Continuous erection method for large-span steel box girder

Abstract

The invention relates to the technical field of bridge construction, and discloses a large-span steel box girder continuous erection method which comprises the following steps: S1, building a plurality of permanent piers, arranging an assembling platform and a portal crane between two permanent piers at the starting end, and arranging pushing equipment on the assembling platform and part of the permanent piers; s2, a first subsection box girder of the steel box girder is hoisted to an assembling platform, a guide girder is arranged on the first subsection box girder, and a buckling tower is arranged on the first subsection box girder; s3, a second subsection box girder of the steel box girder is hoisted to the assembling platform, and then the pushing equipment continues to push the guide girder, the first subsection box girder and the second subsection box girder; and S4, after the remaining segmented box girders of the steel box girders are pushed in place, the guide girders, the buckling towers and the pushing equipment are dismounted, and the steel box girders are fixedly connected to the permanent piers. According to the continuous erecting method for the large-span steel box girder, erecting of the large-span steel box girder on the working ground is achieved, the erecting difficulty is low, and the erecting speed is increased.

Description

Technical Field

[0001] The invention relates to the technical field of bridge construction, and in particular to a method for continuously erecting a large-span steel box girder. Background Art

[0002] Steel box girder, also known as steel plate box girder, is a common structural form for long-span bridges. It is generally used on bridges with larger spans. It is called a steel box girder because it looks like a box. As a type of bridge construction, the steel box girder can divide the bridge body into multiple sections, which are prefabricated in the factory and then transported to the work site for assembly. The span of the existing steel box girder is not long, and it is relatively easy to erect it on the working ground. However, for large-span steel box girders, it cannot be safely erected on the working ground, and its erection difficulty and risk are relatively high. Therefore, a method for continuous erection of large-span steel box girders is urgently needed to solve the above problems. Summary of the invention

[0003] In order to solve the technical problems of high difficulty and risk in erecting large-span steel box girders on the working ground, the present invention provides a method for continuous erection of large-span steel box girders. The guide beam and the buckle tower function accelerate the jacking and pier-mounting speed of the entire steel box girder, thereby reducing the difficulty of erecting the entire steel box girder. At the same time, since multiple jacking equipment are used to push the entire steel box girder, the erection speed is accelerated, the stability is high, and the entire steel box girder is safer when being jacked.

[0004] The present invention provides a method for continuously erecting a large-span steel box girder, comprising the following steps:

[0005] S1. Build multiple permanent piers in sequence along the erection direction of the steel box girder, set up an assembly platform and a gantry crane between the two permanent piers at the starting end, and set up jacking equipment on the assembly platform and other permanent piers except the first permanent pier at the starting end;

[0006] S2. Lift the first segmented box girder of the steel box girder onto the assembly platform by a gantry crane, fix a guide beam on the end of the first segmented box girder away from the starting end, set a buckle tower on the first segmented box girder, and fix the steel strands at both ends of the buckle tower to the first segmented box girder and the guide beam respectively, so that the end of the guide beam not connected to the first segmented box girder does not tilt downward;

[0007] S3, using a jacking device to jack the guide beam and the first segmented box beam forward along the erection direction to above the adjacent permanent pier, using a gantry crane to lift the second segmented box beam of the steel box beam to the assembly platform, and fixing and connecting the first segmented box beam and the second segmented box beam on the assembly platform, and then using a jacking device to jack the guide beam, the first segmented box beam and the second segmented box beam forward along the erection direction to above the adjacent permanent pier;

[0008] S4, repeat step S3 until the remaining segmented box girders of the steel box girder are placed above the corresponding permanent piers, remove the guide beams, buckle towers and jacking equipment, and fix the steel box girder to multiple permanent piers.

[0009] Furthermore, in S1, the assembly platform is arranged in the middle of the two permanent piers at the starting end, and the gantry crane is erected on both sides of the assembly platform; the assembly platform includes a truss and a plurality of first support frames and a second support frame, the bottoms of the plurality of first support frames are evenly arranged on the working ground, the bottoms of the plurality of second support frames are evenly arranged and extend into the working ground, the truss is arranged on the top of the first support frame and the second support frame, the truss is provided with a top plate, the top plate is evenly provided with a plurality of support beams, the assembly platform is provided with a plurality of jacking devices and the jacking devices are evenly arranged on the top of the plurality of second support frames. The gantry crane hoists the steel box girder onto the support beam, and the support beam supports the steel box girder; when the jacking device jacks, the jacking device supports the steel box girder.

