Non-support construction method for single-circle pull-down of radial multi-support cable-supported grid structure

Abstract

The invention relates to a support-free construction method for single-circle pull-down of a radial multi-support cable-supported grid structure. The support-free construction method comprises the steps that firstly, a cable net is pulled and lifted till radial cables are anchored to a circumferential supporting structure; then, a single-circle pull-down tool cable is installed and tensioned at the annular cable clamp, and the annular cable is made to be at the designed elevation; then, the radial beams, the supporting rods and the radial cable clamps are hoisted one by one in blocks, the tool cables are synchronously adjusted and pulled down, and non-closure section first-batch ring beams which are arranged in a staggered and spaced mode are installed in a running water mode; and then the pull-down tool cable is released and removed, and the non-closure section rear batch ring beam and the closure section ring beam are sequentially installed. According to the method, support-free construction of the radial multi-support type cable-supported grid structure is achieved through the single-circle pull-down tool cable, the complex multi-circle pull-down procedure is avoided, the elevation of the annular cable is convenient to adjust and control, the cost of construction measures is reduced, single-truss hoisting is stable, radial cable clamps are convenient to install, and the design requirement that the radial prestress of a lower cable net is independently balanced by a circumferential supporting structure is met.

Description

Technical Field

[0001] The present invention belongs to the technical field of the construction of cable-supported grid structures in civil engineering, and relates to a bracketless construction method for single-loop downward pulling of a radially multi-braced cable-supported grid structure. Background Art

[0002] The cable-supported grid structure is a prestressed space structure form combining rigidity and flexibility, which is composed of an upper grid (including radial beams and ring beams), intermediate struts (the upper end is connected to the radial beam through a pin shaft, and the lower end is connected to the cable through a cable clamp), a lower cable net (including radial cables and circumferential cables), and a peripheral support structure (including an outer compression ring and columns), etc. This structure has the following characteristics: the upper grid improves the overall stiffness of the structure and facilitates the installation of a rigid roof; the lower cable net and intermediate struts provide elastic support points for the upper grid, support the gravity load transmitted from the upper part, and reduce the internal force of the upper grid; the peripheral support structure independently balances or jointly balances the radial prestress of the lower cable net with the upper grid to form an overall prestressed self-balance. Therefore, this structure is light, efficient, has strong space spanning ability, and has good stiffness, and is mostly used for the roof structures of stadiums or football fields with large openings.

[0003] According to the radial prestress balance condition of the lower cable net, the cable-supported grid structure can be divided into two categories and corresponding to two construction methods: ① jointly balanced by the upper grid and the peripheral support structure, corresponding to the bracket construction method; ② independently balanced by the peripheral support structure, corresponding to the bracketless construction method. The basic steps of the bracket construction method are: first, install the peripheral support structure; then assemble the upper grid and intermediate supports on the temporary brackets; then install the lower cable net; finally, tension the radial cables and unload the temporary brackets. The basic steps of the bracketless construction method are: first, install the peripheral support structure; then install and tension the lower cable net; then install and tension the downward pulling tooling cables to make the circumferential cables at the designed elevation; then hoist the upper grid and intermediate struts onto the lower cable net, and at the same time adjust the downward pulling tooling cables to maintain the circumferential cables at the designed elevation; finally, release and remove the downward pulling tooling cables. It can be seen that the main difference between the bracket and bracketless construction methods is that the former constructs the upper grid and struts first and then the lower cable net, and requires temporary brackets; the latter constructs the lower cable net first and then the upper grid and struts, and requires downward pulling tooling cables. From the comparison of construction process measures, the bracketless construction method has low construction measure cost, convenient construction of the lower cable net, short construction period, and high technical requirements.

[0004] According to the layout method of the intermediate struts, the cable-supported grid structure can also be divided into two categories: ① circumferential cable V-braced type: only V-shaped struts are arranged on the circumferential cables, there are no struts on the radial cables, and the shape of the radial cables is an inclined straight line; ② radially multi-braced type: struts are arranged on both the radial cables and the circumferential cables, and the shape of the radial cables is a multi-fold line. Compared with the circumferential cable V-braced type, the radially multi-braced type can provide more elastic support points for the upper grid and is suitable for engineering projects with a larger overhanging span of the roof.

