Suspension bridge main cable rapid positioning method

Abstract

This invention provides a rapid positioning method for the main cable of a suspension bridge, belonging to the field of suspension bridge construction technology. The method includes the installation and positioning of a carbon fiber reference strand, and a method for adjusting the alignment of general strands based on the carbon fiber reference strand. The carbon fiber reference strand requires the installation of a measuring prism and a counterweight device, while the general strands require the installation of temperature sensors as auxiliary facilities for adjustment. This invention introduces a carbon fiber reference strand as a positioning baseline for general strands during the erection of the main cable of a suspension bridge. This can significantly reduce the impact of temperature changes on the alignment of the reference strand, overcome temperature limitations to allow adjustment of general strands at any time, greatly accelerate the positioning efficiency of the main cable alignment, and make alignment adjustment more convenient and accurate.

Description

Technical Field

[0001] This invention belongs to the field of suspension bridge construction technology, and specifically relates to a method for rapid positioning of the main cable of a suspension bridge. Background Technology

[0002] The key to the installation quality of the main cable of a suspension bridge lies in the control of its alignment. The overall alignment quality of the main cable depends on the adjustment of the strand sag. Main cable strand erection is divided into two categories: reference strand erection and general strand erection. Generally, strand number 1 is designated as the reference strand, and the remaining general strands are adjusted for height differences based on this reference strand. The erection accuracy of the reference strand determines the overall erection accuracy of the main cable.

[0003] During the main cable erection, the cable strands are constantly affected by multiple natural factors such as solar radiation and changes in ambient temperature, resulting in significant changes in the alignment of the reference cable strands during the adjustment and positioning process, requiring long-term observation and verification. Generally, during the cable strand erection, the temperature within the main cable cross-section is often unevenly distributed, at which point the reference cable strands cannot serve as an accurate reference, and the installation state of the main cable will deviate significantly from the state of the main cable under the design reference temperature. Therefore, it is necessary to choose to erect the cable in the early morning when the temperature is relatively stable.

[0004] Steel deformation is significantly affected by temperature, while carbon fiber materials exhibit excellent temperature deformation properties. Here, we compare the mechanical properties of 1860 grade steel strand and T300 carbon fiber as examples: 1860 grade steel strand has a linear expansion coefficient of 1.2e-5 / ℃, a density of 8005 kg / m³, an elastic modulus of 195 GPa, and a tensile strength of 1860 MPa; T300 carbon fiber has a linear expansion coefficient of 7.4e-7 / ℃, a density of 1600–2000 kg / m³, an elastic modulus of 230 GPa, and a tensile strength of 3000 MPa. The comparison shows that the deformation of carbon fiber materials due to temperature changes is 1 / 16 that of steel, its mass is 1 / 4 to 1 / 5 that of steel, its elastic modulus is 1.18 times that of steel, and its tensile strength is 1.6 times that of steel, making it very suitable as a reference strand material.

[0005] Based on the above problems, the present invention will propose solutions from the following perspectives: (1) optimize the manufacturing material of the reference strand to reduce the influence of temperature changes on the reference line shape; (2) consider the actual temperature of the general strand during installation and shaping; (3) optimize the line shape adjustment calculation of the general strand from the perspective of temperature correction. Summary of the Invention

[0006] To overcome the problem of difficulty in controlling the installation of cable strands due to temperature differences during the erection of main cables of suspension bridges, this invention provides a rapid positioning method for main cables of suspension bridges. The method aims to achieve linear adjustment and positioning of main cable strands under any temperature field. Using carbon fiber reference strands as a reference, the method fully considers the temperature differences between strands and performs rapid and accurate adjustment and positioning of general strands.

[0007] The technical solution of this invention is: a method for rapid positioning of the main cable of a suspension bridge, comprising:

[0008] Step 1) Installation and positioning of the carbon fiber reference strand;

[0009] Step 2) General strand alignment positioning adjustment method based on carbon fiber reference strand;

[0010] A measuring prism and a counterweight are installed on the carbon fiber reference strand; a temperature sensor is installed on the general strand.

[0011] Furthermore, the carbon fiber reference strand is made of carbon fiber material or carbon fiber composite material.

