Radial single-tower support system of cantilever roof steel structure and construction method

Abstract

The present application relates to a kind of radial single cradle support system of cantilever roof steel structure and construction method.The radial single cradle support system includes construction equipment placing platform (1), intermediate connecting platform (3) and height adjusting structure;The height adjusting structure includes first height adjusting structure (2) and second height adjusting structure (4);The construction equipment placing platform (1), first height adjusting structure (2), intermediate connecting platform (3) and second height adjusting structure (4) are sequentially connected.Compared with prior art, the present application can solve the problems of large amount of material consumption, long installation and removal construction period, great influence on upper structure stress, high requirements for lower construction space and other problems of traditional radial multiple cradle support system.

Description

Technical Field

[0001] This invention relates to the field of building steel structure technology, specifically to a radial single-frame support system and construction method for cantilever roof steel structures. Background Technology

[0002] Nowadays, large-span steel structure roofs are a common structural form in buildings such as large stadiums. Due to their large span and complex structural system, they are often constructed and installed in sections along the circumference. Since they can only bear their own load after the cables are tensioned, a large number of temporary supports are often required, which are then removed after the cables are tensioned.

[0003] Generally, traditional formwork support systems divide the structure into circumferential segments, and then install multiple radial formwork supports on each cantilever segment, from the support to the cantilever end, to meet the load-bearing requirements of the structure before it bears its own load. Because there are many radial formwork supports and the stress at each support is small, the design and construction are relatively simple.

[0004] However, the aforementioned radial multi-scaffold support makes multiple contacts with the superstructure, which complicates the stress on the supported superstructure. Furthermore, multiple scaffolds also lead to higher construction costs, more complex installation and dismantling, and longer construction periods. In addition, due to the presence of multiple scaffolds radially, the substructure of the scaffolds near the cantilever supports will place higher demands on the construction space and conditions below. Summary of the Invention

[0005] The purpose of this invention is to overcome at least one of the defects of the prior art by providing a radial single-frame support system and construction method for cantilever roof steel structures. This radial single-frame support system can solve the problems of traditional radial multi-frame support systems, such as high material consumption, long installation and dismantling cycles, significant impact on the stress of the superstructure, and high requirements for lower construction space.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] One objective of this invention is to provide a radial single-frame support system for a cantilever roof steel structure. This radial single-frame support system includes a construction equipment placement platform, an intermediate connecting platform, and a height adjustment structure. The height adjustment structure includes a first height adjustment structure and a second height adjustment structure. The construction equipment placement platform, the first height adjustment structure, the intermediate connecting platform, and the second height adjustment structure are connected sequentially.

[0008] Furthermore, the first height adjustment structure is a standard segment of the frame, and the second height adjustment structure is a steel pipe column structure.

[0009] Further, the tire rack standard section has one or more. The tire rack standard section adopts the crane standard section. This is also the construction mode of the traditional tire rack support system, and the height is roughly controlled by adjusting the number of nodes.

[0010] Further, the steel pipe column structure has at least four steel pipe columns. Specifically, the second height adjusting structure adopts a round steel pipe, and compared with the traditional full-height crane standard section, the round steel pipe structure can control the spacing and adjust the rigidity in different directions through the conversion structure; and the height of the round steel pipe can be freely adjusted, so that the single tire rack can reach any height, improving the applicability; in addition, the round steel pipe structure is simple, and through several simple openings, it can pass through the lower structure that has been built, reducing the requirements for the lower space and construction conditions.

[0011] Further, the construction equipment placing platform comprises four placing platform I-shaped steels and a placing square plate for placing the construction equipment; the placing platform I-shaped steels are connected after being surrounded to form a mouth-shaped structure, the placing square plate is placed on the top of the placing platform I-shaped steels, and the placing platform I-shaped steels are connected with the first height adjusting structure. Specifically, the construction equipment placing platform is welded by four I-shaped steels. Since the surface of the crane standard section is square, the upper bearing section is in the shape of a mouth, which is convenient for laying the square plate and placing the construction equipment such as the jack.

[0012] Further, the placing platform I-shaped steel is provided with a placing platform stiffener.

