Cable-stayed bridge cable adjustment method and device based on temperature reference strand

Abstract

The application provides a suspension bridge cable adjustment method and device based on temperature reference strands, comprising the following steps: determining a plurality of reference linear measuring points and a plurality of reference temperature measuring points of the erected reference strands, obtaining reference measured coordinates of each reference linear measuring point and reference temperature measured values of each reference temperature measuring point, determining a calculated strand linear shape by an initial linear shape inverse calculation method based on the reference temperature measured values and the measured coordinates of the end points, determining a measured strand linear shape based on the plurality of reference measured coordinates, and determining an optimal linear shape inverse calculation method based on the calculated strand linear shape and the measured strand linear shape; determining a temperature reference strand and a plurality of reference temperature measuring points, and obtaining reference temperature measured values of each reference temperature measuring point; obtaining measured end point coordinates of a to-be-erected general strand, and determining a cable length adjustment amount by the optimal linear shape inverse calculation method based on the reference temperature measured values and the measured end point coordinates of the to-be-erected general strand. The application improves the precision and efficiency of strand adjustment and reduces the construction cost of the suspension bridge.

Description

Technical Field

[0001] This invention relates to the field of suspension bridge cable adjustment technology, and in particular to a method and apparatus for adjusting suspension bridge cables based on temperature reference strands. Background Technology

[0002] Suspension bridges are among the longest-span bridge types in modern engineering. They are bridges where the main cable serves as the primary load-bearing structure. Their key feature is the use of high-strength main cables suspended between bridge towers, which, through suspenders, lift the bridge deck (stiffening girder) to span a considerable distance. Therefore, the construction quality of the main cable directly affects the structural performance of the suspension bridge. It is essential to design a reasonable main cable alignment before construction and to strictly control the accuracy of the main cable erection during construction to achieve the desired bridge alignment.

[0003] As the span of suspension bridges continues to increase, the temperature field they are in also becomes increasingly complex. Under the influence of atmospheric temperature and solar radiation, the alignment of the main cable strands changes significantly during construction, deviating from the design alignment. Therefore, it is necessary to accurately control the cable strand alignment and adjust the strand length during the cable strand erection process to ensure that each strand remains consistent with the design state at the design reference temperature, and that each strand is in a relatively stable state during construction.

[0004] Specifically, firstly, the thermal expansion and contraction caused by temperature affects the length of the cable strands, and this change in length directly affects the sag of the main cable, thus impacting the overall alignment. Secondly, sunlight causes uneven temperature differences in the bridge towers, leading to tower top misalignment and changes in the coordinates of the anchor points of the two cable saddles, severely affecting the accuracy of cable strand erection. Finally, the main cable cross-section exhibits a non-uniform temperature field under sunlight, with the side directly exposed to the sun having a significantly higher temperature than the shaded side, creating a temperature gradient across the main cable cross-section. This gradient can cause localized bending of the main cable, generating additional stress and altering the overall alignment.

[0005] In addition, when erecting cable strands, the first cable strand is selected as the reference cable strand. The reference cable strand is first accurately erected and then used to guide the erection of the other general cable strands. However, during the erection process, due to the influence of construction accuracy, the upper cable strands will inevitably press on the lower cable strands and the reference cable strands, so that the alignment of the reference cable strands will change after being loaded.

[0006] To alleviate the aforementioned problems, some existing technologies employ methods such as layer spacing control and scale strand adjustment to achieve cable strand alignment. The layer spacing control method divides the main cable strands of a suspension bridge into reference strands and general strands. The reference strand (usually one strand or one strand between multiple strands) undergoes multiple absolute elevation controls during stable nighttime temperatures to achieve precise alignment control. For the remaining general strands, layer spacing control is used, adjusting the vertical distance between the adjusted strand and the reference strand to the designed distance to achieve alignment adjustment. However, this method is too time-consuming and requires nighttime operation. For main cable structures with larger spans and thicker cable diameters, uneven temperature distribution is more pronounced, making it difficult to meet specifications. Even nighttime cable adjustments may result in uneven temperature distribution, compromising the accuracy of strand adjustment. Similar to the layer spacing control method, the ruler-based cable strand method involves setting a ruler-based cable strand on one side of the cable strand to be installed. This serves as a reference for the benchmark cable strand, and all cable strands to be erected on the main cable are referenced to this ruler-based cable strand. By controlling the vertical spacing between the cable strand to be adjusted and the ruler-based cable strand to the design distance, the alignment of general cable strands can be adjusted. In addition, this method adds a ruler platform at the saddle of the main cable, and the scale on the ruler platform facilitates the adjustment of the cable strand alignment. Although this method can achieve the adjustment of cable strand alignment, it requires the setting of a ruler platform and additional ruler-based cable strands, which increases the construction cost accordingly.

[0007] In addition to the above, existing technologies also disclose a method for adjusting the length of a cable strand to be erected based on the average temperature of a reference cable strand and the average temperature of a newly erected cable strand. This method requires calculating the theoretical sag of the target alignment of the reference cable strand and the theoretical sag of the target alignment of the newly erected cable strand based on the average temperature of the reference cable strand and the average temperature of the newly erected cable strand, and then calculating the cable strand adjustment amount to achieve the adjustment of the cable strand length. Although this method takes temperature into account when adjusting the cable strand length, the temperature distribution of each cable strand needs to be measured when it is erected, which greatly increases the construction time and reduces the construction efficiency.

[0008] Therefore, improving the accuracy and efficiency of cable strand adjustment in suspension bridges, as well as reducing the construction cost of suspension bridges, are urgent technical problems that need to be solved. Summary of the Invention

[0009] In view of this, embodiments of the present invention provide a method and apparatus for adjusting the cables of a suspension bridge based on temperature reference strands, so as to eliminate or improve one or more defects existing in the prior art.

