body; the support pipe is installed on the top of the support to support the end of the bridge; A river pier anti-collision system is also provided; the river pier anti-collision system includes steel sheet piles and steel pipe supports; the steel sheet piles are driven into the soil on the water side of the temporary pier, and steel pipe supports are provided at the corners on both sides of the steel sheet piles to achieve reinforcement and fixed support for the steel sheet piles; The main bridge comprises side piers, main piers, auxiliary piers, a beam body and temporary piers; the side piers, main piers and auxiliary piers are all positioned under the beam body; the main piers and auxiliary piers are arranged on both sides of the beam body in the width direction; A support frame, a column and a step platform are also provided; one end of the support frame is welded to the lower part of the construction platform, and the other end is fixed to the main pier to support the construction platform; the column is installed between the main pier and the auxiliary pier, and a support frame is arranged in the middle for reinforcement; the step platform is erected on the column, and both ends are fixed on the embedded parts of the main pier and the auxiliary pier; Synchronously construct the temporary support system for assembling steel trusses on the side piers, main piers and temporary piers; The front guide beam anti-supporting wheel box moving device is installed on the temporary pier and moves along the length direction of the track beam; The beam adjusting mechanism 1, the beam adjusting mechanism 2 and the beam adjusting mechanism 3 all include a top pad, a fixing frame, a vertical jack, a positioning clamp, a lower pad, a polytetrafluoroethylene plate, a horizontal jack and a reaction seat; The top pad, fixing frame, vertical jack, positioning card plate and lower pad are positioned and connected in sequence from top to bottom; the vertical jack is positioned in the positioning card plate; the two horizontal jacks are respectively arranged corresponding to the adjacent two sides of the positioning card plate through the reaction seat; It is characterized in that The construction method comprises the following steps: S1. Construction preparation: According to the construction requirements, the construction machinery and tools are inspected before construction to ensure their normal use; at the same time, the materials required for construction are prepared, technical explanations are given to relevant technical personnel, and construction machinery is gradually brought into the site; S2. Support construction: Install support foundations on the ground line and on the side piers and main piers according to the layout position, and construct temporary piers and their upper supports. Install an anti-collision system on the water side of the temporary piers, drive steel sheet piles into the soil, and install steel pipe supports to reinforce them. Install support pipes at the bridge end supports, and install track beams on the top of the supports; S3, gantry crane track construction: Use the truck crane to install the track beam and triangular track beam, fix the triangular front guide beam at the front end of the triangular track beam across the river, install the I-rail on the top of the triangular track beam, install the anti-support wheel box at the bottom of the triangular track beam, and move it to the designated position to contact the track beams at both ends to form a whole; S4. Lifting, transportation and assembly of steel trusses: Use floating boats to transport steel trusses in the river channel. After the floating boats transport the rods to the middle of the river, use gantry cranes to lift and transport them. Assemble the steel trusses according to the final design line shape. Use gantry cranes to install steel trusses symmetrically from the side spans on both sides to the middle of the span. Use large gantry cranes to lift and complete the installation of all steel trusses at both ends of the bridge. When the steel trusses are installed at the main pier position, adjust and position the steel trusses once with the main pier and the side pier as reference points. S5. Remove the supporting pipes at both ends of the bridge to complete the emptying: continue to assemble the steel trusses until the final closing section is reached. After the two ends of the bridge are assembled, use jacks to remove the supporting pipes at both ends of the bridge, and the steel trusses at both ends are empty and freed from constraints. S6. Assemble the beam adjustment system: place the vertical jack in the positioning card plate, the lower pad is placed at the bottom of the positioning card plate, the lower part of the vertical jack, the positioning card plate fixes the vertical jack, the polytetrafluoroethylene plate is placed under the positioning card plate, the top pad is welded and fixed to the top of the vertical jack through the lower fixing frame, one end of the horizontal jack is fixed on the reaction seat, and is placed on the adjacent two sides of the positioning card plate, which can be adjusted horizontally; S7. Use the beam adjustment system to adjust the main pier: embedded parts are embedded around the main pier, one end of the construction platform is connected to the embedded parts and fixed on both sides of the main pier, one end of the support frame is welded to the lower part of the construction platform, and the other end is fixed on the main pier to support the construction platform. The second beam adjustment mechanism is installed on the main pier, and a column is installed between the main pier and the auxiliary pier. A support frame is set in the middle for reinforcement. A step platform is set on the column, and both ends are installed and fixed on the embedded parts of the main pier and the auxiliary pier; S8. Construction of the beam adjustment system of the temporary pier at the cantilever end: The beam adjustment mechanism 3 is installed on the temporary pier, and the anti-support wheel box can move on the track beam of the temporary pier; S9. Dismantle the gantry crane track beam and brackets: adjust the linearity and use the truck crane to dismantle the gantry crane, track beams and brackets. The construction of the entire bridge is completed and enters the system conversion.

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