A method for measuring the elevation of an adjustable track type box girder crash barrier

Abstract

The application discloses a kind of adjustable track box girder crash barrier elevation measurement methods, box girder is placed in the elevation measurement device of a kind of adjustable track box girder crash barrier designed to assist, the device includes rail, wedge steel plate, connecting steel bar, steel plate, reinforcing rib plate, anti-rollover support frame, the rail is directly anchored on measuring platform, the wedge steel plate is welded into a whole and placed on rail, the connecting steel bar is used to connect two sides wedge steel plate, the steel plate, reinforcing rib plate is directly welded to wedge steel plate bottom end, the anti-rollover support frame is welded to one side of wedge steel plate, the device can be adjusted support mechanism according to actual beam length and beam cross slope size, it is convenient to install, strong flexibility, easy to operate, high practicality, the elevation measurement method of a kind of adjustable track box girder crash barrier in the application is with the aid of rail platform, simplifies measurement procedure, saves the measurement time of box girder crash barrier elevation, improves work efficiency.

Description

Technical Field

[0001] This invention belongs to the field of bridge construction, specifically relating to a method for measuring the elevation of an adjustable track box girder crash barrier. Background Technology

[0002] With the development of municipal industrialization, more and more prefabricated municipal structural components are being transferred to production workshops for prefabrication. The requirements for on-site assembly of prefabricated structures are becoming increasingly stringent, especially for box girder crash barriers. As an auxiliary structure of the box girder, the crash barrier is a crucial safety feature. To ensure good integrity between the prefabricated crash barrier and the edge beam, strict requirements are placed on the levelness of the top surface of the box girder crash barrier during the initial prefabrication stage. This necessitates the development of a measuring device suitable for box girders of different span sizes to simplify the measurement process, maximize accuracy during component production, improve production efficiency, and reduce production costs and safety hazards.

[0003] In the prior art, Chinese utility model patent 201821176808.5 discloses a novel optimized prefabricated crash barrier construction platform. This platform includes a support frame, a walkway platform, and an adjustable support frame. Bolts are provided at the lower end of the support frame, which is fixed to the ground. The walkway platform is fixedly installed at the upper end of the support frame, with a handrail on one side. The adjustable support frame is located on the other side of the walkway platform and includes a support part, a screw, and a nut. One end of the screw is connected to the walkway platform, and the other end has a groove that matches the lower end steel structure of the crash barrier's outer formwork. The upper end of the outer formwork is fixedly connected to the upper end of the inner formwork, and the lower end of the inner formwork is bolted to the box girder. This application addresses the design of a crash barrier working platform and the platform's support for the crash barrier, which differs from the simplified measurement method addressed in this application. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for measuring the elevation of an adjustable track-type box girder anti-collision wall, which simplifies the measurement process, ensures maximum accuracy during component production, improves production efficiency, and reduces production costs and safety hazards.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] A method for measuring the elevation of an adjustable track-mounted box girder crash barrier, comprising the following steps:

[0007] Step 1: Design an auxiliary measuring device for the elevation of an adjustable track-type box girder anti-collision wall on a measuring platform. This device includes an adjustable box girder rail on the measuring platform, a first wedge-shaped steel plate and a second wedge-shaped steel plate, connecting reinforcing bars, steel plates, and reinforcing ribs on the rails. The rails are arranged longitudinally at equal intervals along the length of the box girder as the first, second, and third rails and anchored to the measuring platform. The connecting reinforcing bars are placed on the second rail, laterally connecting the first and third rails. The first and second wedge-shaped steel plates are integrally connected and placed on the first and third rails. The bottom of the first and second wedge-shaped steel plates are welded with steel plates and reinforcing ribs integrally welded to them. Anti-rollover support frames are welded to the sides of the first and second wedge-shaped steel plates. Once the auxiliary measuring device for the anti-collision wall elevation is assembled, when the box girder is placed on the auxiliary measuring device, the center of the bottom support of the box girder is aligned with the second rail.

[0008] Step 2: Lift the box girder and place it in front of the measuring platform, determine the support position at the bottom of the box girder, and determine the placement position of the first wedge steel plate and the second wedge steel plate on the rail based on the longitudinal length of the support positions on both sides of the bottom of the box girder.

