A method for adjusting the internal force balance of a wind-resistant cable of a membrane structure

Abstract

The application provides a membrane structure wind-resistant cable internal force balance adjustment construction method, which comprises the following steps: determining the original length of the wind-resistant cable; determining the stage tension value and the stage torque value corresponding to different tension stages; installing the wind-resistant cable; tensioning the wind-resistant cable in stages; detecting the torque in each stage to obtain a detected torque value; and adjusting the length of the wind-resistant cable through a balance adjustment device when the detected torque value is not within the allowable error range of the stage torque value. The length of the wind-resistant cable is adjusted by using the corresponding relationship between the stage tension value and the stage torque value, which is scientific and reasonable, has high reliability, ensures the internal force balance of the wind-resistant cable, and is easy to control, has a simplified process and accurate adjustment.

Description

Technical Field

[0001] This invention belongs to the field of membrane structure construction technology, and in particular relates to a construction method for balancing the internal forces of wind-resistant cables in membrane structures. Background Technology

[0002] Membrane structures are architectural structures formed by combining high-strength flexible thin-film materials with a support system. They are characterized by lightweight, large spans, short construction periods, and wide applicability, and are widely used in sports, commerce, culture, transportation, industry, and landscaping. The support system typically uses a steel structure as the supporting structure, combined with wind-resistant cables to form an overall load-bearing system. In existing technologies, during the tensioning and installation of wind-resistant cables, adjustable cable ends are used to adjust the length of the wind-resistant cables at both ends to ensure the tension value meets design requirements. Because the stress is more concentrated at the cable ends, this easily leads to uneven distribution of internal forces along different lengths of the wind-resistant cables. This uneven internal force can cause localized deformation and loosening of the wind-resistant cables. Especially since tolerances are unavoidable in the manufacturing and installation of the support structure and membrane fabric, this further exacerbates the deformation and loosening of the wind-resistant cables, making it difficult to achieve good wind resistance. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a construction method for balancing the internal forces of wind-resistant cables in membrane structures. This method is easy to control, has a simplified process, and allows for precise adjustments. Through multiple adjustments in stages, the balance of the internal forces of the wind-resistant cables is ensured.

[0004] The technical solution adopted in this invention is: a construction method for balancing the internal forces of wind-resistant cables in a membrane structure, characterized by comprising the following steps:

[0005] Determine the original length of the wind-resistant cable;

[0006] Determine the stage tension and stage torque values ​​corresponding to different tensioning stages;

[0007] Install the wind-resistant cable;

[0008] The wind-resistant cable is tensioned in stages: torque is detected at each stage to obtain the detected torque value; when the detected torque value is not within the allowable error range of the stage torque value, the length of the wind-resistant cable is adjusted by a balancing adjustment device.

[0009] Furthermore, determining the original length of the wind-resistant cable includes the following steps:

[0010] Determine the design tension value and the number of stages for the phased tensioning of the wind-resistant cable;

[0011] Based on the design tensile force value, calculate the service length of the wind-resistant cable;

[0012] Based on the design tensile force value and the usage length, the original length of the wind-resistant cable is calculated.

[0013] Furthermore, the method for calculating the length is as follows:

[0014] ;

[0015] Wherein, F is the design tensile force of the wind-resistant cable;

[0016] m is the mass of the wind-resistant cable;

[0017] l represents the service length of the wind-resistant cable;

[0018] n is the number of stages in the phased tensioning process;

[0019] f n The vibration frequency of the wind-resistant cable;

[0020] EI represents the bending stiffness of the wind-resistant cable.

[0021] Furthermore, the method for calculating the original length is as follows:

[0022] ;

[0023] in:

[0024] l0 is the original length of the wind-resistant cable;

[0025] l represents the service length of the wind-resistant cable;

[0026] F is the design tensile force value of the wind-resistant cable;

[0027] A is the cross-sectional area of ​​the wind-resistant cable;

[0028] E is the elastic modulus of the wind-resistant cable.

