A measuring method for a prestressed anchoring system of a four-main-cable system

Abstract

This invention discloses a measurement method for a four-main-cable prestressed anchorage system, comprising the following steps: establishing working benchmarks based on the actual site environment to form an independent control network for the anchorage system; calculating the positioning coordinates of the anchorage system and converting all coordinate systems into bridge site construction coordinates; simultaneously developing calculation programs for the rear anchor surface and piers; calculating the design plane coordinates using measured elevations; and completing the positioning support installation measurement and pier construction measurement work using a Leica TS60 total station with a three-dimensional coordinate method. Anchorage duct positioning rulers and anchorage duct calibrators are used for anchorage duct positioning and extension measurements. Cable saddle installation is completed by accurately setting out the baseline using a total station and measuring the inclination angle using a high-precision inclination sensor. This method effectively solves the problems of complex structure, high calculation difficulty, large measurement workload, and high measurement accuracy in a four-main-cable prestressed anchorage system.

Description

Technical Field

[0001] This invention relates to the field of construction measurement technology for gravity anchorages of suspension bridges, and in particular to a measurement method for a four-main-cable prestressed anchorage system. Background Technology

[0002] The Yanji Yangtze River Bridge is a four-main-cable steel truss suspension bridge with a main span of 1860m and different sags. The anchorage is equipped with four anchor chambers in total, at the front, rear, left, and right. The piers and anchor blocks form a closed space.

[0003] The anchoring system is a prestressed anchoring system, consisting of cable strand anchoring connection structures and prestressed anchoring structures. There are two types of cable strand anchoring connection structures: single-strand anchoring connection structures and double-strand anchoring connection structures. The single-strand anchoring connection structure consists of two tie rods, a single-strand connecting plate, and a connecting cylinder. The double-strand anchoring connection structure consists of four tie rods, a double-strand connecting plate, and a connecting cylinder.

[0004] The Huanggang side anchorage system consists of 100 single-strand anchors and 384 double-strand anchors. The design drawings require an allowable error of 10mm for the anchor groove, ±5mm for the center coordinates of the anchorage duct, and ±0.10° for the angle of the anchorage duct. The positioning and measurement work for the four-main-cable prestressed anchorage system is extensive and requires high accuracy.

[0005] The anchoring system is a three-dimensional spatial anchoring system with a complex structure. The positioning and measurement of the anchoring system involves the transformation of four coordinate systems: the 2000 National Geodetic Coordinate System, the independent coordinate system of the bridge site construction, the independent coordinate system of the anchoring system, and the independent coordinate system of the slot. The calculation of the anchoring system is also complex. Summary of the Invention

[0006] The purpose of this invention is to provide a measurement method for a four-main-cable prestressed anchorage system, which can effectively solve the measurement and positioning problem of a four-main-cable prestressed anchorage system.

[0007] The objective of this invention is achieved as follows:

[0008] A measurement method for a four-main-cable prestressed anchorage system, characterized by the following steps:

[0009] S1: Based on the control points of the pile intersection and the surrounding conditions of the anchoring system, five working base points in the form of forced centering piers are set up around the anchoring system.

[0010] S2: Anchoring system calculation and coordinate system transformation: Determine the direction of each axis of the four coordinate systems, calculate the coordinates of the anchoring duct at the front and rear anchor surfaces in the independent coordinate system of the anchoring system, calculate the coordinates of each slot in the independent coordinate system of the slot, and convert the 2000 National Geodetic Coordinate System, the independent coordinate system of the anchoring system and the independent coordinate system of the slot into the independent coordinate system of the bridge site construction.

[0011] S3: Installation measurement and deformation observation of positioning bracket: The installation angle of the positioning bracket and the deformation observation of the positioning bracket were carried out using the three-dimensional coordinate method of Leica TS60 total station;

[0012] S4: Compile a program to calculate the alignment of the rear anchor face and install the rear anchor face: Compile a program to calculate the relationship between the height of the rear anchor face and the mileage alignment based on the design drawings, and adjust the installation angle of the rear anchor face on site according to the measured elevation;

[0013] S5: On the installed anchor face template, use the three-dimensional coordinate method of Leica TS60 total station to lay out the center of the anchor hole, and install the slot template according to the center of the anchor hole.