[0010] Furthermore, in S1, the jacking equipment includes a longitudinal movement device and two lifting cylinders located on both sides of the longitudinal movement device, the cylinder rod of the lifting cylinder is fixedly connected to the lifting beam and can drive it to move, the longitudinal movement device includes a load-bearing base, a longitudinal movement frame and a transverse movement slider, the load-bearing base and the two lifting cylinders are arranged on the assembly platform and part of the permanent pier, the longitudinal movement frame is movably arranged on the load-bearing base, the load-bearing base is provided with a longitudinal push cylinder, the cylinder rod of the longitudinal push cylinder is fixedly connected to the longitudinal movement frame and can drive it to move, the transverse movement slider is movably arranged on the longitudinal movement frame, and the longitudinal movement frame is provided with a correction cylinder, the cylinder rod of the correction cylinder is fixedly connected to the transverse movement slider and can drive it to move. The lifting cylinder is started to drive the lifting beam to move up and down, thereby realizing the lifting and lowering adjustment of the steel box girder; the longitudinal push cylinder is started to drive the longitudinal frame and the transverse slide block to move forward and backward, thereby realizing the forward and backward pushing adjustment of the steel box girder; the deviation correction cylinder is started to drive the transverse slide block to move forward and backward, thereby realizing the left and right deviation correction adjustment of the steel box girder.

[0011] Furthermore, in S1, tracks are provided on both outer sides of the two permanent piers at the starting end, and the rollers on both sides of the gantry crane are respectively located in the two tracks and can slide.

[0012] Furthermore, in S2, the steel box girder includes N segmented box girders, and the N segmented box girders are sequentially arranged as the first segmented box girder, the second segmented box girder, the third segmented box girder...the Nth segmented box girder from the front end to the rear end of the steel box girder; each segmented box girder includes a plurality of box girder segments, and the plurality of box girder segments are welded one by one on the assembly platform.

[0013] Further, the S2 includes: S21, using a gantry crane to first lift the guide beam and part of the first segmented box beam to the assembly platform, and weld and fix the guide beam and part of the first segmented box beam on the assembly platform, and the guide beam is located at the front end of the part of the first segmented box beam; S22, using a pushing device to push the guide beam and part of the first segmented box beam forward along the erection direction, so that the guide beam is suspended and located outside the assembly platform; S23, using a gantry crane to lift the remaining part of the first segmented box beam to the assembly platform, and weld and fix the part of the first segmented box beam and the remaining part of the segmented box beam on the assembly platform, and the first segmented box beam is located on the assembly platform; S24, using an external truck crane to set the buckle tower in the middle of the first segmented box beam so that the buckle tower is close to the front end of the first segmented box beam, and the steel strands at both ends of the buckle tower are respectively fixed to the rear end of the first segmented box beam and the guide beam.

[0014] Further, the S3 includes: S31, pushing the guide beam and the first segmented box beam forward along the erection direction by means of a pushing device, so that the front end of the guide beam contacts the pushing device on the next permanent pier; S32, the gantry crane first lifts part of the segmented box beam of the second segmented box beam to the assembly platform, and welds and fixes part of the segmented box beam of the second segmented box beam and the rear end of the first segmented box beam on the assembly platform; S33, continuing to push the guide beam, the first segmented box beam and part of the segmented box beam of the second segmented box beam forward along the erection direction by means of a pushing device; S34, the gantry crane then lifts the remaining part of the segmented box beam of the second segmented box beam to the assembly platform, and welds and fixes part of the segmented box beam of the second segmented box beam and the remaining part of the segmented box beam on the assembly platform, and the second segmented box beam is located on the assembly platform; S35, continuing to push the guide beam, the first segmented box beam and the second segmented box beam forward along the erection direction by means of a pushing device.

[0015] Further, in said S4, step S3 is repeated until the third segmented box girder ... the Nth segmented box girder of the steel box girder is placed above the corresponding permanent pier, the guide beam, the buckle tower and the jacking equipment are removed, a support is provided on the top of the permanent pier, and the bottom of the steel box girder is fixedly connected to the support.

[0016] Further, in S2, the width of the guide beam gradually decreases from its rear end to its front end, and the front end of the guide beam is inclined forward and upward.

[0017] Compared with the prior art, the present invention has the following technical effects:

[0018] After the assembly platform, gantry crane and jacking equipment of the present invention are set up, the erection of the steel box girder begins. First, the first segmented box girder of the steel box girder is hoisted, and a guide beam and a buckle tower are set on the first segmented box girder. The jacking equipment first pushes the guide beam and the first segmented box girder, and then hoists the second segmented box girder. After that, the jacking equipment continues to push the guide beam, the first segmented box girder and the second segmented box girder; the jacking operation is repeated until the third segmented box girder...the Nth segmented box girder of the steel box girder is pushed into place, and then the guide beam, buckle tower and jacking equipment are removed, and the steel box girder is divided into two sections and welded and fixedly connected to the supports of multiple permanent piers. The role of the guide beam and the buckle tower is to facilitate the jacking operation of the steel box girder so as to realize the pier-mounting of the steel box girder, speed up the jacking and pier-mounting speed of the entire steel box girder, and reduce the difficulty of erecting the entire steel box girder. At the same time, due to the use of multiple jacking equipment to push the steel box girder as a whole, the erection speed is accelerated, the stability is high, and the steel box girder as a whole is safer when being pushed. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic flow chart of a method for continuously erecting a large-span steel box girder of the present invention;

