Spoke type cable-supported grid roof and reverse tensioning construction method thereof

Abstract

The invention relates to a spoke type cable-supported grid roof and a reverse tensioning construction method thereof, belongs to the technical field of building construction, and solves the problems that a large number of temporary construction supporting jig frames need to be arranged in a bracket construction method in the prior art, the cost is high, the jig frames can be supported on a lower concrete structure, the interpenetration operation with the concrete structure needs to be considered, and the construction efficiency is high. And the construction process is tedious. The spoke type cable-supported grid roof comprises an upper steel structure, an outermost side pressing ring beam, radial cables and annular cables, the radial cables and the annular cables are connected in a crossed mode to form a cable net system, and the cable net system is connected with the upper steel structure and the outermost side pressing ring beam; in the construction process, the radial cables and the annular cables are reversely tensioned through the vertical construction inhaul cables, and the node elevation of the radial cables and the annular cables is lowered to the designed elevation through the self weight of the upper steel structure. In the construction process, a temporary construction supporting jig frame does not need to be arranged, the construction steps are simple, the construction efficiency is high, and the construction cost is reduced.

Description

Technical Field

[0001] The present application belongs to the field of building construction technology, and specifically relates to a spoke-type cable-supported grid roof and a counter-tensioning construction method thereof. Background Art

[0002] The spoke-type tension structure is often used to construct roofs of large-span spaces such as stadiums due to its large spatial span and stable structure.

[0003] At present, the main construction method used for spoke-type cable-supported grid structures is the bracket method, which first sets up a temporary construction support frame for the upper steel structure. After the upper steel structure is installed, the radial cables and circumferential cables are pulled and tensioned to provide the overall stiffness of the structure. In general, the bracket method has low construction difficulty and low requirements for simulation and analysis of the construction process. It is currently widely used in various types of spoke-type cable-supported grid structure stadiums. However, the bracket method requires the setting up of a large number of temporary construction support frames. The manufacturing cost of the frame itself is relatively high, and the frame will be supported on the lower concrete structure. It is necessary to consider the interlaced operation with the concrete structure, and the construction process is cumbersome. Summary of the invention

[0004] In view of the above analysis, an embodiment of the present invention aims to provide a spoke-type cable-supported grid roof and a counter-tensioning construction method thereof, so as to solve the problem that in the process of installing the upper steel structure using the bracket construction method in the prior art, a large number of temporary construction support frames need to be set up, the cost is high, and it is necessary to consider the interlaced operations with the concrete structure and the construction process is cumbersome.

[0005] The object of the present invention is achieved in that: On the one hand, a spoke-type cable-supported grid roof is provided, comprising an upper steel structure, an outermost compression ring beam, radial cables and annular cables, wherein the radial cables and the annular cables are cross-connected to form a cable net system, and the cable net system is connected to the upper steel structure and the outermost compression ring beam; During the construction process, vertical construction cables are used to counter-tension the radial cables and annular cables, and the deadweight of the upper steel structure is used to lower the node elevations of the radial cables and annular cables to the designed elevation.

[0006] Furthermore, the upper steel structure includes radial steel beams, cantilever beams, central pressure ring beams, innermost ring beams, outer struts and inner struts at cantilever ends; the outermost pressure ring beams, central pressure ring beams, innermost ring beams and annular cables are all circular ring structures, the central pressure ring beam is located between the outermost pressure ring beams and the innermost ring beams, the annular cables are located below the cantilever beams, and the outer struts and inner struts at cantilever ends are connected between the cantilever beams and the annular cables; the outermost pressure ring beams form a first circular ring, the central pressure ring beams form a second circular ring, the innermost ring beams form a third circular ring, the annular cables have a fourth circular ring diameter, and the first circular ring diameter > the second circular ring diameter > the fourth circular ring diameter > the third circular ring diameter; a plurality of radial steel beams are provided between the outermost pressure ring beams and the central pressure ring beams; a plurality of cantilever beams are provided between the central pressure ring beams and the innermost ring beams.

[0007] Furthermore, the upper steel structure also includes annular connecting beams, which are circular ring structures; the annular connecting beams are arranged in a concentric circle between the outermost compression ring beam and the middle compression ring beam, and are connected to the radial steel beams; and / or, are arranged between the middle compression ring beam and the innermost ring beam, and are connected to the cantilever beam.

[0008] Furthermore, the upper steel structure also includes a radial steel beam support rod, which is connected between the radial cable and the radial steel beam and is configured to support the radial steel beam in an axial force manner.

