Construction method for lifting and tensioning double-layer cable net structure as a whole with equal force

Abstract

The present application relates to a kind of construction methods of upper and lower layer equal force integral lifting and tensioning double-layer cable net structure, for the case of double-layer cable net is connected with outer pressure ring, ring cable, upper and lower layer radial cable and its connecting component are assembled on ground, and the outer end of upper and lower layer cable net is provided with puller while equal force traction upper and lower layer radial cable, wherein upper layer main control traction length, the traction force of lower layer main control is equal to upper layer, finally, lower layer radial cable, upper layer radial cable are anchored in sequence to cable net tensioning forming, realize the integral traction and tensioning of double-layer cable net structure.Upper and lower layer radial cable is simultaneously equal force traction, maintains good construction form, avoids connecting component in high-altitude after loading;By setting displacement sensor on upper layer puller and arranging total oil supply, oil return tee joint distribution valve and branch tee joint distribution valve between upper and lower layer puller oil line system, both ensure the stroke control of pump station to upper layer puller, also ensure the equal force of upper and lower layer traction, reduce half of hydraulic pump station investment.

Description

Technical Field

[0001] This invention belongs to the field of civil engineering cable structure construction technology, and relates to a construction method for an upper and lower layer equal-force integral lifting and tensioning double-layer cable net structure. Background Technology

[0002] A double-layer cable net structure generally consists of upper radial cables, lower radial cables, ring cables, connecting members between the upper and lower radial cables, and an outer pressure ring (outer ring beam or outer ring truss). It is a prestressed, self-balancing spatial structural system. Typical double-layer cable net structure forms include cable trusses and cable domes. Double-layer cable net structures are widely used due to their advantages such as lightweight structure, high stiffness, and diverse structural forms.

[0003] The existing construction methods for double-layer cable net structures can be mainly divided into the following three categories:

[0004] 1. Erect temporary support frames for high-altitude installation and tensioning of cable nets:

[0005] First, a temporary support frame is erected at the center of the site. Then, cable nets are installed at high altitude, and the upper and lower layers of cable nets are tensioned in batches and stages until the structure is formed. This method requires the erection of a temporary support frame, which is complex to set up and dismantle, involves a large amount of high-altitude work, has high construction costs, occupies internal space, and affects construction flexibility and safety.

[0006] 2. Pull the upper cable net to lift the entire cable net, and tension the lower cable net to form the overall structure:

[0007] First, the upper cable net is actively pulled using a tooling cable, suspending the lower cable net below it and then lifting it to a high altitude. After the upper cable net is anchored to the outer pressure ring, the pulling equipment for the upper cable net is transferred to the lower cable net, and then the lower cable net is tensioned until the structure is formed. This method requires lifting the upper cable net and tensioning the lower cable net separately, and transferring the pulling equipment to the lower cable net after pulling the upper cable net increases the workload of equipment transfer and extends the construction period.

[0008] 3. Construction method for lifting the lower cable net as a whole and tensioning the double-layer cable net structure:

[0009] The construction method for forming a double-layer cable net, as described in Chinese patent CN111927094A, involves traction of the lower cable net as a whole, lifting it to the point where the outer end of the upper cable net connects to the outer pressure ring. Then, the lower cable net is tensioned until the structure is formed. The traction equipment, fixedly hinged to the outer pressure ring, operates continuously, traction of the lower cable net to support the upper cable net, achieving continuous lifting. This continuous traction process sequentially completes the anchoring of the upper and lower cable nets. This method eliminates the need for secondary equipment transfer, resulting in high construction efficiency and savings in construction costs and time. However, this method is only applicable when the upper and lower cable nets are connected to the outer pressure ring at the same node. Summary of the Invention

[0010] The purpose of this invention is to provide a construction method for lifting and tensioning a double-layer cable net structure with equal force on both upper and lower layers, so as to avoid installing connecting components at high altitude, realize the simultaneous equal force traction and lifting of the entire cable net on both upper and lower layers, and reduce the investment in pumping stations, etc.