[0014] S6: Use an anchoring hole positioning ruler to measure the positioning and extension of the anchoring hole, and use an anchoring hole calibrator for verification;

[0015] S7: Anchor plate positioning measurement of the front anchor surface of the anchoring system: Calculate the three-dimensional coordinates of the top and bottom openings of the front anchor surface, adjust the installation angle of the front anchor surface using the three-dimensional coordinate method of a Leica TS60 total station to meet the specification requirements, and fix it.

[0016] S8: The construction survey of the piers was carried out using the three-dimensional coordinate method with a Leica TS60 total station: the pier alignment was calculated according to the design drawings and an alignment program was compiled, and the design plane coordinates were calculated according to the measured elevation.

[0017] S9: Precise positioning of the cable saddle: The baseline is precisely laid out using the three-dimensional coordinate method of a Leica TS60 total station, and the inclination angle of the cable saddle is measured using a high-precision tilt sensor.

[0018] Based on the above technical solution, in step S1, the plane coordinates of the working base points deployed around the anchoring system are observed using the static Global Navigation Satellite System (GNSS) method, and the elevation of the working base points is observed using the second-order geometric leveling method.

[0019] Based on the above technical solution, in step S1, the three control points and five working base points around the anchoring system form an independent control network for the anchoring system.

[0020] Based on the above technical solution, step S2 includes four coordinate systems: the 2000 National Geodetic Coordinate System, the Bridge Site Construction Independent Coordinate System, the Anchorage System Independent Coordinate System, and the Groove Independent Coordinate System. The Bridge Site Construction Independent Coordinate System uses the design line station mileage as the X-axis and the horizontal and vertical offsets of the design line as the Y-axis. The Anchorage System Independent Coordinate System uses the four anchorage system IP points as the origin, and the line connecting the IP point and the center point of the rear anchor surface as the X-axis direction. The coordinate system conforms to the right-hand screw rule, with the right thumb pointing in the X-axis direction, the index finger pointing in the positive Y-axis direction, and the middle finger pointing in the positive Z-axis direction. The Groove Independent Coordinate System uses the center of each groove as the origin, and the direction definition of each axis is consistent with that of the Anchorage System Independent Coordinate System.

[0021] Based on the above technical solution, in step S2, the three-dimensional coordinates of the anchoring ducts on the front and rear anchor surfaces are calculated in the independent coordinate system of the anchoring system. The plane coordinates of the reference surface of the cable saddle and the reference surface of the rear anchor surface are calculated according to the distribution of each anchoring duct on the cable saddle and the rear anchor surface. The coordinates of the reference surface of the cable saddle and the reference surface of the rear anchor surface are rotated to calculate the rotation angle of each anchoring duct. Based on the calculated rotation angle, the plane coordinates of each anchoring duct on the cable saddle surface and the rear anchor surface are calculated.

[0022] Based on the above technical solution, in step S2, the 2000 National Geodetic Coordinate System is converted into the bridge site construction independent coordinate system. First, a conversion line is established that coincides with the anchorage design axis. The direction of each axis in the conversion line is consistent with the bridge site construction independent coordinate system and extended. At the same time, the coordinates of the 2000 National Geodetic Coordinate System are matched. According to the conversion line, the geodetic coordinates of the control points and working base points are converted into the bridge site construction independent coordinate system.

[0023] Based on the above technical solution, in step S2, the independent coordinate system of the anchoring system is transformed into the independent coordinate system of the bridge site construction through three-dimensional geometric rotation in space.

[0024] Based on the above technical solution, in step S2, the independent coordinate system of the slot is translated into the independent coordinate system of the anchoring system, and then into the independent coordinate system of the bridge site construction.

[0025] Based on the above technical solution, in step S6, an anchoring hole positioning ruler is installed on the positioning bracket. The anchoring hole positioning ruler is used to measure the position of each anchoring hole on the positioning bracket according to the relative spatial relationship of the anchoring holes. A limiting plate is welded according to the anchoring hole positioning ruler. After the limiting plate is installed, the anchoring hole is hoisted to fit the anchoring hole with the limiting plate. An anchoring hole calibrator is installed in the anchoring hole. The center coordinates of the anchoring hole are observed using the three-dimensional coordinate method of a Leica TS60 total station. The deviation value is calculated. If the deviation meets the specification limit, welding reinforcement is performed. Otherwise, the deviation value is readjusted until the specification limit is met.

