Method and system for measuring and cutting the closure section length of a cable-stayed bridge

Abstract

The application discloses a method and system for measuring and cutting the length of a closure segment of a cable-stayed bridge, and the method comprises the following steps: before the closure of the bridge, welding a steel plate (4) to the top plate and the bottom plate of the front end section of a first cantilever beam segment (1) and a second cantilever beam segment (2), and sticking a reflective sticker as a measuring target; erecting a total station on the two end cantilever beam segments, starting to continuously observe the target and record the coordinates and the corresponding temperature after the total station is oriented according to the set reference points; calculating the displacement of the cantilever end caused by the change of 1 DEG C of the temperature according to the obtained coordinates and the corresponding temperature; determining the temperature on the closure day according to the construction organization plan; establishing a full-bridge model by using a finite element, and respectively calculating the longitudinal displacement of the cantilever end caused by the counterweight and the hoisting of the closure segment (3); and calculating the cutting length of each point according to the relative positions of the measuring points. The method is fast in measurement, can accurately obtain the size of the closure segment, improves the cutting precision, reduces the on-site adjustment and rework, and improves the construction efficiency.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of bridge construction, and more particularly relates to a method and system for measuring and cutting the length of a closure segment of a cable-stayed bridge. BACKGROUND

[0002] Cable-stayed bridges have become one of the fastest-growing and most competitive bridge types due to their large overall stiffness, excellent wind resistance, strong spanning capacity, and diverse structural arrangement. In the process of bridge construction, bridge closure is a very critical link. For cable-stayed bridges, closure construction control is particularly important. A cable-stayed bridge is composed of a main girder, stay cables, and a tower, and the stay cables bear most of the load. The structural design requires high-precision construction and measurement to ensure the reasonable cooperation of various components. The closure segment is a key connecting part of the bridge, and its accurate measurement has an important influence on subsequent construction operations and the overall performance of the bridge.

[0003] The common closure methods for cable-stayed bridge steel girders include push closure and temperature cutting. Due to unavoidable deviations during bridge construction and manufacturing, the size of the closure segment is not a completely regular shape, so a large amount of data needs to be obtained through continuous measurement, other significant factors need to be considered, and accurate calculations need to be performed to obtain the accurate closure segment length, so that the closure weld width can be ensured to be within the specified range.

[0004] In the construction process of a cable-stayed bridge, the butt joint of the closure segment requires high-precision measurement to ensure the accuracy of the construction. The accuracy of the closure segment length determines the degree of fit between the last segment of the girder and the already built part, which in turn affects the smooth progress of the entire bridge construction. During the closure segment construction process, any small error in temperature changes, material shrinkage, and load changes can cause structural deformation. Therefore, accurate measurement and adjustment of the closure segment are the key to ensuring construction quality. If the length is not appropriate, it may lead to adjustments and rework during the construction process, increasing construction costs and time. SUMMARY

[0005] To address the aforementioned deficiencies or improvement needs of existing technologies, this invention provides a method and system for measuring and matching the length of the closure segment of a cable-stayed bridge. By welding steel plates to the cantilever ends of the steel box girder and attaching reflective stickers, the measuring points can be kept stationary, reducing errors caused by manual operation. The total station measures the reflective stickers quickly, minimizing the impact of changes in the measuring point position caused by drastic changes in ambient temperature. The matching values ​​for each point are calculated based on the theoretical center station number, eliminating situations where the cantilever end edges are not on the same plane due to construction and manufacturing. By arranging measuring points on the front section of the cantilever and conducting continuous observations, combined with the displacement effect of temperature changes on the cantilever end, and by establishing a bridge model using a finite element program, various loads and actions during actual construction can be simulated. This allows for accurate determination of the closure segment dimensions, improving the accuracy of the closure segment matching, reducing on-site adjustments and rework, and increasing construction efficiency.

[0006] To achieve the above objectives, according to a first aspect of the present invention, a method for measuring and matching the length of the closure segment of a cable-stayed bridge is provided, comprising the following steps:

[0007] S100: Before the bridge is closed, steel plates are welded at the junction of the top plate, bottom plate and web of the front section of the first cantilever beam segment and the second cantilever beam segment. Reflective stickers are attached to the steel plates of the first cantilever beam segment and the second cantilever beam segment in opposite directions as targets for total station measurement.