[0020] Figure 2 It is a structural schematic diagram of the first segmented box girder, guide beam and buckle tower of the present invention;

[0021] Figure 3 The present invention Figure 2 A is a magnified schematic diagram of the structure;

[0022] Figure 4 The present invention Figure 2 A schematic diagram of the structure of B in the middle;

[0023] Figure 5 It is a schematic diagram of the top view of the structure of the jacking device of the present invention;

[0024] Figure 6 It is a structural schematic diagram of the first segmented box girder and the second segmented box girder of the present invention;

[0025] Figure 7 It is a structural schematic diagram of the gantry crane of the present invention;

[0026] Figure 8 It is a schematic diagram of the structure of the steel box girder of the present invention being pushed into place;

[0027] The reference numerals in the accompanying drawings are:

[0028] 1. Permanent pier; 2. Assembly platform; 21. Truss; 22. First support frame; 23. Second support frame; 24. Top plate; 25. Support beam; 26. Guard plate; 3. Gantry crane; 4. Pushing equipment; 41. Lifting cylinder; 411. Lifting beam; 42. Load-bearing base; 421. Longitudinal push cylinder; 43. Longitudinal shift frame; 431. Correction cylinder; 44. Horizontal shift slider; 5. Guide beam; 6. Buckle tower; 7. Steel box girder; 71. First section box girder; 72. Second section box girder. DETAILED DESCRIPTION

[0029] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0030] like Figures 1 to 8 As shown, a method for continuously erecting a large-span steel box girder comprises the following steps:

[0031] S1. Build multiple permanent piers 1 along the erection direction of the large-span steel box girder 7. The jacking direction of the large-span steel box girder 7 is the erection direction. An assembly platform 2 and a gantry crane 3 are set between the two permanent piers 1 at the starting end of the erection direction (i.e., the permanent pier 1 with serial number 145 and the permanent pier 1 with serial number 146). The assembly platform 2 is located below the gantry crane 3. A jacking device 4 is set on the assembly platform 2 and other permanent piers 1 except the first permanent pier 1 at the starting end (i.e., except the permanent pier 1 with serial number 145). The gantry crane 3, the assembly platform 2 and the multiple permanent piers 1 in this embodiment can be set on a horizontal working ground or on a non-horizontal working ground. In this embodiment, they are set on a non-horizontal working ground, and the non-horizontal working ground has a slope, and the slope increases along the erection direction. Among them, the ground where the gantry crane 3 and the assembly platform 2 are located is relatively flat.

[0032] S2. The first segmented box girder 71 of the steel box girder 7 is hoisted onto the assembly platform 2 by means of a gantry crane 3. A guide beam 5 is fixedly arranged at one end of the first segmented box girder 71 away from the starting end, and the width of the guide beam 5 gradually decreases from the rear end to the front end thereof; a buckle tower 6 is arranged on the first segmented box girder 71 by means of an external automobile crane, and the steel strands at both ends of the buckle tower 6 are fixedly connected to the first segmented box girder 71 and the guide beam 5, respectively, so that the end of the guide beam 5 not connected to the first segmented box girder 71 does not tilt downward, specifically, the front end of the guide beam 5 tilts forward and upward; the steel box girder 7 comprises N segmented box girders, and the N segmented box girders are arranged successively from the front end to the rear end of the steel box girder 7 as the first segmented box girder 71, the second segmented box girder 72, the third segmented box girder ... the Nth segmented box girder; each segmented box girder comprises a plurality of box girder segments, and the plurality of box girder segments are welded segment by segment on the assembly platform 2. The segmented box girder includes a plurality of box girder segments, and the gantry crane 3 hoists the box girder segments onto the assembly platform 2. The plurality of box girder segments on a segmented box girder are hoisted in sequence and welded one by one on the assembly platform 2. Among them, the structures of the gantry crane 3, the buckle tower 6 and the guide beam 5 are prior arts, and will not be described in detail here.

