Segmented assembling and sliding construction method for large-span space truss roof

Abstract

The invention provides a large-span space truss roof segmented assembling and sliding construction method, and relates to the technical field of segmented assembling, hydraulic synchronous sliding and horizontal unloading. The segmented assembly technology comprises a segmented division and processing stage, a ground assembly stage, a high-altitude connection and inlaying stage and a quality control and acceptance stage. The hydraulic synchronous slippage technology comprises a construction preparation and design stage, a segmented assembly stage, a slippage system installation and debugging stage, a trial slippage stage, a formal slippage and synchronous control stage and a slippage in-place and butt joint stage. By adopting the reasonable splicing sequence and welding process, strictly controlling the splicing precision and adopting the hydraulic synchronous sliding technology and other solutions, the efficient, low-cost and high-quality construction effect can be achieved.

Description

Technical Field

[0001] The invention provides a segmented assembly and sliding construction method for a large-span space truss roof, and relates to the technical fields of segmented assembly, hydraulic synchronous sliding, and horizontal unloading. Background Art

[0002] With the increasing requirements for spatial span and modeling complexity of modern public buildings (such as stadiums, exhibition centers, transportation hubs, etc.), traditional hoisting methods are difficult to adapt to the construction needs of super-large spans, special-shaped structures and complex site conditions. Limitations of traditional construction methods: The traditional high-altitude bulk method has problems such as large scaffolding consumption and high risk of high-altitude operations, while the overall hoisting method is limited by the capacity of lifting equipment and site conditions. Especially when crossing special sites such as railways and airports, it is impossible to implement intra-span hoisting operations. Coordinated development of structural forms and construction technologies: The emergence of new spatial structural forms such as fish-belly inverted triangle tube trusses and curved grids requires construction methods to achieve technical breakthroughs in ground assembly and segmented sliding in place. Structural innovation and sliding technology form a mutually reinforcing development relationship. Dual drive of economy and safety: Sliding technology reduces the amount of high-altitude operations through ground assembly, and uses a slide rail system to replace a large number of support frames, which can reduce the cost of scaffolding by more than 60%. At the same time, through cumulative sliding or overall jacking technology, the construction period is significantly shortened and construction safety is improved. The development of this construction method is essentially a response to the concept of building industrialization and green construction. Through the "ground assembly + sliding into place" mode, it realizes the efficient and safe construction of large-span spatial structures. Summary of the invention

[0003] The purpose of the present invention is to solve the following problems: Structural stability: The stability of the large-span space truss roof is a key issue before the overall structure is formed. During the segmented assembly process, how to ensure the stability of each part during the assembly and sliding process is the first technical problem to be solved. Assembly accuracy: Due to the complex structure of the large-span space truss roof, high assembly accuracy is required. During the segmented assembly, how to ensure that the size and shape of each part meet the design requirements to ensure the accuracy of the overall assembly is an important technical issue. Sliding synchronization: During the sliding construction process, how to ensure that each part can slide to the predetermined position synchronously and smoothly to avoid excessive stress and deformation is another key problem that needs to be solved.

[0004] The technical solution adopted by the present invention is as follows:

[0005] The segmented assembly and sliding construction method of the large-span space truss roof includes the following steps:

[0006] Step (1) computer simulation analysis is performed on the entire process of roof steel structure construction to determine construction parameters such as stress, deformation, and reaction force of each support point at the most unfavorable point;

[0007] Step (2) Establish a space measurement and control network. Mark the intersection points of the longitudinal and transverse axes of the building, the radial axes of the steel columns and steel beams (2) with the axes of the building rectangular control network on the control network axes by internal division method, perform on-map operations, and calculate the spatial coordinates of each member and node.

[0008] Step (3) The materials entering the site can be used only after passing the inspection, and the surveying instruments such as total stations, theodolites, and levels can be used only after passing the verification.

[0009] Step (4) When pouring the strip foundation of concrete outside the project, embed the connecting pieces of the sliding track (15).

[0010] Step (5) The sliding track outside the project adopts a strip concrete foundation (6). After the foundation concrete (6) reaches the design strength, install the track (15).

[0011] Step (6) Set up fixed support frames and sliding support frames during the steel structure assembly. Remove the fixed support frames during sliding. All support frames are welded with steel pipes and steel sections.

[0012] Step (7) Use the "temporary fixing device for the installation of circular steel pipe trusses" to assemble and temporarily fix the small assembled unit trusses. After passing the measurement, weld and fix them.