[0008] S200: Set up a first total station and a second total station on the first cantilever beam segment and the second cantilever beam segment respectively. Then select a first reference point and a second reference point on the first cantilever beam segment and the second cantilever beam segment respectively. Complete the orientation of the first total station and the second total station by selecting the first reference point and the second reference point, and start continuous observation of the target, recording the coordinates and the corresponding temperature during the measurement.

[0009] S300: Based on the geodetic coordinates X i ′、Y i ′、Z i Converting ′ to the obtained bridge position coordinates X i Y i Z i and its corresponding temperature, Temp (i) Calculate the displacement Δ at the cantilever end for every 1°C change in temperature. T ;

[0010] S400: Based on the construction organization plan and the existing construction procedures, calculate the specific time of closure, and then check the weather station to determine the weather temperature T0 on the day of closure;

[0011] S500: based on finite element, a full bridge model is established, and longitudinal displacements Δ1 and Δ2 generated by the counterweight on the first and second cantilever beam segments and longitudinal displacements Δ3 and Δ4 generated by the hoisting closure segment on the first and second cantilever beam segments are calculated respectively;

[0012] S600: according to the relative position relationship of each measuring point of the roof and floor, the tangent length of each point is calculated.

[0013] Further, in the step S100, the reflective sticker numbers on the small-pile roof are Tx1-TXn in sequence, the reflective sticker numbers on the large-pile roof are Td1-Tdn in sequence, the reflective sticker numbers on the small-pile floor are Dx1-Dxn in sequence, and the reflective sticker numbers on the large-pile floor are Dd1-Ddn in sequence.

[0014] Further, in the step S200, when continuously observing the target, the coordinates of the measuring points are measured every 4 hours from 8 am to 8 pm in the daytime, and the coordinates of the measuring points are measured every 2 hours from 8 pm to 8 am the next day at night, and the coordinates X i ′, Y i ′, Z i ′ and the corresponding temperature Temp (i) .

[0015] Further, in the step S200, after the coordinates X i ′, Y i ′, Z i ′ of each measuring point are measured, the coordinates of the measuring points are converted into bridge coordinates X i , Y i , Z i , and the position relationship between the geodetic coordinates and the bridge coordinates is as follows:

[0016] X i =X i ′cosβ-Y i ′sinβ+Δx

[0017] Y i =Y i ′cosβ+X i ′sinβ+Δy

[0018] Z i =Z i ′

[0019] wherein i is the measuring point numbered Tx1-Txn on the small-pile roof, the measuring point numbered Td1-Tdn on the large-pile roof, the measuring point numbered Dx1-Dxn on the small-pile floor, and the measuring point numbered Dd1-Ddn on the large-pile floor,

[0020] X i The longitudinal direction of the bridge location coordinates.

[0021] Y i The horizontal direction represents the bridge location coordinates.

[0022] Z i The vertical direction of the bridge location coordinates.

[0023] Δx and Δy are the coordinates of the origin of the geodetic coordinate system in the bridge location coordinate system.

[0024] β is the azimuth angle between the geodetic coordinate system and the bridge location coordinate system.

[0025] Furthermore, in step S300, by measuring at each measuring point at temperature Temp... (i) The coordinates X below i , will X i With Temp (i) Fit to linear equation form:

[0026]

[0027] Among them, X i The longitudinal direction of the bridge location coordinates.

[0028] Temp (i) For X i The temperature corresponding to the coordinates

[0029] B is a constant.

[0030] A i The displacement of the cantilever end at each measuring point is measured by the temperature change of 1°C.

[0031] Furthermore, in step S300, since there are a large number of measurement points at the closure joint, in order to reduce errors and improve the accuracy of the results, the displacement change rate of all observation points on each side of the top and bottom plates is averaged. That is, the displacement generated at the cantilever end for each 1°C change in temperature of the top and bottom plates is:

[0032]

[0033] Where n is the number of measurement points.