[0033] S3, using the pushing device 4 to push the guide beam 5 and the first segmented box beam 71 forward along the erection direction to above the adjacent permanent pier 1, using the gantry crane 3 to lift the second segmented box beam 72 of the steel box beam 7 to the assembly platform 2, and on the assembly platform 2, the first segmented box beam 71 and the second segmented box beam 72 are fixedly connected and welded, and then the pushing device 4 is used to push the guide beam 5, the first segmented box beam 71 and the second segmented box beam 72 forward along the erection direction to above the adjacent permanent pier 1;

[0034] S4, repeat step S3 until the remaining segmented box beams of the steel box beam 7 are placed above the corresponding permanent piers 1, that is, until the third segmented box beam of the steel box beam 7 ... the Nth segmented box beam is placed above the corresponding permanent pier 1, remove the guide beam 5, the buckle tower 6 and the jacking device 4, and the steel box beam 7 is fixedly connected to multiple permanent piers 1; specifically, a support is provided on the top of the permanent pier 1, and the bottom of the steel box beam 7 is fixedly connected to the support. In this embodiment, the large-span steel box beam 7 includes two full-span steel couplings, and the two full-span steel couplings are divided into N segmented box beams in total. Each full-span steel coupling is 600m long, and the total length of the large-span steel box beam 7 is 1200m. Generally, the full-span steel coupling is fixedly connected to 7 permanent piers 1, and the two full-span steel coupling frames are fixedly connected to 13 permanent piers 1 in total. When the two full-span steel joints are pushed, they are welded and fixed together (that is, the steel box girder 7 as a whole) for pushing; after the two full-span steel joints are pushed into place, the welding points between the two full-span steel joints are separated and then fixed on 13 permanent piers 1 (that is, permanent piers 1 with serial numbers 145 to 157); among them, the 7th permanent pier 1 (that is, permanent pier 1 with serial number 151) supports and fixes the ends of the two full-span steel joints, and 4 supports are arranged on the 7th permanent pier 1, and every two supports support and fix the ends of one full-span steel joint.

[0035] After the assembly platform 2, the gantry crane 3 and the jacking device 4 of this embodiment are all set up, the erection of the steel box girder 7 begins, and the first segmented box girder 71 of the steel box girder 7 is first hoisted, and the guide beam 5 and the buckle tower 6 are set on the first segmented box girder 71. The jacking device 4 first pushes the guide beam 5 and the first segmented box girder 71, and then hoists the second segmented box girder 72, and then the jacking device 4 continues to push the guide beam 5, the first segmented box girder 71 and the second segmented box girder 72; the jacking operation is repeated until the third segmented box girder ... the Nth segmented box girder of the steel box girder 7 is pushed in place, and then the guide beam 5, the buckle tower 6 and the jacking device 4 are removed, and the steel box girder 7 is divided into two sections and welded and fixedly connected to the supports of multiple permanent piers 1. Since the slope of the non-horizontal working ground increases along the erection direction, the guide beam 5 is located at the front end of the first segmented box beam 71, and the width from the rear end to the front end of the guide beam 5 gradually decreases. The buckle tower 6 also needs to make the front end of the guide beam 5 tilt forward and upward, so the guide beam 5 is easier to be pushed to achieve the pier. The role of the guide beam 5 and the buckle tower 6 is to facilitate the jacking operation of the steel box beam 7 so as to achieve the pier of the steel box beam 7, speed up the jacking and pier speed of the steel box beam 7 as a whole, and reduce the difficulty of erecting the steel box beam 7 as a whole. At the same time, since multiple jacking devices 4 are used to push the steel box beam 7 as a whole, the erection speed is accelerated, the stability is high, and the steel box beam 7 as a whole is safer when being pushed.

[0036] The method for continuously erecting a large-span steel box girder in this embodiment realizes the erection of a large-span steel box girder 7, has low erection difficulty, accelerated erection speed, and ensures safety during erection.

[0037] On the basis of the above embodiment, in S1, the assembly platform 2 is arranged in the middle of the two permanent piers 1 at the starting end, the gantry crane 3 is erected on both sides of the assembly platform 2, and the top of the gantry crane 3 is located above the assembly platform 2;

[0038] The assembly platform 2 includes a truss 21 and a plurality of first support frames 22 and a second support frame 23. The first support frame 22 and the second support frame 23 are composed of a plurality of steel pipes and reinforcing pipes fixedly connected together. The bottoms of the plurality of first support frames 22 are evenly arranged on the working ground (non-horizontal working ground), the bottoms of the plurality of second support frames 23 are evenly arranged and extend into the working ground, and the plurality of first support frames 22 and the second support frames 23 are evenly located in the middle and on the right side of the two permanent piers 1 at the starting end. The truss 21 is arranged on the top of the first support frame 22 and the second support frame 23. A top plate 24 is provided, and the right end of the truss 21 and the right end of the top plate 24 are located on the right side of the two permanent piers 1 at the starting end. A plurality of support beams 25 are evenly arranged on the top plate 24, and the plurality of support beams 25 are arranged in two rows. A plurality of jacking devices 4 are provided on the assembly platform 2, and the jacking devices 4 are evenly arranged on the top of the plurality of second support frames 23. The top plate 24 is arranged to avoid the jacking devices 4, and the plurality of jacking devices 4 are arranged in two rows. In this embodiment, 8 jacking devices 4 are provided, and the 4 jacking devices 4 are in the same row; the plurality of support beams 25 in the same row and the two jacking devices 4 in the same row are on the same horizontal line. Specifically, the gantry crane 3 hoists the box beam segment of the steel box beam 7 onto the support beam 25, and the support beam 25 supports the box beam segment of the steel box beam 7; when the jacking device 4 pushes, the jacking device 4 supports the box beam segment of the steel box beam 7, and the box beam segment leaves the support beam 25.