[0011] The objective of this invention can be achieved through the following technical solutions:

[0012] A construction method for a double-layer cable net structure with equal force lifting and tensioning of upper and lower layers includes the following steps:

[0013] S1. Install the circumferential support structure including the outer ring truss, and arrange the upper and lower layers of tooling ear plates on the outer ring truss. At the same time, lay and assemble the upper radial cable, lower radial cable, ring cable and install the connecting components on the grandstand and the ground.

[0014] S2. Install traction devices at the tooling ear plates at each lifting point on the outer ring truss. Install traction cable reaction tooling and tooling anchors on the outer end anchors at the upper and lower radial cables. The traction devices installed at the upper and lower tooling ear plates are connected to the tooling anchors corresponding to the upper and lower radial cables respectively through traction tooling cables.

[0015] S3. Arrange a hydraulic pump station and oil circuit system next to the lifting point and connect them to each traction device respectively;

[0016] S4. The hydraulic pump station controls the overall traction and lifting of each point to ensure that the upper and lower radial cables of the same frame are simultaneously pulled and lifted with equal force during the traction process. The upper radial cable controls the main traction length, and the lower radial cable controls the main traction force equal to that of the upper radial cable.

[0017] S5. Lift the cable net structure as a whole to the outer end anchorage of the lower radial cable, which is close to the structural lug on the outer ring truss.

[0018] S6. Tension and anchor the lower radial cable, and then continue to tension the upper radial cable until the outer end anchor of the upper radial cable is anchored to the corresponding structural ear plate, and the double-layer cable net structure is tensioned and formed.

[0019] S7. Remove the traction device, traction cable, traction cable reaction tool and tool anchor.

[0020] Furthermore, in S2, there are four traction devices at each lifting point, which are divided into two upper traction devices symmetrically located on both sides of the upper radial cable and two lower traction devices symmetrically located on both sides of the lower radial cable. The nominal force, rated oil pressure, piston stroke, and piston cross-sectional area of ​​the four traction devices are completely identical.

[0021] Furthermore, in S3, the oil circuit system includes an oil supply line and an oil return line, wherein,

[0022] The oil supply pipeline includes a main oil supply pipe connected to the hydraulic pump station, an upper main oil supply pipe and a lower main oil supply pipe connected to the main oil supply pipe through a main oil supply three-way distribution valve. The upper main oil supply pipe is also connected to two upper branch oil supply pipes through an upper oil supply three-way distribution valve. The lower main oil supply pipe is also connected to two lower branch oil supply pipes through a lower oil supply three-way distribution valve. The upper branch oil supply pipe and the lower branch oil supply pipe are respectively connected to the upper puller and the lower puller.

[0023] The return oil pipeline includes a main return oil pipe connected to the hydraulic pump station, an upper main return oil pipe and a lower main return oil pipe connected to the main return oil pipe through a main return oil three-way distribution valve. The upper main return oil pipe is also connected to two upper branch return oil pipes through an upper return oil three-way distribution valve. The lower main return oil pipe is also connected to two lower branch return oil pipes through a lower return oil three-way distribution valve. The upper branch return oil pipe and the lower branch return oil pipe are respectively connected to the upper puller and the lower puller.

[0024] Furthermore, in S3, the upper traction device is equipped with a displacement sensor to monitor the stroke of its hydraulic cylinder. The hydraulic pump station can receive the stroke information fed back by the displacement sensor and control the traction length of the upper radial cable.

[0025] Furthermore, in S4, during the traction process, the hydraulic pump station supplies oil to the four traction devices simultaneously through the main oil supply pipe, and the oil pressure is equal, so as to achieve consistent traction force on the upper radial cable and the lower radial cable.

[0026] Furthermore, the upper main oil supply pipe and the lower main oil supply pipe have the same specifications, and the upper branch oil supply pipe and the lower branch oil supply pipe have the same specifications.

[0027] The upper main return oil pipe and the lower main return oil pipe have the same specifications, and the upper branch return oil pipe and the lower branch return oil pipe have the same specifications.

[0028] Furthermore, after the lower radial cable is tensioned and anchored, the lower oil supply three-way distribution valve is closed to allow oil to be supplied to the upper tensioner independently, thus completing the tensioning and anchoring of the upper radial cable.

[0029] Furthermore, the connecting member is movably connected to the upper radial cable net and the lower radial cable net, respectively.