[0034] Furthermore, in step S500, when establishing the bridge model using finite element method, the main beam and main tower structure are simulated using beam elements, the stay cables are simulated using truss elements, the stay cables and main beam are rigidly connected, the main tower and main beam are not rigidly connected, the counterweight is simulated using uniformly distributed load or concentrated force, the load generated by the hoisting and closure section is applied to the main beam element using concentrated force, and the bridge stiffness needs to be corrected based on the comparison between the previous measured values ​​and the calculated values ​​to make the measured displacement consistent with the calculated displacement.

[0035] Further, in the step S600, when calculating the matching length of each measuring point, taking the theoretical pile number DK of the theoretical center line of the bridge as a reference, the matching length L1 i 、L2 i of each measuring point is calculated respectively; the matching length calculation formula of each measuring point is:

[0036] L1 i =DK-X i +Δ1+Δ3-Δ T ×(T0-T 测 )

[0037] L2 i =X i -DK+Δ2+Δ4-Δ T ×(T0-T 测 )

[0038] Wherein, L1 i is the matching length of the i-th measuring point of the small pile number,

[0039] L2 i is the matching length of the i-th measuring point of the large pile number,

[0040] T0 is the temperature when the closure section is closed,

[0041] T 测 is the temperature when the continuous measurement is performed,

[0042] X i is the coordinate value of each measuring point corresponding to the temperature T 测 .

[0043] Further, after the matching length of each point is calculated, the adjacent measuring points are connected into a straight line to determine the matching length of the remaining positions of the steel beam.

[0044] According to another aspect of the embodiment of the present application, a matching system for measuring the length of the closure section of a cable-stayed bridge is provided, comprising:

[0045] A measuring point setting module is configured to weld steel plates at the positions where the top plate, the bottom plate and the web of the front end cross section of the first cantilever beam section and the second cantilever beam section meet before the closure of the bridge, and the steel plates on the first cantilever beam section and the second cantilever beam section are pasted with reflective stickers in opposite directions as the measuring targets of the total station;

[0046] Data measurement module: a first total station and a second total station are respectively erected on the first cantilever beam segment and the second cantilever beam segment, then a first reference point and a second reference point are respectively selected on the first cantilever beam segment and the second cantilever beam segment, and the orientation of the first total station and the second total station is completed through the first reference point and the second reference point, and continuous observation of the target is started, and the coordinates and the corresponding temperature at the time of measurement are recorded;

[0047] Data analysis module: according to the conversion of the obtained bridge coordinate X i ′, Y i ′, Z i ′ into the obtained bridge coordinate X i , Y i , Z i and the corresponding temperature Temp (i) , the displacement Δ T of the cantilever end caused by the change of 1℃ of the temperature is calculated;

[0048] Closing temperature determination module: according to the construction organization plan, the specific time of closing is calculated based on the existing construction process, and the weather temperature T0 of the closing day is determined by querying the weather station weather;

[0049] Finite element calculation module: based on finite element, a full-bridge model is established, and the longitudinal displacement Δ1 and Δ2 of the counterweight to the first cantilever beam segment and the second cantilever beam segment and the longitudinal displacement Δ3 and Δ4 of the hoisting closure segment to the first cantilever beam segment and the second cantilever beam segment are calculated;

[0050] Cutting length calculation module: according to the relative position relationship of each measuring point of the top and bottom plate, the cutting length of each point is calculated.

[0051] Overall, compared with the prior art, the above technical solutions conceived by the present application can achieve the following beneficial effects:

[0052] 1. The closure segment length measurement and cutting method of the present application realizes fast and efficient measurement through reflective sticker measurement, compared with the traditional method such as manual prism erection measurement, which significantly reduces the operation steps, because the prism does not need to be moved constantly during measurement, which improves the measurement speed, enhances the measurement accuracy and stability, and provides solid data support for accurate cutting of the closure segment.

[0053] 2. The closure section length measurement and cutting method of the present application, by directly welding a steel plate at the cantilever end and firmly attaching a reflective sticker on it, this design ensures the absolute fixation of the measurement points, fundamentally avoids the slight errors that may occur during manual operation, thereby improving the accuracy and reliability of the measurement. In addition, since the measurement method adopted by this method is fast and efficient, it greatly shortens the time required for single measurement, thus effectively reducing the impact of the slight changes in the position of the measurement points caused by the drastic fluctuations in the external environment temperature, further enhancing the stability and timeliness of the measurement results.