[0009] Step 3: The first wedge-shaped steel plate and the second wedge-shaped steel plate are placed vertically on the rail. The measuring platform is measured and the cross slope percentage is verified using a detector from one end of the first rail.

[0010] Step 4: The box girder is lifted and placed on the auxiliary measuring device. The center support of the bottom of the box girder coincides with the center of the second rail of the rail. The elevation of the beam surface of each box girder with a crash barrier is controlled. The prism height h1 and the inner formwork top support height h2 are measured by a total station.

[0011] Step 5: After the box girder is fixed, a measuring ruler is placed on the second rail. The dimensions of the box girder are obtained by measuring the ruler and using a total station. The elevation value of the crash barrier is calculated based on the dimensions of the box girder.

[0012] Step 6: Place the measuring ruler on the top of the crash barrier, observe the measured value, and measure sequentially at certain intervals along the longitudinal direction of the crash barrier to ensure consistent elevation, thus completing the measurement.

[0013] In a further preferred technical solution, in step one, the rails include three rails: a first rail, a second rail, and a third rail, with the top surfaces of the three rails having the same elevation.

[0014] In a further preferred technical solution, the method for measuring the measuring platform in step three is as follows: according to the design requirements, two leveling points are set as measuring points to simulate the slope of the crash barrier on site. Based on the working principle of the level instrument's "horizontal line of sight", the height difference between the two points is measured, and the corresponding slope is released using the wedge-shaped steel plate of the auxiliary measuring device.

[0015] In a further preferred embodiment, the cross slope percentage is controlled between 1.5% and 3%.

[0016] In a further preferred technical solution, the elevation control method in step four is as follows:

[0017] Step 61: Set up the total station at the control point and calibrate the foresight and backsight points;

[0018] Step 62: For each box girder, take measurements at 2m intervals as detail points, set the point number and the height of the reflecting prism, aim at the center point of the prism on the centering rod of the detail point, record the three-dimensional coordinates of the point, and use the same method to measure the next detail point.

[0019] In a further preferred technical solution, in step five, the dimensions of the box girder include the center line HA of the bottom of the box girder measured by a measuring scale, and the distance L from the center of the beam surface to the inner side of the anti-collision wall mold; the elevation value of the anti-collision wall is the measured elevation HB of the prism on the top surface of the anti-collision wall support, which is calculated from the prism height h1, the inner mold top support height h2 obtained in step four, the design height h0 of the box girder, and the design height h of the inner side of the anti-collision wall.

[0020] The method for calculating the elevation HB of the top prism supporting the crash barrier is as follows:

[0021] HB = HA + h + h0 + h1 + h2 - L * percentage of cross slope.

[0022] A further optimized technical solution involves re-measuring the elevation of the crash barrier after the formwork is completed. If the actual height of the crash barrier differs from the designed height by more than 2mm after the re-measuring, the heights of the first and second wedge-shaped steel plates need to be readjusted until the error is within 2mm.

[0023] This invention discloses a method for measuring the elevation of an adjustable track-type box girder crash barrier. In bridge construction practice, this method has yielded the following beneficial effects:

[0024] (1) The present invention provides a method for measuring the elevation of an adjustable track-type box girder anti-collision wall. With the help of a steel rail platform, the measurement time of the box girder anti-collision wall elevation is saved and the work efficiency is improved. This device is easy to install, highly flexible, easy to operate and highly practical.

[0025] (2) The measurement process of the adjustable track box girder anti-collision wall of the present invention is simple. It does not require measuring the cross slope of the base of each anti-collision wall before measuring the elevation of the top surface. The measurement manpower cost is small and the efficiency is high.

[0026] (3) The present invention provides an auxiliary measuring device for the elevation of an adjustable track box girder anti-collision wall. The support mechanism can be adjusted according to the actual beam length and beam cross slope. It is highly versatile, easy to measure, and has the advantages of flexible disassembly and assembly and easy operation. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 A schematic diagram of the structure of an auxiliary measuring device for the elevation of an adjustable track-type box girder anti-collision wall.

[0029] Figure 2 A schematic diagram illustrating the measurement method for an adjustable track-type box girder anti-collision wall.