[0010] One aspect of the present invention provides a method for adjusting the cables of a suspension bridge based on temperature-referenced cable strands, the method comprising:

[0011] Multiple baseline shape measurement points and multiple baseline temperature measurement points are identified for the established baseline cable strands. Among the multiple baseline shape measurement points, there are two baseline endpoint measurement points. The baseline measured coordinates of each of the baseline shape measurement points and the baseline measured temperature values ​​of each of the baseline temperature measurement points are obtained. Based on the baseline measured temperature values ​​and the endpoint measured coordinates corresponding to the two baseline endpoint measurement points, the calculated cable strand shape of the established baseline cable strands is determined through an initial line shape inverse calculation method. Based on the multiple baseline measured coordinates, the measured cable strand shape of the established baseline cable strands is determined. Based on the calculated cable strand shape and the measured cable strand shape of the established baseline cable strands, the optimal line shape inverse calculation method is determined.

[0012] Determine the temperature reference cable strand and multiple reference temperature measuring points of the temperature reference cable strand, and obtain the measured reference temperature value of each reference temperature measuring point;

[0013] Obtain the measured endpoint coordinates of the general cable strand to be erected, and determine the cable length adjustment amount corresponding to the general cable strand to be erected based on the measured values ​​of each reference temperature and the measured endpoint coordinates of the general cable strand to be erected through the optimal linear inverse calculation method.

[0014] In some embodiments of the present invention, the cable length adjustment amount corresponding to the general cable strand to be erected is determined by the optimal linear inverse calculation method based on the measured values ​​of each of the reference temperatures and the measured endpoint coordinates of the general cable strand to be erected, including:

[0015] Based on the measured values ​​of each reference temperature and the measured endpoint coordinates of the general cable strand to be erected, the calculated cable strand shape of the general cable strand to be erected is determined by the optimal line shape back calculation method;

[0016] Multiple measured points of the general cable strand to be erected are determined, and the general measured coordinates of each measured point are obtained. Based on the general measured coordinates, the measured cable strand shape of the general cable strand to be erected is determined.

[0017] The elevation difference at the mid-span of the general cable strand to be erected is determined based on the calculated cable strand shape and the measured cable strand shape of the general cable strand to be erected.

[0018] The cable length adjustment amount of the general cable strand to be erected is calculated based on the elevation difference at the mid-span position.

[0019] In some embodiments of the present invention, the formula for calculating the cable length adjustment is as follows:

[0020] ΔDL i =a*Dh i ;

[0021] Where, ΔDL i This indicates the adjustment amount for the length of a general cable strand to be erected, where 'a' represents a coefficient, and 'Dh' represents the length adjustment amount for the general cable strand to be erected.i This indicates the elevation difference at the mid-span of the general cable strand to be erected.

[0022] In some embodiments of the present invention, the method for determining the optimal alignment based on the calculated and measured alignment of the existing reference cable strands includes:

[0023] Calculate the difference between the calculated cable strand shape and the measured cable strand shape of the established reference cable strand;

[0024] The difference is compared with a preset value;

[0025] When the difference is not greater than the preset value, the initial linearity inverse calculation method is the optimal linearity inverse calculation method;

[0026] When the difference is greater than the preset value, the corresponding parameters in the initial linear inverse calculation method are corrected to obtain the optimal linear inverse calculation method.

[0027] In some embodiments of the present invention, the optimal linear inverse calculation method is obtained by modifying the corresponding parameters in the initial linear inverse calculation method, including:

[0028] The baseline temperature distribution characteristics of the erected baseline cable strands were obtained by finite element simulation and actual measured values ​​of each baseline temperature.

[0029] The total length variation of the erected reference cable strands is determined based on the aforementioned reference temperature distribution characteristics.

[0030] The corrected alignment of the existing reference cable strand is determined based on the change in the total length of the existing reference cable strand;

[0031] The optimal inverse calculation method is obtained by adjusting the corresponding parameters of the finite element simulation method based on the difference between the corrected alignment and the measured alignment of the reference cable strand.

[0032] In some embodiments of the present invention, determining the total change in length of the erected reference cable strands based on the reference temperature distribution characteristics includes:

[0033] Calculate the change in cable length at each point corresponding to the temperature in the reference temperature distribution feature;

[0034] The total change in length of the established reference cable strand is calculated based on the sum of the changes in length at each cable length point.

[0035] In some embodiments of the present invention, the cable length adjustment amount corresponding to the general cable strand to be erected is determined by the optimal linear inverse calculation method based on the measured values ​​of each of the reference temperatures and the measured endpoint coordinates of the general cable strand to be erected, including:

[0036] The maximum temperature difference is calculated based on the measured values ​​of each of the aforementioned reference temperatures;

[0037] The maximum temperature difference is compared with a preset temperature difference threshold.

[0038] When the maximum temperature difference is not greater than the temperature difference threshold, the measured average temperature value is calculated based on the weighted average method, and the cable length adjustment amount corresponding to the general cable strand to be erected is determined by the optimal linear inverse calculation method based on the measured average temperature value and the measured endpoint coordinates of the general cable strand to be erected.

[0039] When the maximum temperature difference is greater than the temperature difference threshold, the reference temperature distribution characteristics of the temperature reference cable strand are determined based on the finite element simulation method. Based on the reference temperature distribution characteristics and the measured endpoint coordinates of the general cable strand to be erected, the cable length adjustment amount corresponding to the general cable strand to be erected is determined by the optimal linear inverse calculation method.

[0040] In some embodiments of the present invention, the formula for calculating the change in cable length at a point is: ΔDS=αl×ΔT, where αl represents the coefficient of linear expansion and ΔT represents the difference between the point temperature and the corresponding design reference temperature.

[0041] According to another aspect of the present invention, a suspension bridge cable adjustment system based on temperature reference strands is also disclosed. The system includes a processor, a memory, and a computer program stored in the memory. The processor is used to execute the computer program, and when the computer program is executed, the system implements the steps of the method as described in any of the above embodiments.

[0042] According to another aspect of the present invention, a computer-readable storage medium is also disclosed, on which a computer program is stored, which, when executed by a processor, implements the steps of the method as described in any of the above embodiments.