[0054] 3. The closure section length measurement and cutting method of the present application, using the theoretical center pile number as the reference, accurately calculating the cutting value of each point, this strategy effectively solves the complex problem of the cantilever end line not in the same plane caused by construction errors, manufacturing deviations and other factors. Through this method, accurate measurement and reasonable cutting of the closure section length can be achieved, thereby greatly improving the accuracy and overall quality of the installation of bridges or other large structures. In addition, the application of this method also reduces the workload of subsequent adjustment, improves the construction efficiency, and provides strong support for the smooth progress and cost control of the engineering project. BRIEF DESCRIPTION OF DRAWINGS

[0055] Figure 1 The closure section elevation view of the closure section length measurement and cutting method of the cable-stayed bridge embodiment of the present application;

[0056] Figure 2 The closure section cross-sectional view of the closure section length measurement and cutting method of the cable-stayed bridge embodiment of the present application;

[0057] Figure 3 The closure section measurement schematic diagram of the closure section length measurement and cutting method of the cable-stayed bridge embodiment of the present application;

[0058] Figure 4 The closure section top plate cutting schematic diagram of the closure section length measurement and cutting method of the cable-stayed bridge embodiment of the present application;

[0059] Figure 5 The closure section bottom plate cutting schematic diagram of the closure section length measurement and cutting method of the cable-stayed bridge embodiment of the present application;

[0060] Figure 6 The flowchart of the closure section length measurement and cutting method of the cable-stayed bridge embodiment of the present application.

[0061] In all the drawings, the same reference signs represent the same technical features, specifically: 1 - first cantilever beam section, 2 - second cantilever beam section, 3 - closure section, 4 - steel plate, 5 - first reference point, 6 - second reference point, 7 - first total station, 8 - second total station. DETAILED DESCRIPTION

[0062] 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 accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0063] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0064] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0065] In this patent, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0066] Combination Figures 1-5 ,like Figure 6 As shown, according to a first aspect of the present invention, a method for measuring and matching the length of the closure segment of a cable-stayed bridge is provided, comprising the following steps:

[0067] S100: Before the bridge is closed, steel plates 4 are welded to the positions where the top plate, bottom plate and web plate of the front section of the first cantilever beam segment 1 and the second cantilever beam segment 2 meet. Reflective stickers are attached to the steel plates 4 on the first cantilever beam segment 1 and the second cantilever beam segment 2 in opposite directions as targets for total station measurement.

[0068] S200: Set up a first total station 7 and a second total station 8 on the first cantilever beam segment 1 and the second cantilever beam segment 2 respectively. Then, select a first reference point 5 and a second reference point 6 on the first cantilever beam segment 1 and the second cantilever beam segment 2 respectively. Orient the first total station 7 and the second total station 8 by selecting the first reference point 5 and the second reference point 6, and start continuous observation of the target, recording the coordinates and the corresponding temperature during the measurement.

[0069] S300: Based on the geodetic coordinates X i ′、Y i ′、Z i Converting ′ to the obtained bridge position coordinates X i Y i Z i and its corresponding temperature, Temp (i) Calculate the displacement Δ at the cantilever end for every 1°C change in temperature. T ;

[0070] S400: Based on the construction organization plan and the existing construction procedures, calculate the specific time of closure, and then check the weather station to determine the weather temperature T0 on the day of closure;

[0071] S500: Based on the finite element method, establish a full bridge model and calculate the longitudinal displacements Δ1 and Δ2 generated by the counterweight on the first cantilever beam segment 1 and the second cantilever beam segment 2, as well as the longitudinal displacements Δ3 and Δ4 generated by the hoisting and closing segment 3 on the first cantilever beam segment 1 and the second cantilever beam segment 2.

[0072] S600: Calculate the cutting length of each point based on the relative positional relationship of each measuring point on the top and bottom plates.