[0030] Furthermore, in S4, the control strategy of the hydraulic pump station during the cable net lifting process is clarified through construction process simulation analysis, including the following steps:

[0031] (4-1) In the k-th construction condition, first specify the stress-free length of the i-th upper traction cable. Where 1≤i≤n, n is the number of radial cables in the upper layer, and in the j-th iteration, where j≥1, the initial tension of the i-th upper layer traction cable is calculated based on the stress-free length. in E represents the length of the i-th upper-level traction tooling cable unit model in the j-th iteration. i,a and A i,a Let be the elastic modulus and cross-sectional area of ​​the i-th upper traction cable, respectively, and the corresponding initial strain applied to the i-th upper traction cable. If the initial tension of the lower traction cable of the i-th skeletal frame is equal to that of the upper traction cable, then the initial strain applied to the lower traction cable of the i-th skeletal frame is... Among them, E i,b and A i,b Let be the elastic modulus and cross-sectional area of ​​the i-th lower traction cable, respectively; perform iterative calculations, updating the initial strains of the upper and lower traction cables in each iteration, until static equilibrium is reached, at which point the upper traction cable reaches the specified stress-free length. Lower traction tooling cable force Equal to the upper traction tooling cable force Here, to accelerate iterative convergence, the lower-level traction tooling cable adopts a small elastic modulus, that is, for E... i,b A reduction should be applied, preferably with a reduction factor of 0.001;

[0032] (4-2) In the (k+1)th construction condition, the stress-free length of the upper traction cable is determined according to the iterative strategy in step (4-1). and the corresponding upper and lower traction cable forces and

[0033] (4-3) Based on the above simulation analysis, the stroke control strategy of the hydraulic pump station for the traction cylinder during the construction process from the k-th working condition to the (k+1)-th working condition is as follows: the cylinder stroke during the construction process from the k-th working condition to the (k+1)-th working condition is... During the construction process from the kth working condition to the (k+1)th working condition, the hydraulic pump station supplies oil pressure to the traction cylinder. for Where A q This refers to the cross-sectional area of ​​the hydraulic cylinder piston of the traction device.

[0034] Compared with the prior art, the present invention sets tensioners in both the upper and lower layers to simultaneously pull the upper and lower cable nets with equal force, thereby achieving overall lifting and tensioning of the cable net structure, which has the following advantages:

[0035] (1) The radial cables of the upper and lower layers are lifted with equal force at the same time, which maintains the good construction form of the cable net and avoids the need to install connecting components at high altitude.

[0036] (2) By installing a displacement sensor on the upper traction device and arranging a main oil supply three-way distribution valve and a branch three-way distribution valve between the upper and lower traction device oil circuit systems, it is possible to ensure that the pump station controls the traction stroke of the upper traction device, ensure that the traction force of the upper and lower layers is equal, and reduce the investment of the hydraulic pump station by half. Attached Figure Description

[0037] Figure 1 This is a three-dimensional axonometric drawing of the double-layer cable net structure to which this invention applies;

[0038] Figure 2 This is a three-dimensional schematic diagram of the ring truss and structural lugs connection of the double-layer cable net structure to which this invention applies;

[0039] Figure 3 This is an elevation view of the first construction step of the present invention;

[0040] Figure 4 This is a three-dimensional schematic diagram of the second construction step of the present invention;

[0041] Figure 5 This is a schematic elevation view of the hydraulic pump station and oil circuit system layout for the third construction step of the present invention.

[0042] Figure 6 This is a schematic diagram of the layout of the upper radial cable tensioner oil supply system in the third construction step of the present invention;

[0043] Figure 7 This is a schematic diagram of the layout of the upper radial cable puller oil return system in the third construction step of the present invention;

[0044] Figure 8 This is a schematic diagram of the layout of the lower radial cable tensioner oil supply system in the third construction step of the present invention;

[0045] Figure 9 This is a schematic diagram of the layout of the lower radial cable puller return oil system in the third construction step of the present invention;

[0046] Figure 10 This is a three-dimensional schematic diagram of the fifth construction step of the present invention;

[0047] Figure 11 This is a three-dimensional schematic diagram of the sixth construction step of the present invention;