[0012] The measuring prisms are multiple and are set at key elevation control points of the carbon fiber reference strands according to the measurement and control requirements.

[0013] Furthermore, the measuring prisms are arranged in pairs, with each pair connected by a connecting rod and a prism clamp above and below the carbon fiber reference strand. Each connecting rod has its ends fixedly connected to both the measuring prism and the prism clamp. The two prism clamps are symmetrically positioned on the upper and lower sides of the carbon fiber reference strand, at the center between the two measuring prisms. The two sides of the clamps are secured with bolts, forming a shape consistent with the carbon fiber reference strand. Measurements are performed in a double-prism configuration using the two measuring prisms as a pair, and the measurement result is the average of the elevations measured by the two measuring prisms.

[0014] Furthermore, the counterweight device consists of multiple units, which are respectively set at the key elevation control points of the carbon fiber reference strand and near the key elevation control points according to the measurement and control needs. The counterweight weight is determined according to the wind resistance conditions at the installation site.

[0015] Furthermore, the key elevation control points include the mid-span of the bridge span and the quarter-span of the bridge span.

[0016] Furthermore, there are multiple temperature sensors, which are respectively deployed at the key elevation control points of the general cable strands, and the measurement results are calculated based on the average temperature of each point; the key elevation control points include the mid-span of the bridge span and the quarter-points of the bridge span.

[0017] Furthermore, in step 1), the installation and positioning of the carbon fiber reference strand adopts an absolute elevation control method. Specifically, the method is as follows: First, the stress-free length is calculated based on the loading conditions of the target alignment of the reference strand as the initial traction amount of the carbon fiber reference strand, thus completing the initial installation of the carbon fiber reference strand. Then, the absolute elevation is measured using a measuring prism installed at the elevation key control point. The difference between the measured absolute elevation and the absolute elevation of the target alignment of the reference strand is used as the control parameter for the next alignment adjustment. The elevation of the elevation key control point is adjusted by adjusting the length of the carbon fiber reference strand. After multiple measurements and repeated adjustments, the elevation of the elevation key control point is finally guaranteed to meet the height error requirements, thus completing the installation of the carbon fiber reference strand.

[0018] Furthermore, the general cable strands are installed after the carbon fiber reference cable strands are installed. There are multiple general cable strands. In step 2), the method for adjusting the linear positioning of the general cable strands based on the carbon fiber reference cable strands adopts a relative distance control method. This method primarily uses relative distance control, supplemented by ensuring the general cable strands are close to the frame. A large caliper is used to measure the sag distance between the general cable strand to be adjusted and the carbon fiber reference cable strand as the measured value. The sag distance, taking into account the temperature effect, is used as the control target value for adjustment and positioning. During the adjustment process, the temperature deformation effect of the carbon fiber reference cable strand can be disregarded; only the temperature deformation of the general cable strands needs to be controlled. The specific control is as follows:

[0019] First, based on the construction temperature, the temperature-corrected target alignment of the general cable strand is obtained. Then, the stress-free cable length is calculated from the target alignment of the general cable strand according to the design loading conditions, serving as the initial traction amount for the general cable strand. The general cable strand to be installed is then brought closer to the already installed general cable strand to complete the initial installation. Next, the temperature of the general cable strand is re-measured. If the temperature changes during the measurement, the target alignment of the general cable strand is readjusted; otherwise, it is controlled according to the previous target alignment. The target sag distance between the target alignment of the general cable strand at the key elevation control point and the benchmark cable strand target alignment is used as the control index for the general cable strand during actual installation. The measured sag distance between the carbon fiber benchmark cable strand and the general cable strand at the corresponding key elevation control points is measured. The difference between the target sag distance and the measured sag distance is the cable strand sag deviation value. By adjusting the length of the general cable strand, the cable strand sag deviation value is checked and adjusted multiple times. After repeated measurements and adjustments, when this deviation value meets the control height error, the cable adjustment is considered complete; otherwise, the aforementioned adjustment process needs to be continued until the allowable deviation range is met.

[0020] Furthermore, the benchmark cable strand target shape is the cable strand shape obtained by shifting the benchmark cable strand empty cable shape provided in the design drawings down by a certain safe distance, and the general cable strand target shape is the cable strand shape that is modified based on the general cable strand empty cable shape provided in the design drawings after taking into account the actual construction temperature.

