Method and device for monitoring closure gap of cast-in-cantilever beam bridge

Abstract

The invention discloses a method and a device for monitoring a closure gap of a cast-in-cantilever beam bridge, and the method comprises the steps: carrying out the multi-day continuous automatic collection of the related environment and deformation data of all closure gaps of a full bridge through installing a monitoring collection device, carrying out the calculation of the collected data through the on-site and remote grading combined calculation, carrying out the overrun monitoring and early warning, and predicting the closure period. Finally, the calculation result and the early warning information are transmitted to related closure workers for application at the application end, a provided data acquisition device is easy and convenient to install and adjust, unmanned automatic monitoring and intelligent combined calculation and real-time automatic over-limit monitoring and early warning are achieved, the closure time period is predicted, comprehensive and high-precision data support is provided for closure construction, and the construction efficiency is improved. And the closure quality is improved.

Description

Technical Field

[0001] The invention relates to the technical field of bridge construction, in particular to a monitoring method and device for a closure of a cantilever cast beam bridge. Background Art

[0002] Closure is one of the most important processes in the construction of cantilever continuous beam bridges. The construction quality of the closure section is an important factor affecting the quality of the entire beam. The length of the cantilever beam section will stretch to a certain extent when the temperature rises, and shorten when the temperature drops. In order to prevent the concrete in the closure section from being tensilely cracked due to the shortening of the completed cantilever segment beam body, the general design requires that the closure be low-temperature closure, that is, the closure mouth is locked to complete the concrete pouring when the temperature is the lowest and the closure mouth spacing is the largest, which can effectively avoid the problem of tensile cracking of the concrete in the closure section.

[0003] Before low-temperature closure, it is required to accurately grasp the changes in temperature and the distance between the closures and the relationship between the two, and determine the best closure time after statistical analysis of the data. This requires accurate observation of changes in temperature and the distance between the closures about a week before the closure, and forming data records, and recording these data needs to be done 24 hours a day. In traditional bridge closure construction, practitioners often use steel rulers and total stations to measure the displacement of the closure measurement points. However, the measurement error of the measuring points with a steel ruler is large, and due to the large number of measuring points at the closure, the workload is large, time-consuming and labor-intensive. The use of total stations for measurement has high requirements for the on-site environment. The total station needs to be adjusted to a position where the line of sight is not blocked and the distance is suitable for measurement. In addition, the manually erected total station cannot be accurately positioned, resulting in inaccurate measured data and difficulty in continuous monitoring. Therefore, people have adopted new observation technologies for bridge closures, such as: 1. Chinese Patent: An observation device for a bridge joint and its use method, application number: 202211291524.1, application date: 2022.10.19, abstract: The present invention discloses an observation device for a bridge joint and its use method, which relates to the technical field of bridge construction, and comprises: at least one support assembly and at least one detection device; wherein, at least one support assembly is used to be detachably assembled on the first side of the bridge joint, and the support assembly is provided with a control unit; at least one detection device is assembled on the support assembly, and the detection device comprises at least two dial indicators, and the two dial indicators are respectively used to monitor the displacement change information of the second side of the bridge joint, and transmit the displacement change information to the control unit. The observation device in the present invention continuously detects and collects the change values ​​of the longitudinal and lateral displacements at the bridge joint by setting a detachable dial indicator, so that the measurement data is more accurate and the adjustment is more convenient.

[0004] 2. Chinese Patent: A cantilever continuous beam bridge closure construction monitoring device and method; Application number: 202011590574.0; Application date: 2020.12.29; Abstract: The present invention relates to the field of building construction, and specifically to a cantilever continuous beam bridge closure construction monitoring device and method. The monitoring device includes a spacing measurement device, a temperature measurement device and a recording device. The spacing measurement device is used to measure the spacing change of the closure mouth, the temperature measurement device is used to measure the temperature change at the closure mouth, and the recording device is used to record the spacing and temperature change of the closure mouth. The monitoring method includes the following steps: S1: installing the spacing measurement device; S2: installing the temperature measurement device; S3: installing the recording device and recording. The cantilever continuous beam bridge closure construction monitoring device and method of the present invention, the monitoring device can accurately record the closure mouth spacing and temperature change data, without the need for manual duty to record the temperature and closure mouth spacing changes all day, saving labor costs, avoiding errors caused by manual observation, and thus providing an accurate basis for determining the optimal closure time, which can effectively ensure the low-temperature closure quality of the continuous beam bridge and improve construction efficiency.

[0005] Through applied research, it was found that the above-mentioned monitoring device and method, in severe weather such as heavy rain, the detection equipment is easy to move, which will interfere with on-site observations and affect the accuracy of the observation data. It is not convenient to continuously detect and collect the changing values ​​of the vertical displacement, which is not conducive to the realization of unmanned automatic monitoring and intelligent joint solution. It cannot automatically predict the joint closure period and cannot provide comprehensive and highly accurate data support for the joint closure construction, thereby improving the quality of the joint closure. Summary of the invention

[0006] The purpose of the present invention is to provide a monitoring method and device for the closure of a cantilever cast beam bridge. The technology uses a closure monitoring device to synchronously monitor the on-site temperature, wind speed and longitudinal, transverse and vertical deformation and displacement data of each closure and upload them to a database. It adopts an on-site and remote hierarchical joint solution method to perform over-limit monitoring and multi-factor joint analysis to obtain the corresponding time-temperature / wind speed / deformation and displacement curve of the closure and predict the optimal closure period, and feeds back the solution results to an application end. It can realize unmanned automatic monitoring and intelligent joint solution, as well as real-time automatic over-limit monitoring and early warning, and predict the closure period, so as to provide comprehensive and highly accurate data support for closure construction and improve the closure quality.