[0009] Furthermore, there are multiple radial steel beams, and the multiple radial steel beams are arranged vertically in parallel.

[0010] Furthermore, the connection point between the first end of the radial cable, the first end of the radial steel beam and the outermost compression ring beam is the first node; the connection point between the second end of the radial cable, the first end of the outer strut, the first end of the inner strut of the cantilever end and the annular cable is the second node; the connection point between the vertical construction cable, the radial cable and the annular cable is located at the second node; the connection point between the second end of the radial steel beam, the second end of the outer strut, the first end of the cantilever beam and the middle compression ring beam is the third node; the connection point between the second end of the inner strut of the cantilever end and the cantilever beam is the fourth node; the connection point between the second end of the cantilever beam and the innermost ring beam is the fifth node, which does not coincide with the fourth node, so that the innermost ring beam is in a cantilevered state.

[0011] On the other hand, a method for anti-tensioning construction of a spoke-type cable-supported grid roof is provided, comprising the following steps: Step 1: Install the outermost compression ring beam; Step 2: Lay radial cables and annular cables on the ground and connect them; Step 3: Use the traction equipment to pull the radial cable and the annular cable upward, and connect the upper end of the vertical construction cable to the second node position of the radial cable and the annular cable; Step 4: Continue to pull the radial cable and the annular cable until the second node is pulled to the pulling elevation, at which time the first end of the radial cable is connected to the outermost compression ring beam at the first node; Step 5: Use vertical construction cables to pull the second node down from the current traction elevation to the initial elevation; Step 6: Hoist the assembled upper steel structure into the air and connect it with the radial cable and the circumferential cable. After all the upper steel structures are installed, under the action of the self-weight of the upper steel structure, the second node elevation of the radial cable and the circumferential cable drops from the initial elevation to the design elevation, and the internal force of the vertical construction cable is automatically released under the action of the self-weight of the upper steel structure. Step 7: Remove the vertical construction cables, the spoke-type cable-supported grid roof structure system has reached the initial design state, and the construction is completed.

[0012] Furthermore, in the third step, after the vertical construction cables are installed, the displacement △ of the second node from the initial elevation to the design elevation is calculated according to the following formula: Displacement △ = N2×L5 / (E×A); In the above formula, N2 is the axial force of the vertical construction cable, kN; L5 is the length of the vertical construction cable, mm; E is the elastic modulus of the vertical construction cable, kN / mm 2 ; A is the cross-sectional area of ​​the vertical construction cable, mm 2 .

[0013] Furthermore, in the third step, when the hoop cable is lifted from the ground to a height of 1 m, the upper end of the vertical construction cable is connected to the second node position.

[0014] Furthermore, in the fifth step, before adjusting the cable force through the vertical construction cable, the lower end of the vertical construction cable is anchored and fixed.

[0015] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects: a) The spoke-type cable-supported grid roof provided by the present invention combines the cables with the grid structure system, combines the flexibility of the cables with the rigidity of the grid structure, fully utilizes their respective characteristics, and brings the cables and the grids into play with their respective optimal stress performance. It has a simple structure, high construction efficiency, and low construction cost, and realizes a larger span structural system with less steel consumption and better economy.

[0016] b) The anti-tensioning construction method of the spoke-type cable-supported grid roof provided by the present invention is as follows: before installing the upper steel structure, the second node of the radial cable and the annular cable is pulled to the pulling elevation, the vertical construction cable is connected to the second node position of the radial cable and the annular cable, and the second node is pulled down from the pulling elevation to the initial elevation by the vertical construction cable; then the upper steel structure is installed, and as the upper steel structure is installed, under the action of the deadweight of the upper steel structure, the force of the vertical construction cable will gradually decrease to 0, and the length of the vertical construction cable will be shortened, so that The second nodes of the vertical construction cables, radial cables and annular cables are displaced vertically downward, thereby pulling the second node that was originally higher than the design elevation down to the final design elevation. The entire process does not require continuous adjustment of the vertical construction cables, but only requires pre-calculating the initial elevations of the vertical construction cables and radial cables. The deadweight of the installed upper steel structure reduces the cable force of the vertical construction cables, thereby dropping them to the design elevation, and achieving the internal force and displacement in the design initial state. The counter-tensioning construction process has no effect on the internal force and displacement in the design initial state.