[0043] The suspension bridge cable adjustment method and apparatus based on temperature reference strands according to the above embodiments of the present invention first determines the calculated strand alignment based on the measured coordinates and measured temperature values ​​of the already erected reference strands. Then, based on the measured coordinates of each reference strand, the actual strand alignment is obtained. Finally, based on the calculated and measured strand alignments, an optimal alignment back-calculation method is determined. During actual construction, the measured reference temperature value of the general strand to be erected is first obtained based on the temperature reference strands. Then, based on the measured reference temperature value and the measured coordinates of the endpoints of the general strand to be erected, the final cable length adjustment is determined using the optimal alignment back-calculation method. This method senses and reconstructs the temperature field distribution of the general strand to be erected in real time, thereby controlling the strand erection alignment. By controlling the strand length, the cable alignment and length under the real-time temperature field are calculated through multi-point temperature back-calculation on the temperature reference strands. Based on relatively reliable temperature parameters, the adjustment length of the general strand to be erected is controlled, ensuring that the actual alignment of each strand remains consistent with the design alignment under different temperature environments, thus avoiding the influence of temperature effects on the strand length. This method improves the accuracy and efficiency of suspension bridge cable strand adjustment and reduces the construction cost of suspension bridges.

[0044] Additional advantages, objects, and features of the invention will be set forth in part in the description which follows, and will also become apparent in part to those skilled in the art upon studying the description, or may be learned by practice of the invention. The objects and other advantages of the invention can be realized and obtained by means of the structures specifically pointed out in the description and drawings.

[0045] Those skilled in the art will understand that the objectives and advantages achievable with the present invention are not limited to those specifically described above, and that the above and other objectives achievable with the present invention will become clearer from the following detailed description. Attached Figure Description

[0046] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, are not intended to limit the scope of the invention. The components in the drawings are not drawn to scale but are merely illustrative of the principles of the invention. For ease of illustration and description of certain parts of the invention, corresponding portions in the drawings may be enlarged, i.e., may appear larger relative to other components in an exemplary device actually manufactured according to the invention. In the drawings:

[0047] Figure 1 This is a schematic flowchart of a suspension bridge cable adjustment method based on temperature reference strands according to an embodiment of the present invention.

[0048] Figure 2 This is a schematic diagram showing the length of the strand under different conditions.

[0049] Figure 3 This is a schematic flowchart of a suspension bridge cable adjustment method based on temperature reference strands, according to another embodiment of the present invention.

[0050] Figure 4 This is a flowchart illustrating a suspension bridge cable adjustment method based on temperature reference strands, according to another embodiment of the present invention.

[0051] Figure 5 This is a schematic diagram showing the distribution of reference line shape measuring points and reference temperature measuring points for a reference cable strand to be erected, according to an embodiment of the present invention.

[0052] Figure 6 This is a schematic diagram showing the arrangement of the reference line shape measuring points and reference temperature measuring points of the reference cable strand to be erected according to an embodiment of the present invention.

[0053] Figure 7 This is a schematic diagram showing the position of the temperature reference cable in an embodiment of the present invention.

[0054] Figure 8 This is a schematic cross-sectional view of the temperature sensor arrangement of a temperature reference cable according to an embodiment of the present invention.

[0055] Figure 9 This is a schematic diagram showing the distribution of reference temperature measuring points in a temperature reference cable according to an embodiment of the present invention. Detailed Implementation

[0056] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments and accompanying drawings. Here, the illustrative embodiments and descriptions of this invention are used to explain the invention, but are not intended to limit the invention.

[0057] It should also be noted that, in order to avoid obscuring the invention with unnecessary details, only the structures and / or processing steps closely related to the solution according to the invention are shown in the accompanying drawings, while other details that are not closely related to the invention are omitted.

[0058] It should be emphasized that the term "including / comprises" as used herein refers to the presence of a feature, element, step, or component, but does not exclude the presence or addition of one or more other features, elements, steps, or components.

[0059] It should also be noted that, unless otherwise specified, the term "connection" in this article can refer not only to a direct connection, but also to an indirect connection with an intermediary, and can refer not only to a wired connection, but also to a wireless connection. The specific meaning can be changed based on the actual application scenario.

[0060] The following is a definition of terms related to this application:

[0061] Suspension bridge: A bridge whose main load-bearing component is a cable or steel chain suspended from towers and anchored to the ground or other structures.

[0062] Main cable: The main load-bearing component of a suspension bridge, consisting of parallel steel wires or steel wire ropes, suspended from the top of the tower and anchored to the beam segments by rivets.

[0063] Precast parallel strand method (PPWS method): High-strength steel wires are made into parallel strands in the factory or construction site and wound on the cable reel. After being transported to the main cable erection site, they are pulled and erected on the catwalk using a traction system. After all the parallel strands are erected, they are tightened to become a main cable.

[0064] Aerial spinning method (AS method): A construction method that uses traction machinery to reciprocate the pulling of high-strength steel wire to create parallel steel wire strands on site.

[0065] Reference strand: The reference strand is an important component of the main cable of a suspension bridge, used to determine the final alignment of the main cable. During erection, the reference strand is positioned using absolute elevation and serves as a benchmark for the erection of other strands. The accuracy of the reference strand directly affects the accuracy of the final alignment of the main cable; therefore, its alignment accuracy must be strictly controlled during erection.

[0066] General cable stock: General cable stock refers to cable stock other than the benchmark cable stock. The positioning of general cable stock depends on the position of the benchmark cable stock, and its installation accuracy is also affected by the benchmark cable stock.

[0067] Controlling the alignment of the main cable of a suspension bridge is a core aspect of construction. Deviations in the cable alignment exceeding the permissible limits will trigger a series of chain reactions, seriously threatening the bridge's safety, durability, and functionality. For example, deviations in the main cable alignment may lead to uneven stress distribution among the strands, resulting in fatigue fracture of the strands over time. Deviations in the main cable alignment can also transmit unbalanced horizontal forces to the bridge towers, causing tower displacement or even instability, severely threatening bridge safety. Deviations in the main cable alignment can cause stress concentration at the anchorage saddles, leading to localized excessive pressure and concrete crushing. Furthermore, deviations in the main cable alignment, transmitted through the suspenders to the bridge deck, can result in abnormal bridge deck alignment, affecting traffic safety.

