Concrete inner formwork supporting system construction method for ultra-large wind tunnel diffusion section

Abstract

The invention discloses a construction method of a concrete inner formwork supporting system for an ultra-large wind tunnel diffusion section. The construction method comprises the steps that S1, full-simulation modeling is conducted on a runner structure and a steel formwork according to a construction drawing by means of the BIM technology; s2, after processing by a factory, re-checking and splicing the steel templates by using BIM data, and pasting two-dimensional codes, and S3, carrying out on-site positioning and paying-off on each section of the inner steel template; s4, before the inner template supporting system is installed, the worker installs the inner template supporting system according to the sequence of animation demonstration of the BIM model; s4, before the inner template supporting system is installed, a BIM engineer makes and installs animation demonstration through the inner steel cylinder template BIM model, visual disclosure is conducted on field management personnel and workers, and the workers install the inner template supporting system according to the sequence of animation demonstration; effective combination of the bottom plate and the steel formwork can be effectively guaranteed, displacement of the steel formwork in the mounting process is prevented, defects existing in construction are reduced, and working efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of concrete flow channel engineering, and in particular to a construction method for a concrete inner formwork support system for a super-large wind tunnel diffusion section. Background Art

[0002] As the automotive industry continues to increase its requirements for performance and efficiency, more and more large automakers and research institutes are planning to build their own large concrete wind tunnel test chambers. The flow channel diffuser section in the wind tunnel is a key part of the wind tunnel design. Its function is to smoothly transition between the fan room and the test section to reduce energy loss and turbulence of the airflow and ensure the uniformity and stability of the airflow in the test section.

[0003] The diffuser section of the flow channel is usually designed to gradually transition from the polygonal circular cross-section of the fan room to the square cross-section of the test section. This design requires very high precision to ensure a smooth transition of the airflow during the diffusion process and avoid unnecessary turbulence and pressure loss. Since the length of the diffuser section is usually more than 30 meters, as the inner wall of the wind tunnel flow channel, in order to ensure the quality of the test section flow channel, such as the uniformity of airflow velocity distribution, the deviation of the average airflow direction from the wind tunnel axis, the pressure gradient along the wind tunnel axis, the uniformity of the cross-sectional temperature distribution, the turbulence of the airflow and the noise level, its spatial positioning and inner surface flatness deviation must not exceed 5mm. At the same time, since the airflow velocity in the wind tunnel is extremely high, reaching 250km / h, it is strictly forbidden to repair the inner surface later. It can be seen that the construction of the automobile wind tunnel requires very high construction accuracy of the inner wall of the wind tunnel. Therefore, the construction of the inner mold support system is the most critical step. Moreover, since the diffuser section of the wind tunnel is a gradually deformed structure, the size of each section is different. Therefore, during the construction process, the traditional wooden formwork plus steel pipe scaffolding formwork system can no longer meet the requirements of on-site construction and quality accuracy. Summary of the invention

[0004] The invention aims to address the deficiencies of the prior art and to provide a method for constructing an internal formwork support system for a diffusion section of an ultra-large wind tunnel, which effectively solves the construction difficulty of a polygonal circular-to-square diffusion section of an ultra-large wind tunnel. By applying this method, an internal formwork support system that meets the construction accuracy requirements can be built to ensure the smooth completion of the construction.

[0005] In order to achieve the above-mentioned purpose, the invention adopts the following technical solutions:

[0006] The construction method of the concrete inner formwork support system for the diffusion section of a super-large wind tunnel includes the following steps:

[0007] S1. Use BIM technology to fully simulate the flow channel structure and steel formwork according to the construction drawings, extract model data, determine the steel formwork size data piece by piece through precise virtual assembly, establish the project steel formwork prefabrication processing family library, and draw nodes for the three-dimensional model of each steel formwork and fastener, and show the four corner elevations of each steel formwork in detail. Feedback the family library steel formwork information to the steel formwork processing manufacturer, and the manufacturer directly extracts the steel formwork model size information for steel formwork processing;

[0008] S2. After the factory finishes processing, the steel formwork is checked and assembled using BIM data, and the QR code is affixed. After inspection and passing, it is transported to the construction site. After the steel formwork arrives at the site, material acceptance is carried out, and the size, flatness, curvature and chord length data of each steel formwork are checked piece by piece according to the QR code data to ensure that the design requirements are met;

