Construction method of large-span string steel-wood composite structure

Abstract

The invention discloses a construction method of a large-span string steel-wood composite structure, which belongs to the technical field of steel-wood composite structure construction, and comprises the following steps: symmetrically setting up two groups of sliding trolleys in the middle of a three-layer concrete floor and steel upright posts and facade steel frames in the middle, welding a splicing bracket and an operating platform at the top of the trolleys, and completing midspan component splicing and initial tensioning; after installation of the remaining steel stand columns and the facade steel frame is completed, the steel stand columns and the facade steel frame sequentially move towards the outer side till assembly and initial tensioning of all components are completed; and then secondary cable force fine adjustment is carried out on the whole steel inhaul cable. In this way, in-situ assembly is conducted from the sliding platform erected on the three-layer concrete floor to the designed elevation of the lower chord wood arch, and the integrity of a steel-wood structure and the installation quality of a steel-wood roof in the whole construction process are guaranteed; during tensioning in the construction process, at least two main structures are connected together through the secondary beams, and the out-of-plane instability risk caused by single-truss tensioning is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of steel-wood hybrid structure construction, and in particular to a construction method of a large-span tensioned steel-wood hybrid structure. Background Art

[0002] At present, there are three main methods for installing the roof in the large-span tensioned steel-wood hybrid structure. The first is the block lifting method, that is, after the construction of the civil structure is completed, multiple sets of lifting brackets are set up at the steel column positions around the roof, and buckle brackets are set up on the lower side of the roof to assemble the trusses. Then it is lifted in multiple blocks, and then the lifting units are assembled in blocks. Among them, the trusses are assembled together with the steel columns, and the servo system is used to lift the whole block. After the trusses in the hall are lifted into place, the buckle brackets are removed, and the column embedding sections and the facade steel frame are installed. The concrete stands and other processes are interspersed in construction. The height of the lifting brackets in this method is the same as the roof The roof is designed to a certain elevation, and the column base is connected to the concrete beam with embedded parts, and the lifting bracket is connected with bolts; the second is the full-floor bracket method, that is, after the construction of the civil structure is completed, the steel tube concrete columns around the roof are hoisted, and the facade steel frame is installed, and then the disc-type full-floor disc-type bracket is set up on the third floor, and the roof trusses are installed in situ from the middle to both sides; the third is the overall lifting method, that is, the overall assembly of the roof (including steel and wood components and tensioning cables) is completed on the ground, and the lifting bracket and hydraulic equipment are set up. The roof is lifted to the design elevation at multiple points simultaneously, and the supports are fixed after it is in place to complete the final tensioning adjustment.

[0003] For example, Chinese patent CN107190848B discloses an assembled steel-wood hybrid structure system and its construction method. The collaborative design of "steel frame + CLT module" combines the strength of steel and the environmental friendliness of wood, and adopts factory prefabrication + on-site assembly mode for construction.

[0004] However, the block-by-block lifting method is difficult to implement and the construction quality control is relatively complicated. During the lifting process, the steel columns need to be cut off and then welded in situ after being lifted into place, which affects the integrity of the steel-wood structure. In addition, the lifting bracket interferes with the existing steel columns. During the lifting process, the bracket faces the condition of being lifted and dismantled at the same time, and there is a risk of overturning and instability. The bracket disassembly and assembly period is too long, which affects the construction progress. When the steel columns are lifted into place for docking, the docking accuracy cannot be guaranteed, resulting in construction errors. The full-span scaffolding method is the most traditional construction technology with low technical difficulty, but the installation and removal of the full-span scaffolding takes a long time, and the rental and installation fees of the buckle scaffolding are extremely high; The overall lifting method uses a lifting bracket placed on top of the column. During the lifting process, the steel column has a weak lateral stiffness, which causes the steel column to move laterally, leaving the joint mouth open and unable to close accurately. In addition, the wooden components cannot be patched, so the feasibility of this method is questionable. The current construction method has the following difficulties in construction: 1. The large-span steel-wood hybrid structure roof has the characteristics of a steel-wood composite system. To ensure the installation quality of the steel-wood roof, the integrity of the steel-wood structure must be maintained as much as possible during installation; 2. When a single-span, long-span, steel-timber composite roof is tensioned, the out-of-plane calculated lengths of the lower chord timber arch and upper chord steel truss are large, posing a risk of out-of-plane instability. 3. The support frame system is located on the third-story concrete floor. The reinforcement design of the three-story concrete structure is configured according to actual usage requirements. The support frame system is located on the concrete floor, which poses a risk of damaging the lower structure. 4. High costs for equipment procurement, component processing and maintenance; 5. The construction period is tight and the project must be completed early; 6. The support frame system interferes with the steel cables and struts of the large-span steel-wood hybrid structure roof, and the support frame system needs to be repeatedly dismantled to avoid interference; 7. Roof installation is a high-altitude operation, and construction safety and accuracy must be guaranteed.