[0007] The present invention is achieved by adopting the following technical solutions: A monitoring method and device for the closure of a cantilever cast-beam bridge. This technology installs a monitoring and collection device to automatically collect the relevant environment and deformation data of all the closures of the entire bridge for multiple days. The collected data is solved through on-site and remote hierarchical joint solution, over-limit monitoring and warning are issued, and the closure period is predicted. Finally, the solution results and warning information are transmitted to the relevant closure staff at the application end for application.

[0008] The monitoring and collection device specifically includes an electrical cabinet, a first side detection frame and a second side detection frame, the first side detection frame and the second side detection frame are respectively installed and fixed on the first side and the second side of the joint, the first side detection frame and the second side detection frame are used in pairs, the first side detection frame and the second side detection frame respectively include a base plate, the base plate is fixedly connected to the bridge deck of the joint on the corresponding side by the base plate fixing bolts, the base plate is a square plate, and is fixed to the bridge deck at both ends of the joint by the base plate fixing bolts, and the base plate fixing bolts can be pre-buried or later driven expansion bolts; an adjusting support plate is installed on the base plate, and the adjusting support plate of the first side detection frame is provided with a second A side bearing plate, a second side bearing plate is arranged on the adjustment support plate of the second side detection frame, the first side bearing plate and the second side bearing plate are relatively extended and installed with corresponding first side assembled horizontal bars and second side assembled horizontal bars, the first side assembled horizontal bars and the second side assembled horizontal bars are arranged in a high and a low manner, three laser ranging sensors for measuring longitudinal, transverse and vertical spacings are correspondingly installed on the first side bearing plate and the first side assembled horizontal bar, and reflective plates for cooperating with laser ranging sensors for measurement are correspondingly arranged on the second side bearing plate and the second side assembled horizontal bar, the laser ranging sensor is connected to the electrical cabinet, and the electrical cabinet is also connected to an environmental data collector.

[0009] Environmental data collection equipment, data transmission equipment and on-site early warning equipment are centrally installed on the electrical cabinet; the environmental data collection equipment includes a temperature collector and an anemometer, wherein the anemometer is installed on the top of a telescopic round rod, and the lower part of the round rod is fastened to a special electrical cabinet; the data transmission equipment adopts an integrated Internet of Things controller, which has the functions of edge computing, graphic programming PLC, 4 / 5G router, open source gateway, expandable IO and protocol converter, and can fully automatically and accurately detect the data of the closure mouth and solve and analyze it, realize the deviation warning and closure period determination, and avoid the high-risk operation of manual night measurement. The on-site early warning equipment is a 4G speaker, which can provide on-site prompts for different types of warning information detected, and can also make real-time calls. The installation of the above-mentioned electrical cabinet related equipment realizes the on-site synchronous monitoring of the temperature, wind speed and three-way deformation displacement data of each closure mouth, and preliminary high-frequency analysis and feedback warning; the data is further uploaded to the database to provide a data source for remote automatic and accurate monitoring of closure mouth data, joint solution and analysis, and prediction of closure period, avoiding the high-risk operation of manual night measurement.

[0010] Monitoring includes the following steps: Step 1: Arrange the monitoring and collection devices according to the measurement point arrangement requirements on the bridge deck on both sides of each closure in the monitoring plan, determine the measurement point groups and number them.

[0011] Step 2: Calculate the initial deviation data of the measuring point group. Manually lay out and measure the positions of each group of measuring points at each closure, and calculate the original axis deviation △y0 and original height difference △z0 of each measuring point group.

[0012] Step three: Install the monitoring and collection device. Use a laser locator to perform cross-line positioning along the bridge axis at the measuring point group to ensure that the midpoint of the base of the collection device falls on the corresponding measuring point and fix it with bolts. The first side detection frame is uniformly placed on the side of the closure to connect all data collection equipment to the Internet of Things controller of the main data collection and transmission device. And take rain protection measures for related equipment to ensure normal operation on rainy days.

[0013] Step 4: Adjust the monitoring and collection device. With the help of the laser locator and the level bubble, the axis and level of the device are accurately adjusted and tightened by adjusting the joint support plate, and the axis and level of the monitoring and collection device and the longitudinal laser sensor are checked to complete the axial adjustment and verification of the device in three directions; adjust the longitudinal ranging laser distance measuring sensor and reflector so that the laser distance measuring sensor and the reflector are vertically aligned with the end of the joint mouth so that the measured distance is exactly the width of the joint mouth.

[0014] Step 5: Data collection, start the instrument and equipment, and begin to continuously collect environmental data and displacement data of multiple joints and multiple measuring points simultaneously; initialize, obtain and record the initial temperature T1, initial three-dimensional spacing DX1, Dy1, and Dz1 of each measuring point group.

[0015] Step 6: Data solution: Through on-site and remote hierarchical joint solution, over-limit monitoring, multi-factor joint analysis and closure period prediction are carried out, and the solution results are fed back to the application end.

[0016] Step 7: Monitoring data application, synchronously transmit the calculated monitoring alarm information, data curve and predicted closure period to the application end for real-time application.

[0017] Further preferred: the first side bearing plate and the second side bearing plate are both composed of two corresponding vertical plates, the two vertical plates are vertically connected to the adjustment support plate, and a slide rail seat is connected between the two vertical plates; a slide rail is installed on the slide rail seat, a slider is slidably installed on the slide rail, and a screw for locking the slider to the guide rail is provided on the slider; the slide rail seat connects the two vertical plates into one, and facilitates the sliding installation of the laser ranging sensor and the corresponding reflector through the slider and the slide rail.

[0018] Further preferably, the first side bearing plate and the second side bearing plate are detachably connected to the corresponding first side assembled horizontal rod and the second side assembled horizontal rod by using mounting bolts.

[0019] Further preferably, a level bubble is installed on each of the first side assembled horizontal rod and the second side assembled horizontal rod.