[0009] S3. Perform on-site positioning and laying out of each cross-section of the inner steel formwork. When performing on-site positioning and laying out of each cross-section of the inner steel formwork, the distance from the center point of the flow channel to each inclined intersection is calculated based on the BIM model and CAD drawings of each flow channel cross section to locate the corresponding cross-section;

[0010] S4. Before installing the internal formwork support system, the BIM engineer uses the internal steel cylinder formwork BIM model to create an installation animation demonstration and conducts a visual briefing for on-site managers and workers. The workers install the internal formwork support system according to the order of the animation demonstration;

[0011] S5. When the concrete construction of the bottom plate plane of the polygonal-to-square main diffusion section and the structural support columns below it is completed and reaches the required strength, the steel formwork units and steel support truss units are positioned and installed.

[0012] The positioning and installation method of the steel formwork unit and the steel support truss unit is as follows:

[0013] P1. Support the external frame unit, install the outer bottom plate steel formwork, the outer corresponding bevel steel formwork and the bevel external support, and pour the wind tunnel diffusion section bottom plate concrete;

[0014] P2. Install the steel formwork units corresponding to the corresponding inner bevel formwork and pour the bottom slab concrete horizontally;

[0015] P3. Integrally install the longitudinal support columns and the remaining transverse support columns of the steel formwork units and steel support truss units corresponding to the inner wall bottom formwork and the side wall formwork. The longitudinal support columns and the transverse support columns are vertically connected to the first horizontal support at the intersection by bolt connection;

[0016] P4. Install the remaining steel formwork units of the inner steel tube formwork and the remaining transverse support columns and longitudinal support columns of the steel support truss units as a whole. The support construction and formwork construction are carried out simultaneously until the second horizontal support;

[0017] P5. Install the steel formwork units and steel support truss units corresponding to the top plate formwork;

[0018] P6. To ensure that the cross-sectional dimensions of the steel formwork meet the design requirements, each layer of installation starts from the octagonal opening and installs the side wall and top plate steel formwork ring by ring to the square opening;

[0019] P7. After the overall installation of the steel formwork unit and the steel support truss unit of the inner steel tube formwork is completed, cast the lower inclined plate;

[0020] P8. Support the outer steel formwork of the side wall and pour concrete. After the concrete pouring is completed, tie the outer steel formwork support frame;

[0021] P9. Support the outer steel formwork of the inclined plate and pour concrete. After the pouring of the inclined plate concrete is completed, tie the formwork to the outer support frame;

[0022] P10. Pour top slab concrete.

[0023] In the step S5, the horizontal distance position size and elevation of each symmetrical steel formwork unit are calculated using BIM technology according to the template. After each ring is installed according to the design requirements, the horizontal distance position size and elevation of each symmetrical steel formwork unit are reviewed. Only after they are qualified can the next ring be installed.

[0024] In the S5 step, during the installation of the inner formwork support system, the inner steel cylinder formwork is treated to prevent floating, and the method is as follows: high-strength bolts are pre-embedded and installed during the concrete construction of the base plate plane, and when the inner steel cylinder formwork is to be installed, the high-strength bolts are connected to the longitudinal support columns of the steel support truss unit and the bottom of the inner steel cylinder formwork through a manual hoist, and the structural support columns under the base plate are used to pull the inner steel cylinder formwork to prevent floating.

[0025] The internal formwork support system includes steel formwork units, steel support truss units, external frame units and distribution beam conversion supports. Steel support truss units are arranged on the inner side of the steel formwork units, and external frame units are arranged on the outer side. The distribution beam conversion supports provide a flat contact surface for the main keel of the oblique formwork in the steel formwork unit and the distribution beam in the support truss unit.

[0026] The steel formwork unit comprises a steel formwork, a tie rod and an adjustable diagonal brace. The steel formwork is connected to the main keel and the outer concrete through the tie rod, and the main keel is connected to the steel support truss unit through the adjustable diagonal brace.

[0027] The steel template comprises steel plates and secondary ribs, and the secondary ribs are evenly arranged between two steel plates.

[0028] The pull rod comprises a climbing cone and a pull rod body, and the pull rod body is sleeved with the climbing cone.

[0029] The steel support truss unit includes a support truss main upright, a support truss horizontal rod, a support truss diagonal rod and a distribution beam. The support truss horizontal rod is vertically connected to the support truss main upright, the support truss diagonal rod is obliquely connected to the support truss horizontal rod and the diagonal of the support truss main upright, the support truss main upright includes a round tube and an adjustable support head, and the distribution beam is connected to the top of the support truss main upright through the adjustable support head connected to the top of the round tube.