[0073] like Figure 1 , 2 As shown, in step S100, the steel plate 4 must be kept vertical. The reflective stickers on the top plate of the small pile number are numbered Tx1 to TXn, the reflective stickers on the top plate of the large pile number are numbered Td1 to Tdn, the reflective stickers on the bottom plate of the small pile number are numbered Dx1 to Dxn, and the reflective stickers on the bottom plate of the large pile number are numbered Dd1 to Ddn.

[0074] like Figure 3 As shown, in step S200, the first total station 7 can measure the coordinates of all measuring points on the second cantilever beam segment 2, and the second total station 8 can measure the coordinates of all measuring points on the first cantilever beam segment 1. The selected first reference point 5 and second reference point 6 need to be stable and reliable and not affected by environmental changes.

[0075] In the continuous observation of the targets on the first cantilever beam segment 1 and the second cantilever beam segment 2, the coordinates of the measuring points are measured every 4 hours from 8:00 am to 8:00 pm, and every 2 hours from 8:00 pm to 8:00 am of the next day, and the coordinates (X i ′, Y i ′, Z i ′) and the corresponding temperature Temp (i) are recorded for 3 consecutive days. i ′ is the coordinate longitudinal direction, Y i ′ is the coordinate transverse direction, and Z i ′ is the coordinate vertical direction.

[0076] The measured coordinates (X i ′, Y i ′, Z i ′) of each measuring point are geodetic coordinates, and the geodetic coordinates (X i ′, Y i ′, Z i ′) of the measuring points are converted into bridge coordinates (X i , Y i , Z i ), and the positional relationship between the bridge coordinates and the geodetic coordinates is as follows:

[0077] X i =X i ′cosβ-Y i ′sinβ+Δx

[0078] Y i =Y i ′cosβ+X i ′sinβ+Δy

[0079] Z i =Z i ′

[0080] where i is the small stake number, the measuring points on the top plate numbered Tx1-Txn, the large stake number, the measuring points on the top plate numbered Td1-Tdn, the small stake number, the measuring points on the bottom plate numbered Dx1-Dxn, and the large stake number, the measuring points on the bottom plate numbered Dd1-Ddn,

[0081] X i is the bridge coordinate longitudinal direction,

[0082] Y i is the bridge coordinate transverse direction,

[0083] Z i is the bridge coordinate vertical direction,

[0084] Δx and Δy are the coordinate values of the origin of the geodetic coordinate system under the bridge coordinate system,

[0085] β is the azimuth angle between the geodetic coordinate system and the bridge location coordinate system.

[0086] In step S300, the temperature is measured at each measuring point. (i) The coordinates X below i , will X i With Temp (i) Fit to linear equation form:

[0087]

[0088] Among them, X i The longitudinal direction of the bridge location coordinates.

[0089] Temp (i) For X i The temperature corresponding to the coordinates

[0090] B is a constant.

[0091] A i The displacement of the cantilever end at each measuring point is measured by the temperature change of 1°C.

[0092] Due to the large number of measurement points at the closure section, in order to reduce errors and improve the accuracy of the results, the displacement change rate of all observation points on each side of the top and bottom plates was averaged. That is, the displacement of the cantilever end caused by a 1°C change in temperature of each top and bottom plate is:

[0093]

[0094] Where n is the number of measurement points.

[0095] In step S500, when establishing the bridge model based on finite element method, the main beam and main tower structure are simulated using beam elements, the stay cables are simulated using truss elements, the stay cables and main beam are rigidly connected, the main tower and main beam are not rigidly connected, the counterweight is simulated using uniformly distributed load or concentrated force, the load generated by hoisting and closing section 3 is applied to the main beam element using concentrated force, and the bridge stiffness needs to be corrected based on the comparison between the measured value and the calculated value to make the measured displacement consistent with the calculated displacement.