[0039] Furthermore, guard plates 26 are provided around the top plate 24 to protect the workers on the assembly platform 2 from falling.

[0040] On the basis of the above embodiments, in S1, the jacking device 4 includes a longitudinal movement device and two jacking cylinders 41 located on both sides of the longitudinal movement device. Generally, two jacking devices 4 are symmetrically arranged on the permanent pier 1. The cylinder rod of the jacking cylinder 41 is fixedly connected to the jacking beam 411 and can drive it to move. The longitudinal movement device includes a load-bearing base 42, a longitudinal movement frame 43 and a transverse movement slider 44. The load-bearing base 42 and the two jacking cylinders 41 are arranged on the assembly platform 2 and part of the permanent pier 1. The longitudinal movement frame 43 is movably arranged on the load-bearing base 42. A longitudinal push cylinder 421 is arranged on the top, and two longitudinal push cylinders 421 are arranged in this embodiment, and the two longitudinal push cylinders 421 are located on both sides of the load-bearing base 42; the cylinder rod of the longitudinal push cylinder 421 is fixedly connected to the longitudinal frame 43 and can drive it to move, and the transverse sliding block 44 is movably arranged on the longitudinal frame 43, and a deviation correction cylinder 431 is arranged on the longitudinal frame 43, and the cylinder rod of the deviation correction cylinder 431 is fixedly connected to the transverse sliding block 44 and can drive it to move, and four longitudinal push cylinders 421 are arranged in this embodiment, and the four longitudinal push cylinders 421 are evenly located on both sides of the longitudinal frame 43. The jacking device 4 of this implementation realizes the adjustment of the steel box girder 7 in three directions. Specifically, the jacking beam 411 and the transverse sliding block 44 support the box girder segment of the steel box girder 7. The lifting cylinder 41 is started, driving the lifting beam 411 to move up and down, thereby realizing the lifting and lowering adjustment of the steel box girder 7; the longitudinal pushing cylinder 421 is started, driving the longitudinal frame 43 and the transverse sliding block 44 to move forward and backward, thereby realizing the front and rear pushing adjustment of the steel box girder 7; the deviation correcting cylinder 431 is started, driving the transverse sliding block 44 to move left and right, thereby realizing the left and right deviation correcting adjustment of the steel box girder 7.

[0041] The lifting cylinder 41 drives the two lifting beams 411 to move upward, and the two lifting beams 411 support the steel box beam 7. Then the lifting cylinder 41 drives the steel box beam 7 and the two lifting beams 411 to move upward; at this time, the longitudinal push cylinder 421 drives the longitudinal frame 43 and the transverse slide block 44 to move to the rear end, and the lifting cylinder 41 drives the steel box beam 7 and the two lifting beams 411 to move downward, so that the transverse slide block 44 supports the steel box beam 7. The lifting beam 411 no longer supports the steel box beam 7, and the longitudinal push cylinder 421 drives the longitudinal frame 43, the transverse slide block 44 and the steel box beam 7 to move to the front end, and finally realizes the jacking of the steel box beam 7. When it is found that the position of the steel box beam 7 is offset, the correction cylinder 431 is started, and the correction cylinder 431 adjusts the position of the transverse slide block 44 to correct the left and right positions of the steel box beam 7. Furthermore, since the slope of the non-horizontal working ground increases along the erection direction, pads can be provided on the jacking beam 411 and the transverse sliding block 44 as required, and the pads further support the steel box beam 7 .

[0042] Preferably, the load-bearing base 42 is a plate-type structure. In order to ensure a small friction coefficient, a mirror stainless steel plate is laid on the load-bearing base 42, and a polymer plate is attached to the bottom of the longitudinal frame 43. The theoretical dynamic friction coefficient between the two is 5%, and the maximum stroke of the longitudinal push cylinder 421 is 500mm. Specifically, the transverse sliding block 44 is placed inside the longitudinal frame 43, and a mirror stainless steel plate and a polymer plate are also laid between the transverse sliding block 44 and the longitudinal frame 43 to reduce the friction between the two.