[0048] Explanation of markings in the diagram:

[0049] 1. Outer ring truss; 2. Upper radial cable net; 3. Lower radial cable net; 4. Support rod; 5. Ring cable; 6. Tooling ear plate; 7. Peripheral support structure; 8-11. Traction tooling cable; 12. Traction cable reaction tooling; 13. Tooling anchor; 14. Outer end anchor; 15. Hydraulic pump station; 16. Structural ear plate; 17. Main oil supply pipe; 18. Main oil supply three-way distribution valve; 19. Upper main oil supply pipe; 20. Lower main oil supply pipe. 1. Upper layer oil supply three-way distribution valve 22; upper layer branch oil supply pipes 23, 24; lower layer oil supply three-way distribution valve 25; lower layer branch oil supply pipes 26, 27; main return oil pipe 28; main return oil three-way distribution valve 29; upper layer main return oil pipe 30; lower layer main return oil pipe 31; upper layer return oil three-way distribution valve 32; upper layer branch return oil pipes 33, 34; lower layer return oil three-way distribution valve 35; lower layer branch return oil pipes 36, 37. Detailed Implementation

[0050] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0051] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0052] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0053] Unless otherwise specified, the functional components or structures in the following embodiments or examples are conventional components or structures used in the art to achieve the corresponding functions.

[0054] To avoid installing connecting components at high altitudes, achieve simultaneous equal-force traction and lifting of the entire cable net across upper and lower layers, and reduce pump station investment, this invention provides a construction method for an upper and lower layer equal-force overall lifting and tensioning double-layer cable net structure, comprising the following steps:

[0055] S1. Install the circumferential support structure including the outer ring truss, and arrange the upper and lower layers of tooling ear plates on the outer ring truss. At the same time, lay and assemble the upper radial cable, lower radial cable, ring cable and install the connecting components on the grandstand and the ground.

[0056] S2. Install traction devices at the tooling ear plates at each lifting point on the outer ring truss. Install traction cable reaction tooling and tooling anchors on the outer end anchors at the upper and lower radial cables. The traction devices installed at the upper and lower tooling ear plates are connected to the tooling anchors corresponding to the upper and lower radial cables respectively through traction tooling cables.

[0057] S3. Arrange a hydraulic pump station and oil circuit system next to the lifting point and connect them to each traction device respectively;

[0058] S4. The hydraulic pump station controls the overall traction and lifting of each point to ensure that the upper and lower radial cables of the same frame are simultaneously pulled and lifted with equal force during the traction process. The upper radial cable controls the main traction length, and the lower radial cable controls the main traction force equal to that of the upper radial cable.

[0059] S5. Lift the cable net structure as a whole to the outer end anchorage of the lower radial cable, which is close to the structural lug on the outer ring truss.

[0060] S6. Tension and anchor the lower radial cable, and then continue to tension the upper radial cable until the outer end anchor of the upper radial cable is anchored to the corresponding structural ear plate, and the double-layer cable net structure is tensioned and formed.

[0061] S7. Remove the traction device, traction cable, traction cable reaction tool and tool anchor.

[0062] In some specific implementations, in S2, there are four traction devices at each lifting point, which are divided into two upper traction devices symmetrically located on both sides of the upper radial cable and two lower traction devices symmetrically located on both sides of the lower radial cable. The nominal force, rated oil pressure, piston stroke, and piston cross-sectional area of ​​the four traction devices are completely identical.

[0063] In a more specific implementation, in S3, the oil circuit system includes an oil supply line and an oil return line, wherein,

[0064] The oil supply pipeline includes a main oil supply pipe connected to the hydraulic pump station, an upper main oil supply pipe and a lower main oil supply pipe connected to the main oil supply pipe through a main oil supply three-way distribution valve. The upper main oil supply pipe is also connected to two upper branch oil supply pipes through an upper oil supply three-way distribution valve. The lower main oil supply pipe is also connected to two lower branch oil supply pipes through a lower oil supply three-way distribution valve. The upper branch oil supply pipe and the lower branch oil supply pipe are respectively connected to the upper puller and the lower puller.