[0029] Furthermore, the wind-resistant cable includes a steel cable and a connecting cylinder, an anchor cup, a balancing device, and a fixed cable head arranged symmetrically at both ends of the steel cable. The two ends of the balancing device are threadedly connected to the anchor cup and the fixed cable head, respectively.

[0030] Furthermore, it also includes determining the correction length of the wind-resistant cable before installation, and adjusting the length of the wind-resistant cable to the correction length using the anchor cup.

[0031] Furthermore, the equalization adjustment device includes a bidirectional adjustment cable, a bidirectional adjustment nut, and a thrust nut; the bidirectional adjustment nut is threadedly connected to the middle of the bidirectional adjustment cable; the thrust nut is symmetrically arranged on both sides of the bidirectional adjustment nut and threadedly connected to the bidirectional adjustment cable.

[0032] Furthermore, the installation of the wind-resistant cable also includes attaching a tensile stress patch to the bidirectional adjusting cable rod to determine the actual tensile force value of the wind-resistant cable.

[0033] Furthermore, the method for calculating the stage torque value is as follows:

[0034] T = K·F·d;

[0035] Where T is the stage torque value;

[0036] K is the torque coefficient;

[0037] F represents the stage tension value;

[0038] d is the diameter of the bidirectional adjusting cable.

[0039] Furthermore, the torque detection includes turning the bidirectional adjusting nut to a set angle using a torque wrench to extend the equalizing adjustment device; then turning the set angle in the opposite direction to obtain the detected torque value; the allowable error range of the stage torque value is 0.9-1.1 times the stage torque value.

[0040] The advantages and positive effects of this invention are:

[0041] (1) By utilizing the correspondence between stage tension value and stage torque value, the length of the wind-resistant cable is adjusted, which is scientific, reasonable, and highly reliable, ensuring the balance of internal forces of the wind-resistant cable;

[0042] (2) By setting up an internal force equalization device, it is more convenient to perform torque detection and wind-resistant cable internal force adjustment, with a wider adjustment range, strong operability, saving time and effort, and significantly improving the installation efficiency of wind-resistant cable.

[0043] (3) This method is easy to control, has a simplified process, and is precise in adjustment. Through multiple adjustments in stages, it improves the balance of the internal forces of the wind-resistant cable and effectively avoids the concentration of force on the fixed cable head during the tightening of the wind-resistant cable. It is conducive to the overall membrane structure being subjected to balanced forces and improves the safety of the on-site construction process. Attached Figure Description

[0044] Figure 1 This is a construction flowchart of a specific embodiment of the present invention;

[0045] Figure 2 This is a schematic diagram of a wind-resistant cable structure according to a specific embodiment of the present invention;

[0046] Figure 3 This is a schematic diagram of a bidirectional adjusting nut structure according to a specific embodiment of the present invention.

[0047] In the picture:

[0048] 1. Fixed cable head; 2. Two-way adjusting nut; 3. Thrust nut; 4. Fixed pin; 5. Two-way adjusting cable rod; 6. Anchor cup; 7. Connecting cylinder; 8. Steel cable. Detailed Implementation

[0049] The embodiments of the present invention will now be described with reference to the accompanying drawings.

[0050] This invention proposes a construction method for balancing the internal forces of wind-resistant cables in membrane structures, such as... Figure 1 As shown, it includes the following steps:

[0051] S1. Determine the original length of the wind-resistant cable;

[0052] Specifically, the following steps are included:

[0053] S11. Determine the design tension value and the number of stages for phased tensioning of the wind-resistant cable;

[0054] Specifically, the design tensile force value of the wind-resistant cable can be determined according to the design requirements of the structure. The design requirements specify the maximum tensile force value of each wind-resistant cable under wind load, which is the design tensile force value.