[0030] The labels in the diagram are as follows:

[0031] 11-First rail, 12-Second rail, 13-Third rail, 21-First wedge steel plate, 22-Second wedge steel plate, 3-Connecting reinforcing bar, 4-Steel plate, 5-Reinforcing rib plate, 6-Anti-tipping support frame, 7-Total station, 8-Inner formwork of anti-collision wall, 9-Outer formwork of anti-collision wall, A-Height of beam surface elevation point A, B-Height of beam surface elevation point B, a-Reading of beam surface elevation point A, b-Height of beam surface elevation point B, reading of beam surface elevation point B. Detailed Implementation

[0032] 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.

[0033] like Figure 1 As shown, an auxiliary measuring device for the elevation of an adjustable track-type box girder anti-collision wall includes adjustable box girder rails set on the measuring platform. The rails are arranged longitudinally at equal intervals along the length of the box girder as a first rail 11, a second rail 12, and a third rail 13 and anchored to the measuring platform. The top surfaces of the three rails have the same elevation.

[0034] A first wedge-shaped steel plate 21 and a second wedge-shaped steel plate 22, a connecting steel bar 3, a steel plate 4, and a reinforcing rib 5 are installed on the rail. The connecting steel bar 3 is installed on the second rail 12 and connects the first rail 11 and the third rail 13 laterally. The first rail 11 and the third rail 13 are respectively welded with the first wedge-shaped steel plate 21 and the second wedge-shaped steel plate 22. The steel plate 4 and the reinforcing rib 5 are welded together with the steel plate 4 on both sides of the bottom of the first wedge-shaped steel plate 21 and the second wedge-shaped steel plate 22. The anti-rollover support frame 6 is welded to the sides of the first wedge-shaped steel plate 21 and the second wedge-shaped steel plate 22, so that the anti-rollover support frame 6 is integrated with the first wedge-shaped steel plate 21 and the second wedge-shaped steel plate 22. The auxiliary measuring device for the elevation of the anti-collision wall is assembled. When the box girder is placed on the auxiliary measuring device, the center of the bottom support of the box girder is aligned with the second rail 12.

[0035] Before the box girder is lifted and placed on the measuring platform, the longitudinal length of the girder at the junction of the bottom and web is measured, the total length of the box girder bottom is determined, and the position of the center support at the bottom of the box girder is determined. Based on the longitudinal length of the support positions on both sides of the bottom of the box girder, the placement positions of the first wedge-shaped steel plate 21 and the second wedge-shaped steel plate 22 on the rails of the measuring platform are determined.

[0036] The first wedge-shaped steel plate 21 and the second wedge-shaped steel plate 22 are placed vertically on the rail. The measuring platform is controlled by a detector from one end of the first rail 11. According to the design position of the crash barrier, the inner and outer lines of the crash barrier are marked on the bridge surface and marked with ink lines. Two lines are required for each side of the crash barrier. The measuring platform is measured according to the design requirements. The adjustable first and second wedge-shaped steel plates are used to simulate the slope of the crash barrier on site. According to the working principle of the level instrument's "horizontal line of sight", the height difference between two points is measured to determine whether the corresponding cross slope has been measured. Let A and B be two leveling points, and a and b be the corresponding leveling readings. The height difference between points A and B is hAB = HB - HA = ba. To facilitate the measurement of the cross slope, we first level the four points of the construction platform of the crash barrier. The height of the steel plates is adjusted according to the measured height difference until the four points are on the same water surface.

[0037] The box girder is lifted and placed on the auxiliary measuring device. The bottom of the girder is positioned by sliding along the rails, ensuring the center of the support at the bottom of the box girder coincides with the center of the second rail 12. The elevation of the girder surface is controlled for each box girder with a crash barrier. The prism height h1 and the inner formwork top support height h2 are measured using a total station. The elevation control steps are as follows: The total station is placed at the control point, centered and leveled, and the elevation of the girder surface of each box girder with a crash barrier is measured. This facilitates adjustment of the crash barrier formwork to the appropriate height to ensure the overall height of the box girder and crash barrier meets design specifications. The specific steps are as follows:

[0038] (1) Setting up station information

[0039] Enter the station information input screen and input the detailed information for the station: point number, instrument height, point number code, and confirm. If the point information is already stored in the job creation, the system will automatically retrieve the point's coordinates and elevation. If the point is not set in the file, the screen will display the coordinates and elevation. At this point, input the above station information to complete the setup.