[0017] c) The reverse tensioning construction method of the spoke-type cable-supported grid roof provided by the present invention adopts the technical scheme of "first tensioning radial cables and annular cables in vertical construction, and then installing the upper steel structure" compared to the traditional spoke-type cable-supported roof construction method which adopts the construction scheme of "first installing the upper steel structure and then tensioning the radial cables to improve the overall stiffness of the structure". The overall tensioning sequence is the opposite of the traditional spoke-type cable-supported roof construction method, which can achieve the effect of not requiring the setting of a tire frame, has the advantages of low cost, no need to consider the interlaced operation with the concrete structure, and simple construction steps. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of this specification. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0019] Figure 1 A three-dimensional axial schematic diagram of the spoke-type cable-supported grid roof provided by the present invention; Figure 2 A top view of the spoke-type cable-supported grid roof provided by the present invention; Figure 3 A schematic diagram of the structure of the first type of spoke-type cable-supported grid roof provided by the present invention; Figure 4 A schematic diagram of the structure of the second type of spoke-type cable-supported grid roof provided by the present invention; Figure 5Schematic diagram of the construction process of the spoke-type cable-supported grid roof provided by the present invention Figure 1 ; Figure 6 Schematic diagram of the construction process of the spoke-type cable-supported grid roof provided by the present invention Figure 2 ; Figure 7 Schematic diagram of the construction process of the spoke-type cable-supported grid roof provided by the present invention Figure 3 ; Figure 8 Schematic diagram of the construction process of the spoke-type cable-supported grid roof provided by the present invention Figure 4 ; Fig. 9 The force analysis diagram of the spoke-type cable-supported grid roof provided by the present invention without considering the anti-tensioning construction; Fig.10 A force analysis diagram of the spoke-type cable-supported grid roof provided by the present invention considering the anti-tensioning construction; Fig.11 A schematic diagram of setting a heavy counterweight for the vertical construction cable provided by the present invention; Fig.12 A schematic diagram of the vertical construction cable provided by the present invention being anchored to the stand beam; Fig.13 A schematic diagram of the vertical construction cable provided by the present invention being anchored to an anchor pile.

[0020] Reference numerals: 1. Upper steel structure; 2. Outermost compression ring beam; 3. Radial cables; 4. Annular cables; 5. Vertical construction cables; 6. Radial steel beams; 7. Cantilever beams; 8. Center compression ring beams; 9. Annular connecting beams; 10. Innermost ring beams; 11. Outer support rods; 12. Inner support rods at cantilever ends; 13. Radial steel beam support rods; 14. Grandstands; 15. Grandstand beams; 16. Anchor piles; 17. Heavy objects. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. It should be noted that, in the absence of conflict, the embodiments in the present disclosure and the features in the embodiments can be combined, separated, interchanged and / or rearranged with each other. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0022] In the accompanying drawings, the size and relative size of components may be exaggerated for clarity and / or descriptive purposes. When the exemplary embodiments may be implemented differently, a specific process sequence may be performed in a different order than described. For example, two successively described processes may be performed substantially simultaneously or in an order opposite to the order described. In addition, the same reference numerals represent the same components.

[0023] The terms used here are for the purpose of describing specific embodiments, and are not intended to be restrictive. As used here, unless the context clearly indicates otherwise, the singular forms "one (kind, person)" and "said (the)" are also intended to include plural forms. In addition, when the terms "comprise" and / or "include" and their variations are used in this specification, it is explained that there are stated features, integral bodies, steps, operations, parts, assemblies and / or their groups, but it is not excluded that there are or add one or more other features, integral bodies, steps, operations, parts, assemblies and / or their groups. It should also be noted that, as used here, the terms "substantially", "approximately" and other similar terms are used as approximate terms and not as degree terms, so that they are used to explain the inherent deviations of the measured values, calculated values ​​and / or the values ​​provided that will be recognized by those of ordinary skill in the art.

[0024] Example 1 A specific embodiment of the present invention, as Figures 1 to 4 As shown, a spoke-type cable-supported grid roof is disclosed, comprising an upper steel structure 1, an outermost compression ring beam 2, radial cables 3 and annular cables 4, wherein the radial cables 3 and the annular cables 4 are cross-connected to form a cable net system, and the cable net system is connected to the upper steel structure 1 and the outermost compression ring beam 2, and is configured to stabilize the upper steel structure 1; during the construction process, the radial cables 3 and the annular cables 4 are tensioned by vertical construction cables 5, and the node elevations of the radial cables 3 and the annular cables 4 are lowered to the design elevation by the deadweight of the upper steel structure 1. The vertical construction cables 5 are only used during the construction process, and the radial cables 3 and the annular cables 4 are tensioned to the traction elevation position by the vertical construction cables 5, and the traction elevation is greater than the design elevation, and the vertical construction cables 5 are removed after the construction is completed.