[0005] When the radial prestress of the lower cable net is independently balanced by the circumferential support structure and the scaffold-free construction method is adopted accordingly, the general construction methods and technical understandings in the past were as follows: To facilitate the installation of the upper grid and the middle struts, it was necessary to set up downward-pulling tooling cables at the connection between the lower end of each strut and the cable net before. After tensioning, the linear shape of the radial cables was made consistent with the designed state. Therefore, for the V-strut cable-supported grid structure with circumferential cables, only a single circle of downward-pulling tooling cables was set at the circumferential cable clamps, while for the multi-strut cable-supported grid structure with radial cables, multiple circles of downward-pulling tooling cables needed to be set. Compared with the single-circle downward-pulling tooling cables, the multiple-circle downward-pulling tooling cables greatly increased the number of downward-pulling anchor points in the stands and the construction measure costs, and had a long construction period, cumbersome regulation, and high implementation difficulty.

[0006] Chinese Patent Application CN201710445379.0 discloses a scaffold-free construction method for a ring cable-supported grid structure. First, the radial cables and circumferential cables of the structure are lifted to a high altitude by an oblique traction method, and then the assembled counterweight cables and reaction frame devices are installed below the cable net of the structure and the assembled counterweight cables are tensioned to form a supporting cable net. Then, the upper grid is hoisted to the supporting cable net in units, and at the same time, the assembled counterweight cables are adjusted through the reaction frame devices to make the control nodes at the designed elevation. Finally, the assembled counterweight cables and reaction frame devices are removed, and the structure is formed. Although this patent puts forward the overall idea of the scaffold-free construction method for the ring cable-supported grid structure, and only sets a single circle of downward-pulling tooling cables at the circumferential cable clamps for the multi-strut cable-supported grid structure with radial cables in its Embodiment 2, it has not proposed solutions to the following key technical problems: ① When hoisting a single radial beam and struts, how to smoothly connect the lower ends of multiple struts to the radial cables and circumferential cables, and how to change the radial cables from oblique straight lines to multi-fold lines; ② After unhooking the single-piece hoisting, the lateral stability problems of the single-piece radial beam, struts, and radial cables; ③ The installation of the previous batches of radial beams, ring beams, and struts makes the linear shape of the corresponding radial cables of the corresponding bays change from oblique straight lines to multi-fold lines, and the radial cable forces increase accordingly, and the inward radial displacement of the circumferential support structure also gradually increases. How to avoid a large axial pressure on the ring beam in the upper grid to ensure that the radial prestress of the lower cable net is independently balanced by the circumferential support structure. Therefore, the present invention will propose solutions to the above key technical problems. Summary of the Invention

[0007] The purpose of the present invention is to provide a scaffold-free construction method with a single-circle downward pull for a multi-strut cable-supported grid structure with radial cables, which does not require setting multiple circles of downward-pulling tooling cables, and only sets a single circle of downward-pulling tooling cables at the circumferential cable clamps to achieve scaffold-free construction, greatly reducing the number of downward-pulling anchor points in the stands and the construction measure costs, having stable single-piece hoisting, small axial pressure on the ring beam in the upper grid, and ensuring that the radial prestress of the lower cable net is independently balanced by the circumferential support structure.

[0008] The purpose of the present invention can be achieved through the following technical solutions:

[0009] A bracketless construction method for single - loop downward pull of a radial multi - strut cable - supported lattice structure, comprising the following steps:

[0010] S1. Install the surrounding support structure;

[0011] S2. Lay the circumferential cable and radial cables to form the lower cable net, install circumferential cable clamps to clamp the circumferential cable, and connect the radial cables to the circumferential cable clamps;

[0012] S3. Hoist and lift the lower cable net until the radial cables are anchored to the peripheral support structure;

[0013] S4. Install and tension the single - loop downward - pull tooling cable at the circumferential cable clamp to make the circumferential cable at the designed elevation. Meanwhile, the shape of the radial cable is an inclined straight line;