[0013] Further, the intermediate connecting platform comprises four intermediate connecting platform I-shaped steels, and the intermediate connecting platform I-shaped steels are sequentially connected to form a rectangular structure. Specifically, by adjusting the length of the I-shaped steel, the spacing of the lower round steel pipe in two directions is controlled, and the effect of improving the bending stiffness in the potential stress direction is achieved.

[0014] Further, the intermediate connecting platform I-shaped steel is provided with an intermediate connecting platform stiffener.

[0015] Further, the steel pipe column is provided with a horizontal X-shaped support in the section perpendicular to the round steel pipe every 7-12 m, preferably 10 m.

[0016] The second object of the present application is a construction method of the radial single tire rack support system of the cantilever roof steel structure, which comprises the following steps:

[0017] Step one: according to the single support stress characteristics, the force transmitted by the upper structure is calculated, and the appropriate crane standard section is selected as the tire rack standard section, and whether the support point and the section of the upper structure need to be modified are determined;

[0018] Step two: according to the crane standard section size of the cradle standard section and the lower construction space and the required operation space of the upper construction instrument, the required support height is determined to determine the number of nodes and the length of the lower steel pipe column;

[0019] Step three: according to the stress requirement, strength and stability, the size of the lower steel pipe column is determined; according to the radial and circumferential bending stiffness, the spacing of the circular steel pipe in the two directions is determined;

[0020] Step four: according to the operation space of the construction equipment required at the upper support, the size of the construction equipment placing platform is determined; according to the crane standard section size of the cradle standard section and the arrangement of the lower steel pipe column, the size of the intermediate connecting platform is determined;

[0021] Step five: according to the results of the whole process simulation analysis, the preliminary construction scheme is fine-tuned to determine the final construction step, and the acceptance standard is formulated according to the simulation analysis structure; specifically, after the overall structure size is determined, the whole process simulation analysis software is used to judge the safety and reliability of the structure under the horizontal load, the horizontal displacement (load) that may exist in the construction, and the rare horizontal displacement (load) in the construction, considering the strength and stability.

[0022] Step six: according to the determined construction steps, the whole lifting construction installation is carried out, the stress, displacement of the structure during lifting is monitored, and the monitoring process and whole process analysis are compared and analyzed, and the structure construction is completed.

[0023] Compared with the prior art, the present application has the following advantages:

[0024] (1) The present application only sets one cradle in the radial direction, and the total material consumption is much less than that of the traditional multiple cradles, thereby reducing the material cost;

[0025] (2) The present application only sets one cradle in the radial direction, and the installation and disassembly period is shortened;

[0026] (3) The present application only sets one cradle in the radial direction, and there is only one upper support point, so the load distribution change of the upper structure when it is supported and supported by itself is small, and therefore the influence of the cradle on the upper structure is smaller;

[0027] (4) The present application only sets one cradle in the radial direction, and the distance between the cradle and the cantilever support is necessarily greater than the distance between the cradle closest to the support in the multiple cradle system and the support, so the required conditions for the lower construction space are more relaxed, and the occupied site space is extremely small. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is the overall structure schematic diagram of the cradle support system in the present application;

[0029] Figure 2is a placement platform schematic diagram of the construction equipment of the present application;

[0030] Figure 3 is a first height adjusting structure in the present application, which is composed of a crane standard section;

[0031] Figure 4 is a middle connection platform schematic diagram of the present application;

[0032] Figure 5 is a support schematic diagram of the radial single tire frame in a certain project in the present application;

[0033] Figure 6 is a X-direction displacement analysis result diagram of the tire frame support system in Example 1 of the present application under the action of X-direction wind load;

[0034] Figure 7 is a limit bearing capacity calculation schematic diagram of the tire frame support system in Example 1 of the present application under the action of X-direction wind load;

[0035] The labels shown in the figure are: 1- construction equipment placement platform; 11- placement platform I-shaped steel; 12- placement square plate; 13- placement platform stiffener; 2- first height adjusting structure; 3- middle connection platform; 31- middle connection platform I-shaped steel; 32- connection platform stiffener; 33- connection platform end plate; 4- second height adjusting structure. DETAILED DESCRIPTION

[0036] The present application will be described in detail below in combination with the drawings and specific examples. The present embodiment is implemented on the premise of the technical solution of the present application, and detailed implementation and specific operation process are given, but the protection scope of the present application is not limited to the following examples.