[0030] In the P1 step, the external frame unit is supported by using a disc-type scaffolding to erect the frame.

[0031] The beneficial effects of the invention are as follows: the invention first constructs the bottom plate steel formwork, and then constructs the side wall and top plate steel formwork ring by ring from the flow channel diffusion ring section to the rectangular section, which can effectively ensure the effective combination of the bottom plate and the steel formwork, prevent displacement during the installation of the steel formwork, and timely review the inner diameter of the flow channel to speed up the construction progress. At the same time, it reduces the drawbacks in the construction and improves work efficiency to meet the formwork requirements at the main diffusion section of the octagonal to quadrilateral transformation. BIM engineers participate in the design, processing and installation of the inner steel formwork throughout the process. By applying this method, an inner formwork support system that meets the construction accuracy requirements can be built to ensure the smooth completion of the construction, effectively solving the construction technical problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a elevation view of the template and keel support of the present invention;

[0033] Figure 2 It is the keel and support plane layout diagram of the present invention;

[0034] Figure 3 It is a rectangular side segment template and keel support diagram of the present invention;

[0035] Figure 4 This is a diagram of the variable cross-section template and keel support of the present invention;

[0036] Figure 5 It is the octagonal segment template and keel support diagram of the present invention;

[0037] Figure 6 It is a schematic diagram of the keel support truss upright structure of the present invention;

[0038] Figure 7 It is a schematic diagram of the steel template structure of the present invention;

[0039] Figure 8 It is a schematic diagram of the pull rod structure of the present invention;

[0040] Fig. 9 It is a schematic diagram of the connection between the partial beam conversion support and the oblique formwork of the present invention;

[0041] Fig.10 It is a schematic diagram of the connection structure between the template and keel support and the external frame of the present invention;

[0042] In the figure: 1-steel formwork unit; 11-steel formwork; 111-steel plate; 112-secondary rib; 113-main keel; 12-pull rod; 121-pull rod body; 122-climbing cone; 13-adjustable diagonal brace; 2-steel support truss unit; 21-longitudinal support column; 211-round tube; 212-adjustable support head; 22-transverse support column; 23-support truss diagonal rod; 24-distribution beam; 3-external frame unit; 4-distribution beam conversion support; 5-high-strength bolt; 6-manual hoist;

[0043] The following is a detailed description of the embodiments of the invention with reference to the accompanying drawings. DETAILED DESCRIPTION

[0044] The invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0045] like Figure 1-Figure 10 As shown, take the octagonal shape into a square as an example:

[0046] The construction method of the concrete inner formwork support system for the diffusion section of a super-large wind tunnel includes the following steps:

[0047] S1. Use BIM technology to fully simulate the flow channel structure and steel template 11 according to the construction drawings, extract model data, determine the size data of the steel template 11 piece by piece through precise virtual assembly, draw nodes for the three-dimensional model of each template and fastener, and show the four corner elevations of each template in detail. Establish a prefabrication processing family library of the project steel template 11, draw nodes for the three-dimensional model of each steel template 11 and fastener, and show the four corner elevations of each steel template 11 in detail. Feedback the family library steel template 11 information to the steel template 11 processing manufacturer, and the manufacturer directly extracts the steel template 11 model size information to process the steel template 11;

[0048] S2. After the factory completes the processing, the BIM data is used to review and assemble the steel formwork 11, and the QR code is affixed. After inspection, it is transported to the construction site. After the steel formwork 11 arrives at the site, the material acceptance is carried out, and the size, flatness, curvature and chord length data of each steel formwork 11 are reviewed piece by piece according to the QR code data to ensure that the design requirements are met;

[0049] S3. The construction personnel quickly determine the information data and positioning information of the steel template 11 by scanning the QR code, quickly complete the precise positioning and installation of the steel template, and perform on-site positioning and laying out of each cross-sectional segment of the inner steel template 11. When performing on-site positioning and laying out of each cross-sectional segment of the inner steel template 11, the distance from the center point of the flow channel to each inclined intersection is calculated based on the BIM model and CAD drawings of each flow channel cross section to locate the corresponding cross-sectional segment;