[0013] Step (8) Divide the overall assembly blocks according to the shape and span of the roof steel structure truss. Each cone is taken as a block. The entire roof steel structure truss is installed successively in each block from one end of the roof to the other end.

[0014] Step (9) After the overall assembly is completed, remove the fixed support frames and transfer the load to the sliding support frames.

[0015] Step (10) Install the jacking system. Connect the sliding shoes on each track (15) with tie rods, or set up diagonal braces between the sliding support frames and the roof steel structure truss to ensure the structural stability.

[0016] Step (11) Before the trial sliding, check the track and its support system, the sliding support frames and their connections with the roof steel structure truss. Start the trial sliding after all the detection equipment is working properly.

[0017] Step (12) Overall sliding: Mark every 3 m on the sliding track as a sliding step sequence. During sliding, use the method of measuring with a ruler to record the distance of each stroke and check the synchronism of the sliding of the sliders (11).

[0018] The whole process monitoring and safety guarantee include: Analyze the stress state of the key nodes of the truss in real time through the strain monitoring device; Set up a multi-level alarm mechanism to automatically cut off the hydraulic power and start braking under abnormal working conditions.

[0019] Furthermore, the asynchrony in step (1) is not greater than 50 mm, and during construction, it is controlled to be not greater than 30 mm.

[0020] Furthermore, in step (2), a space measurement and control network is established. The intersection points of the longitudinal and transverse axes of the building and the radial axes of the steel columns and steel beams with the axes of the building rectangular control network are marked on the control network axes using the internal division method to indicate the axis dimensions of each member, and graphical operations are carried out. The spatial coordinates of each member and node are calculated, and an assembly position diagram is drawn.

[0021] Furthermore, when pouring the concrete strip foundation (6) outside the project in step (4), connectors for the sliding track (15) are pre-embedded; when constructing the concrete floor slab (3), steel plates (14) are pre-embedded under the short columns corresponding to the Bailey truss trestle system; at the positions of the underground structure shear walls and floor slabs, bracket steel bars are added and reinforced H-shaped steel beams are pre-embedded, and the track (15) is laid on top.

[0022] Furthermore, in step (5), the sliding track (15) outside the project uses a concrete strip foundation (6). After the foundation concrete reaches the design strength, the track (15) is installed. The short columns are connected to the floor slab (5) and the cross beam by welding, and the track (15) is connected to the track beam by fixed clamping plates.

[0023] Furthermore, in step (6), the fixed support frame is a lattice tower structure, which is connected to the concrete foundation (6) by pre-embedded bolts or welded to the pre-embedded steel plate (5) on the concrete. Its upper part is temporarily welded to the nodes of the roof steel structure truss with steel pipes. Unloading nodes are provided at the bottom of the fixed support frame, and its structure is as Figure 3 shown.

[0024] Furthermore, during assembly in step (7), for the intersecting nodes of complex truss members, cast steel nodes or spherical nodes can be used. The installation angles are determined through a computer three-dimensional model, and a total station is used on-site to accurately position the intersecting openings to ensure the installation accuracy of the nodes.

[0025] Furthermore, in step (8), the overall assembly blocks are divided according to the shape and span of the roof steel structure truss, with each cone as a block. The entire roof steel structure truss is installed block by block in sequence from one end of the roof to the other end. The main truss of each block is assembled from both ends to the middle, and the secondary trusses are sequentially patched along with the main trusses to reduce the cumulative installation error and the installation error during closure.

[0026] Furthermore, in step (9), the vertical unloading is to unload the fixed support frames at non-track positions in a "synchronous and proportional" manner. The process is as follows: The jack (4) tightens the lower steel beam of the fixed support frame → the steel column is cut off → the steel plate (5) is padded → the jack (4) is raised → the steel plate (5) is removed → the cylinder of the jack (4) retracts. Repeat the process until the unloading is completed, and then the fixed support frame is removed. The horizontal unloading is to release the horizontal force between the sliding support frame sliding shoe and the track (15) under the action of the self-weight of the structure and vertical displacement, so as to reduce the horizontal load on the track during the sliding stage. The "synchronous and equidistant" method is adopted. The process is as follows: The jack (4) tightens the bottom of the sliding support frame → the temporary car stop (20) and the locking device are removed → the jack (4) is released → devices such as the sliding car stop (21) are installed → staged unloading is carried out until the unloading is completed. Lubricating oil is applied to the contact surface between the bottom of the sliding shoe and the track (15) to prepare for sliding, as Figure 4 shown.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] 1. Improve construction efficiency: The segmented assembly and sliding construction method can decompose the construction process of the long-span space truss roof into multiple relatively independent stages, which is conducive to organizing flow operations and improving construction efficiency.