[0065] The return oil pipeline includes a main return oil pipe connected to the hydraulic pump station, an upper main return oil pipe and a lower main return oil pipe connected to the main return oil pipe through a main return oil three-way distribution valve. The upper main return oil pipe is also connected to two upper branch return oil pipes through an upper return oil three-way distribution valve. The lower main return oil pipe is also connected to two lower branch return oil pipes through a lower return oil three-way distribution valve. The upper branch return oil pipe and the lower branch return oil pipe are respectively connected to the upper puller and the lower puller.

[0066] In a more specific embodiment, in S3, the upper traction device is equipped with a displacement sensor to monitor the stroke of its cylinder. The hydraulic pump station can receive the stroke information fed back by the displacement sensor and control the traction length of the upper radial cable.

[0067] In a more specific implementation, in S4, during the traction process, the hydraulic pump station supplies oil to the four traction devices simultaneously through the main oil supply pipe, and the oil pressure is equal, so as to achieve consistent traction force on the upper radial cable and the lower radial cable.

[0068] In a more specific implementation, after the lower radial cable is tensioned and anchored, the lower oil supply three-way distribution valve is closed to allow oil to be supplied to the upper tensioner separately, thus completing the tensioning and anchoring of the upper radial cable.

[0069] In a more specific embodiment, the upper main oil supply pipe and the lower main oil supply pipe have the same specifications, and the upper branch oil supply pipe and the lower branch oil supply pipe have the same specifications.

[0070] The upper main return oil pipe and the lower main return oil pipe have the same specifications, and the upper branch return oil pipe and the lower branch return oil pipe have the same specifications.

[0071] In some specific embodiments, the connecting member can be a strut, a sling, or other components. For example, when the connecting member is a strut, both ends of the strut are hinged to the upper radial cable net and the lower radial cable net, respectively.

[0072] In some specific implementations, in S4, the control strategy of the hydraulic pump station during the cable net lifting process is clarified by conducting construction process simulation analysis, including the following steps:

[0073] (4-1) In the k-th construction condition, first specify the stress-free length of the i-th upper traction cable. Where 1≤i≤n, n is the number of radial cables in the upper layer, and in the j-th iteration, where j≥1, the initial tension of the i-th upper layer traction cable is calculated based on the stress-free length. in E represents the length of the i-th upper-level traction tooling cable unit model in the j-th iteration. i,a and A i,aLet be the elastic modulus and cross-sectional area of ​​the i-th upper traction cable, respectively, and the corresponding initial strain applied to the i-th upper traction cable. If the initial tension of the lower traction cable of the i-th skeletal frame is equal to that of the upper traction cable, then the initial strain applied to the lower traction cable of the i-th skeletal frame is... Among them, E i,b and A i,b Let be the elastic modulus and cross-sectional area of ​​the i-th lower traction cable, respectively; perform iterative calculations, updating the initial strains of the upper and lower traction cables in each iteration, until static equilibrium is reached, at which point the upper traction cable reaches the specified stress-free length. Lower traction tooling cable force Equal to the upper traction tooling cable force Here, to accelerate iterative convergence, the lower-level traction tooling cable adopts a small elastic modulus, that is, for E... i,b A reduction should be applied, preferably with a reduction factor of 0.001;

[0074] (4-2) In the (k+1)th construction condition, the stress-free length of the upper traction cable is determined according to the iterative strategy in step (4-1). and the corresponding upper and lower traction cable forces and

[0075] (4-3) Based on the above simulation analysis, the stroke control strategy of the hydraulic pump station for the traction cylinder during the construction process from the k-th working condition to the (k+1)-th working condition is as follows: the cylinder stroke during the construction process from the k-th working condition to the (k+1)-th working condition is... During the construction process from the kth working condition to the (k+1)th working condition, the hydraulic pump station supplies oil pressure to the traction cylinder. for Where A q This refers to the cross-sectional area of ​​the hydraulic cylinder piston of the traction device.

[0076] In some specific implementations, in S7, when the cable net is lifted as a whole until the outer end anchorage is close to the structural ear plate, a layered tensioning and anchoring method is adopted. In the initial stage of traction and lifting, the elevation of the ring cable at each lifting point is lower than that of the structural ear plate. As the cable net is lifted as a whole, the outer end anchorage of the lower radial cable will inevitably approach the structural ear plate before the outer end anchorage of the upper radial cable. Therefore, the lower radial cable is tensioned and anchored first. After the lower cable is anchored, the upper radial cable is tensioned until its outer end anchorage is anchored and connected to the structural ear plate, and the structure is tensioned and formed.