[0020] Further preferred: the first side assembled horizontal rod and the second side assembled horizontal rod both include an assembled connection assembly and multiple rod bodies, and two adjacent rod bodies are connected by the assembled connection assembly. The assembled connection assembly includes a connection plate and a connection bolt. The connection plate and the rod body are provided with connection holes. The connection plates are placed on both sides of the rod body, and then the bolts are passed through the connection holes and the nuts are tightened to connect the two adjacent rod bodies. The first side assembled horizontal rod and the second side assembled horizontal rod are connected with standard rod bodies according to the width of the joint to adjust the total length of the horizontal rod; the first section of the standard rod body is fastened to the load-bearing plate with bolts, and it is ensured to be parallel to the plane of the adjustment support plate and the axial axis to ensure the accuracy of the distance measurement of the laser sensor installed on the horizontal rod later.

[0021] Further preferred: the front end of the first side assembled horizontal bar is provided with a lateral extension frame, on which a laser distance measuring sensor for measuring lateral displacement is installed, and the front end of the second side assembled horizontal bar is provided with a corresponding reflector for cooperating with the laser distance measuring sensor for measuring lateral displacement. The front end bottom of the first side assembled horizontal bar is provided with a laser distance measuring sensor for measuring vertical displacement, and the front end top of the second side assembled horizontal bar is provided with a corresponding reflector for cooperating with the laser distance measuring sensor for measuring vertical displacement; the first side bearing plate is provided with a laser distance measuring sensor for measuring longitudinal displacement, and the laser distance measuring sensor is slidably installed through a slider and a slide rail and a slide rail seat between the two vertical plates of the first side bearing plate, and a reflector for cooperating with the laser distance measuring sensor for measuring longitudinal displacement is provided on the second side bearing plate, and the reflector is slidably installed through a slider and a slide rail and a slide rail seat between the two vertical plates of the second side bearing plate, so as to realize longitudinal fine adjustment for measuring the width of the joint. The laser distance measuring sensor and the reflector are provided with a rain shield to prevent rain from wetting the surface and affecting data collection.

[0022] Further preferred: the middle position of the adjustment support plate is supported and connected to the base plate through a single-rod ball joint bearing, and the adjustment support plates on both sides of the single-rod ball joint bearing are provided with arc-shaped waisted circular holes, and the adjustment support plate adjustment fastening bolts used to adjust the adjustment support plate to a limited position are passed through the arc-shaped waisted circular holes, and the adjustment support plate adjustment fastening bolts are connected to the base plate. The single-rod ball joint bearing is a single-rod TBS ball joint bearing, which has screw threads at both ends, and the base plate and the adjustment support plate are connected by screw holes in the middle of the base plate and the adjustment support plate, and the two can be universally rotated relative to each other; four arc-shaped waisted circular holes are symmetrically opened at a certain distance inward at the four corners of the adjustment support plate with the midpoint of the plate as the center of the circle; the adjustment support plate adjustment fastening bolts are welded to the corresponding positions of the diagonal of the base plate, so that the base plate and the adjustment support plate can be fastened and the horizontal and axial directions of the support can be adjusted.

[0023] Further preferably, the adjusting support plate is provided with a level bubble. There are two level bubbles, which are arranged on both sides of the top surface of the adjusting support plate respectively, for assisting in leveling the adjusting support plate.

[0024] The on-site and remote hierarchical joint solution is to perform the first-level high-frequency solution on the collected data on-site to realize data over-limit monitoring, and then upload the relevant data after settlement to the database; perform the second-level multi-factor joint analysis remotely and automatically predict the closure period, and the solution results are synchronously transmitted to the application end for early warning and other applications, which includes the following steps: a. The IoT controller at each closure collects environmental data and the longitudinal, transverse, and vertical spacing Dxt, Dyt, and Dzt of each measurement point group along the bridge once every minute, and determines whether each data is empty to determine whether the corresponding equipment is operating normally. If it is empty, an early warning will be issued to indicate that the corresponding numbered equipment is abnormal.

[0025] b. Over-limit monitoring of a single closure: ① Calculate the difference between Dxt, Dyt, Dzt and Dx1, Dy1, Dz1 of each measuring point group at the current moment, and obtain the corresponding △Dxt=Dxt-Dx1, △Dyt=Dyt-Dy1 and △Dzt=Dzt-Dz1; then superimpose with the original axis deviation △y0 and the original height difference △z0 to obtain the real-time deviation value of the corresponding item △yt=△Dyt+△y0 and △zt=△Dzt+△z0; then compare with the corresponding deviation limit △yt required by the specification 00 and △z 00 By comparison, we get Ky=△ yt / △y 00 、Kz=△ zt / △z 00 ; ② The axis deviation ratio Ky and height difference ratio Kz of each measuring point group are judged respectively. When they are both less than or equal to 1, it means that the axis deviation and height difference are within the limit; when they are greater than 1 and less than 1.2, and they are exceeded for 2 consecutive times, it is prompted that the axis deviation or height difference of the corresponding measuring point group exceeds the specification limit, and relevant personnel need to pay attention and take corrective measures; when they are greater than 1.2, it is prompted that the axis deviation or height difference of the corresponding measuring point group is abnormally exceeded, and the device may be abnormally touched, which needs to be checked and eliminated; ③ Over-limit information will be prompted by the on-site loudspeaker voice prompt, uploaded to the database and passed on to the person in charge.

[0026] c. Calculation of deformation of each joint: Under the condition of no over-limit, the calculation is performed every 10 minutes, that is, the longitudinal, transverse and vertical displacement increments of all measuring point groups of each joint are averaged to obtain △Dxi, △Dyi and △Dzi, and the spatial displacement increment is further calculated: , i is the joint number.