[0055] In existing technologies, the tensioning of wind-resistant cables is generally carried out in stages. A predetermined proportion of the design tension is applied to the wind-resistant cable in each stage, gradually increasing until the tension in the final stage reaches 100% of the design tension. Staged tensioning allows for a smoother deformation and stress release process, reducing instantaneous impacts and improving the balance of internal forces within the wind-resistant cable, while also enhancing the stability of the tensioning operation. The number of stages and the tension value at each stage are usually determined empirically, or other methods from existing technologies can be used, and are not limited here. For example, in a specific embodiment, the wind-resistant cable is used in membrane structure construction. The span of the support structure at the bottom of the membrane structure is 180m, and the design tension value of the wind-resistant cable is 385KN. The wind-resistant cable is tensioned in three stages, with the corresponding stage tension values ​​being 30%, 60%, and 100% of the design tension value, respectively.

[0056] S12. Calculate the service length of the wind-resistant cable based on the design tensile force value.

[0057] The specific calculation method is as follows:

[0058] ;

[0059] Where F is the design tensile force of the wind-resistant cable;

[0060] m is the unit mass of the wind-resistant cable;

[0061] l represents the service length of the wind-resistant cable;

[0062] n is the number of tensioning stages;

[0063] f n The vibration frequency of the wind-resistant cable;

[0064] EI represents the bending stiffness of the wind-resistant cable.

[0065] Since the design tensile force of the wind-resistant cable has been determined, and the unit mass, vibration frequency, and bending stiffness of the wind-resistant cable are product parameters, all of which are known values, the service length of the wind-resistant cable can be calculated using the above formula.

[0066] S13. Calculate the original length of the wind-resistant cable based on the design tensile force and the service length.

[0067] The specific calculation method is as follows:

[0068] Let the initial length of the wind-resistant cable be l0, and the service length be l. Based on the design tension value of the wind-resistant cable, the elongation of the wind-resistant cable after tensioning is Δl = l - l0. Furthermore, according to the elongation calculation formula:

[0069] ;

[0070] Wherein, F is the design tensile force of the wind-resistant cable;

[0071] A is the cross-sectional area of ​​the wind-resistant cable;

[0072] E is the elastic modulus of the wind-resistant cable.

[0073] Substituting the two formulas and transforming them, we get:

[0074] ;

[0075] in:

[0076] l0 is the original length of the wind-resistant cable;

[0077] l represents the service length of the wind-resistant cable;

[0078] F is the design tensile force value of the wind-resistant cable;

[0079] A is the cross-sectional area of ​​the wind-resistant cable;

[0080] E is the elastic modulus of the wind-resistant cable;

[0081] The original length of the wind-resistant cable was determined.

[0082] S2. Determine the tension and torque values ​​corresponding to different tensioning stages;

[0083] In the prior art, wind-resistant cables typically include a steel cable 8 and connecting cylinders 7, anchor cups 6, bidirectional adjusting rods 5, and fixed cable heads 1 arranged symmetrically at both ends of the steel cable 8. During tensioning, the length of the wind-resistant cable is adjusted by rotating the anchor cups 6.

[0084] In the embodiments of this application, such as Figure 2 As shown, the wind-resistant cable also includes a balancing adjustment device, which is located between the anchor cup 6 and the fixed cable head 1, with its two ends threadedly connected to both. Both the anchor cup 6 and the balancing adjustment device have a set length adjustment range. During tensioning, when the anchor cup 6 reaches the upper limit of its adjustment range, the overall length of the wind-resistant cable can be further adjusted through the balancing adjustment device, expanding the adjustable range of the wind-resistant cable length and allowing the wind-resistant cable to be adjusted to a length that achieves the best internal force balance effect, thereby improving the accuracy of the adjustment.

[0085] Specifically, the equalization adjustment device includes a bidirectional adjusting rod 5, a bidirectional adjusting nut 2, and a thrust nut 3. The bidirectional adjusting nut 2 is threadedly connected to the middle of the bidirectional adjusting rod 5, and the thrust nut 3 is symmetrically arranged on both sides of the bidirectional adjusting nut 2 and threadedly connected to the bidirectional adjusting rod 5. The two ends of the bidirectional adjusting rod 5 are respectively threadedly connected to the anchor cup 6 and the fixed cable head 1. By turning the bidirectional adjusting nut 2, the bidirectional adjusting rod 5 can be rotated. Depending on the direction of turning, the two ends of the bidirectional adjusting rod 5 can be retracted or extended from the anchor cup 6 and the fixed cable head 1, thereby realizing the adjustment of the anti-wind cable length.