[0021] The beneficial effects of this invention are:

[0022] Based on the excellent temperature deformability of carbon fiber materials, ensuring that the deformation caused by temperature changes is negligible, this invention introduces a carbon fiber reference strand as the positioning reference line for general strands during the erection of the main cable of a suspension bridge. This can greatly reduce the impact of temperature changes on the alignment of the reference strand, overcome temperature limitations, and allow for adjustments to general strands at any time, significantly accelerating the positioning efficiency of the main cable alignment and making alignment adjustments more convenient and accurate.

[0023] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the following describes the preferred embodiments of the present invention in detail with reference to the accompanying drawings. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the arrangement of carbon fiber reference strand auxiliary facilities in the fast positioning method for main cables of suspension bridges according to the present invention.

[0026] Figure 2 This is a schematic diagram of the main cable cross-section arrangement of a rapid positioning method for the main cable of a suspension bridge according to the present invention;

[0027] Figure 3 This is a schematic diagram of a counterweight device for a rapid positioning method of the main cable of a suspension bridge according to the present invention;

[0028] Figure 4 This is a schematic diagram of a double prism for a rapid positioning method of the main cable of a suspension bridge according to the present invention;

[0029] Figure 5 This is a schematic diagram of the general cable strand auxiliary facilities layout for a rapid positioning method for the main cable of a suspension bridge according to the present invention;

[0030] Figure 6 This is a schematic diagram of the cross-section of the carbon fiber reference strand in the method for rapid positioning of the main cable of a suspension bridge according to the present invention;

[0031] Figure 7 This is a schematic diagram of the carbon fiber reference strand alignment adjustment in a rapid positioning method for the main cable of a suspension bridge according to the present invention.

[0032] Figure 8 This is a schematic diagram of the general strand alignment adjustment of a rapid positioning method for the main cable of a suspension bridge according to the present invention;

[0033] Figure 9 This is a schematic diagram of the general strand sag distance measurement of a rapid positioning method for the main cable of a suspension bridge according to the present invention;

[0034] Reference numerals in the attached figures: 1. Carbon fiber reference strand; 2. General strand; 3. Measuring prism; 3-1. Prism clamp; 3-2. Connecting rod; 4. Counterweight device; 4-1. Strand clamp device; 4-2. Counterweight box; 4-3. Support frame; 4-4. Hanging rod; 5. Temperature sensor; 6. Target line shape of reference strand; 7. Target line shape of general strand; 8. Large caliper. Detailed Implementation

[0035] The present invention will now be described in detail with reference to the embodiments shown in the accompanying drawings. However, it should be noted that these embodiments are not intended to limit the present invention. Equivalent transformations or substitutions of functions and methods made by those skilled in the art based on these embodiments are all within the protection scope of the present invention.

[0036] Example 1

[0037] like Figure 1 As shown, the present invention provides a method for rapid positioning of the main cable of a suspension bridge, comprising:

[0038] Step 1) Installation and positioning of carbon fiber reference strand 1;

[0039] Step 2) A general method for adjusting the linear positioning of strand 2 based on carbon fiber reference strand 1;

[0040] A measuring prism 3 and a counterweight device 4 are installed on the carbon fiber reference strand 1; a temperature sensor 5 is installed on the general strand 2.

[0041] The main cable of this invention uses ordinary cable strand 2, which is made of high-strength steel wire and belongs to existing technology. The carbon fiber reference cable strand 1 is an innovative technology of this invention. Multiple ordinary cable strands 2 are set, and all the ordinary cable strands 2 together constitute the main cable structure of the suspension bridge. The carbon fiber reference cable strand 1 serves as a reference line to assist in the rapid positioning of each ordinary cable strand 2.

[0042] Traditional methods use strand No. 1 as the reference strand, which becomes part of the main cable structure after adjustment. In this invention, a carbon fiber reference strand is designed to replace the traditional No. 1 strand. After adjustment, it needs to be removed and is not part of the main cable structure.