[0037] Example 1

[0038] A certain actual case analysis of the radial single tire frame support system used in the construction of the steel structure roof of a certain stadium is combined with the drawings to further illustrate the present application.

[0039] Figure 1 is a schematic diagram of the overall structure of the tire frame support system in the present application, and the construction equipment placement platform 1, the first height adjusting structure 2, the middle connection platform 3 and the second height adjusting structure 4 are connected in sequence by welding.

[0040] Figure 2The platform 1 is placed for the construction equipment of the cradle in the application. After considering the construction space required by the upper jacks, the platform is designed to be arranged in the shape of a "mouth" by four platform I-beams 11 with a cross section of 700 mm x 300 mm x 13 mm x 24 mm, and a platform square plate 12 for placing the construction equipment is welded on the top of the platform I-beams 11. In actual engineering, limiting facilities should be arranged to deal with the movement of the upper structure in the roof cable tensioning, and platform stiffening ribs 13 are welded on the platform I-beams 11 to ensure the local compression safety.

[0041] Figure 3 The crane standard section is used for the first height adjusting structure 2 in the application. According to the 880 kN load transmitted by the upper structure, 63 crane standard sections are determined to be used. Each standard section has a size of 1.6 m x 2.8 m, and the corner column uses a square tube column with a cross-sectional size of 135 mm x 10 mm. The transverse support and the inclined support are the same, and a 70 angle steel with a cross-sectional size of 70 mm x 70 mm x 5 mm is used. According to the height of the support point from the ground, it is determined to use 7 standard sections, and the total height is 19.6 m.

[0042] Figure 4 The platform 3 is used for the intermediate connection platform in the cradle in the application. In order to resist the movement during the tensioning of the roof cable, a 1.6 m x 2 m square arrangement is used, and the cross-sectional size of the member is the same as that of the I-beam with a cross-sectional size of 700 mm x 300 mm x 13 mm x 24 mm. In actual engineering, corresponding stiffening ribs 32 for the connection platform and end plates 33 for the connection platform are added at the connection section of the conversion I-beam and the cradle column to avoid local compression damage. At the connection section of the conversion I-beam and the lower steel pipe column, the end plate 33 for the connection platform is set to meet the requirements of variable cross-section welding, and the stiffening rib 32 for the connection platform is set to avoid local compression damage. The end plate 33 for the connection platform is set on the top of the round steel pipe, and is a square plate, which is convenient for contact with the bottom of the conversion I-beam and convenient for welding.

[0043] It should be noted that the description herein is only as a size reference, and the construction method described includes but is not limited to the size described in the application example. In fact, it should be considered that the conversion structure should be appropriately extended by a certain distance at both ends in order to cover the upper and lower components to complete the complete weld, and measures such as stiffening ribs should be applied to ensure the local compression strength. In addition, for the round steel pipe, considering that the interval is relatively small in height, it is approximately considered as an axial compression member, and according to the relevant specifications, Φ325 x 20 hot-rolled round pipes are selected for calculation in this case, and the length of the round steel pipe is determined to be 30 m in combination with the overall height requirement.

[0044] Figure 5It is a schematic diagram of the actual use of the radial single cradle in the present application. Its upper part is supported on the ring beam of the roof steel structure, the middle part is converted into four steel pipe columns through the intermediate connecting platform 3, passes through the lower part of the built stadium stand and is connected with the bottom fixed foundation, and the construction equipment is fixed on the construction equipment placing platform 1.