[0014] S5. Reserve the closure section, hoist the radial beams, struts and radial cable clamps to the lower cable net section by section and block by block. Meanwhile, adjust the tension of the downward - pull tooling cable to maintain the circumferential cable at the designed elevation. During this period, hoist the non - closure - section first - batch ring beams from the outside to the inside in a staggered interval and flowing - water manner;

[0015] S6. Symmetrically and gradually release the downward - pull tooling cable in a cyclic manner until the downward - pull tooling cable is slack and then remove it;

[0016] S7. Continue to install the non - closure - section later - batch ring beams from the outside to the inside in circles;

[0017] S8. Install the ring beam of the closure section from the inside to the outside.

[0018] Further, in S5, the hoisting steps of the radial beam, strut and radial cable clamp are as follows:

[0019] (1) Lift the radial beam off its assembly jig;

[0020] (2) Install the strut and pin - connect its upper end to the radial beam;

[0021] (3) Install the radial cable clamp and pin - connect its lower end to the strut;

[0022] (4) With the strut in a natural vertical state, adjust the spatial attitude of the radial beam so that the horizontal inclination angle of the line connecting the center of the pin hole at the outer end of the radial beam and the center of the radial cable clamp at the lower end of the first strut from the outside is less than the horizontal inclination angle of the inclined straight line of the radial cable in S4;

[0023] (5) Lower the lifting hook and adjust its position, and pin - connect the outer end of the radial beam to the peripheral support structure;

[0024] (6) Continue to lower the lifting hook so that the radial beam rotates vertically around the outer - end pin, move the radial cable clamp at the lower end of the first strut from the outside, and clamp the radial cable at the preset marked position;

[0025] (7) Then lower the lifting hook, and successively clamp the radial cable clamps to the radial cables according to the marked positions from the outside to the inside in the manner of step (7) until the innermost strut is pinned to the circumferential cable clamp.

[0026] (8) Install temporary stability measures and release the hook to remove the lifting appliance.

[0027] Furthermore, in step (8), before releasing the hook for single-truss hoisting, temporary guy ropes are symmetrically arranged between the two outer ends of the radial beam and the peripheral support structure, and temporary diagonal braces are symmetrically arranged between the two sides of the strut connecting the circumferential cables and the adjacent circumferential cable clamps.

[0028] Further, in S2, the lower cable net is installed on the stands and / or the ground.

[0029] Further, in S3 and S4, during the lifting process of the lower cable net, when the circumferential cable clamp is disengaged by 1.2 - 1.8 m, connect the upper end of the downward pulling tooling cable to the circumferential cable clamp and the lower end to the stand outside the peripheral support structure.

[0030] Compared with the prior art, the present invention has the following advantages:

[0031] (1) The single-loop downward pulling tooling cable is adopted to realize the scaffold-free construction of the radially multi-strut cable-supported lattice structure. Not only is it unnecessary to set up temporary scaffolds on the stands, but also only a single-loop downward pulling tooling cable is set at the circumferential cable clamp, avoiding the complex procedures of multi-loop downward pulling, facilitating the adjustment of the circumferential cable elevation, reducing the implementation difficulty and construction measure cost. In addition, the single-truss hoisting is stable, the installation of the radial cable clamp is convenient, the stress level of the ring beam of the upper grid is low, and the prestress flow path is clear, meeting the design requirement that the radial prestress of the lower cable net is independently balanced by the peripheral support structure.

[0032] (2) The ring beam is divided into a closure segment ring beam and a non-closure segment ring beam, and the latter is further subdivided into a first batch and a second batch, and they are arranged and installed in a specific manner, avoiding the problem that the ring beam shares the radial prestress of the cable net due to the circumferential closing effect, and enabling the radial prestress of the cable net to be independently borne by the peripheral support structure.

[0033] (3) When hoisting a single truss, the radial cable clamp is first installed at the lower end of the strut, and as the lifting hook is lowered, the radial cable clamps are successively clamped to the radial cables according to the marked positions from the outside to the inside. This method of installing the radial cable clamp avoids the problem that when the radial cable clamp first clamps the radial cable, the radial cable clamp twists with the cable body after the radial cable is stressed, making it difficult to align the holes and insert the pin shafts between the lower end of the strut and the radial cable clamp during single-truss hoisting. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is an overall three-dimensional axonometric view of the stadium applicable to the present invention.