[0029] 2. Reduce construction costs: By a reasonable assembly sequence and welding process, the usage of temporary supports and scaffolding can be reduced, thus reducing construction costs. At the same time, the application of the hydraulic synchronous sliding technology can also reduce the input of manpower and material resources, further reducing construction costs.

[0030] 3. Ensure construction quality: The segmented assembly and sliding construction method is conducive to controlling the assembly accuracy and sliding synchronism, thereby ensuring construction quality. In addition, this method can also reduce the risks of high-altitude operations and cross operations, improving construction safety.

[0031] 4. Solve technical problems such as the assembly of spatial irregular cones, the stability of the sliding load-bearing support frames, and the setting of sliding tracks, ensuring the synchronous sliding of the roof steel structure and structural safety.

[0032] 5. Adopt the construction method of assembling outside the project and sliding as a whole, reducing the number of component hoisting times, and the steel consumption of the support frames is reduced compared with the traditional method. Since the input of large-scale machinery is reduced, the pollution during construction is reduced, achieving the goals of energy conservation, emission reduction, and noise reduction in building construction.

[0033] In summary, the segmented assembly and sliding construction method for the long-span space truss roof needs to solve technical problems such as structural stability, assembly accuracy, and sliding synchronism. By adopting reasonable assembly sequences and welding processes, strictly controlling assembly accuracy, and using solutions such as hydraulic synchronous sliding technology, construction effects of high efficiency, low cost, and high quality can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is the construction flow chart;

[0035] Figure 2 is the side view of the roof truss;

[0036] Figure 3 is the schematic diagram of the unloading node of the fixed support frame;

[0037] Figure 4 is the schematic diagram of the sliding shoe structure on the concrete foundation;

[0038] Figure 5 is the schematic diagram of the horizontal unloading after assembly;

[0039] Figure 6 is the construction schematic diagram of the prestressed steel cable.

[0040] In the figure: 1. Stiffening rib; 2. Reinforcing beam; 3. Base plate; 4. 50t jack; 5. Steel base plate; 6. Concrete foundation; 7. Lateral angle steel; 8. Press block; 9. Base plate of the support structure; 10. Stiffening rib; 11. Slide block; 12. Cross shear member; 13. Anchor bar; 14. 20-mm-thick base plate; 15. Track; 16. Stiffening rib; 17. Press block; 18. Slide block; 19. Base plate; 20. Temporary car stop; 21. Sliding car stop; 22. Slide block; 23. Steel cable; 24. Cable node;

[0041] 25. Cable ear plate; 26. Guide pulley; 27. Fixed fixture; 28. Winch. Specific embodiments

[0042] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. In the specific implementation process, as Figure 1 shown, it is the flow chart of the segmented assembly and sliding construction of the large-span space truss roof; as Figure 2 shown, by adopting a reasonable assembly sequence and welding process, the structural stability can be ensured. The assembly sequence from the center to the edge is adopted, and at the same time, a reasonable welding process is adopted to avoid the influence of the high temperature generated during the welding process on the steel structure. As Figure 3 shown, when assembling the steel structure, fixed support frames and sliding support frames are set up, and the fixed support frames are removed during sliding. The support frames are all welded with steel pipes and section steels. At the same time, as Figure 4As shown, it is also necessary to adopt methods such as pre-assembly and simulated assembly to discover and solve possible problems in advance; adopt the hydraulic synchronous sliding technology: to ensure the sliding synchronism, the hydraulic synchronous sliding technology can be adopted. This technology realizes the synchronous and stable sliding of each part through a hydraulic jack cluster (4) and a synchronous drive device; overall sliding; the fixed support frame is a lattice tower structure, which is connected to the concrete foundation (6) by embedded bolts or welded to the embedded steel plate (5) on the concrete. Its upper part is temporarily welded to the nodes of the roof steel structure truss with steel pipes, and unloading nodes are arranged at the bottom of the fixed support frame. As Figure 5 shown, the sliding support frame is a space truss structure, the lower part is supported on the sliding track through sliding shoes, and the upper part is welded to the nodes of the roof steel structure truss. A sliding shoe device is installed at the bottom of the sliding support frame, and the sliding shoes are locked longitudinally with steel wedges and transversely with sliding shoe limiting devices to ensure the stability during the steel structure assembly. In addition, as Figure 6 shown, the stability of the structure is enhanced by setting up temporary supports and cables, etc.; strictly control the assembly accuracy: during the assembly process, the dimensions and shapes of each part should be strictly controlled to ensure compliance with the design requirements. High-precision measuring equipment and tools are used to monitor and adjust the assembly process in real time.