[0005] Based on this, the present invention designs a large-span tensioned steel-wood hybrid structure construction method to solve the above problems. Summary of the Invention

[0006] In view of the above-mentioned shortcomings of the prior art, the present invention provides a construction method for a large-span tensioned steel-wood hybrid structure.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: A construction method for a large-span steel-wood hybrid structure comprises the following steps: Step 1: Set up two sets of sliding trolleys symmetrically in the middle of the three-story concrete floor, and simultaneously install the central steel columns and facade steel frames; Step 2: Weld the assembly bracket on the upper part of the sliding trolley, and use steel to build an operating platform for construction workers on the top of the assembly bracket; Step 3: Use a truck crane and tower crane to hoist the lower chord timber arch, upper chord steel trusses, struts, steel cables, timber secondary beams, and steel secondary beams; install the first lower chord timber arch and corresponding timber secondary beams at the A15 and A16 axes; then install the second lower chord timber arch, corresponding timber secondary beams, and the upper chord steel trusses, struts, and steel secondary beams corresponding to the first lower chord timber arch; repeat this operation to complete the installation of the remaining parts; install the corresponding steel cables, and complete the initial tensioning; Step 4: Move the two sets of sliding trolleys outward to the A14 and A17 axes respectively, and install the lower chord wooden arch, upper chord steel truss, struts and corresponding wooden and steel secondary beams at the corresponding positions according to the operations in steps 2 and 3. Simultaneously install the wooden and steel secondary beams between A14 and A15 and between A16 and A17. Then install the steel cables at the A14 and A17 axes and complete the initial tensioning. Step 5: Complete the installation of the remaining steel columns and facade steel frames; Step 6: Repeat steps 2, 3 and 4 until the construction of the A4-A27 axis hybrid structure is completed; then the steel cables are fine-tuned for the secondary cable tension as a whole.

[0008] Furthermore, two sets of sliding trolleys are set up for the entire construction process, and the slideways of the two sets of sliding trolleys are symmetrically distributed on the upper side of the three-story concrete floor to facilitate synchronous construction on both sides.

[0009] Furthermore, the three-layer concrete beam includes a main beam and a secondary beam; the slideway is fixed to the three-layer concrete slab, the main beam of the three-layer concrete beam and the secondary beam of the three-layer concrete beam through a sliding trolley fulcrum; wherein the number of sliding trolley fulcrums connected to the three-layer concrete beam exceeds the number of sliding trolley fulcrums connected to the three-layer concrete slab.

[0010] Furthermore, the sliding trolley is made of welded steel pipes and steel sections, and the slideway carries and distributes the load to guide the sliding direction of the sliding trolley.

[0011] Furthermore, a total of 33 sliding trolley fulcrums are set for the operating condition of the sliding trolley, and a total of 24 sliding trolley fulcrums are set for the walking condition.

[0012] Furthermore, the operating platform is fully paved with steel grilles and surrounded by protective fences; adjustable top supports for supporting the lower chord wooden arch are welded on the assembled bracket.

[0013] Furthermore, a wooden pad beam that matches the curvature of the bottom of the lower chord wooden arch is set above the adjustable top support; the wooden pad beam is wrapped with a flexible material to protect the wooden arch beam.

[0014] Furthermore, the erection height of the assembled bracket varies with the linear shape of the wooden arch.

[0015] Furthermore, a top-down support is provided below the weak concrete structure to protect the lower concrete structure.

[0016] Furthermore, during the assembly process, the two adjacent frames and the wooden and steel secondary beams are tensioned simultaneously.