[0043] like Figure 6As shown, based on the excellent temperature deformation properties of carbon fiber materials, the carbon fiber reference strand 1 is made of carbon fiber material or carbon fiber composite material; the carbon fiber composite material is an inorganic high-performance fiber with a carbon content higher than 90%, which is transformed from organic fibers through a series of heat treatments. Carbon fiber filaments are preferred as the carbon fiber material. The main advantage of using carbon fiber material or carbon fiber composite material in this invention is its excellent temperature deformation properties.

[0044] During installation, the deformation caused by temperature changes in the carbon fiber reference strand 1 is ensured to be negligible. The cross-sectional area of ​​the carbon fiber reference strand 1 can be appropriately reduced compared to the general strand 2, depending on the cost considerations.

[0045] like Figure 1 As shown, there are multiple measuring prisms 3, which are respectively set at the key control points of the elevation of the carbon fiber reference strand 1 according to the measurement and control needs.

[0046] like Figure 4 As shown, to avoid measurement errors caused by the difficulty of maintaining a vertical state for a single prism during actual use, the measuring prisms 3 are arranged in pairs. The two measuring prisms 3 are set above and below the carbon fiber reference strand 1 through their respective connecting rods 3-2 and prism clamps 3-1, ensuring that the centers of the prisms at the upper and lower ends, the connecting rods 3-2, and the prism clamps 3-1 are all on the same straight line. The two ends of each connecting rod 3-2 are fixedly connected to the measuring prism 3 and the prism clamp 3-1, respectively. The two prism clamps 3-1 are symmetrically arranged on the upper and lower sides of the carbon fiber reference strand 1 and are located at the center between the two measuring prisms 3. The two sides of the two prism clamps 3-1 are fastened with bolts, and the shape formed is consistent with the carbon fiber reference strand 1. Measurements are performed in the double-prism mode composed of two measuring prisms 3 as a pair. The measurement result is the average of the elevations measured by the two measuring prisms 3, which is the theoretical accurate value of the center elevation.

[0047] like Figure 1 As shown, there are multiple counterweight devices 4, which are respectively set at the key elevation control points of the carbon fiber reference strand 1 and near the key elevation control points, according to the measurement and control requirements. The counterweight weight is determined based on the wind resistance conditions at the installation site.

[0048] The counterweight device 4 increases the lateral stiffness and wind resistance of the carbon fiber reference strand 1 by applying pressure. The counterweight device can be set with the required weight and dimensions.

[0049] like Figure 3As shown, the counterweight device 4 is fixed to the carbon fiber reference strand 1 via a cable clamp device 4-1. A hanging rod 4-4 is provided below the cable clamp device 4-1, and a counterweight box 4-2 is connected to the hanging rod 4-4. A support frame 4-3 is horizontally installed inside the counterweight box 4-2 to maintain its balance. Counterweights are added to the counterweight box 4-2 as needed. After filling, the counterweight cover is promptly closed to prevent items from falling out. The cable clamp device 4-1 is existing technology and will not be described in detail here.

[0050] like Figure 2 As shown, the carbon fiber reference strand 1 is positioned below the cross-section of the main cable (i.e., general strand 2) during positioning adjustment, serving as the reference line for the positioning adjustment of the remaining general strands 2; as Figure 1 As shown, the measuring prism 3 is set at the key elevation control points of the carbon fiber reference cable strand 1 (e.g., at the mid-span or quarter-span of the bridge span) according to the measurement and control requirements; the counterweight device 4 is set at the key elevation control points of the carbon fiber reference cable strand 1 (e.g., at the mid-span or quarter-span of the bridge span) and its vicinity as needed, and increases its self-weight by adding weight to improve lateral stiffness and wind resistance stability. The size of the counterweight device 4 can be determined as needed.

[0051] Furthermore, such as Figure 5 As shown, there are multiple temperature sensors 5. The general cable strand 2 is greatly affected by temperature during installation. When adjusting the alignment, temperature sensors need to be installed at key control points of the general cable strand 2 (such as the mid-span of the bridge span, the quarter point of the bridge span, etc.) to fully consider the influence of temperature deformation. The measurement results are calculated based on the average temperature of each point.