[0026] Based on the above technical solution, in step S9, the installation coordinates of the cable saddle are accurately located using the three-dimensional coordinate method of the Leica TS60 total station, the elevation coordinates of the cable saddle are determined using the trigonometric elevation difference method of the Leica TS60 total station, and the inclination angle of the cable saddle is measured using a high-precision tilt sensor.

[0027] This invention establishes an independent control network for the anchoring system by setting up working benchmarks and control points in the form of forced centering piers around the anchoring system. Based on the defined directions and rotation angles of each axis of the independent coordinate system of the anchoring system on the design drawings, the three-dimensional coordinates of the anchoring ducts on the front and rear anchor surfaces are calculated. Similarly, based on the defined directions and rotation angles of each axis of the slot independent coordinate system on the design drawings, the three-dimensional coordinates of the slot are calculated. The 2000 National Geodetic Coordinate System is converted to a bridge site construction independent coordinate system using the transformation line method. The independent coordinate system of the anchoring system is then converted to a bridge site construction independent coordinate system using the spatial three-dimensional geometry method. Finally, the independent coordinate system of the slot is first converted to the independent coordinate system of the anchoring system using the translation method, and then converted to the bridge site construction independent coordinate system.

[0028] This invention uses an anchorage positioning ruler and an anchorage calibrator to position the anchorage. After the positioning bracket is installed, the assembled anchorage positioning ruler is adjusted on the positioning bracket. The center of the anchorage positioning ruler is observed using a Leica TS60 total station, and the center of the anchorage positioning ruler is adjusted to the center of the anchorage to be positioned. A limiting plate is welded according to the structural dimensions of the anchorage to be positioned. The limiting plates of adjacent anchorages are welded according to the spatial relationship between the positioned anchorage and adjacent anchorages until the limiting plates of all anchorages are welded. After the limiting plates of the anchorages are welded, the anchorages are hoisted and adjusted to be in close contact with the limiting plates using a hand-operated hoist. After the anchorages are adjusted, the anchorage calibrator is installed at the top of the anchorage. The center coordinates of the anchorages are observed using the three-dimensional coordinate method with a Leica TS60 total station. If the deviation value meets the specification limit, welding reinforcement is performed; otherwise, the adjustment is readjusted according to the deviation value until the specification limit is met.

[0029] The present invention has the following advantages:

[0030] 1. By setting up forced centering pier-style working benchmarks around the anchoring system, an independent control network for the anchoring system is established, eliminating systematic errors in the measurement of the anchoring system.

[0031] 2. All four coordinate systems were converted to an independent coordinate system for bridge site construction, which unified the measurement benchmark and made it more convenient;

[0032] 3. By observing the deformation of the positioning bracket, the deformation pattern of the positioning bracket is understood to correct the anchoring channel to be positioned, thus ensuring the straightness of the anchoring channel.

[0033] 4. An anchoring hole positioning rulers are used to achieve batch positioning of anchoring holes, and anchoring hole calibrators are used to verify and ensure the high efficiency and accuracy of anchoring hole positioning.

[0034] This invention can effectively solve the problems of complex structure, high calculation difficulty, large measurement workload and high measurement accuracy of the four main cable system prestressed anchorage system. Attached Figure Description

[0035] Figure 1 A flowchart of a measurement method for a four-main-cable prestressed anchorage system;

[0036] Figure 2 This is a layout diagram of the independent control network of the anchoring system in an embodiment of the present invention;

[0037] Figure 3 This is a schematic diagram of the structure of the anchoring hole positioning ruler in an embodiment of the present invention;

[0038] Figure 4 This is a schematic diagram of the main scale structure of the anchoring hole positioning ruler in an embodiment of the present invention;

[0039] Figure 5 This is a schematic diagram of the left ruler structure of the anchoring hole positioning ruler in an embodiment of the present invention;

[0040] Figure 6 This is a schematic diagram of the right ruler structure of the anchoring hole positioning ruler in an embodiment of the present invention;