[0035] Figure 2Partial three - dimensional axonometric drawing of the stadium applicable to the present invention.

[0036] Figure 3 Elevation schematic diagram of the first construction step of the stadium applicable to the present invention.

[0037] Figure 4 Elevation schematic diagram of the second construction step of the stadium applicable to the present invention.

[0038] Figure 5 Elevation schematic diagram of the third construction step of the stadium applicable to the present invention.

[0039] Figure 6 Elevation schematic diagram of the fourth construction step of the stadium applicable to the present invention.

[0040] Figure 7 Elevation schematic diagram of the fifth construction step of the stadium applicable to the present invention.

[0041] Figure 8 Plan schematic diagram of the fifth construction step of the stadium applicable to the present invention (staggered interval layout schematic diagram).

[0042] Figure 9 Schematic diagram of the hoisting process of a single - bay radial steel beam of the stadium applicable to the present invention.

[0043] Figure 10 Schematic diagram of the lateral stability measures for hoisting a single - bay radial steel beam of the stadium applicable to the present invention.

[0044] Figure 11 Elevation schematic diagram of the sixth construction step of the stadium applicable to the present invention.

[0045] Figure 12 Plan schematic diagram of the seventh construction step of the stadium applicable to the present invention.

[0046] Figure 13 Plan schematic diagram of the eighth construction step of the stadium applicable to the present invention.

[0047] Description of the marks in the figure:

[0048] 1 - Peripheral support structure, 2 - Circumferential cable, 3 - Radial cable, 4 - Strut, 5 - Ring beam, 6 - Radial beam, 7 - Circumferential cable clamp, 8 - Radial cable clamp, 9 - First - batch non - closure - section ring beam, 10 - Second - batch non - closure - section ring beam, 11 - Closure - section ring beam, 12 - Lower - pulling tooling cable, 13 - Traction tooling cable, 14 - Crane hoisting cable, 15 - Temporary inclined strut, 16 - Temporary guy wire. Detailed implementation manners

[0049] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. These embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation manners and specific operation processes are given. However, the protection scope of the present invention is not limited to the following embodiments.

[0050] In the following embodiments or examples, if there is no special description of functional components or structures, it means that they are all conventional components or conventional structures adopted in the art to achieve corresponding functions.

[0051] In order to avoid the complex process of multi-loop pulling down, and to meet the design requirements such as the radial prestress of the lower cable net being independently balanced by the circumferential support structure, etc., the present invention proposes a method for a radial multi-strut cable-supported lattice structure to achieve scaffold-free construction by using a single-loop pulling-down tooling cable. The following key problems need to be solved: ① When hoisting a single radial beam and struts, how to smoothly connect the lower ends of multiple struts to the radial cable and circumferential cable, and the radial cable changes from an inclined straight line to a multi-fold line; ② After the single-piece hoisting hook is released, the lateral stability problem of the single-piece radial beam, struts and radial cable; ③ The installation of the previous batch of radial beams, ring beams and struts causes the linear shape of the corresponding radial cable to change from an inclined straight line to a multi-fold line, and the radial cable force increases accordingly, and the inward radial displacement of the circumferential support structure also gradually increases. How to avoid a large axial pressure in the ring beam in the upper grid to ensure that the radial prestress of the lower cable net is independently balanced by the circumferential support structure.