[0086] Furthermore, such as Figure 3 As shown, the bidirectional adjusting nut 2 has a fastening hole that extends from its side to the screw hole. A fixing pin 4 is provided in the fastening hole. By tightening the fixing pin 4, the bidirectional adjusting nut 2 can be fastened to the bidirectional adjustable screw, preventing the two from rotating relative to each other during torque testing.

[0087] In this application, the bidirectional adjusting cable rod 5 is used as the object for on-site torque detection. The principle is as follows: torque is generated by rotating the bidirectional adjusting cable rod 5, simultaneously changing the length of the bidirectional adjusting cable rod 5 between the anchor cup 6 and the fixed cable head 1, thereby changing the length of the wind-resistant cable after tension. This ensures a one-to-one correspondence between the length of the wind-resistant cable and the torque value required to generate the torque. In other words, it achieves a one-to-one correspondence between the tension value and the torque value at each stage, serving as a basis for judging whether the internal force of the wind-resistant cable is balanced. The above process does not consider internal material deformation, assuming that the bidirectional adjusting cable rod 5 has sufficient rigidity and will not undergo internal deformation during the adjustment process.

[0088] In this embodiment, tension is applied to the wind-resistant cable in three stages: the first stage tension is 30% of the design tension, the second stage tension is 60% of the design tension, and the third stage tension is 100% of the design tension. During tensioning, the first stage tension is applied to the wind-resistant cable, and the torque value of the wind-resistant cable in this state is detected after the application is completed to obtain the first stage torque value. Then, the tension is increased to the second stage tension value, and the torque value of the wind-resistant cable in this state is detected to obtain the second stage torque value. Finally, the tension is increased to the third stage tension value, which is 100% of the design tension value, and the torque value of the wind-resistant cable in this state is detected to obtain the third stage torque value. Finally, a tension-torque stage comparison table is formed, consisting of the first stage tension value, the second stage tension value, the third stage tension value, the first stage torque value, the second stage torque value, and the third stage torque value.

[0089] Specifically, the calculation methods for torque values ​​at different stages are as follows:

[0090] T = K·F·d;

[0091] Where T is the stage torque value;

[0092] K is the torque coefficient;

[0093] F represents the stage tension value;

[0094] d is the diameter of the torque object; in this application, d is the diameter of the bidirectional adjusting cable 5.

[0095] S3. Install wind-resistant cables;

[0096] Before installing the wind-resistant cable, the corrected length of the wind-resistant cable needs to be determined based on the actual site conditions.

[0097] Typically, due to unavoidable tolerances in the manufacturing and installation of the supporting structure and membrane fabric beneath the wind-resistant cable, or loosening and deformation caused by external environmental factors, a correction length is added to the original length of the wind-resistant cable to ensure it can adapt to the on-site conditions and has an adjustable margin. This correction length can be determined based on experience. For example, in a specific embodiment, the calculated original length of the wind-resistant cable is 179.6m, and based on the actual conditions of the construction site, the corrected length of the wind-resistant cable is 179.75m, which is 0.15m longer than the original length.

[0098] After determining the correction length of the wind-resistant cable, select a suitable length of wind-resistant cable and adjust the length of the wind-resistant cable to the correction length using the anchor cup 6. The adjustment range of the anchor cup 6 can be set according to the span of the support structure. In this embodiment, the length adjustment range of the anchor cup 6 is 220-520mm.