[0052] Furthermore, such as Figure 7 As shown, the installation and positioning of the carbon fiber reference strand 1 in step 1) adopts an absolute elevation control method. Specifically, it is as follows: First, based on the loading conditions of the target alignment 6 of the reference strand (including the self-weight of the carbon fiber reference strand 1 and the loading of the counterweight device 4), the stress-free length is deduced as the initial traction of the carbon fiber reference strand 1, and the initial installation of the carbon fiber reference strand 1 is completed. Then, the absolute elevation is measured by the measuring prism 3 installed at the elevation key control point. The difference between the measured absolute elevation and the absolute elevation of the target alignment 6 of the reference strand is used as the control parameter for the next alignment adjustment. The elevation of the elevation key control point is adjusted by adjusting the length of the carbon fiber reference strand 1. After repeated measurements and adjustments, the elevation of the elevation key control point is finally guaranteed to meet the height error requirements, and the installation of the carbon fiber reference strand 1 is completed.

[0053] Furthermore, such as Figure 8 and Figure 9As shown, the general cable strand 2 is installed after the carbon fiber reference cable strand 1 is installed. There are multiple general cable strands 2. In step 2), the linear positioning adjustment method of the general cable strand 2 based on the carbon fiber reference cable strand 1 adopts a relative distance control method. It is supplemented by the close contact between the general cable strands 1 and the frame, and the relative distance control is the main method. The sag distance between the general cable strand 2 to be adjusted and the carbon fiber reference cable strand 1 is measured with a large caliper 8 as the measured value. The sag distance considering the influence of temperature is used as the control target value for adjustment and positioning. During the adjustment process, the influence of temperature deformation of the carbon fiber reference cable strand 1 can be ignored, and only the temperature deformation of the general cable strand 2 needs to be controlled. The specific control is as follows:

[0054] First, based on the construction temperature, the temperature-corrected target alignment 7 of the general cable strand is obtained. Then, based on the design loading conditions (mainly including the self-weight of the cable strand), the stress-free cable length is calculated from the target alignment 7 and used as the initial traction amount for the general cable strand 2. The general cable strand 2 to be installed is then brought closer to the already installed general cable strand 2 (except for the installation of the first general cable strand 2), completing the initial installation. Subsequently, the temperature of the general cable strand 2 is re-measured. If the temperature changes during the measurement, the target alignment 7 of the general cable strand is revised again; if there is no change, it is controlled according to the previous target alignment 7. The general cable strand target alignment at the key elevation control point is then... The target sag distance of the datum line 7 relative to the target datum line 6 of the reference cable strand serves as the control indicator for the general cable strand 2 during actual installation. The measured sag distance between the corresponding key control points of the carbon fiber reference cable strand 1 and the general cable strand 2 is measured. The difference between the target sag distance and the measured sag distance is the cable strand sag deviation value. The cable strand sag deviation value is checked and adjusted multiple times by adjusting the length of the general cable strand 2. After repeated measurement and adjustment, when this deviation value meets the control height error, the cable adjustment is considered complete. Otherwise, the aforementioned adjustment process needs to be continued until the allowable deviation range is met.

[0055] Furthermore, the target alignment 6 of the reference cable strand is the cable strand alignment obtained by shifting the reference cable strand empty cable alignment provided in the design drawings down by a safe distance. The target alignment 7 of the general cable strand is the cable strand alignment modified based on the general cable strand empty cable alignment provided in the design drawings, taking into account the actual construction temperature. The empty cable alignment is the alignment state of the main cable of the suspension bridge when no suspenders are attached.

[0056] like Figure 9 As shown, the large caliper 8 is specifically a sag measuring tool consisting of a vertical main scale and two horizontal sliding calipers. The main scale has graduations on its surface. In actual use, the main scale is kept vertical, the lower sliding caliper is fixed to the lower edge of the carbon fiber reference strand 1, and the upper sliding caliper is fixed to the upper edge of the general strand 2 to be adjusted. The actual sag distance can be obtained by subtracting half of the cross-sectional height of the carbon fiber reference strand 1 and the general strand 2 to be adjusted from the difference in the scale readings of the upper and lower calipers.