[0052] Specifically, the present invention provides a scaffold-free construction method for single-loop pulling down of a radial multi-strut cable-supported lattice structure, which can be seen Figures 1 to 13 as shown, and includes the following steps:

[0053] S1. Install the surrounding support structure;

[0054] S2. Lay the circumferential cable and radial cable to form the lower cable net, install circumferential cable clamps to clamp the circumferential cable, and connect the radial cable to the circumferential cable clamps;

[0055] S3. Hoist and lift the lower cable net until the radial cable is anchored to the circumferential support structure;

[0056] S4. Install and tension the single-loop pulling-down tooling cable at the circumferential cable clamp to make the circumferential cable at the designed elevation. At the same time, the linear shape of the radial cable is an inclined straight line;

[0057] S5. Leave a closure section, and hoist the radial beam, struts and radial cable clamps to the lower cable net one by one in blocks. At the same time, adjust the tension of the pulling-down tooling cable to maintain the circumferential cable at the designed elevation. During this period, the non-closure section first batch of ring beams are hoisted in a flowing manner from the outside to the inside at staggered intervals;

[0058] S6. Symmetrically and gradually release the pulling-down tooling cable in a cyclic manner until the pulling-down tooling cable is slack and then removed;

[0059] S7. Continue to install the ring beams of the batches after the non-closure section from the outside to the inside in circles;

[0060] S8. Install the ring beams of the closure section from the inside to the outside.

[0061] In some specific embodiments, in S5, the hoisting steps of the radial beams, struts, and radial cable clamps are as follows:

[0062] (1) Lift the radial beam off its assembly jig;

[0063] (2) Install the strut and pin-connect its upper end to the radial beam;

[0064] (3) Install the radial cable clamp and pin-connect it to the lower end of the strut;

[0065] (4) With the strut in a natural vertical state, adjust the spatial attitude of the radial beam so that the horizontal inclination angle of the connection line between the center of the pin hole at the outer end of the radial beam and the center of the radial cable clamp at the lower end of the first strut from the outside is less than the horizontal inclination angle of the radial cable diagonal line in S4;

[0066] (5) Lower the hook and adjust the position, and pin-connect the outer end of the radial beam to the circumferential support structure;

[0067] (7) Continue to lower the hook so that the radial beam rotates vertically around the outer end pin, move the radial cable clamp at the lower end of the first strut from the outside, and clamp the radial cable at the preset marked position;

[0068] (8) Then lower the hook, and successively clamp the radial cables by the radial cable clamps in the order of step (7) from the outside to the inside until the innermost strut is pin-connected to the circumferential cable clamp;

[0069] (9) Install temporary stability measures and release the hook to remove the lifting tool.

[0070] In a more specific embodiment, in step (9), before releasing the hook for single-piece hoisting, temporary guy ropes are symmetrically arranged between the two sides of the outer end of the radial beam and the circumferential support structure, and temporary diagonal braces are symmetrically arranged between the two sides of the strut connecting the circumferential cable and the adjacent circumferential cable clamps.

[0071] In some specific embodiments, in S2, the lower cable net is installed on the grandstand and / or the ground.

[0072] In some specific embodiments, in S3 and S4, during the lifting process of the lower cable net, when the circumferential cable clamp is disengaged by 1.2 - 1.8 m, connect the upper end of the downward pulling tooling cable to the circumferential cable clamp and the lower end to the grandstand outside the circumferential support structure.

[0073] Each of the above embodiments can be implemented alone, or can be combined in any pair or more combinations.

[0074] The above implementation is described in more detail below in conjunction with specific examples.

[0075] Embodiment 1:

[0076] Taking the cable-supported grid roof structure of a football field as an example, its perimeter support structure 1 is composed of annular plane steel trusses and V-shaped steel columns. The upper grid is composed of ring beams 5 and radial beams 6, with a total of 72 beams. There are 5 vertical struts 4 on each radial cable 3, and 1 vertical strut and 1 oblique strut 4 on each annular cable clamp. The radial prestress of the lower cable net is independently balanced by the perimeter support structure 1, see Figure 1 and Figure 2 .

[0077] The specific steps of the non-bracket construction method are as follows:

[0078] Step 1: Install the perimeter support structure 1, see Figure 3 .