[0099] In this embodiment, the installation method of the wind-resistant cable is as follows: Winches are installed on both sides of the span direction of the supporting structure; the wind-resistant cable is lifted using a truck-mounted crane and placed at a predetermined position on one side of the supporting structure. One end of the fixed cable head 1 is connected to a four-wheeled trolley, and simultaneously, the fixed cable head 1 is connected to the traction rope of the winch on the other side. The winch is started, and the wind-resistant cable is moved via the traction rope, achieving rapid installation of the wind-resistant cable. After confirming the accurate position of the wind-resistant cable, the fixed cable heads 1 at both ends are initially fixed to the tensioning equipment.

[0100] Subsequently, tensile stress patches are attached to the bidirectional adjusting cable rod 5 to determine the actual tension value of the wind-resistant cable during the tensioning process.

[0101] S4. Tension the wind-resistant cable in stages;

[0102] Specifically, this includes performing torque detection at each stage to obtain the detected torque value; when the detected torque value is outside the allowable error range of the stage torque value, adjusting the length of the wind-resistant cable through a balancing adjustment device.

[0103] The specific method for torque detection is as follows: after the tensioning equipment applies the corresponding stage tension to the wind-resistant cable, the angle is set by turning the bidirectional adjusting nut 2 with a torque wrench; during this process, the bidirectional adjusting cable rod 5 rotates synchronously with the bidirectional adjusting nut 2, causing the equalization adjusting device to extend; then the set angle is turned in the opposite direction to obtain the detected torque value.

[0104] In one specific embodiment, before adjustment, a straight line is drawn along the axis of the bidirectional adjusting rod 5 on the side of the bidirectional adjusting nut 2 and the side of the anchor cup. The bidirectional adjusting nut 2 is rotated 60° by turning it with a torque wrench to extend the equalizing adjustment device. Then, the bidirectional adjusting nut 2 is turned in the opposite direction to align the straight line on the bidirectional adjusting nut 2 with the straight line on the anchor cup. The torque value on the torque wrench is read, which is the detection torque value at the current stage.

[0105] The allowable error range for the stage torque value is 0.9-1.1 times the stage torque value. When the obtained test torque value is within this range, it can be determined that the internal force of the wind-resistant cable is balanced. When the obtained test torque value is not within this range, the length of the wind-resistant cable needs to be adjusted.

[0106] In this application, the length of the wind-resistant cable is adjusted by a balancing adjustment device. The specific adjustment method is as follows: when the detected torque value is greater than the maximum value within the allowable error range of the stage torque value, the balancing adjustment device is extended by turning the bidirectional adjusting nut 2 with a torque wrench; when the detected torque value is less than the minimum value within the allowable error range of the stage torque value, the balancing adjustment device is shortened by turning the bidirectional adjusting nut 2 with a torque wrench; after each adjustment, the torque is detected using the above torque detection method until the detected torque value reaches the allowable error range of the stage torque value, then it is determined that the internal force of the wind-resistant cable is balanced in that stage, and the adjustment is completed.

[0107] After ensuring the balance of internal forces in the wind-resistant cable at each stage, the bidirectional adjusting nut 2 is locked by the fixing pin 4 to ensure its accurate position.

[0108] In this application, when adjusting the length of the wind-resistant cable using the equalization adjustment device, the equalization adjustment devices at both ends of the wind-resistant cable can be adjusted simultaneously, or the two ends can be adjusted alternately; preferably, the method of adjusting both ends simultaneously is adopted.

[0109] By employing the torque detection and wind-resistant cable length adjustment methods described above, the length of the wind-resistant cable is checked and adjusted multiple times in stages to ensure that the wind-resistant cable is in a state of internal force equilibrium at each stage, thereby achieving the effect of overall internal force equilibrium of the wind-resistant cable.

[0110] The advantages and positive effects of this invention are:

[0111] (1) By utilizing the correspondence between stage tension value and stage torque value, the length of the wind-resistant cable is adjusted, which is scientific, reasonable, and highly reliable, ensuring the balance of internal forces of the wind-resistant cable;

[0112] (2) By setting up an internal force balancing adjustment device, it is more convenient to perform torque detection and wind-resistant cable internal force adjustment. The adjustment range is wider, the operability is strong, time and effort are saved, and the installation efficiency of wind-resistant cable is significantly improved.