[0057] Example 2

[0058] like Figures 8-9 As shown, the general cable strand 2 is installed after the carbon fiber reference cable strand 1 is installed. The positioning of the general cable strand 2 adopts a relative distance control method, with the general cable strand 1 being closely attached to the frame as a secondary measure and relative distance control as the primary measure. The sag distance Δf between the general cable strand 2 to be adjusted and the carbon fiber reference cable strand 1 is measured using a large caliper 8 as the measured value. The sag distance Δf3, which takes into account the influence of temperature, is used as the control target value for adjustment and positioning. During the adjustment process, the influence of temperature deformation of the reference cable strand can be ignored, and only the temperature deformation of the general cable strand 2 needs to be controlled. First, the installation temperature difference (i.e., installation temperature - reference temperature) is obtained based on the construction temperature. The general cable strand empty cable shape provided in the design drawings is corrected based on the installation temperature difference to obtain the target general cable strand shape 7. The design loading conditions (mainly including the self-weight of the cable strand) are then considered. The stress-free cable length is calculated by reverse calculation of the target alignment 7 of the general cable strand to control the traction of the cable strand. The difference between the elevation of the target alignment 7 of the general cable strand at the control point and the measured elevation of the carbon fiber reference cable strand 1, and the target sag distance △f3, are used as the control index for the general cable strand 2 during actual installation. After the general cable strand 2 is pulled into place according to the target stress-free cable length, the alignment is verified and adjusted. The sag distance △f and temperature at the control point are measured again. The cable strand length is adjusted according to the measured deviation △f2 = △f - △f3. If the temperature changes during the test, the target sag distance △f3 of the general cable strand 2 is calculated again. If there is no change, the control is performed according to the previous index. When the measured deviation △f2 meets the control accuracy, the cable adjustment is considered to be completed. Otherwise, the aforementioned adjustment process needs to be continued until the allowable deviation range is met.

[0059] The carbon fiber reference strand 1 is used as a reference strand instead of the traditional No. 1 strand. It is removed after guiding the erection of other general strands 2. The No. 1 strand is also installed in the same way as the general strand 2.

[0060] The method is applicable to suspension bridges where the main cable is erected using the prefabricated parallel wire strand (PPWS) method.

[0061] Example 3

[0062] according to Figure 5 As shown, the difference from Embodiments 1 and 2 is that: if the construction site does not have the conditions for purchasing and installing the temperature sensor 5, a contact thermometer can be used instead of a thermometer for measurement. When using it, attention should be paid to sufficient heat exchange. During the temperature test, several measuring points can be selected and evenly distributed along the bridge span to ensure the accuracy of the measurement results.

[0063] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Parts and structures not described in detail in this embodiment are common knowledge in the industry and will not be described in detail here.

Claims

1. A method for rapid positioning of the main cable of a suspension bridge, characterized in that, include: Step 1) Installation and positioning of carbon fiber reference strand (1); Step 2) General strand (2) linear positioning adjustment method based on carbon fiber reference strand (1); The carbon fiber reference strand (1) is equipped with a measuring prism (3) and a counterweight device (4); the general strand (2) is equipped with a temperature sensor (5); The carbon fiber reference strand (1) replaces the traditional No. 1 cable and is removed after the cable adjustment is completed. It is not part of the main cable structure. In step 2), the linear positioning adjustment method of the general strand (2) based on the carbon fiber reference strand (1) adopts the relative distance control method. The method is mainly based on the close contact between the general strands (2) and the relative distance control. The sag distance between the general strand (2) to be adjusted and the carbon fiber reference strand (1) is measured by a large caliper (8) as the measured value. The sag distance considering the temperature effect is used as the control target value for adjustment and positioning. The temperature deformation effect of the carbon fiber reference strand (1) is not considered during the adjustment process. Only the temperature deformation of the general strand (2) needs to be controlled.

2. The method for rapid positioning of the main cable of a suspension bridge according to claim 1, characterized in that, The carbon fiber reference strand (1) is made of carbon fiber material or carbon fiber composite material.

3. The method for rapid positioning of the main cable of a suspension bridge according to claim 1, characterized in that, The measuring prism (3) consists of multiple prisms, which are set at the key elevation control points of the carbon fiber reference strand (1) according to the measurement and control requirements.