[0079] Step 2: Lay the annular cable 2 and radial cable 3 on the stand and the ground, install the annular cable clamp 7 to clamp the annular cable 2, and connect the radial cable 3 with the annular cable clamp 7, see Figure 4 ;

[0080] Step 3: Build a working platform on the circumferential support structure 1, use hydraulic tensioning equipment and traction tooling rope 13 to pull and lift the cable net; after the annular cable clamp is about 1.5m away, connect the upper end of the pull-down tooling rope 12 to the annular cable clamp 7. After the lower cable net is lifted into place as a whole, anchor the outer end cable head of the radial cable 3 to the circumferential support structure 1, see Figure 5 ;

[0081] Step 4: Connect the lower end of the pull-down tooling cable 12 to the main structure of the stand, and use a hydraulic jack to tension the pull-down tooling cable 12 so that the annular cable 2 is at the designed elevation, see Figure 6 ;

[0082] Step 5: Leave the joint section, and hoist the radial beams 6, the struts 4 and the radial cable clamps 8 to the lower cable net one by one, and adjust the corresponding pull-down tooling cable force to maintain the annular cable 2 at the designed elevation (see Figure 7 ), during which the first batch of ring beams 9 of the non-closed section were hoisted from the outside to the inside in a staggered manner (see Figure 8 ).

[0083] In this step, the specific steps of hoisting the single radial beam 6, the strut 4 and the radial cable clamp 8 are as follows:

[0084] ① Lift the radial beam 6 to separate it from the assembly frame;

[0085] ② Install the support rod 4 so that its upper end is pin-connected with the radial beam 6;

[0086] ③ Install the radial cable clamp 8 and pin-connect it to the lower end of the strut 4;

[0087] ④ When the strut 4 is in a natural vertical state, adjust the spatial attitude of the radial beam 6 through the crane sling 14 so that the horizontal inclination angle of the oblique straight line between the center of the outer end pin hole of the radial beam 6 and the center of the radial cable clamp 8 at the lower end of the first strut on the outside is less than the horizontal inclination angle of the oblique straight line of the radial cable 3 after the completion of step four;

[0088] ⑤ Lower the hook and adjust the position, then pin-connect the outer end of the radial beam 6 to the circumferential support structure 1;

[0089] ⑥ Continue to lower the hook, and the radial beam 6 rotates vertically around the outer end pin shaft, move the radial cable clamp 8 at the lower end of the first strut 4 on the outside, and clamp the radial cable 3 according to the preset marked position;

[0090] ⑦ Continue to lower the hook, and successively clamp the radial cable 3 with the radial cable clamps 8 from outside to inside according to the marked positions until the inner strut 4 is pin-connected to the circumferential cable clamp 7;

[0091] ⑧ Install temporary stability measures and unhook and remove the lifting appliance. During the processes of step ⑥ and ⑦, the single-piece hoisting weight is gradually borne by the radial cable 3, and the cable shape of the radial cable 3 changes from an oblique straight line to a multi-fold line (see Figure 9 ). Before unhooking the single-piece hoisting, symmetrically arrange temporary guy ropes 16 between the two sides of the outer end of the radial beam 3 and the circumferential support structure 1, and symmetrically arrange temporary diagonal braces 15 between the two sides of the circumferential cable strut 4 and the adjacent circumferential cable clamps 7 to ensure the lateral stability of the single piece (see Figure 10 ).

[0092] The sixth step: Symmetrically and gradually release the downward pulling tooling cable 12 in a graded manner until the downward pulling tooling cable 12 is slack and then removed, see Figure 11 ;

[0093] The seventh step: Install the non-closure section subsequent batch of ring beams 10 circle by circle from outside to inside, see Figure 12 .

[0094] The eighth step: Install the closure section ring beam 11 from outside to inside, and the structure is formed, see Figure 13 .

[0095] In this embodiment, when installing the ring beams in the upper grid, they are divided into closure-section ring beams and non-closure-section ring beams according to their positions. Among them, the latter are further subdivided into non-closure-section first-batch ring beams and non-closure-section second-batch ring beams. The non-closure-section first-batch ring beams are arranged in a staggered and spaced manner, and are installed in the order from outside to inside after the installation of two adjacent radial beams, and are installed before the release of the downward pulling tooling cable; after the release of the downward pulling tooling cable, the non-closure-section second-batch ring beams are installed in circles from outside to inside; then, the closure-section ring beams are installed from outside to inside. This method of installing ring beams avoids the problem that the ring beams share the radial prestress of the cable net due to the circumferential closure effect, and enables the radial prestress of the cable net to be independently borne by the circumferential supporting structure. It should be noted here that the setting of the non-closure-section first-batch ring beams and the non-closure-section second-batch ring beams satisfies the "staggered and spaced installation". Specifically, in the non-closure-section first-batch ring beams, along the direction of the radial cable, a non-closure-section second-batch ring beam is arranged between two adjacent non-closure-section first-batch ring beams. Similarly, along the circumferential direction of the circumferential cable, a non-closure-section second-batch ring beam is also arranged between two adjacent non-closure-section first-batch ring beams.