[0025] In this embodiment, the upper steel structure 1 includes a radial steel beam 6, a cantilever beam 7, a central pressure ring beam 8, a circumferential connecting beam 9, an innermost ring beam 10, an outer support rod 11 and an inner support rod 12 at the cantilever end; the outermost pressure ring beam 2, the central pressure ring beam 8 and the innermost ring beam 10 are all circular ring structures, the central pressure ring beam 8 is located between the outermost pressure ring beam 2 and the innermost ring beam 10, the outermost pressure ring beam 2 forms a first circular ring, the central pressure ring beam 8 forms a second circular ring, and the innermost ring beam 10 forms a third circular ring, and the diameter of the first circular ring is greater than the diameter of the second circular ring and greater than the diameter of the third circular ring. Ring diameter; a plurality of radial steel beams 6 are arranged between the outermost compression ring beam 2 and the middle compression ring beam 8; a plurality of cantilever beams 7 are arranged between the middle compression ring beam 8 and the innermost ring beam 10; the annular cable 4 is a ring structure, having a fourth ring diameter, and the third ring diameter < the fourth ring diameter < the second ring diameter; the annular cable 4 is located below the cantilever beam 7, and an outer support rod 11 and an inner support rod 12 at the cantilever end are connected between the cantilever beam 7 and the annular cable 4, and the cantilever beam 7, the outer support rod 11 and the inner support rod 12 at the cantilever end form a triangular support structure.

[0026] In this embodiment, the outer support rods 11, the inner support rods 12 at the cantilever ends, the radial cables 3, the radial steel beams 6 and the cantilever beams 7 are arranged in groups in the form of supporting structure units. All components of each group of supporting structure units are located in the same vertical plane. Multiple supporting structure units are evenly and symmetrically arranged around a circle with the center of the roof as the center. All supporting structure units form a stable roof structure system through the outermost compression ring beam 2, the middle compression ring beam 8, the innermost ring beam 10 and the annular cable 4 of the circular ring structure.

[0027] The connection point between the first end of the radial cable 3, the first end of the radial steel beam 6 and the outermost compression ring beam 2 is the first node; the connection point between the second end of the radial cable 3, the first end of the outer strut 11, the first end of the inner strut 12 of the cantilever end and the annular cable 4 is the second node; the connection point between the vertical construction cable 5, the radial cable 3 and the annular cable 4 is located at the second node; the connection point between the second end of the radial steel beam 6, the second end of the outer strut 11, the first end of the cantilever beam 7 and the central compression ring beam 8 is the third node; the connection point between the second end of the inner strut 12 of the cantilever end and the cantilever beam 7 is the fourth node; the connection point between the second end of the cantilever beam 7 and the innermost ring beam 10 is the fifth node, which does not coincide with the fourth node, so that the innermost ring beam 10 is in a cantilevered state.

[0028] In this embodiment, the annular connecting beam 9 is a circular ring structure, which is arranged in a concentric circle between the outermost compression ring beam 2 and the middle compression ring beam 8, and is connected to the radial steel beam 6; and / or, it is arranged between the middle compression ring beam 8 and the innermost ring beam 10, and is connected to the cantilever beam 7.

[0029] In one alternative embodiment, see Figure 4The upper steel structure 1 also includes a radial steel beam support rod 13, which is connected between the radial cable 3 and the radial steel beam 6, and can provide a support point for the radial steel beam 6 in the form of axial force. Among them, the radial steel beam support rod 13 is also a part of the supporting structure unit, and is located in the same vertical plane as other components of the radial steel beam support rod 13. There are multiple radial steel beams 6, and multiple radial steel beams 6 are arranged vertically in parallel. By setting the radial steel beam support rod 13, the radial steel beam support rod 13 is connected to the radial cable 3, and prestress is applied to the radial cable 3 and the annular cable 4. The radial steel beam support rod 13 will provide a support point for the radial steel beam 6 in the form of axial force, optimize the bending moment distribution of the radial steel beam 6, effectively reduce the cross-sectional size of the radial steel beam 6, and improve the economy.