[0050] S4. Before installing the inner formwork support system, the BIM engineer uses the inner steel tube formwork BIM model to make an installation animation demonstration and conducts visual briefings to on-site managers and workers. The workers install the inner formwork support system according to the order of the animation demonstration. The inner formwork support system includes a steel formwork unit 1, a steel support truss unit 2, an external frame unit 3, and a distribution beam conversion support 4. The steel support truss unit 2 is set inside the steel formwork unit 1, and the external frame unit 3 is set outside. The distribution beam conversion support 4 is the oblique formwork in the steel formwork unit 1. The main keel 113 and the distribution beam 24 in the supporting truss unit 2 provide a flat contact surface and are steel plate assemblies; the steel formwork unit 1 includes a steel formwork 11, a tie rod 12 and an adjustable diagonal brace 13. The steel formwork 11 is connected to the main keel 113 and the outer concrete through the tie rod 12, and the main keel 113 is connected to the steel supporting truss unit 2 through the adjustable diagonal brace 13; the adjustable diagonal brace 13 uses an adjustable diagonal brace to level the formwork. The main keel 113 uses No. 12 double channel steel. The steel formwork 11 includes a steel plate 111 and a secondary rib 112. The thickness of the steel plate 111 is 6mm, the secondary rib 112 adopts No. 8 single channel steel, and the secondary rib 112 is evenly arranged between the two steel plates 111; the tie rod 12 includes a climbing cone 122 and a tie rod body 121, the tie rod body 121 is sleeved with the climbing cone 122, the tie rod body 121 is a D20 tie rod, and a water stop screw can be added in the middle; the steel support truss unit 2 includes a support truss main vertical rod 21, a support truss horizontal rod 22, a support truss diagonal rod 23 and a distribution beam 24, the support truss horizontal rod 22 is vertically connected to the support truss main vertical rod 21, and the support truss diagonal rod 23 is obliquely connected to At the diagonal position of the supporting truss horizontal rod 22 and the supporting truss main vertical rod 21, the supporting truss main vertical rod 21 includes a round tube 211 and an adjustable support head 212, the round tube is φ160mm, the supporting truss horizontal rod 22 is double No. 10 channel steel, the supporting truss diagonal rod 23 is single No. 12 channel steel, the distribution beam 24 is connected to the top of the supporting truss main vertical rod 21 through the adjustable support head 212 connected to the top of the round tube 211, the distribution beam 24 is used to evenly transfer the top formwork and concrete load to the supporting bridge, and the distribution beam 24 is No. 28 I-beam;

[0051] S5. According to the template, use BIM technology to calculate the horizontal distance position size and elevation of each symmetrical steel formwork unit 1. After each ring is installed according to the design requirements, check the horizontal distance position size and elevation of each symmetrical steel formwork unit 1. Only after passing the test can the next ring be installed. When the concrete construction of the bottom plate plane of the polygonal to square main diffusion section and the structural support column below it is completed and reaches the strength, the steel formwork unit 1 and the steel support truss unit 2 are positioned and installed. During the installation of the inner formwork support system, the anti-floating treatment of the inner steel cylinder formwork is carried out. The method is: when the bottom plate plane concrete construction is carried out, the high-strength bolts 5 are pre-embedded and installed. When the inner steel cylinder formwork is to be installed, the high-strength bolts 5 are connected with the longitudinal support columns 21 of the steel support truss unit 2 and the bottom of the inner steel cylinder formwork through a manual hoist 6. The structural support column under the bottom plate is used to pull the inner steel cylinder formwork to prevent floating. The positioning and installation method of the steel formwork unit 1 and the steel support truss unit 2 is as follows:

[0052] P1. Support the external frame unit 3. The external frame unit 3 adopts a disc-type scaffolding to set up the frame, install the outer bottom plate steel formwork 11, the outer corresponding bevel steel formwork 11 and the bevel external support, and pour the wind tunnel diffusion section bottom plate concrete;

[0053] P2. Install the steel formwork unit 1 corresponding to the corresponding inner bevel formwork, and pour the bottom slab concrete horizontally;

[0054] P3. The longitudinal support columns 21 and the remaining transverse support columns 22 of the steel formwork unit 1 and the steel support truss unit 2 corresponding to the inner wall bottom formwork and the side wall formwork are integrally installed, and the longitudinal support columns 21 and the transverse support columns 22 are vertically connected to the first horizontal support by bolt connection at the intersection;