[0041] Figure 7 This is a schematic diagram illustrating the application of the anchoring hole positioning ruler in an embodiment of the present invention;

[0042] Figure 8 This is a schematic diagram of the anchoring hole calibrator in an embodiment of the present invention. Detailed Implementation

[0043] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0044] Figure 1 A flowchart of a measurement method for a four-main-cable prestressed anchorage system is shown below. Figure 1 As shown, this embodiment of the invention provides a measurement method for a four-main-cable prestressed anchorage system, comprising the following steps:

[0045] S1: Based on the control points of the pile intersection and the surrounding conditions of the anchoring system, five working base points in the form of forced centering piers are set up around the anchoring system.

[0046] The plane coordinates of the working base points set up around the anchoring system were observed using the static GNSS method, and the elevation of the working base points was observed using the second-order geometric leveling method.

[0047] Figure 2 This is a layout diagram of the independent control network for the anchoring system. The independent control network for the anchoring system consists of 3 control points and 5 working base points around the anchoring system.

[0048] S2: Anchoring System Calculation and Coordinate System Transformation: Determine the direction of each axis in the four coordinate systems, calculate the coordinates of the anchoring duct at the front and rear anchor surfaces in the independent coordinate system of the anchoring system, calculate the coordinates of each slot in the independent coordinate system of the slot, and convert the 2000 National Geodetic Coordinate System, the independent coordinate system of the anchoring system, and the independent coordinate system of the slot into the independent coordinate system of the bridge site construction.

[0049] The plane coordinate system of the anchoring system design drawings adopts the 2000 National Geodetic Coordinate System, and the elevation system adopts the 1985 National Elevation Datum.

[0050] The independent coordinate system for bridge site construction uses the mileage station of the horizontal curve of the design line as the X-axis, the horizontal and vertical deviation of the design line as the Y-axis, and the Z-axis represents the 1985 National Elevation Datum.

[0051] The independent coordinate system of the anchoring system takes the four anchoring system IP points as the origin, and the line connecting the center point of the IP point and the reference plane of the rear anchor surface as the X-axis direction. The coordinate system conforms to the right-hand screw rule, with the right thumb pointing to the X-axis direction, the index finger pointing to the positive Y-axis direction, and the middle finger pointing to the positive Z-axis direction.

[0052] The independent coordinate system for each slot has its origin at the center of each slot, and the definition of each axis is consistent with that of the anchoring system coordinate system.

[0053] In the independent coordinate system of the anchoring system, the three-dimensional coordinates of the anchoring ducts on the front and rear anchor surfaces are calculated. Based on the distribution of each anchoring duct on the cable saddle and rear anchor surface, the planar coordinates of the reference surface of the cable saddle and the reference surface of the rear anchor surface are calculated. The coordinates of the reference surface of the cable saddle and the reference surface of the rear anchor surface are rotated to calculate the rotation angle of each anchoring duct. Based on the calculated rotation angle, the surface coordinates of each anchoring duct on the cable saddle surface and the rear anchor surface are calculated.

[0054] To convert the 2000 National Geodetic Coordinate System into an independent coordinate system for bridge site construction, a conversion line coinciding with the anchorage design axis is first established. The directions of each axis in this conversion line are consistent with and extended in the independent coordinate system for bridge site construction. At the same time, the coordinates of the 2000 National Geodetic Coordinate System are matched. Based on the conversion line, the geodetic coordinates of the control points and working base points are converted into the independent coordinate system for bridge site construction.

[0055] The independent coordinate system of the anchoring system is transformed into an independent coordinate system for bridge site construction through three-dimensional geometric rotation in space.

[0056] The coordinate system of the slot is translated into an independent coordinate system of the anchoring system, and then into an independent coordinate system of the bridge site construction.

[0057] S3: Installation measurement and deformation observation of positioning bracket: The installation angle of the positioning bracket and the deformation observation of the positioning bracket were carried out using the three-dimensional coordinate method of Leica TS60 total station.

[0058] After the upper anchor block foundation reinforcement is tied, the position of the bracket embedded part is laid out on the top surface of the reinforcement using the three-dimensional coordinate method of Leica TS60 total station and the embedded iron plate is welded.