[0096] like Figure 4 , 5 As shown, in step S600, when calculating the cut length at each measuring point, the theoretical station number DK of the bridge's theoretical centerline is used as the reference, and the cut length L1 at each measuring point is calculated respectively. i L2 i The formula for calculating the cutting length at each measuring point is:

[0097] L1 i =DK-X i+ Δ1+ Δ3- Δ T ×(T0-T 测 )

[0098] L2 i = X i -DK+ Δ2+ Δ4- Δ T ×(T0-T 测 )

[0099] Wherein, L1 i is the length of the small pile number of the i-th measuring point,

[0100] L2 i is the length of the large pile number of the i-th measuring point,

[0101] T0is the temperature when the closure section is closed,

[0102] T 测 is the temperature when the continuous measurement is measured,

[0103] X i is the coordinate value of each measuring point corresponding to the temperature T 测 .

[0104] After the calculation of the length of each point, the adjacent measuring points are connected in sequence to form a straight line segment, and the length of the remaining position of the steel beam is determined, so as to construct the overall profile of the steel box girder; In this process, it is necessary to ensure that the connection between each measuring point and its adjacent point is accurate, and it is also necessary to finely adjust these straight line segments according to the calculated length of the cut, so as to accurately determine the length of the cut of the steel box girder at the remaining positions. This can ensure that each part of the steel beam can be butt jointed together in the manufacturing and installation process, so as to meet the design accuracy and strength requirements. Through this way, the processing and installation work of the steel box girder can be efficiently promoted, and the smooth progress of the whole project can be ensured.

[0105] According to the second aspect of the present application, a cable-stayed bridge closure section length measurement and cutting system is provided, comprising:

[0106] The measuring point setting module is used for welding steel plates 4 at the positions where the top plate, bottom plate and web of the front end cross section of the first and second cantilever beam sections 1 and 2 are connected before the closure of the bridge, and the steel plates 4 on the first and second cantilever beam sections 1 and 2 are pasted with reflective stickers towards opposite directions as the total station measurement target;

[0107] Data measurement module: first total station 7 and second total station 8 are respectively arranged on the first cantilever beam section 1 and the second cantilever beam section 2, then first reference point 5 and second reference point 6 are selected on the first cantilever beam section 1 and the second cantilever beam section 2 respectively, and the orientation of the first total station 7 and the second total station 8 is completed through the first reference point 5 and the second reference point 6, and continuous observation of the target is started, and the coordinates and the corresponding temperature during measurement are recorded;

[0108] Data analysis module: according to the conversion of the obtained bridge coordinate X i ', Y i ', Z i ' into the bridge coordinate X i , Y i , Z i and the corresponding temperature Temp (i) , the displacement Δ T of the cantilever end caused by the change of 1 DEG C of the temperature is calculated;

[0109] Closing temperature determination module: according to the construction organization plan, the specific time of closing is calculated based on the existing construction process, and the weather temperature T0 of the closing day is determined by querying the weather station weather;

[0110] Finite element calculation module: based on finite element, a full-bridge model is established, and the longitudinal displacement Δ1 and Δ2 of the first cantilever beam section 1 and the second cantilever beam section 2 caused by the counterweight and the longitudinal displacement Δ3 and Δ4 of the first cantilever beam section 1 and the second cantilever beam section 2 caused by the hoisting closing section 3 are calculated respectively;

[0111] Cutting length calculation module: according to the relative position relationship of each measuring point of the top and bottom plate, the cutting length of each point is calculated.

[0112] The closing section length measurement and cutting method of the application can ensure that the measuring point is fixed and immovable, reduce the error caused by manual operation, the total station can measure the reflective sticker at a faster speed, and the influence of the position change of the measuring point caused by the sharp change of the external environment temperature can be reduced, the cutting value of each point can be calculated based on the theoretical center pile number, the situation that the cantilever end edge line is not in the same plane caused by construction and manufacturing can be eliminated, the measuring point is arranged on the front end section of the cantilever and continuous observation is carried out, the displacement influence of the cantilever end caused by temperature change is combined, the bridge model is established by combining the finite element program, various loads and actions in the actual construction process can be simulated, the closing section size can be accurately obtained, the accuracy of the closing section cutting can be improved, the on-site adjustment and rework can be reduced, and the construction efficiency can be improved.