[0055] P4. Install the remaining steel formwork units 1 of the inner steel tube formwork and the remaining transverse support columns 22 and longitudinal support columns 21 of the steel support truss units 2 as a whole, and carry out support construction and formwork construction simultaneously until the second horizontal support;

[0056] P5. Install the steel formwork unit 1 and steel support truss unit 2 corresponding to the top plate formwork;

[0057] P6. To ensure that the cross-sectional dimensions of the steel template 11 meet the design requirements, each layer is installed ring by ring from the octagonal opening to the square opening of the side wall and top plate steel template 11;

[0058] P7. After the overall installation of the steel formwork unit 1 and the steel support truss unit 2 of the inner steel tube formwork is completed, cast the lower inclined plate;

[0059] P8. Support the outer steel formwork of the side wall and pour concrete. After the concrete pouring is completed, tie the outer steel formwork support frame;

[0060] P9. Support the outer steel formwork of the inclined plate and pour concrete. After the pouring of the inclined plate concrete is completed, tie the formwork to the outer support frame;

[0061] P10. Pour top slab concrete.

[0062] In the description of the invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the invention.

[0063] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0064] In the invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be fixedly connected, detachably connected, or integrated; it can be mechanically connected, electrically connected, or able to communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0065] The invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the invention is not limited to the above-mentioned method. As long as various improvements are made using the method concept and technical solution of the invention, or they are directly applied to other occasions without improvement, they are all within the scope of protection of the invention.

Claims

1. A construction method for a concrete inner formwork support system for a super-large wind tunnel diffusion section, characterized in that: The steps are: S1. Use BIM technology to fully simulate the flow channel structure and steel template (11) according to the construction drawings, extract model data, determine the size data of the steel template (11) piece by piece through precise virtual assembly, establish a family library of prefabricated processing of the project steel template (11), and draw nodes for the three-dimensional model of each steel template (11) and fasteners, and display the four corner elevations of each steel template (11) in detail. Feedback the family library steel template (11) information to the steel template (11) processing manufacturer, and the manufacturer directly extracts the steel template (11) model size information to process the steel template (11); S2. After the factory completes the processing, the steel formwork (11) is checked and assembled using the BIM data, and the QR code is affixed. After inspection and approval, the steel formwork (11) is transported to the construction site. After the steel formwork (11) is delivered to the site, the material acceptance is carried out. The size, flatness, curvature and chord length data of each steel formwork (11) are checked piece by piece according to the QR code data to ensure that the design requirements are met; S3. Conduct on-site positioning and laying out of each cross-sectional segment of the inner steel formwork (11). When conducting on-site positioning and laying out of each cross-sectional segment of the inner steel formwork (11), the distance from the center point of the flow channel to each inclined intersection is calculated based on the BIM model and CAD drawings of each flow channel cross section to locate the corresponding cross-sectional segment; S4. Before installing the internal formwork support system, the BIM engineer uses the internal steel cylinder formwork BIM model to create an installation animation demonstration and conducts a visual briefing for on-site managers and workers. The workers install the internal formwork support system according to the order of the animation demonstration; S5. When the concrete construction of the bottom plate plane of the polygonal-to-square main diffusion section and the structural support columns below it is completed and reaches the required strength, the steel formwork unit (1) and the steel support truss unit (2) are positioned and installed.

2. The method for constructing a concrete inner formwork support system for a super-large wind tunnel diffusion section according to claim 1 is characterized in that: The positioning and installation method of the steel formwork unit (1) and the steel support truss unit (2) is as follows: P1. Support the external frame unit (3), install the outer bottom plate steel formwork, the outer corresponding bevel steel formwork and the bevel external support, and pour the wind-driven diffusion section bottom plate concrete; P2. Install the corresponding steel formwork unit (1) on the inner side of the corresponding bevel formwork and pour the bottom slab concrete horizontally; P3. The longitudinal support columns (21) and the remaining transverse support columns (22) of the steel formwork units (1) and the steel support truss units (2) corresponding to the inner wall bottom formwork and the side wall formwork are integrally installed, and the longitudinal support columns (21) and the transverse support columns (22) are vertically connected to the first horizontal support at the intersection by bolt connection; P4. The remaining steel formwork units (1) and the remaining steel support truss units (2) of the inner steel tube formwork are integrally installed, and the lateral support columns (22) and longitudinal support columns (21) of the remaining steel support truss units (2) are simultaneously carried out to the second horizontal support by the support construction and formwork construction; P5. Install the steel formwork unit (1) and the steel support truss unit (2) corresponding to the top plate formwork; P6. To ensure that the cross-sectional dimensions of the steel template (11) meet the design requirements, each layer is installed from the octagonal opening to the square opening, starting from the side wall and top plate steel templates (11) ring by ring; P7. After the overall installation of the steel formwork unit (1) and the steel support truss unit (2) of the inner steel tube formwork is completed, the lower inclined plate is cast; P8. Support the outer steel formwork of the side wall and pour concrete. After the concrete pouring is completed, tie the outer steel formwork support frame; P9. Support the outer steel formwork of the inclined plate and pour concrete. After the pouring of the inclined plate concrete is completed, tie the formwork to the outer support frame; P10. Pour top slab concrete.