[0068] To address the issue of cable strand alignment deviations caused by temperature effects during the adjustment of the main cable strand alignment in long-span suspension bridges, this application proposes a suspension bridge cable adjustment method and device based on temperature-referenced cable strands for the PPWS and AS methods. This method and device can guide the PPWS and AS methods in avoiding the influence of temperature on the cable strand alignment during cable strand erection, enabling precise adjustment of cable length and control of cable strand alignment under various temperature environments.

[0069] This application is applicable to the precise control of the erection of reference strands and general strands during the construction of the superstructure of suspension bridges. It uses the measured temperature reference strand temperature field to calculate the adjustment amount of the general strand length to be erected. The method of adjusting the cable length of suspension bridges based on this application generally includes: determining the optimal alignment back calculation method based on the measured temperature of the already erected reference strand, the temperature reference strand measured temperature step, the cable length adjustment amount calculation step, and the cable alignment adjustment step.

[0070] In the following description, embodiments of the invention will be illustrated with reference to the accompanying drawings. In the drawings, the same reference numerals represent the same or similar parts, or the same or similar steps.

[0071] Figure 1 This is a flowchart illustrating a suspension bridge cable adjustment method based on temperature reference strands according to an embodiment of this application. Figure 1 As shown, the cable adjustment method for the suspension bridge includes at least steps S10 to S30.

[0072] Step S10: Determine multiple baseline shape measurement points and multiple baseline temperature measurement points for the established baseline cable strands. Among the multiple baseline shape measurement points, there are two baseline endpoint measurement points. Obtain the baseline measured coordinates of each of the baseline shape measurement points and the baseline measured temperature value of each of the baseline temperature measurement points. Based on the baseline measured temperature values ​​and the endpoint measured coordinates corresponding to the two baseline endpoint measurement points, determine the calculated cable strand shape of the established baseline cable strands using the initial line shape inverse calculation method. Determine the measured cable strand shape of the established baseline cable strands based on the multiple baseline measured coordinates. Determine the optimal line shape inverse calculation method based on the calculated cable strand shape and the measured cable strand shape of the established baseline cable strands.

[0073] In this step, based on the measured alignment and temperature data of the established reference cable strand, the catenary equation for the actual alignment of the reference cable strand is calculated and corrected, resulting in a method for back-calculating the cable strand alignment based on measured temperature. For example... Figure 5 As shown, multiple baseline shape measuring points 2 and multiple baseline temperature measuring points 3 can be arranged along the length direction (also known as the longitudinal direction) of the erected baseline cable strand 1; marker targets are installed on the surface of the baseline cable strand, and the baseline measured coordinates n of each point are measured at a certain frequency using automatic measuring equipment. i (i = 1, 2…n, where n is the total number of baseline measurement points), and based on the baseline measured coordinates n of each point. i The measured cable strand shape y0 of the established reference cable strand is obtained. While measuring the measured coordinates of each reference point on the established reference cable strand 1, multiple temperature sensors can be installed on the established reference cable strand 1 to measure the measured reference temperature T at each reference temperature point. k (k = 1, 2…m, where m is the total number of reference temperature measurement points), and further obtain the temperature distribution data T0 of multiple points where reference cable strands have been erected at the same time. After obtaining the measured coordinates of each reference point and the measured temperature values ​​of each reference temperature point, the calculated cable strand shape y0' of the erected reference cable strand is further determined using the initial line shape back calculation method. Finally, the obtained calculated cable strand shape y0' is compared with the measured cable strand shape y0, and through repeated measurements and back-calculation, the corresponding parameters in the cable strand shape calculation process based on the measured temperature field are compared and corrected to obtain the optimal line shape back calculation method. Based on this optimal line shape back calculation method, the cable length adjustment amount corresponding to the general cable strand to be erected is determined.

[0074] For example, determining the optimal alignment back-calculation method based on the calculated and measured alignment of the already erected reference cable strand includes: calculating the difference between the calculated and measured alignment of the already erected reference cable strand; comparing the difference with a preset value; when the difference is not greater than the preset value, the initial alignment back-calculation method is the optimal alignment back-calculation method; when the difference is greater than the preset value, correcting the corresponding parameters in the initial alignment back-calculation method to obtain the optimal alignment back-calculation method. In this step, if the difference between the calculated cable strand alignment y0' and the measured cable strand alignment y0 of the already erected reference cable strand 1 is large, then the key parameters related to temperature and cable strand length in the initial alignment back-calculation method are corrected. Key parameters include solar radiation intensity, thermal radiation absorption coefficient of the material, specific heat coefficient, thermal conductivity coefficient, etc., so that the calculated cable strand alignment y0' of the already erected reference cable strand 1 calculated based on the corrected optimal alignment back-calculation method is basically consistent with the measured cable strand alignment y0.

[0075] Furthermore, the optimal alignment inverse calculation method is obtained by correcting the corresponding parameters in the initial alignment inverse calculation method, which may specifically include the following steps: simulating the reference temperature distribution characteristics of the erected reference cable strands based on the finite element simulation method and the measured reference temperature values; determining the total length change of the erected reference cable strands based on the reference temperature distribution characteristics; determining the corrected alignment of the erected reference cable strands based on the total length change of the erected reference cable strands; and correcting the corresponding parameters of the finite element simulation method based on the difference between the corrected alignment and the measured cable strand alignment of the erected reference cable strands to obtain the optimal alignment inverse calculation method. In this embodiment, the temperature field is reconstructed using a finite element method combined with measured reference temperature values. This accurately simulates the reference temperature distribution characteristics of the erected reference cable strand under actual temperature conditions. By combining the linear change characteristics of the cable strand at the measured temperature, the total cable length change under any temperature condition is obtained, leading to a corrected linear shape. Finally, the corrected linear shape is compared with the measured cable strand linear shape. If the difference is too large, the key parameters related to cable strand length in the numerical simulation algorithm are corrected, ultimately ensuring that the calculated cable strand linear shape obtained based on the optimal linear shape back-calculation method is basically consistent with the measured cable strand linear shape. For example, key parameters related to temperature and cable strand length in the numerical simulation algorithm include solar radiation intensity, the material's thermal radiation absorption coefficient, specific heat coefficient, and thermal conductivity coefficient.