[0027] d. Data upload: Every 10 minutes, the temperature Ti and wind speed data Vi of each closure and the calculated △Dxi, △Dyi, △Dzi, and △Di are uploaded to the database.

[0028] e. Multi-factor joint analysis: On the remote solution platform, with time t as the dependent variable and Ti, Vi, △Dxi, △Dyi, △Dzi, and △Di of each joint as the independent variables, the multi-factor coupled deformation-displacement curves of t-Ti-Vi-(△Dxi, △Dyi, △Dzi, △Di) are automatically solved and drawn.

[0029] f. Closure period prediction: Take the average of △Di, Ti and Vi of more than t closures at the same time to get △D, T and V; then, within the limit of t=0-24h, superimpose the data of each day (j=1, 2, 3...n, n is the total number of monitoring days) to draw the tT and t-△D curves; in the tT curve, automatically intercept all continuous periods with a daily temperature difference of less than 5℃ and superimpose them to get the intersection, then eliminate the period with a temperature difference of less than 5℃, and compare and select the period with the lowest overall temperature t0-t2 ; In the daily t-△D curve, obtain the corresponding curve segment of the t0-t2 period for superposition analysis, and cut out the corresponding period t3-t4 where the curve is stable (small deformation displacement increment); that is, t3-t4 is the suitable period for joint closure in the next day; then based on the tV curve, check whether the wind speed corresponding to the t3-t4 period on the last day affects the joint closure construction. If there is no excessive wind speed, t3-t4 is finally determined as the best construction period for joint closure. If there is an excessive wind speed, continue monitoring one day later. Since the thermal conductivity of concrete is small, theoretically t4=t2, and the period t4-t5 corresponding to the delayed stable curve segment of the t-△D curve segment corresponding to t3-t4 can also be used as a supplementary period for joint closure.

[0030] The technical effects and advantages of the present invention are as follows: The monitoring and collection device used in the monitoring method of the closure of the cantilever cast-beam bridge is arranged on the bridge deck adjacent to the closure, which will not interfere with the construction work of the closure; the device is connected to the bridge body with bolts and is firmly installed; the device structure has a universal adjustment support, which is easy and accurate to adjust; it is equipped with an assembled horizontal rod, and the length of the horizontal rod can be freely adjusted according to the different widths of the closure; it completely replaces manual work to automatically and accurately monitor the data of the closure at multiple measurement points at high frequency around the clock, avoiding dangerous manual measurement work at night; it can automatically and continuously monitor the deformation value of the closure on site, analyze it at high frequency and quickly warn of the over-limit situation, to ensure efficient monitoring of the closure and over-limit correction prompts; remote continuous recording Record and analyze multi-factor coupled deformation and displacement curves, and predict the closure period by superimposing multiple factors. In general, the closure mouth on-site temperature, wind speed and three-dimensional deformation and displacement data of each closure mouth are synchronously monitored through the closure mouth monitoring device and uploaded to the database. The on-site and remote hierarchical joint solution method is adopted to carry out over-limit monitoring and multi-factor joint analysis to obtain the corresponding time-temperature / wind speed / deformation displacement curve of the closure mouth and predict the best closure period, and the solution results are fed back to the application end. Unmanned automatic monitoring and intelligent joint solution are realized, which can automatically monitor and warn of over-limit in real time and predict the closure period, provide comprehensive and highly accurate data support for closure construction, and improve the quality of closure. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the installation relationship of the monitoring and collection device at the closure; Figure 2 It is a structural diagram of the monitoring and collection device; Figure 3 It is a schematic diagram of the installation relationship between the base plate and the adjustment support plate; The parts names and numbers in the figure are: 1. Electrical cabinet; 2. Environmental data collector; 3. First side of joint; 4. Detection frame on first side; 5. Detection frame on second side; 6. Second side of joint; 7. Base plate; 8. Base plate fixing bolts; 9. Adjustment of support plate and adjustment of fastening bolts; 10. Adjustment of support plate; 11. Second side load-bearing plate; 12. Mounting bolts; 13. Level bubble; 14. Second side assembled horizontal bar; 15. Reflector; 16. Assembled connection assembly; 17. Lateral extension frame; 18. Laser ranging sensor; 19. First side assembled horizontal bar; 20. First side load-bearing plate; 21. Slide rail seat; 22. Arc-shaped waist hole; 23. Single-rod ball joint bearing; 24. Slide rail; 25. Slider. DETAILED DESCRIPTION

[0032] In order to describe the present technology more clearly, the present technology is further described in detail below with reference to the accompanying drawings and embodiments. Example

[0033] A monitoring method for the closure of a cantilever cast-beam bridge is to install a monitoring and collection device to automatically collect the relevant environment and deformation data of all the closures of the entire bridge for multiple days, solve the collected data through on-site and remote hierarchical joint solving, conduct over-limit monitoring and warning, and predict the closure period, and finally transmit the solution results and warning information to the relevant closure staff at the application end for application.

[0034] The monitoring and collection device includes an electrical cabinet 1, a first side detection frame 4 and a second side detection frame 5. The first side detection frame 4 and the second side detection frame 5 are respectively installed and fixed on the first side 3 and the second side 6 of the joint. The first side detection frame 4 and the second side detection frame 5 are used in pairs. The first side detection frame 4 and the second side detection frame 5 each include a base plate 7. The base plate 7 is fixedly connected to the bridge deck of the joint on the corresponding side through the base plate fixing bolts 8. The base plate is a square plate, which is fixed to the bridge deck at both ends of the joint through the base plate fixing bolts 8. The base plate fixing bolts 8 can be pre-buried or later driven expansion bolts; an adjusting support plate 10 is installed on the base plate 7, and a first side bearing plate 20 is arranged on the adjusting support plate 10 of the first side detection frame 4. A second side bearing plate 11 is arranged on the adjustment support plate 10 of the two side detection frames 5, and corresponding first side assembled horizontal bars 19 and second side assembled horizontal bars 14 are relatively extended and installed on the first side bearing plate 20 and the second side bearing plate 11, and the first side assembled horizontal bars 19 and the second side assembled horizontal bars 14 are arranged one high and one low. Three laser distance measuring sensors 18 for measuring longitudinal, transverse and vertical spacings are correspondingly installed on the first side bearing plate 20 and the first side assembled horizontal bar 19, and reflective plates 15 for cooperating with the laser distance measuring sensors 18 for measurement are correspondingly arranged on the second side bearing plate 11 and the second side assembled horizontal bar 14. The laser distance measuring sensor 18 is connected to the electrical cabinet 1, and the electrical cabinet 1 is also connected to the environmental data collector 2.