[0113] Those skilled in the art can understand that the above description is only the preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for measuring and cutting the length of a closure segment of a cable-stayed bridge, characterized in that, It comprises the following steps: S100: Before the bridge closure, steel plates (4) are welded at the positions where the top plate, bottom plate and web of the front end section of the first cantilever beam segment (1) and the second cantilever beam segment (2) meet, respectively, the steel plates (4) on the first cantilever beam segment (1) and the second cantilever beam segment (2) are pasted with reflective stickers in opposite directions as the target for total station measurement; S200: A first total station (7) and a second total station (8) are respectively erected on the first cantilever beam segment (1) and the second cantilever beam segment (2), then a first reference point (5) and a second reference point (6) are respectively selected on the first cantilever beam segment (1) and the second cantilever beam segment (2), the orientation of the first total station (7) and the second total station (8) is completed through the selection of the first reference point (5) and the second reference point (6), and continuous observation of the target is started, and the coordinates and the corresponding temperature at the time of measurement are recorded; S300: According to the conversion of the geodetic coordinates X i , Y i , Z i to the bridge coordinates X i , Y i , Z i and the corresponding temperature Temp (i) , the displacement Δ T of the cantilever end caused by a change of 1℃ in temperature is calculated. S400: According to the construction organization plan, the specific time of closure is calculated based on the existing construction process, and the weather temperature T0 of the closure day is determined by querying the weather station; S500: Based on the finite element, a full-bridge model is established, and the longitudinal displacements Δ1 and Δ2 of the first cantilever beam segment (1) and the second cantilever beam segment (2) caused by the counterweight and the longitudinal displacements Δ3 and Δ4 of the first cantilever beam segment (1) and the second cantilever beam segment (2) caused by the hoisting closure segment (3) are calculated respectively; S600: According to the relative position relationship of each measuring point of the top and bottom plates, the tangent length of each point is calculated.

2. The method according to claim 1, wherein the length of the closure segment of the cable-stayed bridge is measured and cut. In the step S100, the numbers of the reflective stickers on the small-pile-number measuring top plate are Tx1-TXn, the numbers of the reflective stickers on the large-pile-number measuring top plate are Td1-Tdn, the numbers of the reflective stickers on the small-pile-number measuring bottom plate are Dx1-Dxn, and the numbers of the reflective stickers on the large-pile-number measuring bottom plate are Dd1-Ddn.

3. The method according to claim 1, wherein the method is characterized in that, In the step S200, when continuously observing the target, the coordinates of the measuring point are measured every 4 hours from 8 a.m. to 8 p.m. in the daytime, and every 2 hours from 8 p.m. to 8 a.m. in the night, continuously for 3 days and the coordinates X at the time of measurement are recorded i ', Y i ', Z i , and the corresponding temperature Temp (i) .

4. The method according to claim 3, wherein the length of the closure segment of the cable-stayed bridge is measured and cut. The step S200, in measuring the coordinates X i ', Y i ', Z i ' of each measuring point are geodetic coordinates, and then the geodetic coordinates of the measuring point are converted into bridge coordinates X i , Y i , Z i . The positional relationship between the geodetic coordinates and the bridge coordinates is as follows: X i = X i ' cos β - Y i ' sin β + Δx Y i = Y i ' cos β + X i ' sin β + Δy Z i = Z i ' Wherein, i is the measuring point numbered Tx1-TXn on the small-pile-number measuring top plate, the measuring point numbered Td1-Tdn on the large-pile-number measuring top plate, the measuring point numbered Dx1-Dxn on the small-pile-number measuring bottom plate, and the measuring point numbered Dd1-Ddn on the large-pile-number measuring bottom plate, X i is the longitudinal direction of the bridge site coordinates, Y i is the bridge position coordinate transverse direction, Z i is the vertical direction of the bridge site coordinates, Δx and Δy are the coordinate values of the origin of the geodetic coordinate system in the bridge coordinate system, β is the azimuth angle of the geodetic coordinate system and the bridge coordinate system.

5. The method according to any one of claims 1-4, wherein, In step S300, the temperature at each measuring point is measured... (i) The coordinates X below i , will X i With Temp (i) Fit to linear equation form: wherein X i is the longitudinal direction of the bridge site coordinates, Temp (i) is X i Temperature corresponding to the coordinates, B is a constant, A i The displacement of the cantilever tip for each measurement point for each 1 °C change in temperature at that point.