[0076] Furthermore, determining the total change in length of the erected reference cable strands based on the reference temperature distribution characteristics includes: calculating the point change in cable length corresponding to the temperature at each point in the reference temperature distribution characteristics; and calculating the total change in length of the erected reference cable strands based on the sum of the point changes in cable length. Specifically, the point change in cable length corresponding to each temperature point can be calculated using the following formula: ΔDS = αl × ΔT, where αl represents the linear expansion coefficient of the cable strand, and ΔT represents the difference between the point temperature and the corresponding design reference temperature.

[0077] Step S20: Determine the temperature reference cable strand and multiple reference temperature measuring points of the temperature reference cable strand, and obtain the measured reference temperature value of each reference temperature measuring point.

[0078] The temperature reference cable in this step can guide the erection of all general cable strands. When erecting any general cable strand, the cable length adjustment amount can be determined based on the measured reference temperature value of this temperature reference cable. For example... Figure 9 As shown, multiple reference temperature measuring points 8 can be set along the length direction (also known as the longitudinal direction) of the temperature reference cable strand 5; reference Figure 8Each reference temperature measuring point 8 is equipped with multiple temperature sensors 4. In some embodiments, the last strand of the main cable to be erected can be selected as the temperature reference strand 5 for temperature monitoring, thereby using the measured reference temperature data as the temperature distribution data for all other general strands to be erected. After the temperature reference strand is pulled into the saddle, it is initially erected between the two towers, and multiple temperature sensors are installed on the temperature reference strand. During the adjustment of the remaining general strands to be erected, the temperature distribution data of the temperature reference strand at the same moment is measured in real time, and this temperature distribution data is used as the adjustment temperature of the currently erected general strand.

[0079] During the cyclic construction of the cable strands, after the two layers of general cable strands are erected, when it is necessary to erect the general cable strand in the groove where the temperature reference cable strand is located, the temperature reference cable strand is temporarily lifted and the corresponding general cable strand is erected. After the general cable strands are erected, the temperature reference cable strand is temporarily placed into the saddle, and the remaining general cable strands are erected. The cyclic construction is carried out until all cable strands are erected.

[0080] Understandably, when measuring the actual measured value of the reference temperature strand in real time, it can be done manually by construction personnel or by installing temperature sensors. Furthermore, the last general strand to be erected can be selected as the temperature reference strand, and one temperature reference strand can be selected for each layer of general strands in the main cable, or one for every two or more layers of general strands. The selection of the temperature reference strand can be determined based on the cross-sectional shape of the main cable or the construction sequence of the strands, with the principle of maximizing the number of applicable layers without affecting the accurate erection of the strands.

[0081] Step S30: Obtain the measured endpoint coordinates of the general cable strand to be erected, and determine the cable length adjustment amount corresponding to the general cable strand to be erected based on the measured values ​​of each reference temperature and the measured endpoint coordinates of the general cable strand to be erected through the optimal linear inverse calculation method.

[0082] This step specifically obtains the measured endpoint coordinates of the general cable strand to be erected, and determines the cable length adjustment amount corresponding to the general cable strand to be erected based on the optimal linear inverse calculation method determined in step S10.

[0083] For example, the cable length adjustment amount corresponding to the general cable strand to be erected is determined by the optimal alignment back calculation method based on the measured values ​​of each reference temperature and the measured endpoint coordinates of the general cable strand to be erected. Specifically, this includes the following steps: determining the calculated cable strand alignment of the general cable strand to be erected based on the measured values ​​of each reference temperature and the measured endpoint coordinates of the general cable strand to be erected using the optimal alignment back calculation method; determining multiple measured alignment measurement points for the general cable strand to be erected, and obtaining the general measured coordinates of each measured alignment measurement point; determining the measured cable strand alignment of the general cable strand to be erected based on each general measured coordinate; determining the mid-span elevation difference of the general cable strand to be erected based on the calculated cable strand alignment and the measured cable strand alignment of the general cable strand to be erected; and calculating the cable length adjustment amount of the general cable strand to be erected based on the mid-span elevation difference.

[0084] Specifically, the formula for calculating the cable length adjustment is as follows:

[0085] ΔDL i =a*Dh i ;

[0086] Where, ΔDL i This indicates the adjustment amount for the length of a general cable strand to be erected, where 'a' represents a coefficient, and 'Dh' represents the length adjustment amount for the general cable strand to be erected. i This indicates the elevation difference at the mid-span of the general cable strand to be erected.

[0087] Figure 2 A schematic diagram showing the strand length under different conditions, such as Figure 2 As shown in (a), the cable strand alignment in the unloaded state is determined by the design support coordinates (a, b), (c, d) and the design reference temperature, with a design strand length of DL. However, during construction, the actual support coordinates and temperature differ from the design conditions, such as... Figure 2 As shown in (b) of the diagram, in the actual support coordinates (a) ’ b ’ ), (c ’ d ’ Under these conditions, the cable alignment changes, but the strand length remains DL. Further considering the actual construction temperature, changes in strand temperature will cause changes in cable length, such as... Figure 2 As shown in (c), in the actual support coordinates (a) ’ b ’ ), (c ’ d ’ Under the combined influence of temperature and actual temperature field, the cable alignment deviates more significantly from the design state, and the strand length also changes under temperature, becoming DS. At this point, the strand length DS is a function related to temperature T, i.e., DS = f(T). However, during construction, after the initial erection of the general strands, the preliminary alignment and strand length DS' are obtained, such as... Figure 2As shown in (d), the linear shape is supported by the actual coordinates (a). ’ b ’ ), (c ’ d ’ Due to the influence of many factors such as temperature field and initial construction errors, there is a certain deviation from the designed cable alignment, so fine adjustments are required to meet the requirements.