[0030] The present embodiment also provides a reverse tensioning construction method for a spoke-type cable-supported grid roof. After installing the outer compression ring beam, the radial cables 3 and the annular cables 4 are first pulled, so that the second nodes of the radial cables 3 and the annular cables 4 are pulled to the pulling elevation. After the pulling of the radial cables 3 and the annular cables 4 is completed, the vertical construction cables 5 are connected to the second node positions of the radial cables 3 and the annular cables 4, and the vertical construction cables 5 are used to pull down the second node from the pulling elevation to the initial elevation; then the upper steel structure 1 is installed. After the upper steel structure 1 is installed, the force of the vertical construction cables 5 will gradually decrease to 0. At this time, the length of the vertical construction cables 5 will be shortened, so that the vertical construction cables 5 and the second nodes of the radial cables 3 and the annular cables 4 will undergo downward vertical displacement, thereby pulling down the second node that was originally higher than the design elevation to the final design elevation. The whole process does not require continuous adjustment of the vertical construction cables 5, but only requires pre-calculating the initial elevations of the vertical construction cables 5 and the radial cables 3, and reducing the cable force of the vertical construction cables 5 through the deadweight of the upper steel structure 1 after installation, thereby dropping to the design elevation.

[0031] Among them, the initial elevation is higher than the design elevation by a certain distance, and this distance is equal to the shortening of the vertical construction cable 5 when the cable force of the vertical construction cable 5 is reduced to 0, that is, the vertical displacement △ of the second node. The initial elevation can be calculated by the axial force, cross-sectional area, elastic modulus and length of the vertical construction cable 5.

[0032] Different states of the spoke-type cable-supported grid roof during the anti-tensioning construction process refer to Figures 5 to 8 .

[0033] Specifically, the anti-tensioning construction method of the spoke-type cable-supported grid roof includes the following steps: Step 1: Install the outermost compression ring beam 2; Step 2: laying radial cables 3 and annular cables 4 on the ground, and connecting the radial cables 3 and the annular cables 4; Step 3: Use the traction equipment to pull the radial cable 3 and the annular cable 4 upwards. When the second node is lifted to a height of about 1m from the ground, that is, when the annular cable 4 is lifted to a height of about 1m from the ground, connect the upper end of the vertical construction cable 5 to the annular cable 4 at the second node; Step 4: Continue to pull the radial cable 3 and the annular cable 4 by the pulling device until the second node of the radial cable 3 and the annular cable 4 is pulled to the pulling elevation, at which time the first end of the radial cable 3 is connected to the outermost compression ring beam 2 at the first node; Step 5: tension and anchor the lower end of the vertical construction cable 5 to the anchor pile 16. At this time, the cable force is adjusted by the vertical construction cable 5, and the second node of the vertical construction cable 5 and the radial cable 3 and the annular cable 4 is pulled down from the current traction elevation to the initial elevation; Step 6: Assemble the upper steel structure 1 on the ground, hoist it to high altitude, and connect it with the radial cables 3 and the annular cables 4. After all the upper steel structures 1 are installed, under the action of the self-weight of the upper steel structure 1, the second node elevation of the radial cables 3 and the annular cables 4 drops from the initial elevation to the design elevation, and the internal force of the vertical construction cables 5 is automatically released under the action of the self-weight of the upper steel structure 1. In this process, the length of the vertical construction cable 5 will be shortened as the elevation of the second node decreases, because the vertical construction cable 5 is a fixed-length cable, and the stress-free length is the elevation from the bottom anchor point of the vertical construction cable 5 to the design elevation; therefore, when the top elevation of the vertical construction cable 5 reaches the initial elevation, that is, when the elevation of the second node reaches the initial elevation, the vertical construction cable 5 reaches the initial internal force due to elongation; and as the installation of the upper steel structure 1 is completed, when the elevation of the second node of the radial cable 3 and the annular cable 4 drops from the initial elevation to the design elevation, the length of the vertical construction cable 5 becomes the stress-free length, so the internal force of the vertical construction cable 5 becomes 0, and after the upper steel structure 1 is installed, the internal force of the vertical construction cable 5 is automatically released under the deadweight of the upper steel structure 1; Step 7: After the upper steel structure 1 is installed, the vertical construction cables 5 are removed. At this time, the spoke-type cable-supported grid roof structure system has reached the initial design state. The initial state refers to the state in which the deformation of the structure under the action of its own weight is basically zero.

[0034] In the fifth step, the vertical construction cable 5 can be anchored by a weight 17, anchored to the stand beam 15, anchored to the anchor pile 16, etc. Figures 11 to 13 The anchoring method of the vertical construction cable 5 can be comprehensively judged based on whether the second nodes of the radial cable 3 and the annular cable 4 correspond to the inner or outer side of the stand 14. For example, when the second nodes of the radial cable 3 and the annular cable 4 correspond to the inner side of the stand 14, the anchoring method of the weight 17 anchored to the stand beam 15 is adopted; when the second nodes of the radial cable 3 and the annular cable 4 correspond to the outer side of the stand 14, the anchoring method of the anchor pile 16 is adopted.