[0045] Figure 6 、 Figure 7 It is a schematic diagram of the X-direction displacement analysis result and ultimate bearing capacity calculation of the cradle support system under the action of X-direction wind load. In fact, three working conditions are considered in the actual design process. First, working condition one, only considering that the structure bears the vertical load transmitted from the upper part and the lateral wind load. Then, working condition two, considering the vertical load transmitted from the upper part and the lateral wind load, and setting a 50 mm horizontal displacement at the top of the cradle to simulate the movement of the cradle caused by the stretching of the radial cable. Finally, working condition three, on the basis of working condition two, the 50 mm horizontal displacement is expanded to 500 mm to simulate the movement of the cradle in the extreme case. The stress of the cradle support system under the three working conditions is investigated, and the ultimate bearing capacity of the structure is analyzed through stability analysis. The calculation results show that the strength of the original cradle support system meets the requirements, and the safety reserve is low without horizontal support; and if horizontal contact is set at the intermediate connecting platform and horizontal X-shaped support is set every 10 m at the circular steel pipe, the material is structural steel, which can make the safety factor of the ultimate bearing capacity reach 5, thereby ensuring the safety and reliability of the single cradle support system.

[0046] The above is only a preferred embodiment of the present application, and is not intended to limit the other forms of the present application. Any person skilled in the art can modify or change the above disclosed technical content to equivalent embodiments. However, any simple modification, equivalent change and modification made according to the technical essence of the present application to the above embodiments without departing from the technical solution content of the present application still belongs to the protection scope of the present application.

Claims

1. A construction method for a radial single-frame support system for a cantilever roof steel structure, characterized in that, The radial single-frame support system includes a construction equipment placement platform (1), a first height adjustment structure (2), an intermediate connecting platform (3), and a second height adjustment structure (4) connected in sequence. The first height adjustment structure (2) is a standard segment of the frame, and the second height adjustment structure (4) is a steel pipe column structure; The construction equipment placement platform (1) includes four I-beams (11) for placing the platform and a square plate (12) for placing the construction equipment; the I-beams (11) for placing the platform are connected in a U-shape, and the square plate is placed on top of the I-beams (11) for placing the platform. The I-beams (11) for placing the platform are connected to the first height adjustment structure (2). The intermediate connecting platform (3) includes four intermediate connecting platform I-beams (31), which are connected together after being arranged in a square shape. The construction method for this radial single-frame support system includes the following steps: Step 1: Calculate the force transmitted from the superstructure based on the single support force characteristics, select a suitable crane standard section as the standard segment of the frame, and determine whether the support points and cross-sections of the superstructure need to be modified. Step 2: Based on the dimensions of the standard crane section of the jig, the construction space below, and the operating space required for the construction equipment above, determine the required support height, the number of sections, and the length of the lower steel pipe column; Step 3: Determine the dimensions of the lower steel pipe column based on the stress requirements, strength, and stability; determine the spacing of the circular steel pipes in the radial and circumferential bending stiffness directions. Step 4: Determine the dimensions of the construction equipment placement platform (1) based on the required operating space for construction equipment at the upper support; determine the dimensions of the intermediate connecting platform (3) based on the dimensions of the crane standard section of the frame standard segment and the arrangement of the lower steel pipe columns; Step 5: Based on the results of the full-process simulation analysis, the preliminary construction plan was fine-tuned, the final construction steps were determined, and acceptance standards were formulated based on the simulation analysis structure. Step Six: Carry out the overall lifting and installation according to the determined construction steps. During the lifting process, monitor the stress and displacement of the structure throughout the entire process, and compare and analyze the monitoring process with the overall process analysis. The structural construction is then completed.

2. The construction method of the radial single-frame support system for a cantilever roof steel structure according to claim 1, characterized in that, The aforementioned standard segments of the tire frame may be one or more.

3. The construction method of the radial single-frame support system for a cantilever roof steel structure according to claim 1, characterized in that, The steel pipe column structure has at least four steel pipe columns.

4. The construction method of the radial single-frame support system for a cantilever roof steel structure according to claim 1, characterized in that, The I-beam (11) for the placement platform is provided with stiffening ribs (13).

5. The construction method of the radial single-frame support system for a cantilever roof steel structure according to claim 1, characterized in that, The intermediate connecting platform is provided with stiffening ribs (32) on the I-beam (31).

6. The construction method of the radial single-frame support system for a cantilever roof steel structure according to claim 3, characterized in that, The steel pipe column is provided with horizontal X-shaped supports at intervals of 7-12 m within the cross section perpendicular to the circular steel pipe.

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