[0088] When determining the cable length adjustment, the cable strand alignment is first obtained based on the design drawings, i.e., the cable strand length DL under the design reference temperature. Then, the tower top offset at the moment of cable strand erection is obtained through on-site measurements, leading to the actual support coordinates. Simultaneously, based on the measured cable strand temperature field distribution data and the actual support coordinates, the calculated cable strand alignment of the general cable strand to be erected is calculated using the catenary cable strand alignment equation. At the same time, multiple measured alignment points of the general cable strand to be erected are measured to obtain the measured cable strand alignment, which is compared with the calculated cable strand alignment considering temperature effects to obtain the mid-span elevation difference Dh. For the catenary equation, the mid-span elevation difference Dh has a linear relationship with the cable strand adjustment length ΔDL: ΔDL / Dh = a. Therefore, the cable strand length adjustment ΔDL = a × Dh is obtained, and DS = DS` - ΔDL = DS` - a × Dh.

[0089] Furthermore, based on the ΔDL calculated from the measured temperature field, the length of the general cable strands to be erected can be directly adjusted. Specifically, during adjustment, a scale can be set at the cable saddle at the top of the tower and marked on the cable strands. The general cable strands to be erected are tightened and loosened at the anchorage, while the extension or shortening of the cable length is precisely controlled by the scale value at the cable saddle.

[0090] In the above embodiments, the method of calculating the strand shape based on the temperature field and the method of calculating the strand length adjustment can be combined to form an intelligent algorithm. While measuring the temperature of the reference strand temperature field, the strand adjustment considering the temperature effect can be calculated in real time, providing convenient and efficient guidance for the construction of general strands.

[0091] In some embodiments of the present invention, the determination of the cable length adjustment corresponding to the general cable strand to be erected based on the measured values ​​of each of the reference temperatures and the measured endpoint coordinates of the general cable strand to be erected using the optimal linear inverse calculation method further includes the following steps: calculating the maximum temperature difference based on the measured values ​​of each of the reference temperatures; comparing the maximum temperature difference with a preset temperature difference threshold; when the maximum temperature difference is not greater than the temperature difference threshold, calculating the measured average temperature value based on the weighted average method, and determining the cable length adjustment corresponding to the general cable strand to be erected based on the measured average temperature value and the measured endpoint coordinates of the general cable strand to be erected using the optimal linear inverse calculation method; when the maximum temperature difference is greater than the temperature difference threshold, determining the reference temperature distribution characteristics of the temperature reference cable strand based on the finite element simulation method, and determining the cable length adjustment corresponding to the general cable strand to be erected based on the reference temperature distribution characteristics and the measured endpoint coordinates of the general cable strand to be erected using the optimal linear inverse calculation method.

[0092] In the above embodiment, reference temperature distribution data of the reference cable strand at a certain moment is first obtained through multi-point temperature sensors. The obtained reference temperature distribution data is distributed along the longitudinal direction of the cable strand, and there are certain differences between the various temperature values. At this time, the difference between the maximum and minimum temperatures in the reference temperature distribution data at that moment is calculated, and it is determined whether the difference is within the preset temperature difference threshold range. For example, the preset temperature difference threshold can be set to 3 degrees Celsius; that is, if the maximum temperature difference is less than or equal to 3 degrees Celsius, the weighted average method is used to obtain the measured average temperature value, and the cable length adjustment amount is further determined by the optimal linear inverse calculation method based on the measured average temperature value and the measured endpoint coordinates. If the maximum temperature difference is greater than 3 degrees Celsius, the reference temperature distribution characteristics of the temperature reference cable strand are determined by the finite element simulation method, and the cable length adjustment amount of the general cable strand to be erected is further determined by the optimal linear inverse calculation method based on the reference temperature distribution characteristics and the measured endpoint coordinates.

[0093] For example, when the maximum temperature difference is less than or equal to 3 degrees Celsius, the weighted average method is used to obtain T0. At this point, the measured temperature of the cable strand differs from the design reference temperature by ΔT. Then, based on the linear expansion coefficient αl of the cable strand steel, the difference in cable strand length ΔDS under the influence of temperature difference is calculated: ΔDS = αl × ΔT. Therefore, the cable strand length under the measured temperature field is the sum of the cable strand length DL at the reference temperature and the difference in cable strand length ΔDS under the influence of temperature difference. Further, based on the cable strand length and the measured endpoint coordinates, the cable strand shape can be obtained.

[0094] The suspension bridge cable adjustment method based on temperature-referenced cable strands described in the above embodiments uses a temperature field of a reference cable strand that is essentially identical to the cable strand to be erected in terms of spatial location and time. It calculates the cable strand length in real-time using a temperature-based inverse calculation method, and further obtains precise cable strand adjustment values, eliminating cable strand shape errors caused by temperature. Furthermore, this method identifies parameters in the temperature-based inverse calculation formula for cable strand shape based on a reference cable strand, and integrates cable strand length adjustment methods to form an intelligent algorithm. During general cable strand erection, it calculates cable strand adjustment amounts based on the real-time temperature field, making the method simple and efficient.

[0095] like Figure 3 As shown, a method for adjusting the cables of a suspension bridge based on temperature reference strands in one embodiment may further include the following steps: S1, actual measurement of the alignment and temperature of the reference strand; S2, correction of the alignment using a reverse calculation method; S3, calculation of the strand adjustment amount; S4, formation of an intelligent algorithm for cable length adjustment considering the temperature field; S5, selection of a temperature reference strand for actual temperature measurement; S6, calculation of the cable length adjustment value based on the intelligent algorithm; S7, adjustment of the cable length; S8, cyclic construction of the strands.

[0096] The following is a specific embodiment to illustrate the above method in detail:

[0097] Taking the cable strand erection of a suspension bridge constructed using the parallel wire strand method as an example, Figure 5 This is a schematic diagram showing the distribution of the baseline shape measuring points and the baseline temperature measuring points for the reference cable strand to be erected. Figure 6 This is a schematic diagram showing the arrangement of the baseline shape measuring points and the baseline temperature measuring points for the reference cable strand to be erected. Figure 7 This is a schematic diagram showing the position of the temperature reference cable. Figure 8 A schematic diagram of the cross-section of the temperature sensor arrangement for the temperature reference cable strand. Figure 9 This is a schematic diagram showing the distribution of reference temperature measuring points for the temperature reference cable.