[0043] On the basis of the above embodiments, in S1, a plurality of jacking devices 4 on the assembly platform 2 and two jacking devices 4 on the permanent pier 1, each two jacking devices 4 are provided with hydraulic power by a hydraulic pump station at the same time. The hydraulic pump station is connected to the jacking cylinder 41, the longitudinal push cylinder 421 and the deviation correction cylinder 431 on the jacking device 4 through a high-pressure oil pipe.

[0044] On the basis of the above embodiments, in S1, a plurality of displacement sensors are provided on the jacking device 4, and the plurality of displacement sensors monitor the extension and contraction of the jacking cylinder 41, the longitudinal pushing cylinder 421 and the deviation correction cylinder 431 on the jacking device 4. The jacking device 4 realizes its own state monitoring through the plurality of displacement sensors. Specifically, the jacking displacement, jacking displacement and deviation correction displacement of the steel box girder 7 are monitored during each jacking process of the jacking device 4. The jacking displacement, jacking displacement and deviation correction displacement are directly measured by the displacement sensors (pull rope sensors) in three directions on the jacking device 4, which not only directly reflect the displacement of the steel box girder 7, but also reflect the synchronization error of each jacking point action. The plurality of displacement sensors cooperate with the wireless transmission system, and the measured values ​​of the displacement sensors are transmitted to and displayed in real time on the human-computer interaction interface of the main control console. The operator judges the synchronization of each point based on the feedback data. If the displacement synchronization error of each point is large, it should be stopped immediately and the cause of the problem should be found. The offset of the steel box girder 7 and the guide beam 5 is also monitored. Other sensors such as deformation sensors and temperature sensors may be provided on the guide beam 5. In order to prevent deformation of the steel box beam 7 caused by excessive local thrust, the steel box beam 7 is reinforced. If the offset of the steel box beam 7 is too large and causes it to deviate, it will affect the construction quality.

[0045] On the basis of the above embodiments, in S1, tracks are arranged on both outer sides of the two permanent piers 1 at the starting end, and the rollers on both sides of the gantry crane 3 are respectively located in the two tracks and can slide. Generally, the gantry crane 3 is provided with a motor for driving the rollers thereon to rotate, which will not be described in detail here. The rollers on both sides of the gantry crane 3 slide in the two tracks, so that the box beam segment lifted by the gantry crane 3 can be placed at a certain place on the assembly platform 2 according to the requirements. Specifically, the box beam segment is transported to the bottom of the gantry crane 3 through the external setting, and the rollers on both sides of the gantry crane 3 slide in the two tracks so that the gantry crane 3 is aligned with the box beam segment as a whole. The electric hoist on the gantry crane 3 first slides to the top of the box beam segment, and then slides to lift the box beam segment to the top of the assembly platform 2. The gantry crane 3 slides again as a whole so that the lifted box beam segment is aligned with a certain place on the assembly platform 2, and the electric hoist puts down the box beam segment at this time.

[0046] On the basis of the above embodiments, the present embodiment performs fixed connection between the first segmented box girder 71, the guide beam 5 and the buckle tower 6. Specifically, the S2 comprises: S21, the gantry crane 3 firstly hoists the guide beam 5 and the partial segmented box beam of the first segmented box girder 71 onto the assembly platform 2, and welds and fixes the guide beam 5 and the partial segmented box beam of the first segmented box girder 71 on the assembly platform 2, wherein the guide beam 5 is located at the front end of the partial segmented box beam of the first segmented box girder 71; S22, the guide beam 5 and the partial segmented box beam of the first segmented box girder 71 are pushed forward along the erection direction by the pushing device 4 on the assembly platform 2 and a permanent pier 1 (that is, the permanent pier 1 with serial number 146), so that the guide beam 5 is suspended; The first segmented box girder 71 is empty and located outside the assembly platform 2. The weight of the first segmented box girder 71 is greater than the weight of the guide beam 5. The guide beam 5 is suspended in the air and will not cause the two to fall. S23, use the gantry crane 3 to lift the remaining segmented box beams of the first segmented box girder 71 to the assembly platform 2, and weld and fix the partial segmented box beams and the remaining segmented box beams of the first segmented box girder 71 on the assembly platform 2. The first segmented box girder 71 is located on the assembly platform 2; S24, use the external automobile crane to set the buckle tower 6 in the middle of the first segmented box girder 71 and make the buckle tower 6 close to the front end of the first segmented box girder 71, and fix the steel strands at both ends of the buckle tower 6 to the rear end of the first segmented box girder 71 and the guide beam 5, respectively. In this embodiment, the first segmented box girder 71, the guide beam 5 and the buckle tower 6 are fixedly connected and pushed, and then the remaining segmented box beams are lifted, welded and pushed into place, and finally the steel box girder 7 is fixedly connected to multiple permanent piers 1.