3. The method for constructing a concrete inner formwork support system for a super-large wind tunnel diffusion section according to claim 2 is characterized in that: In the step S5, the horizontal distance position size and elevation of each symmetrical steel formwork unit (1) are calculated using BIM technology according to the template. After each ring is installed according to the design requirements, the horizontal distance position size and elevation of each symmetrical steel formwork unit (1) are checked. Only after they are qualified can the next ring be installed.

4. The method for constructing a concrete inner formwork support system for a super-large wind tunnel diffusion section according to claim 3 is characterized in that: In the step S5, during the installation of the inner formwork support system, the inner steel cylinder formwork is subjected to anti-floating treatment, and the method is as follows: high-strength bolts (5) are pre-buried and installed during the bottom plate plane concrete construction, and when the inner steel cylinder formwork is to be installed, the high-strength bolts (5) are connected to the longitudinal support columns (21) of the steel support truss unit (2) and the bottom of the inner steel cylinder formwork through a manual hoist (6), and the structural support columns under the bottom plate are used to pull the inner steel cylinder formwork to prevent floating.

5. The method for constructing a concrete inner formwork support system for a super-large wind tunnel diffusion section according to claim 4 is characterized in that: The inner formwork support system comprises a steel formwork unit (1), a steel support truss unit (2), an external frame unit (3) and a distribution beam conversion support (4); the steel support truss unit (2) is arranged on the inner side of the steel formwork unit (1), and the external frame unit (3) is arranged on the outer side; the distribution beam conversion support (4) provides a flat contact surface for the main keel (113) of the oblique formwork in the steel formwork unit (1) and the distribution beam (24) in the support truss unit (2).

6. The method for constructing a concrete inner formwork support system for a super-large wind tunnel diffusion section according to claim 5, characterized in that: The steel formwork unit (1) comprises a steel formwork (11), a tie rod (12) and an adjustable diagonal brace (13); the steel formwork (11) is connected to the main keel (113) and the outer concrete via the tie rod (12); the main keel (113) is connected to the steel support truss unit (2) via the adjustable diagonal brace (13).

7. The method for constructing a concrete inner formwork support system for a super-large wind tunnel diffusion section according to claim 6, characterized in that: The steel template (11) comprises a steel plate (111) and secondary ribs (112), and the secondary ribs (112) are evenly distributed between the two steel plates (111).

8. The method for constructing a concrete inner formwork support system for a super-large wind tunnel diffusion section according to claim 7, characterized in that: The pull rod (12) comprises a climbing cone (122) and a pull rod body (121), and the pull rod body (121) is sleeved with the climbing cone (122).

9. The method for constructing a concrete inner formwork support system for a super-large wind tunnel diffusion section according to claim 8, characterized in that: The steel support truss unit (2) comprises a support truss main vertical pole (21), a support truss horizontal pole (22), a support truss diagonal pole (23) and a distribution beam (24); the support truss horizontal pole (22) is vertically connected to the support truss main vertical pole (21); the support truss diagonal pole (23) is obliquely connected to the diagonal position between the support truss horizontal pole (22) and the support truss main vertical pole (21); the support truss main vertical pole (21) comprises a circular tube (211) and an adjustable support head (212); the distribution beam (24) is connected to the top of the support truss main vertical pole (21) through the adjustable support head (212) connected to the top of the circular tube (211).

10. The method for constructing a concrete inner formwork support system for a super-large wind tunnel diffusion section according to claim 9, characterized in that: In the step P1, the external frame unit (3) is supported by using a disc-type scaffolding to erect the frame.

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