[0098] like Figure 5 and Figure 6 As shown, firstly, after the reference cable strand 1 is set up to the designed alignment, reference alignment measurement point 2 and reference temperature measurement point 3 are selected on the reference cable strand 1, and temperature sensor 4 and prism 9 are installed respectively. Multiple sets of measured data on the reference cable strand alignment and corresponding temperature field distribution at different times are obtained. Based on the measured data, the alignment inverse calculation method is corrected to obtain the optimal alignment inverse calculation method. Furthermore, based on the reference measured coordinates of each reference alignment measurement point, the measured cable strand alignment under the measured temperature data can be obtained. Simultaneously, based on the measured reference temperature values ​​of each reference temperature measurement point, the calculated cable strand alignment of the set-up reference cable strand 1 is calculated using the initial alignment inverse calculation method. When the measured cable strand alignment differs significantly from the calculated cable strand alignment, the theoretical parameters of the alignment inverse calculation method need to be corrected until the theoretical calculation result is basically consistent with the measured cable strand alignment. At this point, the alignment inverse calculation method is the optimal alignment inverse calculation method.

[0099] Furthermore, based on the above steps, an intelligent algorithm for adjusting cable strands under real-time temperature field distribution is formed. This involves obtaining the actual support coordinates and the measured temperature field distribution of the cable strands through on-site measurements. Then, based on the cable strand alignment in the design drawings, the cable strand alignment under the actual support coordinates and measured temperature field is calculated. The calculated cable strand length is DS. Simultaneously, the cable strand alignment to be erected is measured to obtain its alignment and cable strand length DS. i The elevation difference Dh at the mid-span position is obtained by comparing the linear shapes of the two. i The corresponding adjustment value ΔDL for the strand length is then... i =a*Dh i .

[0100] Based on the above method of calculating the strand shape by temperature back calculation and the formula for calculating the strand length adjustment value, an intelligent algorithm for the strand adjustment value under temperature field distribution is formed to measure the strand temperature distribution in real time and quickly calculate the length adjustment value.

[0101] like Figure 7 As shown, the last general cable strand of the main cable is selected as the temperature reference strand 5, and it is initially erected without adjusting its length. This temperature reference strand is located at a certain distance above the general cable strand 6 to be erected and the already erected general cable strand 7. Its influence from sunlight and atmospheric temperature is basically the same as that of the general cable strand 6 to be erected. Therefore, at this time, the temperature distribution of the temperature reference strand 5 is basically consistent with that of the general cable strand 6 to be erected. Multiple reference temperature measuring points 8 are arranged longitudinally and laterally along the temperature reference strand 5, and temperature sensors 4 are installed for temperature monitoring. The temperature data of multiple reference temperature measuring points are measured in real time during the adjustment of the remaining general cable strands 6 to be erected. This measured reference temperature data is used as the adjustment temperature of the general cable strands 6 to be erected.

[0102] Based on the measured reference temperature, the real-time strand length adjustment value is calculated using the aforementioned combined algorithm (specifically, an algorithm combining the method of inverse calculation of strand shape based on temperature field and the method of calculating strand length adjustment). Simultaneously, a scale is set at the cable saddle at the top of the tower, and markings are made on the strands (see reference). Figure 4 At the anchor point, the general cable strands to be erected are tightened and loosened, and the length of the cable is precisely controlled by the scale value at the cable saddle to adjust the elongation or shortening value, so that the adjusted cable strand shape is consistent with the adjusted shape obtained based on the measured temperature and measured endpoint coordinates.

[0103] Furthermore, the length of all general strands in the main cable is adjusted based on the measured temperature data of temperature reference strand 5. Considering the strand cross-section design during construction, there will be conflicts between the positions of the strands to be erected and the temperature reference strand within the saddle every two layers. Therefore, it is necessary to lift and initially erect the temperature reference strand 5 again. After the general strand 6 at that position is erected, the temperature reference strand is placed back into the saddle slot, and the erection of the remaining general strands continues in a cyclical manner until all strands are erected. In addition, during the strand erection period, the strand alignment can be measured at night when the temperature is stable to verify the effect of the length adjustment.

[0104] Accordingly, the present invention also provides a suspension bridge cable adjustment system based on temperature reference strands. The system includes a processor, a memory, and a computer program stored in the memory. The processor is used to execute the computer program. When the computer program is executed, the system implements the steps of the method as described in any of the above embodiments.

[0105] The suspension bridge cable adjustment method and apparatus based on temperature reference strands disclosed in the above embodiments of the present invention obtains temperature parameters that are almost identical to those of the general strands to be erected by measuring the temperature field distribution of the temperature reference strands. This allows for precise adjustment of the strand length of the general strands to be erected. Furthermore, the temperature reference strand in this application is selected as the last general strand erected and placed around the already erected strands, ensuring unobstructed sunlight and an ambient temperature close to that of the already erected strands, making the temperature parameters almost identical to those of the strands to be erected. This application identifies parameters based on the temperature distribution and alignment of the reference strands and comprehensively considers the actual support coordinates and the strand deformation caused by the strand temperature, forming a real-time temperature-based intelligent algorithm for cable length adjustment. This ensures that the length and alignment of the strands to be erected remain consistent with the design specifications. Moreover, this method can eliminate the influence of temperature on the alignment of the erected strands, enabling cable length adjustment at any time of day and weather, while guaranteeing the accuracy of suspension bridge cable length adjustment.

[0106] This invention also provides a computer-readable storage medium and a computer program product having a computer program stored thereon, which, when executed by a processor, performs the steps of the method described in any of the above embodiments. The computer-readable storage medium may be a tangible storage medium, such as random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, register, floppy disk, hard disk, removable storage disk, CD-ROM, or any other form of storage medium known in the art.

[0107] Those skilled in the art will understand that the exemplary components, systems, and methods described in conjunction with the embodiments disclosed herein can be implemented in hardware, software, or a combination of both. Whether implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this invention. When implemented in hardware, it can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this invention are programs or code segments used to perform the desired tasks. The programs or code segments can be stored in a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried in a carrier wave.

[0108] It should be clarified that the present invention is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present invention is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of the present invention.

[0109] In this invention, features described and / or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or combined with or in place of features of other embodiments.