6. The method according to claim 5, wherein the length of the closure segment of the cable-stayed bridge is measured and cut. In the step S300, since the number of measuring points at the closure gap is large, in order to reduce the error and improve the accuracy of the results, the displacement change rate of all observation points of each side top plate and bottom plate is averaged, that is, the displacement of the cantilever end caused by the temperature change of each measuring top and bottom plate by 1℃ is: Wherein, n is the number of measuring points.

7. The method according to any one of claims 1-4, wherein, In the step S500, when the bridge model is established by using the finite element, the main beam and the main tower structure are simulated by beam elements, the stay cables are simulated by truss elements, the stay cables and the main beam are rigidly connected, the main tower and the main beam are not fixed, the counterweight is simulated by uniform load or concentrated force, the load generated by the hoisting closure segment is loaded on the main beam element in the form of concentrated force, and the bridge stiffness needs to be corrected according to the comparison between the measured value and the calculated value, so that the measured displacement is consistent with the calculated displacement.

8. The method according to any one of claims 1-4, wherein, In the step S600, when calculating the matching length of each measuring point, the theoretical pile number DK of the theoretical center line of the bridge is taken as the reference to calculate the matching length L1 i , L2 i of each measuring point respectively; the matching length calculation formula of each measuring point is: L1 i = DK - X i + Δ1+ Δ3- Δ T ×(T0-T 测 ) L2 i = X i -DK + Δ2 + Δ4 - Δ T × (TO - T 测 ) wherein L1 i is the length of the tangent at the i-th measuring point, L2 i L2 L2 L2 L2 L2 L2 L2 L2 L2 L2 L2 L2 L2 L T0 is the temperature of the closure segment at the time of closure, T 测 for the temperature at the time of continuous measurement, X i corresponding temperature T 测 the coordinate values of each measuring point at the time.

9. The method according to claim 8, wherein the length of the closure segment of the cable-stayed bridge is measured and cut. After the calculation of the cutting length of each point is completed, the adjacent measuring points are connected into a straight line to determine the cutting length of the remaining positions of the steel beam.

10. A cable-stayed bridge closure segment length measurement and cutting system, characterized in that, The application realizes the length measurement and cutting method of the closure section of the cable-stayed bridge according to any one of claims 1-9, comprising: The measuring point setting module is used for welding a steel plate (4) at the position where the top plate, the bottom plate and the web of the front end section of the first cantilever beam section (1) and the second cantilever beam section (2) are connected before the closure of the bridge, and the steel plates (4) on the first cantilever beam section (1) and the second cantilever beam section (2) are pasted with reflective stickers in opposite directions as the measurement target of the total station; The data measurement module is used for erecting a first total station (7) and a second total station (8) on the first cantilever beam section (1) and the second cantilever beam section (2) respectively, then selecting a first reference point (5) and a second reference point (6) on the first cantilever beam section (1) and the second cantilever beam section (2) respectively, and completing the orientation of the first total station (7) and the second total station (8) by selecting the first reference point (5) and the second reference point (6), and starting to continuously observe the target, and recording the coordinates and the corresponding temperature at the time of measurement; Data analysis module: according to the conversion of the earth coordinates X i ', Y i ', Z i ' into the bridge coordinates X i , Y i , Z i and the corresponding temperature Temp (i) , the displacement Δ T of the cantilever end caused by the change of 1℃ of the temperature is calculated. The closure temperature determination module is used for calculating the specific time of the closure on the basis of the existing construction process according to the construction organization plan, and then querying the weather of the weather station to determine the weather temperature T0 of the closure day; The finite element calculation module is used for establishing a full-bridge model based on finite elements, and calculating the longitudinal displacement Δ1 and Δ2 of the first cantilever beam section (1) and the second cantilever beam section (2) caused by the counterweight and the longitudinal displacement Δ3 and Δ4 of the first cantilever beam section (1) and the second cantilever beam section (2) caused by the hoisting closure section (3) respectively. The cutting length calculation module is used for calculating the cutting length of each point according to the relative position relationship of each measuring point of the top plate and the bottom plate.

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