[0035] Since the overall rigidity of the spoke-type cable-supported grid structure is relatively soft, different construction forming methods have a greater impact on the internal force of the initial design state. However, the anti-tensioning construction method of the embodiment is safe and reliable, and will not affect the initial design state, and can achieve the internal force and displacement under the initial design state. The following is a comparison of the initial state internal force and displacement of the spoke-type cable-supported grid roof structure without considering the impact of the anti-tensioning construction process and considering the impact of the anti-tensioning construction process, to verify that the anti-tensioning construction process in this embodiment has no impact on the internal force and displacement of the initial design state.

[0036] For example, see Fig.10 The span L3 of the radial steel beam 6 is 40m, and the entire span of the cantilever beam 7 is 25 meters, among which the span L2 of the cantilever beam 7 between the third node and the fourth node is 21m, and the span L1 of the cantilever beam 7 between the fourth node and the fifth node is 4m. The horizontal distance L4 of the annular cable 4 relative to the outermost compression ring beam 2 is 49.5m, the length L5 of the vertical construction cable 5 is 40m, H1 is 9.7m, and H2 is 5m. The cross-sectional dimensions of the radial steel beam 6 are 2500mm×500mm×30mm×40mm for the box beam mouth, the cross-sectional dimensions of the cantilever beam 7 are 1200mm×500mm×20mm×30mm for the box beam mouth, the cross-sectional dimensions of the outer compression ring beam are 1200mm×1400mm×40mm×40mm for the box beam mouth, the cross-sectional dimensions of the central compression ring beam 8 are circular tube Ф800mm×40mm, the cross-sectional dimensions of the innermost ring beam 10 are circular tube Ф300mm×300mm×14mm×14mm for the box beam mouth, the cross-sectional dimensions of the outer support rod 11 are circular tube Ф600mm×16mm, the cross-sectional dimensions of the inner support rod 12 at the cantilever end are circular tube Ф450mm×14mm, the diameter of the radial cable 3 is 120mm, the diameter of the annular cable 4 is 320mm, and the diameter of the vertical construction cable 5 is 60mm. The axial force of the radial cable 3 is N1, the axial force of the vertical construction cable 5 is N2, the axial force of the annular cable 4 is N3, the axial force of the inner support rod 12 of the cantilever end is N4, and the axial force of the outer support rod 11 is N5.

[0037] The comparison of the internal forces in the initial state of the design without considering the anti-tensioning construction and considering the anti-tensioning construction under the action of deadweight is shown in Table 1. From the data in Table 1, it can be seen that the anti-tensioning construction method in this embodiment can achieve the same internal forces as the initial state of the design without considering the anti-tensioning construction, which proves that the anti-tensioning construction method is safe and reliable and will not affect the initial state of the design.

[0038] Table 1 Comparison of initial internal forces under self-weight without considering anti-tension construction and considering anti-tension construction Exemplarily, during the anti-tensioning construction process, the displacement change process of the second node position of the radial cable 3 and the annular cable 4 is as follows: After the outermost compression ring beam 2 is installed, the radial cable 3 and the annular cable 4 are pulled so that the pulling elevation of the second node of the radial cable 3 and the annular cable 4 is 1044.9 mm higher than the design elevation; Install the vertical construction cable 5, and control the initial elevation of the second node of the radial cable 3 and the annular cable 4 to be 49.8 mm higher than the design elevation through the vertical construction cable 5, where 49.8 mm is the displacement △ calculated by the finite element method; After the upper steel structure 1 is installed, the design elevation calculated by finite element calculation of the second node construction simulation of the radial cable 3 and the annular cable 4 is only 1.2 mm different from the design elevation of the annular cable 4 in the drawing, which is close to 0.

[0039] After the vertical construction cable 5 is installed, the difference between the initial elevation of the second node of the radial cable 3 and the annular cable 4 and the design elevation is calculated, that is, the displacement △ of the second node from the initial elevation to the design elevation is calculated. The displacement △ is calculated by the following formula: Displacement △ = N2×L5 / (E×A); In the above formula, N2 is the axial force of the vertical construction cable 5, L5 is the length of the vertical construction cable 5, E is the elastic modulus of the vertical construction cable 5, A is the cross-sectional area of ​​the vertical construction cable 5, A=πd2 / 4, and d is the diameter of the vertical construction cable 5.