[0043] During the sliding process, the sliding process can also be monitored and adjusted in real time by setting up limit cards and monitoring devices, etc., to ensure the accuracy and safety of sliding. Markings are made every 3 m on the sliding track as a sliding step sequence. When sliding, the method of using a ruler to measure is adopted to record the distance of each stroke and check the synchronism of sliding; the computer control center controls the synchronism of sliding further by the distance signals fed back by sensors on each track. The synchronous deviation of the same track is not greater than 10 mm, and the synchronous deviation of different tracks is not greater than 15 mm. During the sliding process, the working states of the sliding track, hydraulic crawling jacking device, hydraulic pump source system, computer control system, and sensing detection system should be observed at any time. Unloading after assembly: After the overall assembly is completed, the fixed support frame is removed, and the load is transferred to the sliding support frame. Unloading is carried out in sequence according to the structural units divided in the construction drawing. First, vertical unloading is carried out, and then horizontal unloading. During the unloading process, the stress and strain during the unloading process are monitored through the installed strain gauges and prisms to ensure the structural safety during the unloading process. Vertical unloading is to unload the fixed support frames at non-track positions in a "synchronous and proportional" manner. The process is as follows: The jack (4) jacks up the lower steel beam (2) of the fixed support frame → cut off the steel column → pad the steel plate (14) → raise the jack (4) → remove the steel plate (14) → the jack (4) retracts the cylinder. Repeat the cycle until the unloading is completed, and then remove the fixed support frame. Horizontal unloading is to release the horizontal force between the sliding shoes of the sliding support frame and the track under the action of the self-weight of the structure and vertical displacement, so as to reduce the horizontal load on the track during the sliding stage. The method of "synchronous and equal distance" is adopted. The process is as follows: The jack (4) jacks up the bottom of the sliding support frame → remove the temporary car stop (20) and the locking device → release the jack (4) → install devices such as the sliding car stop (21) → unload in stages until the unloading is completed. Lubricating oil is applied to the contact surface between the bottom of the sliding shoe and the track to prepare for sliding.

Claims

1. A construction method for segmental assembly and sliding of a long-span space truss roof, characterized in that, It includes the following steps: Step (1): Conduct computer simulation analysis on the whole process of the construction of the roof steel structure to determine construction parameters such as the stress, deformation, and reaction forces of each support point at the most unfavorable points; Step (2): Establish a space measurement and control network. For the intersection points of the longitudinal and transverse axes of the building, the radial axes of the steel columns and steel beams (2) with the axes of the building rectangular control network, use the internal division method to mark the axis dimensions of each member on the control network axis, conduct on-map operations, and calculate the spatial coordinates of each member and node; Step (3): The materials entering the site can be used only after passing the inspection, and the measuring instruments such as total stations, theodolites, and levels can be used only after passing the verification; Step (4): When pouring the concrete strip foundation outside the project, embed the connectors of the sliding track (15); Step (5): The sliding track outside the project uses a concrete strip foundation (6). After the foundation concrete (6) reaches the design strength, install the track (15); Step (6): Set up fixed support frames and sliding support frames during the steel structure assembly. Remove the fixed support frames during sliding. The support frames are all welded with steel pipes and sections; Step (7): Use the "temporary fixing device for the installation of circular steel pipe trusses" to temporarily fix the small assembled unit trusses. After passing the measurement, weld and fix them; Step (8): Divide the overall assembly blocks according to the shape and span of the roof steel structure truss. Each cone is a block. The entire roof steel structure truss is installed successively in each block from one end of the roof to the other end; Step (9): After the overall assembly is completed, remove the fixed support frames and transfer the load to the sliding support frames; Step (10): Install the jacking system. Connect the sliding shoes on each track (15) with tie rods, or set up diagonal braces between the sliding support frames and the roof steel structure truss to ensure the structural stability; Step (11): Before the trial sliding, check the track and its support system, the sliding support frames and their connections with the roof steel structure truss. Start the trial sliding after all the detection equipment works normally; Step (12): Overall sliding: Mark every 3 m on the sliding track as a sliding step sequence. When sliding, use the method of measuring with a ruler to record the distance of each stroke and check the synchronism of the sliding of the sliders (11); The whole process monitoring and safety guarantee include: Analyze the stress state of the key nodes of the truss in real time through the strain monitoring device; Set up a multi-level alarm mechanism to automatically cut off the hydraulic power and start braking under abnormal working conditions.