[0110] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, various modifications and variations of the embodiments of the present invention are possible. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for adjusting the cables of a suspension bridge based on temperature-referenced cable strands, characterized in that, The method includes: Multiple baseline shape measurement points and multiple baseline temperature measurement points are identified for the established baseline cable strands. Among the baseline shape measurement points, two baseline endpoint measurement points are included. The baseline measured coordinates of each baseline shape measurement point and the baseline measured temperature value of each baseline temperature measurement point are obtained. Based on the baseline measured temperature values ​​and the endpoint measured coordinates corresponding to the two baseline endpoint measurement points, the calculated cable strand shape of the established baseline cable strands is determined using an initial line shape inverse calculation method. The measured cable strand shape of the established baseline cable strands is determined based on the multiple baseline measured coordinates. The optimal line shape inverse calculation method is determined based on the calculated and measured cable strand shapes of the established baseline cable strands. Specifically, the catenary equation for the actual line shape of the baseline cable strands is calculated and corrected based on the measured line shape and temperature data of the established baseline cable strands, resulting in the optimal line shape inverse calculation method based on the measured temperature. Determine the temperature reference cable strand and multiple reference temperature measuring points of the temperature reference cable strand, and obtain the measured reference temperature value of each reference temperature measuring point; Obtain the measured endpoint coordinates of the general cable strand to be erected, and determine the cable length adjustment amount corresponding to the general cable strand to be erected based on the measured values ​​of each reference temperature and the measured endpoint coordinates of the general cable strand to be erected through the optimal linear inverse calculation method.

2. The suspension bridge cable adjustment method based on temperature reference strands according to claim 1, characterized in that, Based on the measured values ​​of each reference temperature and the measured endpoint coordinates of the general cable strand to be erected, the cable length adjustment amount corresponding to the general cable strand to be erected is determined by the optimal linear inverse calculation method, including: Based on the measured values ​​of each reference temperature and the measured endpoint coordinates of the general cable strand to be erected, the calculated cable strand shape of the general cable strand to be erected is determined by the optimal line shape back calculation method; Multiple measured points of the general cable strand to be erected are determined, and the general measured coordinates of each measured point are obtained. Based on the general measured coordinates, the measured cable strand shape of the general cable strand to be erected is determined. The elevation difference at the mid-span of the general cable strand to be erected is determined based on the calculated cable strand shape and the measured cable strand shape of the general cable strand to be erected. The cable length adjustment amount of the general cable strand to be erected is calculated based on the elevation difference at the mid-span position.

3. The suspension bridge cable adjustment method based on temperature reference strands according to claim 2, characterized in that, The formula for calculating the cable length adjustment is: ； in, This indicates the adjustment amount for the length of the general cable strand to be erected. Represents the coefficient. This indicates the elevation difference at the mid-span of the general cable strand to be erected.

4. The suspension bridge cable adjustment method based on temperature reference strands according to claim 1, characterized in that, The optimal alignment back-calculation method, based on the calculated and measured alignment of the existing benchmark cable strands, includes: Calculate the difference between the calculated cable strand shape and the measured cable strand shape of the established reference cable strand; The difference is compared with a preset value; When the difference is not greater than the preset value, the initial linearity inverse calculation method is the optimal linearity inverse calculation method; When the difference is greater than the preset value, the corresponding parameters in the initial linear inverse calculation method are corrected to obtain the optimal linear inverse calculation method.

5. The suspension bridge cable adjustment method based on temperature reference strands according to claim 4, characterized in that, To obtain the optimal inverse linearity calculation method by correcting the corresponding parameters in the initial linearity calculation method, the following steps are included: The baseline temperature distribution characteristics of the erected baseline cable strands were obtained by finite element simulation and actual measured values ​​of each baseline temperature. The total length variation of the erected reference cable strands is determined based on the aforementioned reference temperature distribution characteristics. The corrected alignment of the existing reference cable strand is determined based on the change in the total length of the existing reference cable strand; The optimal inverse calculation method is obtained by adjusting the corresponding parameters of the finite element simulation method based on the difference between the corrected alignment and the measured alignment of the reference cable strand.

6. The suspension bridge cable adjustment method based on temperature reference strands according to claim 5, characterized in that, Determining the total change in length of the erected reference cable strands based on the aforementioned reference temperature distribution characteristics includes: Calculate the change in cable length at each point corresponding to the temperature in the reference temperature distribution feature; The total change in length of the established reference cable strand is calculated based on the sum of the changes in length at each cable length point.

7. The suspension bridge cable adjustment method based on temperature reference strands according to claim 1, characterized in that, Based on the measured values ​​of each reference temperature and the measured endpoint coordinates of the general cable strand to be erected, the cable length adjustment amount corresponding to the general cable strand to be erected is determined by the optimal linear inverse calculation method, including: The maximum temperature difference is calculated based on the measured values ​​of each of the aforementioned reference temperatures; The maximum temperature difference is compared with a preset temperature difference threshold. When the maximum temperature difference is not greater than the temperature difference threshold, the measured average temperature value is calculated based on the weighted average method, and the cable length adjustment amount corresponding to the general cable strand to be erected is determined by the optimal linear inverse calculation method based on the measured average temperature value and the measured endpoint coordinates of the general cable strand to be erected. When the maximum temperature difference is greater than the temperature difference threshold, the reference temperature distribution characteristics of the temperature reference cable strand are determined based on the finite element simulation method. Based on the reference temperature distribution characteristics and the measured endpoint coordinates of the general cable strand to be erected, the cable length adjustment amount corresponding to the general cable strand to be erected is determined by the optimal linear inverse calculation method.

8. The suspension bridge cable adjustment method based on temperature reference strands according to claim 6, characterized in that, The formula for calculating the change in cable length is: , Indicates the coefficient of linear expansion. This represents the difference between the point temperature and the corresponding design reference temperature.

9. A suspension bridge cable adjustment system based on temperature-referenced cable strands, the system comprising a processor, a memory, and a computer program stored in the memory, characterized in that, The processor is configured to execute the computer program, and when the computer program is executed, the system implements the steps of the method as described in any one of claims 1 to 8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the steps of the method as described in any one of claims 1 to 8.

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