[0096] The above description of the embodiments is for the convenience of those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative efforts. Therefore, the present invention is not limited to the above embodiments, and the improvements and modifications made by those skilled in the art without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims

1. A method for constructing a radial multi-braced cable-supported grid structure with a single-circle pull-down without a support, characterized in that: The following steps are involved: S1. Install surrounding support structures; S2, laying the annular cables and radial cables to form the lower cable net, installing the annular cable clamps to clamp the annular cables, and connecting the radial cables to the annular cable clamps; S3, traction and lifting of the lower cable net until the radial cables are anchored to the circumferential support structure; S4. Install and tension a single-loop pull-down tooling cable at the annular cable clamp, so that the annular cable is at the designed elevation, and at the same time, the linear shape of the radial cable is an oblique straight line; S5, leaving the joint section, hoisting radial beams, struts and radial cable clamps to the lower cable net one by one in blocks, and at the same time, adjusting the tension of the pull-down tooling cable to maintain the annular cable at the designed elevation. During this period, hoist the first batch of ring beams of the non-joint section from the outside to the inside in a staggered manner; S6, releasing the pull-down tooling rope symmetrically and cyclically until the pull-down tooling rope is loosened and then removed; S7, continue to install the batch of ring beams of the non-jointed section from outside to inside one circle at a time; S8. Install the ring beam of the joint section from the inside to the outside.

2. A bracket-free construction method for a radial multi-braced cable-supported grid structure with a single-circle pull-down according to claim 1, characterized in that: In S5, the steps for lifting radial beams, struts and radial cable clamps are: (1) Lifting the radial beam off its assembly frame; (2) Install the support rod and connect its upper end to the radial beam pin; (3) Install the radial cable clamp and pin it to the lower end of the support rod; (4) Keeping the struts in a naturally vertical state, adjust the spatial posture of the radial beam so that the horizontal inclination angle of the line between the center of the pin hole at the outer end of the radial beam and the center of the radial cable clamp from the lower end of the first strut on the outside is smaller than the horizontal inclination angle of the radial cable inclined straight line in S4; (5) Lower the hook and adjust the position to pin the outer end of the radial beam to the peripheral support structure; (6) Continue to lower the hook, so that the radial beam rotates vertically around the outer end pin, and moves the radial cable clamp at the lower end of the first outer support rod to clamp the radial cable according to the preset marked position; (7) Then, lower the hook and clamp the radial cable according to the marked positions with the radial cable clamps from outside to inside in accordance with step (7) until the innermost support rod is pinned to the annular cable clamp; (8) Install temporary stabilization measures, loosen the hook and remove the sling.

3. The method for constructing a radial multi-braced cable-supported grid structure with a single-circle pull-down without a support according to claim 2, characterized in that: In step (8), before the single-beam lifting hook is released, temporary guy ropes are symmetrically arranged between the outer ends of the radial beam and the circumferential support structure on both sides, and temporary diagonal braces are symmetrically arranged between the adjacent annular cable clamps on both sides of the support rods connecting the annular cables.

4. The method for constructing a radial multi-braced cable-supported grid structure with a single-circle pull-down without a support according to claim 1, characterized in that: In S2, the lower cable net is installed on the stands and / or the ground.

5. The method for constructing a radial multi-braced cable-supported grid structure with a single-circle pull-down without a support according to claim 1, characterized in that: In S3 and S4, during the lifting process of the lower cable net, when the annular cable clamp is freed by 1.2 to 1.8 m, the upper end of the pull-down tooling cable is connected to the annular cable clamp, and the lower end is connected to the stand outside the circumferential support structure.

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