2. The method for segmental assembly and sliding construction of a long-span space truss roof according to claim 1, characterized in that, In the said step (1), the non-synchronism is not more than 50 mm, and it is controlled at not more than 30 mm during construction.

3. The method for segmental assembly and sliding construction of a long-span space truss roof according to claim 1, characterized in that, In the said step (2), establish a space measurement and control network. For the intersection points of the longitudinal and transverse axes of the building, the radial axes of the steel columns and steel beams with the axes of the building rectangular control network, use the internal division method to mark the axis dimensions of each member on the control network axis, conduct on-map operations, calculate the spatial coordinates of each member and node, and draw the assembly position map.

4. The large-span space truss roof segmental assembly and sliding construction method according to claim 1, characterized in that, In the said step (4), when pouring the concrete strip foundation (6) outside the project, embed the connectors of the sliding track (15); when constructing the concrete floor slab (3), embed the steel plates (14) under the short columns of the corresponding Bailey truss trestle system; at the positions of the underground structure shear walls and floors, add bracket steel bars and embed the reinforced H-shaped steel beams, and lay the track (15) on top.

5. The method for segmental assembly and sliding construction of a long-span space truss roof according to claim 1, characterized in that, In step (5), the external engineering sliding track (15) uses a concrete strip foundation (6). After the foundation concrete reaches the designed strength, the track (15) is installed. The short columns are welded to the floor slab (5) and the cross beam, and the track (15) is connected to the track beam by a fixed clamping plate.

6. The method for segmental assembly and sliding construction of a long-span space truss roof according to claim 1, characterized in that, In step (6), the fixed support frame is a lattice tower structure, which is connected to the concrete foundation (6) by embedded bolts or welded to the embedded steel plate (5) on the concrete. Its upper part is temporarily welded to the nodes of the roof steel structure truss by steel pipes. An unloading node is arranged at the bottom of the fixed support frame, and its structure is shown in Figure 2.

7. The method for segmental assembly and sliding construction of a long-span space truss roof according to claim 1, characterized in that, In step (7) during assembly, for the complex intersecting nodes of the truss members, cast steel nodes or spherical nodes can be used. The installation angles are determined by a computer three-dimensional model, and a total station is used on-site to accurately position the intersecting openings to ensure the installation accuracy of the nodes.

8. The method for segmental assembly and sliding construction of a long-span space truss roof according to claim 1, characterized in that, In step (8), the overall assembly blocks are divided according to the shape and span of the roof steel structure truss, with each cone being a block. The entire roof steel structure truss is installed block by block in sequence from one end of the roof to the other end. The main truss of each block is assembled from both ends to the middle, and the secondary trusses are sequentially filled in as the main trusses are assembled to reduce the cumulative installation error and the installation error during closure.

9. The method for segmental assembly and sliding construction of long-span space truss roof according to claim 1, characterized in that, In step (9), the vertical unloading is to unload the fixed support frames at non-track positions in a "synchronous and proportional" manner. The process is as follows: the jack (4) presses against the lower steel beam of the fixed support frame → the steel column is cut off → the steel plate (5) is padded → the jack (4) is raised → the steel plate (5) is removed → the cylinder of the jack (4) retracts. Repeat the cycle until the unloading is completed, and then the fixed support frame is removed. The horizontal unloading is to release the horizontal force between the sliding support frame sliding shoes and the track (15) under the action of the self-weight of the structure and the vertical displacement to reduce the horizontal load on the track during the sliding stage. The "synchronous and equidistant" method is adopted, and the process is as follows: the jack (4) presses against the bottom of the sliding support frame → the temporary car stop (20) and the locking device are removed → the jack (4) is released → devices such as the sliding car stop (21) are installed → graded unloading until the unloading is completed. Lubricating oil is applied to the contact surface between the bottom of the sliding shoe and the track (15) to prepare for sliding, as shown in Figure 4.

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