4. The method for rapid positioning of the main cable of a suspension bridge according to claim 3, characterized in that, The measuring prisms (3) are arranged in pairs. The two measuring prisms (3) are set above and below the carbon fiber reference strand (1) by their respective connecting rods (3-2) and prism clamps (3-1). The two ends of each connecting rod (3-2) are fixedly connected to the measuring prism (3) and the prism clamp (3-1) respectively. The two prism clamps (3-1) are symmetrically arranged on the upper and lower sides of the carbon fiber reference strand (1) and located at the center between the two measuring prisms (3). The two sides of the two prism clamps (3-1) are fastened by bolts, and the shape formed is consistent with the carbon fiber reference strand (1). The measurement is performed in the double prism mode composed of two measuring prisms (3) as a pair, and the measurement result is the average value of the elevation measured by the two measuring prisms (3).

5. The method for rapid positioning of the main cable of a suspension bridge according to claim 3, characterized in that, The counterweight device (4) consists of multiple units, which are respectively set at the key elevation control points of the carbon fiber reference strand (1) and near the key elevation control points according to the measurement and control needs. The counterweight weight is determined according to the wind resistance conditions of the installation site.

6. A method for rapid positioning of the main cable of a suspension bridge according to claim 3 or 5, characterized in that, The key elevation control points include the mid-span of the bridge span and the quarter-span of the bridge span.

7. The method for rapid positioning of the main cable of a suspension bridge according to claim 1, characterized in that, The temperature sensors (5) are multiple and are respectively installed at the key elevation control points of the general cable strands (2). The measurement results are calculated based on the average temperature of each point. The key elevation control points include the mid-span of the bridge span and the dividing points of the bridge span.

8. The method for rapid positioning of the main cable of a suspension bridge according to claim 1, characterized in that, In step 1), the installation and positioning of the carbon fiber reference strand (1) adopts the absolute elevation control method. Specifically, the stress-free length is first calculated based on the loading conditions of the target alignment (6) of the reference strand as the initial traction amount of the carbon fiber reference strand (1) to complete the initial installation of the carbon fiber reference strand (1). Then, the absolute elevation is measured by the measuring prism (3) installed at the elevation key control point. The difference between the measured absolute elevation and the absolute elevation of the target alignment (6) of the reference strand is used as the control parameter for the next alignment adjustment. The elevation of the elevation key control point is adjusted by adjusting the length of the carbon fiber reference strand (1). After repeated measurements and adjustments, the elevation of the elevation key control point is finally guaranteed to meet the height error requirements, and the installation of the carbon fiber reference strand (1) is completed.

9. The method for rapid positioning of the main cable of a suspension bridge according to claim 1, characterized in that, The general strand (2) is installed after the carbon fiber reference strand (1) is installed. There are multiple general strands (2). The specific control of step 2) is as follows: First, the temperature-corrected general cable strand target shape (7) is obtained based on the construction temperature. Then, the stress-free cable length is calculated from the general cable strand target shape (7) based on the design loading conditions. This is used as the initial traction amount of the general cable strand (2). The general cable strand (2) to be installed is then attached to the already installed general cable strand (2) to complete the initial installation. Subsequently, the temperature of the general cable strand (2) was retested. If the temperature changed during the test, the target line shape (7) of the general cable strand was revised. If there was no change, the control was carried out according to the previous target line shape (7) of the general cable strand. The target sag distance of the target line shape (7) of the general cable strand relative to the target line shape (6) of the reference cable strand was used as the control index of the general cable strand (2) during the actual installation process. The measured sag distance between the carbon fiber reference cable strand (1) and the general cable strand (2) at the corresponding key control points of the elevation was measured. The difference between the target sag distance and the measured sag distance is the cable strand sag deviation value. The cable strand sag deviation value was checked and adjusted multiple times by adjusting the length of the general cable strand (2). After repeated measurement and adjustment, when the deviation value meets the control height error, the cable adjustment is considered to be completed. Otherwise, the aforementioned adjustment process needs to be continued until the allowable deviation range is met.

10. A method for rapid positioning of the main cable of a suspension bridge according to claim 8 or 9, characterized in that, The reference cable strand target shape (6) is the cable strand shape obtained by shifting the reference cable strand empty cable shape provided in the design drawings down by a safe distance. The general cable strand target shape (7) is the cable strand shape that is modified based on the general cable strand empty cable shape provided in the design drawings after taking into account the actual construction temperature.

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