[0077] Each of the above implementation methods can be implemented individually, or in any combination of two or more.

[0078] The above implementation methods will be described in more detail below with reference to specific embodiments.

[0079] Example 1:

[0080] Taking the spoke-shaped, saddle-shaped, double-layer cable net roof structure of a stadium as an example, its double-layer cable net roof structure consists of an outer ring truss 1, an upper radial cable net 2, a lower radial cable net 3, struts 4, and ring cables 5. (See attached diagram.) Figure 1 As shown.

[0081] See Figure 4 The tooling ear plate 6 is welded to the outer ring truss 1; the pullers 8 to 11 in the traction lifting system are hydraulic jacks; the traction tooling cable 12 is made of steel strand; the traction cable reaction tooling 13 is made of steel plate; and the tooling anchor 14 is a multi-hole anti-loosening clip anchor.

[0082] The construction method specifically includes the following steps:

[0083] Step 1: Install the perimeter support structure 7, and install the tooling lugs 6 for connecting the tensioner on the outer ring truss 1. (See...) Figure 2 Lay the upper radial cable 2, lower radial cable 3, and ring cable 5 on the stands and ground, and install the support rod 4. See [reference needed]. Figure 3 The two ends of the strut 4 are hinged to the upper radial cable 2 and the lower radial cable 3, respectively.

[0084] Step Two: Install the traction and lifting system: Install pullers 8-11 at the tooling lugs 6 of each lifting point on the perimeter support structure 7. Install the traction cable reaction tooling 13 and tooling anchors 14 on the outer end anchors 15 of the upper and lower cable nets. Connect the outer end anchors 15 of the cable net to each puller 8-11 through the traction tooling cable 12. Each lifting point includes four pullers, divided into two upper-layer pullers 8 and 9 and two lower-layer pullers 10 and 11. The two pullers corresponding to the upper radial cable 2 and the lower radial cable 3 are symmetrically located on both sides of the radial cable. The nominal force, rated oil pressure, piston stroke, and piston cross-sectional area of ​​the jacks in the four pullers are completely identical. See [link to relevant documentation]. Figure 4 As shown.

[0085] Step 3: Install pump stations and oil circuit systems near the lifting points, including hydraulic pump stations, oil supply lines, oil return lines, and three-way distribution valves. The oil supply lines for the four pullers 8, 9, 10, and 11 at each lifting point are connected to the upper main oil supply line 20 and the lower main oil supply line 21 via a main oil supply three-way distribution valve 19 through a main oil supply line 18. The upper main oil supply line 20 is connected to the two upper branch oil supply lines 23 and 24 via an upper oil supply three-way distribution valve 22, and the lower main oil supply line 21 is connected to the two lower branch oil supply lines 26 and 27 via a lower oil supply three-way distribution valve 25. The oil return lines for the four pullers 8, 9, 10, and 11 are connected to the main return line 28 via a main return three-way distribution valve. 29 connects the upper main return oil pipe 30 and the lower main return oil pipe 31. The upper main return oil pipe 30 is connected to the two upper branch return oil pipes 33 and 34 via the upper return oil three-way distribution valve 32. The lower main return oil pipe 31 is connected to the two lower branch return oil pipes 36 and 37 via the lower return oil three-way distribution valve 35. The specifications of the upper main supply oil pipe 20 and the lower main supply oil pipe 21 should be consistent. The specifications of the four supply oil pipes, namely the upper two branch supply oil pipes 23 and 24 and the lower two branch supply oil pipes 26 and 27, should be consistent. The specifications of the upper main return oil pipe 30 and the lower main return oil pipe 31 should be consistent. The specifications of the four return oil pipes, namely the upper two branch return oil pipes 33 and 34 and the lower two branch return oil pipes 36 and 37, should be consistent. See [reference needed] Figures 5 to 9 .