[0059] After the upper anchor block foundation is poured, the laitance on the embedded iron plate is cleaned, and the corner points of the support legs are laid out again using the three-dimensional coordinate method of Leica TS60 total station.

[0060] During the installation of the positioning bracket, the three-dimensional coordinates of the top and bottom openings of the positioning bracket are observed to calculate the installation angle of the positioning bracket. The positioning bracket is adjusted until the installation angle meets the specification tolerance requirements and the cross-section of the positioning bracket is perpendicular to the center line of the main cable. After the adjustment is completed, the positioning bracket is added to fix the positioning bracket.

[0061] The deformation results at the top observation point of the rear support are mainly used as the basis for correcting the deformation of the rear anchor beam, while the deformation results at the top observation point of the front support are mainly used as the basis for correcting the deformation of the upper anchor rod.

[0062] The deformation observation points of the positioning bracket are continuously observed at various time periods to obtain the initial state observation values, calculate the displacement of the observation points, and correct any point on the rear anchor beam to ensure the correct position of the rear anchor beam under the design temperature state.

[0063] S4: Compile a program to calculate the alignment of the rear anchor face and install the rear anchor face: Compile a program to calculate the relationship between the height of the rear anchor face and the mileage alignment based on the design drawings, and adjust the installation angle of the rear anchor face on site according to the measured elevation.

[0064] Based on the design drawings of the rear anchor surface, a linear relationship between the elevation and mileage of the rear anchor surface was established, and a calculation program was developed in the CASIO 5800P calculator. The elevation of the points to be measured on the rear anchor surface was observed using the three-dimensional coordinate method with a Leica TS60 total station. The measured elevation was input into the CASIO 5800P calculator, and the program was run to obtain the design mileage corresponding to the measured elevation. The difference between the measured mileage and the design mileage was compared to adjust the height of the rear anchor surface support until the angle and line of the rear anchor surface were consistent with the design.

[0065] S5: On the installed anchor face template, use a Leica TS60 total station to lay out the center of the anchor hole using the three-dimensional coordinate method, and install the slot template according to the center of the anchor hole.

[0066] After the rear anchor surface is installed, re-observe the rear anchor surface to ensure that the rear anchor surface line is accurate. Use a Leica TS60 total station to lay out the center point of the anchoring hole on the rear anchor surface using the three-dimensional coordinate method. Then, based on the center of the anchoring hole laid out on the rear anchor surface, pop out the longitudinal and transverse axes.

[0067] Install the slot template according to the longitudinal and transverse axes of the anchoring hole center on the rear anchor surface. After the slot template is installed, use a Leica TS60 total station to observe the center coordinates of the slot using the three-dimensional coordinate method. The center coordinate deviation of the slot should not be greater than 5mm. Otherwise, the slot template should be readjusted until it meets the specification requirements.

[0068] S6: Use an anchoring hole positioning ruler to measure the positioning and extension of the anchoring hole, and use an anchoring hole calibrator for verification.

[0069] Figure 3 This is a schematic diagram of the structure of the anchoring hole positioning ruler in an embodiment of the present invention. Figure 3 As shown, the components are: positioning bracket 1, limiting plate 3, main ruler 4, left ruler 5, right ruler 6, magnetic vertical ruler 7, vertical ruler extension end 8, anchoring channel 9, and connecting hole 10.

[0070] Figure 4 This is a schematic diagram of the main scale of the anchoring hole positioning ruler in an embodiment of the present invention. Figure 4 As shown, the main ruler 4 is a magnetic steel ruler with a length of 150cm, a width of 5cm, and a thickness of 3cm. The main ruler 4 is marked with graduation lines, with the zero mark in the middle of the main ruler 4. The graduations increase towards both ends, with the smallest graduation value being 1mm. There are four connecting holes 10 at the left and right ends of the main ruler 4, which are respectively connected to the left ruler 5 and the right ruler 6. A magnetic vertical ruler 7 is installed at the zero mark of the main ruler 4.