[0017] Compared with the existing technology, the present invention has the following advantages: 1. By constructing a sliding platform from the three-story concrete floor to the designed elevation of the lower chord wooden arch for in-situ assembly, the integrity of the steel-wood structure and the installation quality of the steel-wood roof throughout the construction process are guaranteed; 2. The construction method described in this article assembles the beams one by one from the mid-span toward both sides. That is, first assemble the A15 and A16 axes, and then symmetrically install the single-span large-span steel-timber hybrid structure and connecting secondary beams one by one in the direction of the A4 and A27 axes on both sides. During the construction process, at least two main structures are connected together by secondary beams during tensioning, avoiding the risk of out-of-plane instability caused by tensioning a single beam. 3. The sliding platform has 33 fulcrums for the working condition and 24 fulcrums for the walking condition. A slideway is installed under each fulcrum to act as a distribution beam. In addition, the slideways are mainly arranged on the concrete main beams and secondary beams, and a few are arranged on the concrete floor slabs. For weak concrete structures, a return support is installed below to avoid damage to the lower concrete main structure. 4. Only two sets of sliding platforms are required throughout the entire process, which reduces equipment procurement, component processing, and maintenance costs. Furthermore, this method of sliding construction offers high construction efficiency and ensures a guaranteed construction schedule. 5. Two sliding platforms are set up during the entire construction process, and construction is carried out simultaneously on both sides, which greatly shortens the construction period; 6. The assembly bracket is equipped with inclined columns to avoid interference between the trolley and the main structure steel cables and struts, reducing the repeated disassembly and assembly process of the support frame system and improving construction efficiency; 7. Because this construction method is in-situ assembly, and an operating platform and protective fence are set on the top of the assembly bracket, the risk of high-altitude operations is reduced and the construction safety and accuracy are ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0019] Figure 1 This is a schematic elevation diagram of the erected sliding platform for the construction of a large-span tensioned steel-wood hybrid structure; Figure 2 This is a cross-sectional diagram of the erected side span sliding platform for the initial span (A15-A16 axis) of the large-span tensioned steel-timber hybrid structure. Figure 3 This is a cross-sectional diagram of the mid-span sliding platform erected for the construction of the initial span (A15-A16 axis) of the large-span tensioned steel-timber hybrid structure. Figure 4This is a plan view of the relative positions of the erected sliding platform and the roof for the construction of the starting span (A15-A16 axis) of the large-span tensioned steel-timber hybrid structure; Figure 5 This is a plan view of the relative positions of the erected sliding platform and the roof for the terminal span (A5-A26 axes) of the long-span tensioned steel-timber hybrid structure. Figure 6 This is a plan view of the relative positions of the erected sliding platform and the concrete main structure for the construction of the starting span (A15-A16 axis) of the large-span tensioned steel-timber hybrid structure; Figure 7 This is a plan view of the relative positions of the erected sliding platform and the concrete main structure for the construction of the terminal span (A5~A26 axes) of the large-span tensioned steel-wood hybrid structure.

[0020] The numbers in the figure represent: 10. Large-span steel-wood composite roof with tensioned chords; 11. Three-story concrete floor; 12. Three-story concrete beams; 13. Three-story concrete slab; 14. Lower chord wooden arch; 15. Upper chord steel truss; 16. Struts; 17. Steel cables; 18. Steel corbels; 19. Steel columns and facade steel frames; 20. Sliding trolley; 21. Slideway; 22. Operating platform; 23. Wooden secondary beam; 24. Sliding trolley fulcrum; 25. Steel secondary beam. A5-A27 are the axis numbers corresponding to the locations where the hybrid structure is installed; BD to BR are numbered 12. DETAILED DESCRIPTION

[0021] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only 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 making any creative efforts shall fall within the scope of protection of the present invention.

[0022] The terms “left,” “right,” “front,” “back,” “up,” and “down” mentioned in the following description are oriented in the viewing direction of the front view.