[0040] (2) Rear viewpoint information settings

[0041] Enter the rear viewpoint information input screen, enter the rear viewpoint number. If the information for that point already exists in memory, the screen will display the rear view azimuth. If the information for that point does not exist in the file, enter the rear viewpoint coordinates according to the on-screen prompts, then aim at the rear viewpoint target, and confirm to complete the rear viewpoint information setting.

[0042] After the viewpoint calibration is completed, the detail point measurement begins. When measuring the first point, the point number and reflecting prism height need to be set. Then, aim at the center point of the prism on the centering rod where the detail point is located, press the confirmation button to start the measurement, record the three-dimensional coordinates of the point, and use the same method to measure the next detail point. To ensure the appearance quality of the crash barrier after pouring, the detail points are denser during measurement, with one point every 2m for each box girder.

[0043] After the box girder is fixed, a measuring ruler is placed on the second rail 12 to measure the center line HA of the bottom of the box girder. The measuring elevation HB of the prism on the top surface of the crash barrier support is measured by a total station. Based on the design height h0 of the box girder, the design height h of the inner side of the crash barrier, the prism height h1, the inner formwork top support height h2, the measuring elevation HA of the bottom center line of the box girder, and the distance L from the center of the beam surface to the inner side of the crash barrier formwork, the measured elevation value of the crash barrier is calculated as follows: HB = HA + h + h0 + h1 + h2 - L * cross slope percentage, where the cross slope percentage is controlled between 1.5% and 3%.

[0044] Place the measuring ruler on top of the crash barrier, observe the measured value, and measure sequentially at certain intervals along the longitudinal direction of the crash barrier to ensure consistent elevation, thus completing the measurement.

[0045] After the formwork is completed, the elevation is re-measured. If the actual height of the crash barrier differs from the design height by more than 2mm, the formwork height needs to be readjusted until the error is within the design allowable range.

[0046] A method for measuring the elevation of an adjustable track-mounted box girder crash barrier, comprising the following steps:

[0047] Step 1: Before the box girder is lifted and placed on the measuring platform, the length of the girder is measured to determine the position of the bottom support of the girder. Based on the longitudinal length of the support positions on both sides of the bottom of the box girder, the placement positions of the first wedge steel plate 21 and the second wedge steel plate 22 on the rails of the measuring platform are determined.

[0048] Step 2: Place the auxiliary measuring device on the rail and measure from one end of the rail, ensuring that the measuring device is perpendicular to the rail;

[0049] Step 3: Lift and install the box girder onto the auxiliary measuring device, ensuring that the center of the bottom of the box girder is aligned with the center of the second rail 12;

[0050] Step 4: Place the measuring ruler on the second rail 12 and calculate the measured elevation value of the crash barrier based on the box girder dimensions;

[0051] Step 5: Place the measuring ruler on top of the crash barrier, observe the measured value, and measure sequentially at certain intervals along the longitudinal direction of the crash barrier to ensure consistent elevation, thus completing the measurement.

[0052] The present invention provides a method for measuring the elevation of an adjustable track box girder anti-collision wall. With the help of an auxiliary measuring device specifically designed for the elevation of adjustable track box girder anti-collision walls, the support mechanism can be adjusted according to the actual beam length and beam cross slope. This method is easy to install, highly flexible, simplifies the measurement process, saves measurement time for box girder anti-collision wall elevation, and improves work efficiency.

[0053] The above is merely one implementation of this invention. Other similar methods and structural substitutions can be made based on the same idea, and are not limited to the steps and structural components already described. In summary, the scope of protection of this invention also includes other variations and substitutions that are obvious to those skilled in the art.