[0047] On the basis of the above embodiments, the S3 includes: S31, pushing the guide beam 5 and the first segmented box beam 71 forward along the erection direction through the assembling platform 2 and the jacking device 4 on the permanent pier 1 (that is, the permanent pier 1 with serial number 146), so that the front end of the guide beam 5 contacts the jacking device 4 on the next permanent pier 1 (that is, the permanent pier 1 with serial number 147); S32, the gantry crane 3 first lifts the partial segmented box beam of the second segmented box beam 72 to the assembly platform 2, and welds and fixes the partial segmented box beam of the second segmented box beam 72 and the rear end of the first segmented box beam 71 on the assembly platform 2; S33, continuing to push the guide beam 5 and the first segmented box beam 71 forward along the erection direction through the jacking device 4 on the assembly platform 2 and at least two permanent piers 1. The box girder 71 and some of the segmented box girders of the second segmented box girder 72 are pushed forward along the erection direction. When pushing the first segmented box girder 71 and the second segmented box girder 72, the pushing equipment 4 on the permanent pier 1 with serial numbers 146 and 147 is in operation; S34, the gantry crane 3 then hoists the remaining segmented box girders of the second segmented box girder 72 onto the assembly platform 2, and welds and fixes some of the segmented box girders and the remaining segmented box girders of the second segmented box girder 72 on the assembly platform 2, and the second segmented box girder 72 is located on the assembly platform 2; S35, the guide beam 5, the first segmented box girder 71 and the second segmented box girder 72 are continued to be pushed forward along the erection direction through the pushing equipment 4 on the assembly platform 2 and at least two permanent piers 1. In this embodiment, the first segmented box girder 71, the guide beam 5 and the buckle tower 6 are fixedly connected and pushed, and then the second segmented box girder 72, the third segmented box girder...the Nth segmented box girder are lifted, welded and pushed into place, and finally the steel box girder 7 is fixedly connected to multiple permanent piers 1.

[0048] The embodiments described above are only preferred embodiments of the present invention and are only used to explain the present invention, not to limit the scope of implementation of the present invention. For those skilled in the art, other implementation methods can certainly be easily made by replacement or modification based on the technical contents disclosed in this specification. Therefore, all changes and improvements made to the principles and process conditions of the present invention should be included in the scope of the patent application of the present invention.

Claims

1. A method for continuously erecting a large-span steel box girder, characterized in that: The following steps are involved: S1, a plurality of permanent piers (1) are sequentially built along the erection direction of the steel box girder (7), an assembly platform (2) and a gantry crane (3) are arranged between the two permanent piers (1) at the starting end, and a jacking device (4) is arranged on the assembly platform (2) and other permanent piers (1) except the first permanent pier (1) at the starting end; S2, hoisting the first segmented box girder (71) of the steel box girder (7) onto the assembly platform (2) by means of a gantry crane (3), fixing a guide beam (5) on the end of the first segmented box girder (71) away from the starting end, setting a buckle tower (6) on the first segmented box girder (71), and fixing the steel strands at both ends of the buckle tower (6) to the first segmented box girder (71) and the guide beam (5) respectively, so that the end of the guide beam (5) not connected to the first segmented box girder (71) does not tilt downward; S3, using a pushing device (4) to push the guide beam (5) and the first segmented box beam (71) forward along the erection direction to above the adjacent permanent pier (1), using a gantry crane (3) to lift the second segmented box beam (72) of the steel box beam (7) onto the assembly platform (2), and fixing the first segmented box beam (71) and the second segmented box beam (72) on the assembly platform (2), and then using a pushing device (4) to push the guide beam (5), the first segmented box beam (71) and the second segmented box beam (72) forward along the erection direction to above the adjacent permanent pier (1); S4, repeat step S3 until the remaining segmented box beams of the steel box beam (7) are placed above the corresponding permanent pier (1), remove the guide beam (5), the buckle tower (6) and the jacking equipment (4), and fix the steel box beam (7) to the permanent pier (1).

2. The method for continuously erecting a large-span steel box girder according to claim 1, characterized in that: In S1, the assembly platform (2) is arranged in the middle of two permanent piers (1) at the starting end, and the gantry crane (3) is erected on both sides of the assembly platform (2); the assembly platform (2) comprises a truss (21) and a plurality of first support frames (22) and a second support frame (23); the bottoms of the plurality of first support frames (22) are evenly arranged on the working ground, the bottoms of the plurality of second support frames (23) are evenly arranged and extend into the working ground, the truss (21) is arranged on the top of the first support frames (22) and the second support frames (23), a top plate (24) is arranged on the truss (21), and a plurality of support beams are evenly arranged on the top plate (24), and a plurality of jacking devices (4) are arranged on the assembly platform (2), and the jacking devices (4) are evenly arranged on the top of the plurality of second support frames (23).