[0086] Step 4: Use a hydraulic pump station to control the overall traction and lifting of the cable net at each point. During the process, the upper and lower radial cables of the same frame are simultaneously pulled and lifted with equal force. Displacement sensors are installed on the upper traction devices 10 and 11 to monitor the stroke of the upper traction device cylinders. The pump station and the upper traction device cylinder stroke are controlled in a closed loop to achieve the main control traction length of the upper cable. At the same time, the four traction devices 8 to 11 of the same frame are all supplied with oil by the same main oil supply pipe 18. The oil pressure is equal and the piston cross-sectional area of ​​the four traction devices is equal, so as to achieve consistent traction force between the upper and lower layers.

[0087] Step 5: Lift the entire structure until the outer end anchorage 15 of the lower radial cable is close to the structural ear plate 17, and then tension and anchor it in layers. First, tension and anchor the lower radial cable 3, see [link to relevant documentation]. Figure 10 .

[0088] Step Six: After the lower radial cable is anchored, close the lower oil supply three-way distribution valve 25 to allow oil supply to the upper tensioner independently. Continue tensioning the upper radial cable 3 until its outer end anchor 15 is anchored to the structural ear plate 17. The structure is then tensioned and formed. See [link / reference]. Figure 11 .

[0089] Step 7: Then remove the traction devices 8-11, traction cable 12, traction cable reaction device 13, and tooling anchor 14.

[0090] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A construction method for a double-layer cable net structure with equal force lifting and tensioning of upper and lower layers, characterized in that, Includes the following steps: S1. Install the circumferential support structure including the outer ring truss, and arrange the upper and lower layers of tooling ear plates on the outer ring truss. At the same time, lay and assemble the upper radial cable, lower radial cable, ring cable and install the connecting components on the grandstand and the ground. S2. Install traction devices at the tooling ear plates at each lifting point on the outer ring truss. Install traction cable reaction tooling and tooling anchors on the outer end anchors at the upper and lower radial cables. The traction devices installed at the upper and lower tooling ear plates are connected to the tooling anchors corresponding to the upper and lower radial cables respectively through traction tooling cables. S3. Arrange a hydraulic pump station and oil circuit system next to the lifting point and connect them to each traction device respectively; S4. The hydraulic pump station controls the overall traction and lifting of each point to ensure that the upper and lower radial cables of the same frame are simultaneously pulled and lifted with equal force during the traction process. The upper radial cable controls the main traction length, and the lower radial cable controls the main traction force equal to that of the upper radial cable. S5. Lift the cable net structure as a whole to the outer end anchorage of the lower radial cable, which is close to the structural lug on the outer ring truss. S6. Tension and anchor the lower radial cable, and then continue to tension the upper radial cable until the outer end anchor of the upper radial cable is anchored to the corresponding structural ear plate, and the double-layer cable net structure is tensioned and formed. S7. Remove the traction device, traction cable, traction cable reaction tool and tool anchor.

2. The construction method for a double-layer cable net structure with equal force lifting and tensioning of upper and lower layers according to claim 1, characterized in that, In S2, there are four traction devices at each lifting point. They are divided into two upper traction devices symmetrically located on both sides of the upper radial cable and two lower traction devices symmetrically located on both sides of the lower radial cable. The nominal force, rated oil pressure, piston stroke, and piston cross-sectional area of ​​the four traction devices are completely identical.

3. The construction method for a double-layer cable net structure with equal force lifting and tensioning of upper and lower layers according to claim 2, characterized in that, In S3, the oil circuit system includes an oil supply line and an oil return line, wherein, The oil supply pipeline includes a main oil supply pipe connected to the hydraulic pump station, an upper main oil supply pipe and a lower main oil supply pipe connected to the main oil supply pipe through a main oil supply three-way distribution valve. The upper main oil supply pipe is also connected to two upper branch oil supply pipes through an upper oil supply three-way distribution valve. The lower main oil supply pipe is also connected to two lower branch oil supply pipes through a lower oil supply three-way distribution valve. The upper branch oil supply pipe and the lower branch oil supply pipe are respectively connected to the upper puller and the lower puller. The return oil pipeline includes a main return oil pipe connected to the hydraulic pump station, an upper main return oil pipe and a lower main return oil pipe connected to the main return oil pipe through a main return oil three-way distribution valve. The upper main return oil pipe is also connected to two upper branch return oil pipes through an upper return oil three-way distribution valve. The lower main return oil pipe is also connected to two lower branch return oil pipes through a lower return oil three-way distribution valve. The upper branch return oil pipe and the lower branch return oil pipe are respectively connected to the upper puller and the lower puller.