[0040] The axial force N2 of the vertical construction cable 5, the axial force N4 of the inner brace 12 of the cantilever end, and the axial force N5 of the outer brace 11 are determined according to the following steps: The axial force N2 of the vertical construction cable 5 considering the anti-tensioning construction method can be estimated from the mechanical equilibrium, N2=N5×cos a + N4×cos b, wherein the axial force N4 of the inner brace 12 of the cantilever end and the axial force N5 of the outer brace 11 can be obtained by not considering the anti-tensioning construction method. N4 and N5, see Fig. 9 N2=570kN×0.804+170kN×0.796=594kN. The result of finite element analysis is N2=560 kN, which is only 6% different. The axial force of the vertical construction cable 5 can be simply estimated by mechanical balance by ignoring N4 and N5 in the finite element calculation results of the anti-tensioning construction method, see Fig.10 For example, N2=560 kN, L5=40000 mm, E=160 kN / mm 2 , d=30mm, A=2827mm 2 , then displacement △ = 560 kN × 40000 mm / (160 kN / mm 2 ×2827 mm 2) = 49.5mm, which is basically consistent with the displacement △ result of 49.8mm calculated by finite element method.

[0041] Compared with the prior art, the spoke-type cable-supported grid roof and the anti-tensioning construction method thereof provided in this embodiment have the following beneficial effects: 1. By connecting the vertical construction cables to the second nodes of the radial cables and the annular cables, the cable net system formed by the radial cables and the annular cables is first tensioned and formed using the vertical construction cables, and then the upper steel structure is installed. The entire construction process does not require the setting of any temporary construction support cradles, which can effectively reduce construction costs and avoid the disadvantages of interlacing operations between temporary construction support cradles and concrete structures.

[0042] 2. By controlling the elevation of the second node of the radial cable and the annular cable, the elevation of the second node is first pulled to the traction elevation through the traction equipment, and the elevation of the second node is pulled down from the traction elevation to the initial elevation through the vertical construction cable, and then the upper steel structure is installed. Under the action of the self-weight of the upper steel structure, the elevation of the second node can be finally reduced from the initial elevation to the design elevation, so that the spoke-type cable-supported grid structure reaches the initial design state. The entire construction process does not require repeated tensioning and control of the vertical construction cables. It only needs to accurately calculate the initial elevation of the second node of the radial cable and the annular cable through finite element, and counter-tension the vertical construction cables to the initial elevation. After that, under the action of the self-weight of the upper steel structure, it can automatically reach the design elevation. The construction steps are simple, and there is no need to repeatedly tension and control the vertical construction cables.

[0043] 3. A variety of anchoring methods can be used below the vertical construction cables, such as using heavy counterweights, anchoring to the stand beams, anchoring to anchor piles, etc. During the construction process, the vertical construction cables can adopt different anchoring methods based on the characteristics of the site. For example, the vertical construction cables can be combined with the second nodes of the radial cables and the annular cables to correspond to the inner and outer sides of the stands to comprehensively determine the anchoring method of the vertical construction cables, thereby improving construction efficiency and reducing construction costs.

[0044] The specific implementation methods described above further illustrate the purpose, technical solutions and beneficial effects of the present application in detail. It should be understood that the above description is only the specific implementation method of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A spoke-type cable-supported grid roof, characterized in that: It comprises an upper steel structure (1), an outermost compression ring beam (2), radial cables (3) and annular cables (4), wherein the radial cables (3) and the annular cables (4) are cross-connected to form a cable net system, and the cable net system is connected to the upper steel structure (1) and the outermost compression ring beam (2); During the construction process, the radial cables (3) and the annular cables (4) are tensioned by vertical construction cables (5), and the deadweight of the upper steel structure (1) is used to lower the node elevations of the radial cables (3) and the annular cables (4) to the designed elevation.

2. The spoke-type cable-supported grid roof according to claim 1, characterized in that: The upper steel structure (1) comprises radial steel beams (6), cantilever beams (7), a central compression ring beam (8), an innermost ring beam (10), outer support rods (11) and inner support rods (12) at the cantilever ends; The outermost compression ring beam (2), the middle compression ring beam (8), the innermost ring beam (10) and the annular cable (4) are all circular ring structures; the middle compression ring beam (8) is located between the outermost compression ring beam (2) and the innermost ring beam (10); the annular cable (4) is located below the cantilever beam (7); and an outer support rod (11) and an inner support rod (12) at the cantilever end are connected between the cantilever beam (7) and the annular cable (4); the outermost compression ring beam (2) forms a first circular ring, the middle compression ring beam (8) forms a second circular ring, the innermost ring beam (10) forms a third circular ring, and the annular cable (4) has a fourth circular ring diameter, and the first circular ring diameter> the second circular ring diameter> the fourth circular ring diameter> the third circular ring diameter; A plurality of radial steel beams (6) are provided between the outermost compression ring beam (2) and the middle compression ring beam (8); and a plurality of cantilever beams (7) are provided between the middle compression ring beam (8) and the innermost ring beam (10).