Claims

1. A method for measuring the elevation of an adjustable track-type box girder crash barrier, characterized in that, The method includes the following steps: Step 1: Design an auxiliary measuring device for elevation measurement on the measuring platform. This auxiliary measuring device includes adjustable box girder rails set on the measuring platform. A first wedge-shaped steel plate (21), a second wedge-shaped steel plate (22), connecting steel bars (3), steel plates (4), and reinforcing ribs (5) are set on the rails. The rails are arranged longitudinally at equal intervals along the length of the box girder as a first rail (11), a second rail (12), and a third rail (13) and anchored on the measuring platform. The connecting steel bars (3) are set on the second rail (12) and laterally connect the first rail (11) and the third rail (13). The first wedge-shaped steel plate (21) and the second wedge-shaped steel plate (22) are integrally connected and placed on the first rail (11) and the third rail (13). The bottom of the first wedge-shaped steel plate (21) and the second wedge-shaped steel plate (22) are welded together with the steel plate (4) and the reinforcing rib plate (5) welded together with the steel plate (4). The sides of the first wedge-shaped steel plate (21) and the second wedge-shaped steel plate (22) are welded with anti-rollover support frame (6). The auxiliary measuring device for the elevation of the anti-collision wall is assembled. When the box girder is placed on the auxiliary measuring device, the center of the bottom support of the box girder is aligned with the second rail. Step 2: Lift the box girder and place it in front of the measuring platform, determine the support position at the bottom of the box girder, and determine the placement position of the first wedge steel plate (21) and the second wedge steel plate (22) on the rails based on the longitudinal length of the support positions on both sides of the bottom of the box girder. Step 3: The first wedge-shaped steel plate (21) and the second wedge-shaped steel plate (22) are placed vertically on the rail. The measuring platform is measured and the cross slope percentage is checked using a detector from one end of the first rail. Step 4: The box girder is lifted and placed on the auxiliary measuring device. The center support of the bottom of the box girder coincides with the center second rail (12) of the rail. The elevation of the beam surface of each box girder with anti-collision wall is controlled. The prism height h1 and the inner formwork top support height h2 are measured by total station. Step 5: After the box girder is fixed, a measuring ruler is placed on the second rail (12). The dimensions of the box girder are obtained by measuring the ruler and using a total station. The elevation value of the crash barrier is calculated based on the dimensions of the box girder. Step 6: Place the measuring ruler on the top of the crash barrier, observe the measured value, and measure sequentially at certain intervals along the longitudinal direction of the crash barrier to ensure consistent elevation, thus completing the measurement.

2. The method for measuring the elevation of an adjustable track box girder crash barrier according to claim 1, characterized in that, In step one, the rails include three rails: a first rail (11), a second rail (12), and a third rail (13), with the top surfaces of the three rails having the same elevation.

3. The method for measuring the elevation of an adjustable track box girder crash barrier according to claim 1, characterized in that, In step three, the method for measuring the measuring platform is as follows: according to the design requirements, two leveling points are set as measuring points to simulate the slope of the crash barrier on site. Based on the working principle of the level instrument's "horizontal line of sight", the height difference between the two points is measured, and the corresponding slope is released using the wedge-shaped steel plate of the auxiliary measuring device.

4. The method for measuring the elevation of an adjustable track-type box girder crash barrier according to claim 3, characterized in that, The cross slope percentage is controlled between 1.5% and 3%.

5. The method for measuring the elevation of an adjustable track-type box girder crash barrier according to claim 1, characterized in that, In step four, the method for elevation control is as follows: Step 61: Set up the total station at the control point and calibrate the foresight and backsight points; Step 62: For each box girder, take measurements at 2m intervals as detail points, set the point number and the height of the reflecting prism, aim at the center point of the prism on the centering rod of the detail point, record the three-dimensional coordinates of the point, and use the same method to measure the next detail point.

6. The method for measuring the elevation of an adjustable track box girder crash barrier according to claim 1, characterized in that, In step five, the dimensions of the box girder include the center line HA of the bottom of the box girder measured by a measuring scale, and the distance L from the center of the beam surface to the inner side of the anti-collision wall mold. The elevation value of the anti-collision wall is the measured elevation HB of the prism on the top surface of the anti-collision wall support, which is calculated from the prism height h1, the inner mold top support height h2 obtained in step four, the design height h0 of the box girder, and the design height h of the inner side of the anti-collision wall. The method for calculating the elevation HB of the top prism supporting the crash barrier is: HB = HA + h + h0 + h1 + h2 - L * cross slope percentage.

7. The method for measuring the elevation of an adjustable track box girder crash barrier according to claim 1, characterized in that, After the formwork of the crash barrier is completed, the elevation of the crash barrier is re-measured. If the actual height of the crash barrier is more than 2mm away from the design height after the re-measurement, the height of the first wedge steel plate (21) and the second wedge steel plate (22) need to be readjusted until the error is within 2mm.

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