[0035] Environmental data collection equipment, data transmission equipment and on-site early warning equipment are centrally installed on the electrical cabinet; the environmental data collection equipment includes a temperature collector and an anemometer, wherein the anemometer is installed on the top of a telescopic round rod, and the lower part of the round rod is fastened to a special electrical cabinet; the data transmission equipment adopts an integrated Internet of Things controller, which has the functions of edge computing, graphic programming PLC, 4 / 5G router, open source gateway, expandable IO and protocol converter, and can fully automatically and accurately detect the data of the closure mouth and solve and analyze it, realize the deviation warning and closure period determination, and avoid the high-risk operation of manual night measurement. The on-site early warning equipment is a 4G speaker, which can provide on-site prompts for different types of warning information detected, and can also make real-time calls. The installation of the above-mentioned electrical cabinet related equipment realizes the on-site synchronous monitoring of the temperature, wind speed and three-way deformation displacement data of each closure mouth, and preliminary high-frequency analysis and feedback warning; the data is further uploaded to the database to provide a data source for remote automatic and accurate monitoring of closure mouth data, joint solution and analysis, and prediction of closure period, avoiding the high-risk operation of manual night measurement.

[0036] Monitoring includes the following steps: Step 1: Arrange the monitoring and collection devices according to the measurement point arrangement requirements on the bridge deck on both sides of each closure in the monitoring plan, determine the measurement point groups and number them.

[0037] Step 2: Calculate the initial deviation data of the measuring point group. Manually lay out and measure the positions of each group of measuring points at each closure, and calculate the original axis deviation △y0 and original height difference △z0 of each measuring point group.

[0038] Step three, installation of monitoring and acquisition device, use laser locator to perform cross-line layout and positioning along the axis of the bridge at the measuring point group position, ensure that the midpoint of the base of the acquisition device falls on the corresponding measuring point, and fix it with bolts; the first side detection frame 4 is uniformly placed on the side of the joint mouth, so as to connect all data acquisition equipment to the Internet of Things controller of the main data acquisition and transmission device; and take rain protection measures for related equipment to ensure normal operation on rainy days.

[0039] Step 4: Adjust the monitoring and collection device. With the help of the laser locator and the level bubble, the axis and level of the device are accurately adjusted and tightened by adjusting the joint support plate 10, and the axis and level of the monitoring and collection device and the longitudinal laser sensor are checked to complete the axial adjustment and verification of the device in three directions; adjust the longitudinal ranging laser distance measuring sensor and reflector so that the laser distance measuring sensor and the reflector are vertically aligned with the end of the joint mouth so that the measured distance is exactly the width of the joint mouth.

[0040] Step 5: Data collection, start the instrument and equipment, and begin to continuously collect environmental data and displacement data of multiple joints and multiple measuring points simultaneously; initialize, obtain and record the initial temperature T1, initial three-dimensional spacing DX1, Dy1, and Dz1 of each measuring point group.

[0041] Step 6: Data solution: Through on-site and remote hierarchical joint solution, over-limit monitoring, multi-factor joint analysis and closure period prediction are carried out, and the solution results are fed back to the application end.

[0042] Step 7: Monitoring data application, synchronously transmit the calculated monitoring alarm information, data curve and predicted closure period to the application end for real-time application.

[0043] The on-site and remote hierarchical joint solution is to perform the first-level high-frequency solution on the collected data on-site to realize data over-limit monitoring, and then upload the relevant data after settlement to the database; perform the second-level multi-factor joint analysis remotely and automatically predict the closure period, and the solution results are synchronously transmitted to the application end for early warning and other applications, which includes the following steps: a. The IoT controller at each closure collects environmental data and the longitudinal, transverse, and vertical spacing Dxt, Dyt, and Dzt of each measurement point group along the bridge once every minute, and determines whether each data is empty to determine whether the corresponding equipment is operating normally. If it is empty, an early warning will be issued to indicate that the corresponding numbered equipment is abnormal.

[0044] b. Over-limit monitoring of a single closure: ① Calculate the difference between Dxt, Dyt, Dzt and Dx1, Dy1, Dz1 of each measuring point group at the current moment, and obtain the corresponding △Dxt=Dxt-Dx1, △Dyt=Dyt-Dy1 and △Dzt=Dzt-Dz1; then superimpose with the original axis deviation △y0 and the original height difference △z0 to obtain the real-time deviation value of the corresponding item △yt=△Dyt+△y0 and △zt=△Dzt+△z0; then compare with the corresponding deviation limit △yt required by the specification 00 and △z 00 By comparison, we get Ky=△y t / △y 00 、Kz=△z t / △z 00 ; ② The axis deviation ratio Ky and height difference ratio Kz of each measuring point group are judged respectively. When they are both less than or equal to 1, it means that the axis deviation and height difference are within the limit; when they are greater than 1 and less than 1.2, and they are exceeded for 2 consecutive times, it is prompted that the axis deviation or height difference of the corresponding measuring point group exceeds the specification limit, and relevant personnel need to pay attention and take corrective measures; when they are greater than 1.2, it is prompted that the axis deviation or height difference of the corresponding measuring point group is abnormally exceeded, and the device may be abnormally touched, which needs to be checked and eliminated; ③ Over-limit information will be prompted by the on-site loudspeaker voice prompt, uploaded to the database and passed on to the person in charge.