[0023] Example: In some embodiments, please refer to the accompanying drawings of the specification. Figure 1-Figure 7 A method for constructing a large-span steel-wood hybrid structure comprises the following steps: Step 1: Two sets of sliding trolleys 20 are symmetrically set up in the middle of the three-story concrete floor 11, and the steel columns in the middle and the facade steel frame 19 are installed simultaneously; After the civil construction is completed, construction can begin when the concrete floor of axes A11 to A21 is poured until the component strength reaches 100% of the design strength; two sets of sliding trolleys 20 are symmetrically set up at axes A15 and A16 on the upper side of the three-story concrete floor 11; and the steel columns and facade steel frames 19 at axes A13 to A20 are installed simultaneously; During the whole construction process, two sets of sliding trolleys 20 are set up, and the slideways 21 of the two sets of sliding trolleys 20 are symmetrically distributed on the upper side of the three-story concrete floor 11 to facilitate synchronous construction on both sides; The three-layer concrete beam 12 includes a main beam and a secondary beam; the slideway 21 is fixed to the three-layer concrete slab 13, the main beam of the three-layer concrete beam 12, and the secondary beam of the three-layer concrete beam 12 through the sliding trolley support points 24; the number of the sliding trolley support points 24 connected to the three-layer concrete beam 12 exceeds the number of the sliding trolley support points 24 connected to the three-layer concrete slab 13; The sliding trolley 20 is made of welded steel pipes and steel sections, and the slideway 21 carries and distributes the load and guides the sliding direction of the sliding trolley 20; The sliding trolley 20 is provided with 33 sliding trolley fulcrums 24 in the working state and 24 sliding trolley fulcrums 24 in the walking state; There are only two sets of operating platforms 22 in the whole process, and the cost of equipment procurement, component processing and maintenance is low. In addition, the sliding construction using this method has high construction efficiency and ensures the construction period.

[0024] Step 2: Weld an assembly bracket on the upper part of the sliding trolley 20, and use steel to build an operating platform 22 for construction workers on the top of the assembly bracket; The operating platform 22 is fully paved with steel grids and surrounded by protective fences; an adjustable top support for supporting the lower chord wooden arch 14 is welded on the assembled bracket; A wooden pad beam that matches the curvature of the bottom of the lower chord wooden arch 14 is arranged above the adjustable top support; the wooden pad beam is wrapped with a flexible material to protect the wooden arch beam.

[0025] The erection height of the assembling bracket varies with the linear shape of the wooden arch.

[0026] In the weak concrete structure, a return support is set below to protect the lower concrete structure.

[0027] Step 3: Use a truck crane and tower crane to hoist the lower chord wooden arch 14, upper chord steel truss 15, struts 16, steel cables 17, wooden secondary beams 23, and steel secondary beams 25; install the first lower chord wooden arch 14 and the corresponding wooden secondary beams 23 at the A15 and A16 axes; then install the second lower chord wooden arch 14, the corresponding wooden secondary beams 23, and the upper chord steel truss 15, struts 16, and steel secondary beams 25 corresponding to the first lower chord wooden arch 14; repeat this operation to complete the installation of the remaining parts; install the corresponding steel cables 17, and complete the initial tensioning; The first lower chord wooden arch 14 is installed as follows: the first lower chord wooden arch 14 at the A15 and A16 axes is fixed to the steel corbel 18, and then the steel corbel 18 is fixed to the steel column and the facade steel frame 19; Step 4: The two sets of sliding trolleys 20 move outward to the A14 and A17 axes respectively, and install the lower chord wooden arch 14, upper chord steel truss 15, struts 16 and corresponding wooden secondary beams 23 and steel secondary beams 25 at the corresponding positions according to the operations of steps 2 and 3, and simultaneously install the wooden secondary beams 23 and steel secondary beams 25 between A14 and A15 and A16 and A17; then install the steel cables 17 at the A14 and A17 axes and complete the initial tensioning; Step 5: Complete the installation of the remaining steel columns and facade steel frame 19; Step 6: Repeat steps 2, 3 and 4 until the construction of the A4-A27 axis hybrid structure is completed; then the steel cable 17 is fine-tuned for the secondary cable force as a whole.

[0028] The above steps enable in-situ assembly, thus ensuring the integrity and installation quality of the large-span steel-wood hybrid structure. The frames are assembled symmetrically according to the construction sequence, and at least two frames are required to work together during assembly and tensioning; Two sets of sliding trolleys 20 are set up during the whole construction process. The construction sequence is to assemble one by one from the middle of the span to both sides, that is, first assemble the A15 and A16 axes, and then symmetrically install the single-span large-span tensile steel-wood hybrid structure roof 10, as well as the wooden secondary beams 23 and the steel secondary beams 25 one by one in the direction of the A4 axis and the A27 axis on both sides; thereby balancing the internal forces of the structure, reducing the eccentric force caused by unilateral assembly, and ensuring out-of-plane stability.

[0029] During the assembly process, the two adjacent frames and the wooden secondary beams 23 and the steel secondary beams 25 are tensioned synchronously, thereby reducing the out-of-plane calculated length of the lower chord wooden arch 14 and the upper chord steel truss 15. The overall stiffness of the structure is used to resist the tension stress, avoiding lateral deformation or instability when a single frame is tensioned, and ensuring out-of-plane stability.