4. The construction method for a double-layer cable net structure with equal force lifting and tensioning of upper and lower layers according to claim 3, characterized in that, In S3, the upper traction device is equipped with a displacement sensor to monitor the stroke of its cylinder. The hydraulic pump station can receive the stroke information fed back by the displacement sensor and control the traction length of the upper radial cable.

5. The construction method for a double-layer cable net structure with equal force lifting and tensioning of upper and lower layers according to claim 3, characterized in that, In S4, during the traction process, the hydraulic pump station supplies oil to the four traction devices simultaneously through the main oil supply pipe, and the oil pressure is equal, so as to achieve the same traction force on the upper radial cable and the lower radial cable.

6. The construction method for a double-layer cable net structure with equal force lifting and tensioning of upper and lower layers according to claim 3, characterized in that, The upper main oil supply pipe and the lower main oil supply pipe have the same specifications, and the upper branch oil supply pipe and the lower branch oil supply pipe have the same specifications. The upper main return oil pipe and the lower main return oil pipe have the same specifications, and the upper branch return oil pipe and the lower branch return oil pipe have the same specifications.

7. The construction method for a double-layer cable net structure with equal force lifting and tensioning of upper and lower layers according to claim 3, characterized in that, After the lower radial cable is tensioned and anchored, the lower oil supply three-way distribution valve is closed to allow oil to be supplied to the upper tensioner independently, thus completing the tensioning and anchoring of the upper radial cable.

8. The construction method for a double-layer cable net structure with equal force lifting and tensioning of upper and lower layers according to claim 1, characterized in that, The connecting components are movably connected to the upper radial cable net and the lower radial cable net, respectively.

9. The construction method for a double-layer cable net structure with equal force lifting and tensioning of upper and lower layers according to claim 1, characterized in that, In S4, the control strategy of the hydraulic pump station during the cable net lifting process is clarified through construction process simulation analysis, including the following steps: (4-1) in the k In each construction condition, the first one is specified. i The stress-free length of the upper-level traction cable , where 1≤ i ≤ n , n The number of radial cables in the upper layer, at the th j In the next iteration, j ≥1, calculated based on the stress-free length. i Initial tension of the upper traction cable ,in For the first j The iteration of the ... i The length of the upper-level traction tooling cable unit model. and The first i The elastic modulus and cross-sectional area of ​​the upper-layer traction cable are correspondingly applied to the first... i Initial strain of the upper traction cable ;No. i If the initial tension of the lower traction cable is equal to the initial tension of the upper traction cable, then the tension applied to the first... i Initial strain of the lower layer traction cable ,in, and The first i The elastic modulus and cross-sectional area of ​​the lower traction cable are determined; iterative calculations are performed, updating the initial strain of the upper and lower traction cables in each iteration, until static equilibrium is reached, at which point the upper traction cable reaches the specified stress-free length. Lower traction cable force Equal to the upper traction tooling cable force ; (4-2) in the k In the +1 construction case, the stress-free length of the upper traction cable is determined according to the iterative strategy in step (4-1). and the corresponding upper and lower traction cable forces and ; (4-3) Based on the above simulation analysis, the first... k The working condition to the first k The stroke control strategy for the traction cylinder of the hydraulic pump station during the +1 working condition construction process is as follows: k The working condition to the first k During the +1 working condition, the cylinder stroke is ;No. k The working condition to the first k +1 During the construction process, the hydraulic pump station supplies oil pressure to the traction cylinder. for ,in This refers to the cross-sectional area of ​​the hydraulic cylinder piston of the traction device.

10. The construction method for a double-layer cable net structure with equal force lifting and tensioning of upper and lower layers according to claim 9, characterized in that, In step (4-1), to accelerate iterative convergence, the lower-level traction tooling cable adopts a small elastic modulus, i.e., for... The amount will be reduced accordingly.

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