[0113] (3) This method is easy to control, streamlines the process, and makes precise adjustments. Through multiple adjustments in stages, it improves the balance of the internal forces of the wind-resistant cable, effectively avoids the concentration of force on the fixed cable head during the tightening of the wind-resistant cable, and ensures that it has a good wind-resistant effect; it is conducive to the overall membrane structure being stressed evenly and improves the safety of the on-site construction process.

[0114] The embodiments of the present invention have been described in detail above, but the content described is only a preferred embodiment of the present invention and should not be considered as limiting the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the patent coverage of the present invention.

Claims

1. A method for adjusting the internal force balance of a wind cable of a membrane structure, characterized in that The method comprises the following steps: determining an original length of the wind-resistant cable; determining stage tension values and stage torque values corresponding to different tension stages; installing the wind-resistant cable; tensioning the wind-resistant cable in stages: torque detection is performed at each stage to obtain a detected torque value; the stage torque value is calculated according to the following formula: T = K·F·d; wherein T is the stage torque value; K is a torque coefficient; F is the stage tension value; d is the diameter of a two-way adjusting cable rod; when the detected torque value is not within an allowable error range of the stage torque value, the length of the wind-resistant cable is adjusted by means of the equalizing adjusting device.

2. The method of claim 1, wherein: The method of determining the original length of the wind-resistant cable comprises the following steps: determining a design tension value of the wind-resistant cable and the number of stages of the staged tensioning; calculating a use length of the wind-resistant cable based on the design tension value; calculating the original length of the wind-resistant cable based on the design tension value and the use length.

3. The method of claim 2, wherein: The calculation method of the use length is as follows: ； wherein F is the design tension value of the wind-resistant cable; m is the mass of the wind-resistant cable; l is the use length of the wind-resistant cable; n is the number of stages of the staged tensioning; f n f is the vibration frequency of the anti-wind cable; EI is the bending stiffness of the wind-resistant cable.

4. The method of claim 3, wherein: The calculation method of the original length is as follows: ； wherein: l0 is the original length of the wind-resistant cable; l is the use length of the wind-resistant cable; F is the design tension value of the wind-resistant cable; A is the cross-sectional area of the wind-resistant cable; E is the elastic modulus of the wind-resistant cable.

5. The method of equalizing the internal forces of a wind cable according to any one of claims 1 to 4, characterized in that: The wind-resistant cable comprises a steel cable and, in sequence and symmetrically, a connecting barrel, an anchor cup, the equalizing adjusting device and a fixed cable head at both ends of the steel cable, and the two ends of the equalizing adjusting device are threadedly connected with the anchor cup and the fixed cable head, respectively.

6. The method of claim 5, wherein: The method further comprises, before the wind-resistant cable is installed, determining a corrected length of the wind-resistant cable, and adjusting the length of the wind-resistant cable to the corrected length by means of the anchor cup.

7. The method of claim 5, wherein: The equalizing adjusting device comprises a two-way adjusting cable rod, a two-way adjusting nut and a thrust nut; the two-way adjusting nut is threadedly connected in the middle of the two-way adjusting cable rod; the thrust nuts are symmetrically arranged on both sides of the two-way adjusting nut and are threadedly connected with the two-way adjusting cable rod.

8. The method of claim 7, wherein: The method of installing the wind-resistant cable further comprises pasting a tensile stress patch on the two-way adjusting cable rod for determining an actual tension value of the wind-resistant cable.

9. The method of equalizing the internal forces of a wind cable according to claim 7 or 8, characterized in that: The torque detection comprises rotating the two-way adjusting nut by a torque wrench to a set angle to elongate the equalizing adjusting device; then rotating the set angle in the opposite direction to obtain the detected torque value; the allowable error range of the stage torque value is 0.9-1.1 times the stage torque value.

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