[0071] Figure 5 This is a schematic diagram of the left ruler structure of the anchoring hole positioning ruler in an embodiment of the present invention. Figure 5 As shown, the left ruler 5 is a magnetic steel ruler with a length of 150cm, a width of 4.9cm, and a thickness of 2.9cm. The left ruler 5 is marked with graduation lines, which increase from right to left. The measurement range is from 70cm to 220cm, and the smallest graduation value is 1mm. There are four 10 connecting holes on the right end of the left ruler 5, which connect to the left end of the main ruler 4. The left ruler 5 is equipped with a magnetic vertical ruler 7, which can slide on the left ruler 5. The magnetic vertical ruler 7 is provided with four connecting holes 10, and the extended end 8 of the vertical ruler is connected to the left ruler 5 through the connecting holes 10.

[0072] Figure 6 This is a schematic diagram of the right ruler of the anchoring hole positioning ruler in an embodiment of the present invention. Figure 6As shown, the right ruler 6 is a magnetic steel ruler with a length of 150cm, a width of 4.9cm, and a thickness of 2.9cm. The right ruler 6 is marked with graduation lines, which increase from left to right. The measurement range is from 70cm to 220cm, and the smallest graduation value is 1mm. There are four connecting holes 10 on the left end of the right ruler 6, which connect to the right end of the main ruler 4. A magnetic vertical ruler 7 is attached to the right ruler 6. The magnetic vertical ruler 7 can slide on the right ruler 6. There are four connecting holes 10 on the magnetic vertical ruler 7. The extended end 8 of the vertical ruler is connected to the right ruler 6 through the connecting holes 10.

[0073] Figure 7 This is a schematic diagram illustrating the application of the anchoring hole positioning ruler in an embodiment of the present invention. Figure 7 As shown, after the positioning bracket is installed, the anchoring hole positioning ruler 2 is installed at the bottom of the positioning bracket 1. The center of the main scale 4 of the anchoring hole positioning ruler 2 is observed using the three-dimensional coordinate method of Leica TS60 total station and adjusted to the center of the anchoring hole 9 to be positioned. According to the structural dimensions of the anchoring hole 9 to be positioned, the limiting plate 3 is welded at the left and right scales of the main scale 4 of the anchoring hole positioning ruler 2, which are the radii of the anchoring hole 9 to be positioned. The limiting plate 3 is welded at the lower end of the magnetic vertical ruler 7 of the main scale 4 of the anchoring hole positioning ruler 2.

[0074] Install the anchoring hole positioning ruler 2 horizontally, calculate the relative relationship between the anchoring holes 9 on the left and right sides of the already positioned anchoring hole 9, and slide the magnetic vertical rulers 7 on the left ruler 5 and right ruler 6 according to the relative relationship. After the magnetic vertical rulers 7 are slid into place, according to the structural dimensions of the anchoring hole 9 to be positioned, weld the limiting plates 3 at the left and right scales of the left ruler 5 and right ruler 6 of the anchoring hole positioning ruler 2, which are the radii of the anchoring hole 9 to be positioned. Weld the limiting plates 3 at the lower ends of the magnetic vertical rulers 7 on the left ruler 5 and right ruler 6 of the anchoring hole positioning ruler 2.

[0075] After the limiting plate 3 at the bottom of the positioning bracket 1 is welded, the anchoring hole positioning ruler 2 is installed on the top of the positioning bracket 1 and the limiting plate 3 is welded in the same way. The anchoring hole 9 is hoisted according to the position of the limiting plate 3. The installation of the anchoring hole 9 is completed by the fine adjustment device. The anchoring hole calibrator is installed on the top of the anchoring hole 9. The anchoring hole calibrator can quickly and accurately locate the center of the anchoring hole 9. The three-dimensional coordinates on the prism on the anchoring hole calibrator are observed using the three-dimensional coordinate method of the Leica TS60 total station to obtain the three-dimensional coordinates on the center extension line of the anchoring hole 9. According to the difference between the design coordinates and the measured coordinates corresponding to this elevation, if the difference is greater than 5mm, it needs to be readjusted.

[0076] The steps for extending and positioning the anchoring duct 9 are the same as the installation and positioning methods.

[0077] S7: Anchor plate positioning measurement of the front anchor surface of the anchoring system: Calculate the three-dimensional coordinates of the top and bottom openings of the front anchor surface, adjust the installation angle of the front anchor surface using the three-dimensional coordinate method with a Leica TS60 total station to meet the specification requirements, and then fix it.