[0045] c. Calculation of deformation of each joint: Under the condition of no over-limit, the calculation is performed every 10 minutes, that is, the longitudinal, transverse and vertical displacement increments of all measuring point groups of each joint are averaged to obtain △Dxi, △Dyi and △Dzi, and the spatial displacement increment is further calculated: , i is the joint number.

[0046] d. Data upload: Every 10 minutes, the temperature Ti and wind speed data Vi of each closure and the calculated △Dxi, △Dyi, △Dzi, and △Di are uploaded to the database.

[0047] e. Multi-factor joint analysis: On the remote solution platform, with time t as the dependent variable and Ti, Vi, △Dxi, △Dyi, △Dzi, and △Di of each joint as the independent variables, the multi-factor coupled deformation-displacement curves of t-Ti-Vi-(△Dxi, △Dyi, △Dzi, △Di) are automatically solved and drawn.

[0048] f. Prediction of closure period: take the average of △Di, Ti and Vi of t closures at the same time, and get △D, T and V; then, with t=0-24h as the limit, superimpose the data of each day (j=1, 2, 3...n, n is the total number of monitoring days) to draw tT and t-△D curves; in the tT curve, automatically intercept all continuous periods with daily temperature difference less than 5℃ and superimpose them to get the intersection, then eliminate the period with temperature less than 5℃, and compare and select the period t0-t2 with the lowest overall temperature; in the daily t-△D curve, obtain the corresponding curve segment of the t0-t2 period for superposition analysis, and intercept the corresponding period t3-t4 with stable curve; that is, t3-t4 is the suitable closure period in the next day; then, based on the tV curve, check whether the wind speed corresponding to the t3-t4 period on the last day affects the closure construction. If there is no excessive wind speed, t3-t4 is finally determined as the best construction period for closure. If there is an excessive wind speed, monitoring will be postponed for one day. Since the thermal conductivity of concrete is small, theoretically t4=t2, and t3-t4 corresponds to the extended stable curve segment of the t-△D curve segment, and the time period t4-t5 corresponding to the extended stable curve segment can also be used as a supplementary time period for the joint closing operation.

[0049] The first side bearing plate 20 and the second side bearing plate 11 are both composed of two corresponding vertical plates, the two vertical plates are vertically connected to the adjustment support plate 10, and a slide rail seat 21 is connected between the two vertical plates; a slide rail 24 is installed on the slide rail seat 21, and a slider 25 is slidably installed on the slide rail 24, and a screw for locking the slider 25 and the guide rail 24 is provided on the slider 25; a laser ranging sensor 18 and a reflector 15 for measuring longitudinal displacement are installed on the corresponding slider 25.

[0050] The first side bearing plate 20 and the second side bearing plate 11 are detachably connected to the corresponding first side assembled horizontal rod 19 and the second side assembled horizontal rod 14 by using mounting bolts 12 .

[0051] Level bubbles 13 are installed on the first side assembled horizontal rod 19 and the second side assembled horizontal rod 14 respectively.

[0052] The first side assembled horizontal rod 19 and the second side assembled horizontal rod 14 both include an assembled connection assembly 16 and multiple rod bodies. Two adjacent rod bodies are connected by the assembled connection assembly 16. The assembled connection assembly 16 includes a connection plate and a connection bolt. The connection plate and the rod body are provided with connection holes. The connection plates are placed on both sides of the rod body, and then the bolts are inserted through the connection holes and the nuts are tightened to connect the two adjacent rod bodies. The first side assembled horizontal rod 19 and the second side assembled horizontal rod 14 are connected to the standard rod body according to the width of the joint to adjust the length of the horizontal rod; the first section of the standard rod body is fastened to the load-bearing plate with bolts, and it is ensured to be parallel to the plane and axial axis of the adjustment support plate 10 to ensure the accuracy of the distance measurement of the laser distance measurement sensor installed on the horizontal rod later.

[0053] The front end of the first side assembled horizontal bar 19 is provided with a lateral extension frame 17, on which a laser distance sensor 18 for measuring lateral displacement is installed, and the front end of the second side assembled horizontal bar 14 is provided with a corresponding reflector 15 for cooperating with the laser distance sensor 18 to measure lateral displacement. The front end bottom of the first side assembled horizontal bar 19 is provided with a laser distance sensor 18 for measuring vertical displacement, and the front end top of the second side assembled horizontal bar 14 is provided with a corresponding reflector 15 for cooperating with the laser distance sensor 18 to measure vertical displacement; the first side bearing plate 20 is provided with a laser distance sensor 18 for measuring longitudinal displacement, and the second side bearing plate 11 is provided with a corresponding reflector 15 for cooperating with the laser distance sensor 18 to measure longitudinal displacement. The laser distance sensor 18 and the reflector 15 are provided with rain shields to prevent rain from wetting the surface and affecting data collection.

[0054] The middle position of the adjustment support plate 10 is supported and connected to the base plate 7 by a single-rod ball joint bearing 23. The adjustment support plate 10 on both sides of the single-rod ball joint bearing 23 is provided with arc-shaped waisted circular holes 22. The adjustment support plate adjustment fastening bolts 9 for adjusting the adjustment support plate 10 are inserted into the arc-shaped waisted circular holes 22, and the adjustment support plate adjustment fastening bolts 9 are connected to the base plate 7. The single-rod ball joint bearing 23 is a single-rod TBS ball joint bearing, and screw threads are opened at both ends. The base plate 7 and the adjustment support plate 10 are connected by opening screw threads in the middle of the base plate 7 and the adjustment support plate 10, and the two can be universally rotated relative to each other; four arc-shaped waisted circular holes 22 are opened symmetrically at a certain distance inward at the four corners of the adjustment support plate 10 with the midpoint of the plate as the center of the circle; the adjustment support plate adjustment fastening bolts 9 are welded to the corresponding positions of the diagonal of the base plate 7, so that the base plate 7 and the adjustment support plate 10 can be adjusted, calibrated and fastened.