[0030] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A construction method for a large-span steel-wood hybrid structure, characterized by: The following steps are involved: Step 1: symmetrically set up two sets of sliding trolleys (20) in the middle of the three-story concrete floor (11), and simultaneously install the steel columns in the middle and the facade steel frame (19); Step 2: Weld an assembly bracket on the upper part of the sliding trolley (20), and use steel to build an operating platform (22) for construction workers on the top of the assembly bracket; Step 3: Use a car crane and a tower crane to hoist the lower chord wooden arch (14), the upper chord steel truss (15), the strut (16), the steel cable (17), the wooden secondary beam (23) and the steel secondary beam (25); install the first lower chord wooden arch (14) and the corresponding wooden secondary beam (23) at the A15 and A16 axes; then install the second lower chord wooden arch (14), the corresponding wooden secondary beam (23) and the upper chord steel truss (15), the strut (16) and the steel secondary beam (25) corresponding to the first lower chord wooden arch (14); repeat this operation to complete the installation of the remaining parts in sequence; install the corresponding steel cable (17), and complete the initial tensioning; Step 4: The two sets of sliding trolleys (20) are moved outward to the A14 and A17 axes respectively, and the lower chord wooden arch (14), the upper chord steel truss (15), the strut (16) and the corresponding wooden secondary beams (23) and steel secondary beams (25) are installed at the corresponding positions according to the operations of steps 2 and 3, and the wooden secondary beams (23) and steel secondary beams (25) between A14 and A15 and A16 and A17 are installed simultaneously; then the steel cables (17) at the A14 and A17 axes are installed, and the initial tensioning is completed; Step 5: Complete the installation of the remaining steel columns and facade steel frames (19); Step 6: Repeat steps 2, 3 and 4 until the construction of the A4-A27 axis hybrid structure is completed; and then the steel cable (17) is fine-tuned for the secondary cable force as a whole.

2. The method for constructing a large-span steel-wood hybrid structure according to claim 1, characterized in that: Two sets of sliding trolleys (20) are provided during the entire construction process. The slideways (21) of the two sets of sliding trolleys (20) are symmetrically distributed on the upper side of the three-story concrete floor (11) to facilitate synchronous construction on both sides.

3. The construction method of a large-span steel-wood hybrid structure according to claim 1 is characterized in that: The three-layer concrete beam (12) includes a main beam and a secondary beam; the slideway (21) is fixed to the three-layer concrete slab (13), the main beam of the three-layer concrete beam (12) and the secondary beam of the three-layer concrete beam (12) through the sliding trolley support (24); wherein the number of the sliding trolley support (24) connected to the three-layer concrete beam (12) exceeds the number of the sliding trolley support (24) connected to the three-layer concrete slab (13).

4. The method for constructing a large-span steel-wood hybrid structure according to claim 1, characterized in that: The sliding trolley (20) is formed by welding steel pipes and section steel, and carries and distributes loads through the slideway (21), thereby guiding the sliding direction of the sliding trolley (20).

5. The construction method of a large-span steel-wood hybrid structure according to claim 1 is characterized in that: A total of 33 sliding trolley fulcrums (24) are provided for the operating working condition of the sliding trolley (20), and a total of 24 sliding trolley fulcrums (24) are provided for the walking working condition.

6. The method for constructing a large-span steel-timber hybrid structure according to claim 1, characterized in that: The operating platform (22) is fully paved with steel grids and surrounded by protective fences; an adjustable top support for supporting the lower chord wooden arch (14) is welded on the assembled bracket.

7. The method for constructing a large-span steel-timber hybrid structure according to claim 1, characterized in that: A wooden pad beam that matches the curvature of the bottom of the lower chord wooden arch (14) is arranged above the adjustable top support; the wooden pad beam is made of a wrapped flexible material to protect the wooden arch beam.

8. The method for constructing a large-span steel-timber hybrid structure according to claim 1, characterized in that: The erection height of the assembling bracket varies with the linear shape of the wooden arch.

9. The method for constructing a large-span steel-timber hybrid structure according to claim 1, characterized in that: In the weak concrete structure, a return support is set below to protect the lower concrete structure.

10. The method for constructing a large-span steel-timber hybrid structure according to claim 1, characterized in that: During the assembly process, the two adjacent beams and the wooden secondary beam (23) and the steel secondary beam (25) are tensioned synchronously.

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