[0078] After the front anchor plate is processed, measurement feature points are made at the center of the top opening and the center of the bottom opening respectively. The installation angle of the front anchor plate is calculated based on the three-dimensional coordinates of the top and bottom openings of the front anchor plate. If the installation angle does not meet the requirements, the front anchor plate is readjusted.

[0079] S8: The construction survey of the piers was carried out using the three-dimensional coordinate method with a Leica TS60 total station: the alignment of the piers was calculated according to the design drawings and the alignment program was compiled, and the design plane coordinates were calculated according to the measured elevation.

[0080] Based on the pier design drawings, a linear relationship between the pier's elevation and mileage was established, and a calculation program was developed in the CASIO 5800P calculator. The elevation of the pier's test point was observed using the three-dimensional coordinate method with a Leica TS60 total station. The measured elevation was input into the CASIO 5800P calculator, and the program was run to obtain the design mileage corresponding to the measured elevation of the pier. The difference between the measured mileage and the design mileage was compared to adjust the pier's support height until the pier's formwork installation angle was consistent with the design.

[0081] S9: Precise positioning of the cable saddle: The baseline is precisely laid out using the three-dimensional coordinate method of a Leica TS60 total station, and the inclination angle of the cable saddle is measured using a high-precision tilt sensor.

[0082] The installation coordinates of the cable saddle were accurately located using the three-dimensional coordinate method with a Leica TS60 total station, and the elevation coordinates of the cable saddle were determined using the trigonometric leveling difference method with the Leica TS60 total station. A high-precision tilt sensor was used to measure the tilt angle of the cable saddle, measuring the biaxial tilt angle change with the horizontal plane as a reference surface.

[0083] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of the invention. All equivalent structural changes made based on the description and drawings of the present invention are included within the scope of the present invention.

Claims

1. A measurement method for a four-main-cable prestressed anchorage system, characterized in that: Includes the following steps: S1: Based on the control points of the pile intersection and the surrounding conditions of the anchoring system, five working base points in the form of forced centering piers are set up around the anchoring system. S2: Anchoring system calculation and coordinate system transformation: Determine the direction of each axis of the four coordinate systems, calculate the coordinates of the anchoring duct at the front and rear anchor surfaces in the independent coordinate system of the anchoring system, calculate the coordinates of each slot in the independent coordinate system of the slot, and convert the 2000 National Geodetic Coordinate System, the independent coordinate system of the anchoring system and the independent coordinate system of the slot into the independent coordinate system of the bridge site construction. S3: Installation measurement and deformation observation of positioning bracket: The installation angle of the positioning bracket and the deformation observation of the positioning bracket were carried out using the three-dimensional coordinate method of Leica TS60 total station; S4: Compile a program to calculate the alignment of the rear anchor face and install the rear anchor face: Compile a program to calculate the relationship between the height of the rear anchor face and the mileage alignment based on the design drawings, and adjust the installation angle of the rear anchor face on site according to the measured elevation; S5: On the installed anchor face template, use the three-dimensional coordinate method of Leica TS60 total station to lay out the center of the anchor hole, and install the slot template according to the center of the anchor hole. S6: Use an anchoring hole positioning ruler to measure the positioning and extension of the anchoring hole, and use an anchoring hole calibrator for verification; S7: Anchor plate positioning measurement of the front anchor surface of the anchoring system: Calculate the three-dimensional coordinates of the top and bottom openings of the front anchor surface, adjust the installation angle of the front anchor surface using the three-dimensional coordinate method of a Leica TS60 total station to meet the specification requirements, and fix it. S8: The construction survey of the piers was carried out using the three-dimensional coordinate method with a Leica TS60 total station: the pier alignment was calculated according to the design drawings and an alignment program was compiled, and the design plane coordinates were calculated according to the measured elevation. S9: Precise positioning of the cable saddle: The baseline is precisely laid out using the three-dimensional coordinate method of a Leica TS60 total station, and the inclination angle of the cable saddle is measured using a high-precision tilt sensor.

2. The measurement method for the four-main-cable prestressed anchorage system according to claim 1, characterized in that: In step S1, the plane coordinates of the working base points set up around the anchoring system are observed using the static Global Navigation Satellite System method, and the elevation of the working base points is observed using the second-order geometric leveling method.