3. The spoke-type cable-supported grid roof according to claim 2, characterized in that: The upper steel structure (1) further comprises an annular connecting beam (9), wherein the annular connecting beam (9) is a circular ring structure; The annular connecting beam (9) is arranged in a concentric circle between the outermost compression ring beam (2) and the middle compression ring beam (8), and is connected to the radial steel beam (6); and / or, is arranged between the middle compression ring beam (8) and the innermost ring beam (10), and is connected to the cantilever beam (7).

4. The spoke-type cable-supported grid roof according to claim 2, characterized in that: The upper steel structure (1) further comprises a radial steel beam support rod (13), wherein the radial steel beam support rod (13) is connected between the radial cable (3) and the radial steel beam (6) and is configured to support the radial steel beam (6) in an axial force manner.

5. The spoke-type cable-supported grid roof according to claim 4, characterized in that: The number of the radial steel beams (6) is multiple, and the multiple radial steel beams (6) are arranged vertically in parallel.

6. The spoke-type cable-supported grid roof according to claim 2, characterized in that: The connection point between the first end of the radial cable (3), the first end of the radial steel beam (6) and the outermost compression ring beam (2) is a first node; The connection point between the second end of the radial cable (3), the first end of the outer support rod (11), the first end of the inner support rod (12) of the cantilever end and the annular cable (4) is a second node; the connection point between the vertical construction cable (5) and the radial cable (3) and the annular cable (4) is located at the second node; The connection point between the second end of the radial steel beam (6), the second end of the outer brace (11), the first end of the cantilever beam (7) and the central compression ring beam (8) is a third node; the connection point between the second end of the inner brace (12) of the cantilever end and the cantilever beam (7) is a fourth node; The connection point between the second end of the cantilever beam (7) and the innermost ring beam (10) is a fifth node, which does not coincide with the fourth node, so that the innermost ring beam (10) is in a cantilevered state.

7. A method for reverse tensioning of a spoke-type cable-supported grid roof as claimed in claim 6, characterized in that: The steps include: Step 1: Install the outermost compression ring beam (2); Step 2: laying radial cables (3) and annular cables (4) on the ground, and connecting the radial cables (3) and the annular cables (4); Step 3: Use a pulling device to pull the radial cable (3) and the annular cable (4) upward, and connect the upper end of the vertical construction cable (5) to the second node position of the radial cable (3) and the annular cable (4); Step 4: Continue to pull the radial cable (3) and the annular cable (4) until the second node is pulled to the pulling elevation, and then connect the first end of the radial cable (3) to the outermost compression ring beam (2) at the first node; Step 5: Using the vertical construction cable (5), the second node is pulled down from the current traction elevation to the initial elevation; Step 6: hoist the assembled upper steel structure (1) into the air and connect it with the radial cables (3) and the annular cables (4); after all the upper steel structures (1) are installed, under the action of the self-weight of the upper steel structure (1), the second node elevation of the radial cables (3) and the annular cables (4) is lowered from the initial elevation to the design elevation, and the internal force of the vertical construction cable (5) is automatically released under the action of the self-weight of the upper steel structure (1); Step 7: Remove the vertical construction cables (5). The spoke-type cable-supported grid roof structure has reached the initial design state and the construction is completed.

8. The anti-tensioning construction method of the spoke-type cable-supported grid roof according to claim 7 is characterized in that: In the third step, after the vertical construction cables (5) are installed, the displacement △ of the second node from the initial elevation to the design elevation is calculated according to the following formula: Displacement △ = N2×L5 / (E×A); In the above formula, N2 is the axial force of the vertical construction cable, kN; L5 is the length of the vertical construction cable, mm; E is the elastic modulus of the vertical construction cable, kN / mm 2 ; A is the cross-sectional area of ​​the vertical construction cable, mm 2 .

9. The anti-tensioning construction method of the spoke-type cable-supported grid roof according to claim 7, characterized in that: In the third step, when the hoop cable (4) is lifted from the ground to a height of 1 m, the upper end of the vertical construction cable (5) is connected to the second node position.

10. The anti-tensioning construction method of the spoke-type cable-supported grid roof according to claim 7, characterized in that: In the fifth step, before adjusting the cable force through the vertical construction cable (5), the lower end of the vertical construction cable (5) is anchored and fixed.

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