[0055] The adjusting support plate 10 is provided with a level bubble 13 ; there are two level bubbles 13 , which are arranged on both sides of the top surface of the adjusting support plate 10 , respectively, for assisting in leveling the adjusting support plate 10 .

[0056] The above description is not a limitation of the present application, and the present application is not limited to the above examples. Any changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the present application should fall within the scope of protection of the present application.

Claims

1. A method for monitoring the closure of a cantilever cast beam bridge, characterized in that: By installing monitoring and collection devices, the relevant environment and deformation data of all closures of the entire bridge are collected automatically for many days. The collected data are solved, over-limit monitoring and warning are carried out, and the closure period is predicted through on-site and remote hierarchical joint solving. Finally, the solution results and warning information are transmitted to the relevant closure staff for application at the application end; The monitoring and collecting device comprises an electrical cabinet (1), a first side detection frame (4) and a second side detection frame (5), the first side detection frame (4) and the second side detection frame (5) being respectively mounted and fixed on a first side (3) and a second side (6) of the joint opening, the first side detection frame (4) and the second side detection frame (5) each comprising a base plate (7), the base plate (7) being fixedly connected to the joint opening bridge deck on the corresponding side via base plate fixing bolts (8), an adjusting support plate (10) being mounted on the base plate (7), a first side bearing plate (20) being arranged on the adjusting support plate (10) of the first side detection frame (4), a second side bearing plate (11) being arranged on the adjusting support plate (10) of the second side detection frame (5), the first side bearing plate (20) being arranged on the adjusting support plate (10) of the second side detection frame (5), ) and the second side bearing plate (11) are provided with corresponding first side assembled horizontal bars (19) and second side assembled horizontal bars (14) extending out from each other, the first side assembled horizontal bars (19) and the second side assembled horizontal bars (14) being arranged one high and one low, three laser distance measuring sensors (18) for measuring longitudinal, transverse and vertical spacings are correspondingly installed on the first side bearing plate (20) and the first side assembled horizontal bars (19), and reflective plates (15) for cooperating with the laser distance measuring sensors (18) for measuring are correspondingly arranged on the second side bearing plate (11) and the second side assembled horizontal bars (14), the laser distance measuring sensors (18) are connected to the electrical cabinet (1), and the electrical cabinet (1) is also connected to an environmental data acquisition instrument (2); Monitoring includes the following steps: Step 1: Arrange monitoring and collection devices according to the requirements for the arrangement of measuring points on the bridge deck on both sides of each closure in the monitoring plan, determine the measuring point groups and number them; Step 2: Calculate the initial deviation data of the measuring point group, manually set out and measure the positions of each measuring point group at each closure, and calculate the original axis deviation △y0 and original height difference △z0 of each measuring point group; Step 3: Install the monitoring and acquisition device. Use a laser locator to perform cross-line positioning along the bridge axis at the measuring point group position to ensure that the midpoint of the base of the acquisition device falls on the corresponding measuring point, and then fix it with bolts. The first side detection frame (4) is uniformly placed on the side of the joint mouth so that all data acquisition devices can be connected to the Internet of Things controller of the main data acquisition and transmission device. Rainproof measures are also taken for the relevant equipment to ensure normal operation on rainy days. Step 4: Adjust the monitoring and acquisition device. With the help of a laser locator and a level bubble, the axis and level of the device are precisely adjusted and tightened by adjusting the joint support plate (10). The axis and level of the monitoring and acquisition device and the longitudinal laser sensor are checked to complete the axial adjustment and check of the device in three directions. Step 5: Data acquisition, start the instrument and equipment, and start to continuously collect environmental data and displacement data of multiple joints and multiple measuring points simultaneously; initialize, obtain and record the initial temperature T1, initial three-dimensional spacing DX1, Dy1, Dz1 of each measuring point group; Step 6: Data solution: Through on-site and remote hierarchical joint solution, over-limit monitoring, multi-factor joint analysis and closure period prediction are carried out, and the solution results are fed back to the application end; Step 7: Monitoring data application, synchronously transmit the calculated monitoring alarm information, data curve and predicted closure period to the application end for real-time application.

2. The method for monitoring the closure of a cantilever cast beam bridge according to claim 1, characterized in that: The first side bearing plate (20) and the second side bearing plate (11) are both composed of two corresponding vertical plates, the two vertical plates are vertically connected to the adjustment support plate (10), a slide rail seat (21) is connected between the two vertical plates, a slide rail (24) is installed on the slide rail seat (21), a slider (25) is slidably installed on the slide rail (24), and a screw for locking the slider (25) and the guide rail (24) is provided on the slider (25).

3. The method for monitoring the closure of a cantilever cast beam bridge according to claim 2, characterized in that: The first side bearing plate (20) and the second side bearing plate (11) are detachably connected to the corresponding first side assembled horizontal rod (19) and the second side assembled horizontal rod (14) by means of mounting bolts (12).

4. The method for monitoring the closure of a cantilever cast beam bridge according to claim 1, characterized in that: Level bubbles (13) are respectively installed on the first side assembled horizontal rod (19) and the second side assembled horizontal rod (14).