3. The method for continuously erecting a large-span steel box girder according to claim 1, characterized in that: In S1, the jacking device (4) includes a longitudinal movement device and two jacking cylinders (41) located on both sides of the longitudinal movement device, the cylinder rod of the jacking cylinder (41) is fixedly connected to the jacking beam (411) and can drive it to move, the longitudinal movement device includes a load-bearing base (42), a longitudinal movement frame (43) and a transverse movement slider (44), the load-bearing base (42) and the two jacking cylinders (41) are arranged on the assembly platform (2) and part of the permanent pier (1), the longitudinal movement frame (43) is connected to the jacking beam (411) and the jacking cylinder rod ... 3) is movably arranged on a load-bearing base (42), a longitudinal push cylinder (421) is arranged on the load-bearing base (42), a cylinder rod of the longitudinal push cylinder (421) is fixedly connected to the longitudinal movement frame (43) and can drive the longitudinal movement frame to move, and the transverse movement slider (44) is movably arranged on the longitudinal movement frame (43), a deviation correction cylinder (431) is arranged on the longitudinal movement frame (43), and a cylinder rod of the deviation correction cylinder (431) is fixedly connected to the transverse movement slider (44) and can drive the transverse movement slider to move.

4. The method for continuously erecting a large-span steel box girder according to claim 1, characterized in that: In S1, tracks are arranged on both outer sides of the two permanent piers (1) at the starting end, and the rollers on both sides of the gantry crane (3) are respectively located in the two tracks and can slide.

5. The method for continuously erecting a large-span steel box girder according to claim 1, characterized in that: In S2, the steel box girder (7) includes N segmented box girders, and the N segmented box girders are sequentially arranged from the front end to the rear end of the steel box girder (7) as a first segmented box girder (71), a second segmented box girder (72), a third segmented box girder ... an Nth segmented box girder; each segmented box girder includes a plurality of box girder segments, and the plurality of box girder segments are welded segment by segment on the assembly platform (2).

6. The method for continuously erecting a large-span steel box girder according to claim 5, characterized in that: The S2 includes: S21, the gantry crane (3) first lifts the guide beam (5) and the partial segmental box beam of the first segmental box beam (71) onto the assembly platform (2), and welds and fixes the guide beam (5) and the partial segmental box beam of the first segmental box beam (71) on the assembly platform (2), wherein the guide beam (5) is located at the front end of the partial segmental box beam of the first segmental box beam (71); S22, using a pushing device (4) to push the guide beam (5) and some segmental box beams of the first segmented box beam (71) forward along the erection direction, so that the guide beam (5) is suspended in the air and located outside the assembly platform (2); S23, using a gantry crane (3) to hoist the remaining section box beams of the first section box beam (71) onto the assembly platform (2), and welding and fixing the section box beams of the first section box beam (71) and the remaining section box beams on the assembly platform (2), wherein the first section box beam (71) is located on the assembly platform (2); S24. Use an external truck crane to set the buckle tower (6) in the middle of the first segmented box girder (71) and make the buckle tower (6) close to the front end of the first segmented box girder (71), and fix the steel strands at both ends of the buckle tower (6) to the rear end of the first segmented box girder (71) and the guide beam (5) respectively.

7. The method for continuously erecting a large-span steel box girder according to claim 6, characterized in that: The S3 includes: S31, using a pushing device (4) to push the guide beam (5) and the first segmented box beam (71) forward in the erection direction, so that the front end of the guide beam (5) contacts the pushing device (4) on the next permanent pier (1); S32, the gantry crane (3) first lifts a portion of the second segmented box beam (72) onto the assembly platform (2), and welds and fixes the portion of the second segmented box beam (72) and the rear end of the first segmented box beam (71) on the assembly platform (2); S33, continuing to push the guide beam (5), the first segmented box beam (71) and some segmented box beams of the second segmented box beam (72) forward along the erection direction by using the pushing device (4); S34, the gantry crane (3) then hoists the remaining section box beams of the second section box beam (72) onto the assembly platform (2), and welds and fixes the section box beams of the second section box beam (72) and the remaining section box beams on the assembly platform (2), and the second section box beam (72) is located on the assembly platform (2); S35, continue to push the guide beam (5), the first segmented box beam (71) and the second segmented box beam (72) forward along the erection direction through the pushing device (4).

8. The method for continuously erecting a large-span steel box girder according to claim 7, characterized in that: In said S4, step S3 is repeated until the third segmented box girder ... the Nth segmented box girder of the steel box girder (7) is placed above the corresponding permanent pier (1), the guide beam (5), the buckle tower (6) and the jacking equipment (4) are removed, a support is provided on the top of the permanent pier (1), and the bottom of the steel box girder (7) is fixedly connected to the support.

9. The method for continuously erecting a large-span steel box girder according to claim 1, characterized in that: In S2, the width of the guide beam (5) gradually decreases from its rear end to its front end, and the front end of the guide beam (5) is inclined forward and upward.

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