3. The measurement method for the four-main-cable prestressed anchorage system according to claim 1, characterized in that: In step S1, the three control points and five working base points around the anchoring system form an independent control network for the anchoring system.

4. The measurement method for the four-main-cable prestressed anchorage system according to claim 1, characterized in that: Step S2 includes four coordinate systems: the 2000 National Geodetic Coordinate System, the Bridge Site Construction Independent Coordinate System, the Anchorage System Independent Coordinate System, and the Groove Independent Coordinate System. The Bridge Site Construction Independent Coordinate System uses the design line station mileage as the X-axis and the horizontal and vertical offsets of the design line as the Y-axis. The Anchorage System Independent Coordinate System uses the four anchorage system IP points as the origin, with the line connecting the IP point and the center point of the rear anchor surface as the X-axis direction. The coordinate system conforms to the right-hand screw rule, with the right thumb pointing in the X-axis direction, the index finger pointing in the positive Y-axis direction, and the middle finger pointing in the positive Z-axis direction. The Groove Independent Coordinate System uses the center of each groove as the origin, and the definition of each axis is consistent with that of the Anchorage System Independent Coordinate System.

5. The measurement method for the prestressed anchorage system of the four main cable system according to claim 1, characterized in that: In step S2, the three-dimensional coordinates of the anchoring ducts on the front and rear anchor surfaces are calculated in the independent coordinate system of the anchoring system. Based on the distribution of each anchoring duct on the cable saddle and rear anchor surface, the planar coordinates of the reference surface of the cable saddle and the coordinates of the reference surface of the rear anchor surface are calculated. The coordinates of the reference surface of the cable saddle and the reference surface of the rear anchor surface are rotated to calculate the rotation angle of each anchoring duct. Based on the calculated rotation angle, the surface coordinates of each anchoring duct on the cable saddle surface and the rear anchor surface are calculated.

6. The measurement method for the prestressed anchorage system of the four main cable system according to claim 1, characterized in that: In step S2, the 2000 National Geodetic Coordinate System is converted into the bridge site construction independent coordinate system. First, a conversion line is established that coincides with the anchorage design axis. The direction of each axis in the conversion line is consistent with the bridge site construction independent coordinate system and extended. At the same time, the coordinates of the 2000 National Geodetic Coordinate System are matched. According to the conversion line, the geodetic coordinates of the control points and working base points are converted into the bridge site construction independent coordinate system.

7. The measurement method for the prestressed anchorage system of the four main cable system according to claim 1, characterized in that: In step S2, the independent coordinate system of the anchoring system is transformed into the independent coordinate system of the bridge site construction through three-dimensional geometric rotation in space.

8. The measurement method for the prestressed anchorage system of the four main cable system according to claim 1, characterized in that: In step S2, the independent coordinate system of the slot is translated into the independent coordinate system of the anchoring system, and then into the independent coordinate system of the bridge site construction.

9. The measurement method for the prestressed anchorage system of the four main cable system according to claim 1, characterized in that: In step S6, an anchoring hole positioning ruler is installed on the positioning bracket. Using the anchoring hole positioning ruler, the position of each anchoring hole is measured on the positioning bracket according to the relative spatial relationship of the anchoring holes. A limiting plate is welded according to the anchoring hole positioning ruler. After the limiting plate is installed, the anchoring hole is hoisted to fit the anchoring hole with the limiting plate. An anchoring hole calibrator is installed on the anchoring hole. The center coordinates of the anchoring hole are observed using the three-dimensional coordinate method of a Leica TS60 total station. The deviation value is calculated. If the deviation meets the specification limit, welding reinforcement is performed. Otherwise, the adjustment is readjusted according to the deviation value until the specification limit is met.

10. The measurement method for the prestressed anchorage system of the four main cable system according to claim 1, characterized in that: In step S9, the installation coordinates of the cable saddle are accurately located using the three-dimensional coordinate method of a Leica TS60 total station, the elevation coordinates of the cable saddle are determined using the trigonometric elevation difference method of a Leica TS60 total station, and the inclination angle of the cable saddle is measured using a high-precision tilt sensor.

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