5. The method for monitoring the closure of a cantilever cast beam bridge according to claim 4, characterized in that: The first side assembled horizontal rod (19) and the second side assembled horizontal rod (14) both include an assembled connection assembly (16) and a plurality of rod bodies. Two adjacent rod bodies are connected via the assembled connection assembly (16). The assembled connection assembly (16) includes a connection plate and a connection bolt. The connection plate and the rod body are both provided with connection holes. The connection plates are placed on both sides of the rod body. Then, bolts are inserted through the connection holes and nuts are tightened to connect the two adjacent rod bodies.

6. The method for monitoring the closure of a cantilever cast beam bridge according to claim 1, characterized in that: The front end of the first side assembled horizontal rod (19) is provided with a lateral extension frame (17), and a laser distance sensor (18) for measuring lateral displacement is installed on the lateral extension frame (17). The front end of the second side assembled horizontal rod (14) is correspondingly provided with a reflective plate (15) for cooperating with the laser distance sensor (18) to measure lateral displacement.

7. The method for monitoring the closure of a cantilever cast beam bridge according to claim 1, characterized in that: The middle position of the adjustment support plate (10) is supported and connected to the base plate (7) via a single-rod ball joint bearing (23); arc-shaped waist-shaped holes (22) are provided on the adjustment support plate (10) on both sides of the single-rod ball joint bearing (23); adjustment support plate adjustment fastening bolts (9) for adjusting the limit position of the adjustment support plate (10) are passed through the arc-shaped waist-shaped holes (22); and the adjustment support plate adjustment fastening bolts (9) are connected to the base plate (7).

8. The method for monitoring the closure of a cantilever cast beam bridge according to claim 1, characterized in that: The adjustment support plate (10) is provided with a level bubble (13).

9. The method for monitoring the closure of a cantilever cast beam bridge according to claim 1, characterized in that: The on-site and remote hierarchical joint calculation is to perform the first-level high-frequency calculation on the collected data on-site to realize data over-limit monitoring, and then upload the relevant data after settlement to the database; The second-level multi-factor joint analysis is performed remotely and the closure period is automatically predicted. The solution results are synchronously transmitted to the application end for early warning and other applications, which includes the following steps: a. The IoT controller at each closure collects environmental data and the longitudinal, transverse, and vertical spacing Dxt, Dyt, and Dzt of each measuring point group along the bridge once every minute, and determines whether each data is empty to determine whether the corresponding equipment is operating normally. If it is empty, an early warning will be issued to indicate that the corresponding numbered equipment is abnormal; b. Over-limit monitoring of a single closure: ① Calculate the difference between Dxt, Dyt, Dzt and Dx1, Dy1, Dz1 of each measuring point group at the current moment, and obtain the corresponding △Dxt=Dxt-Dx1, △Dyt=Dyt-Dy1 and △Dzt=Dzt-Dz1; then superimpose with the original axis deviation △y0 and the original height difference △z0 to obtain the real-time deviation value △y of the corresponding item t =△Dy t +△y0 and △z t =△Dz t +△z0; then compare with the corresponding deviation limit △y required by the specification 00 and △z 00 By comparison, we get Ky=△y t / △y 00 、Kz=△z t / △z 00 ; ② The axis deviation ratio Ky and height difference ratio Kz of each measuring point group are judged respectively. When both are less than or equal to 1, it means that the axis deviation and height difference are within the limit; when they are greater than 1 and less than 1.2, and they are exceeded for two consecutive times, it is prompted that the axis deviation or height difference of the corresponding measuring point group exceeds the specification limit, and relevant personnel need to pay attention and take corrective measures; when they are greater than 1.2, it is prompted that the axis deviation or height difference of the corresponding measuring point group is abnormally exceeded, which needs to be checked and eliminated; ③ Over-limit information will be prompted by the on-site loudspeaker, uploaded to the database and passed to the person in charge; c. Calculation of deformation of each joint: Under the condition of no over-limit, the calculation is performed every 10 minutes, that is, the longitudinal, transverse and vertical displacement increments of all measuring point groups of each joint are averaged to obtain △Dxi, △Dyi and △Dzi, and the spatial displacement increment is further calculated: , i is the joint number; d. Data upload: Every 10 minutes, upload the temperature Ti and wind speed data Vi of each closure and the calculated △Dxi, △Dyi, △Dzi, and △Di to the database; e. Multi-factor joint analysis: On the remote solution platform, with time t as the dependent variable and Ti, Vi, △Dxi, △Dyi, △Dzi, and △Di of each joint opening as the independent variables, the multi-factor coupled deformation displacement curves of t-Ti-Vi-(△Dxi, △Dyi, △Dzi, and △Di) are automatically solved and drawn; f. Prediction of closure period: take the average of △Di, Ti and Vi of t closures at the same time, and get △D, T and V; then, with t=0-24h as the limit, superimpose the data of each day (j=1, 2, 3...n, n is the total number of monitoring days) to draw tT and t-△D curves; in the tT curve, automatically intercept all continuous periods with daily temperature difference less than 5℃ and superimpose them to get the intersection, then eliminate the period with temperature less than 5℃, and compare and select the period t0-t2 with the lowest overall temperature; in the daily t-△D curve, obtain the corresponding curve segment of the t0-t2 period for superposition analysis, and intercept the corresponding period t3-t4 with stable curve; that is, t3-t4 is the suitable closure period in the next day; then, based on the tV curve, check whether the wind speed corresponding to the t3-t4 period on the last day affects the closure construction. If there is no excessive wind speed, t3-t4 is finally determined as the best construction period for closure. If there is an excessive wind speed, monitoring will be postponed for one day. Since the thermal conductivity of concrete is small, theoretically t4=t2, and t3-t4 corresponds to the extended stable curve segment of the t-△D curve segment, and the time period t4-t5 corresponding to the extended stable curve segment can also be used as a supplementary time period for the joint closing operation.

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