A batch detection method for three-dimensional posture of embedded rod groups in arch abutments of large-span arch bridges

Abstract

The present invention discloses a batch detection method for the three-dimensional posture of the pre-embedded rod group of the arch seat of a large-span arch bridge, which relates to the field of bridge engineering technology. It includes selecting the main site and the auxiliary site based on the arch seat, setting up a measurement scanning device, constructing a central construction coordinate system for encryption processing, making the coordinates of all sites consistent with the same reference object, obtaining the transformation matrix K, obtaining the arch seat inclination, the coordinates of the plane center point and the horizontal distance based on the design drawings, generating the normal vector n1 and the upper and lower planes п1 and п2, intercepting the point cloud to fit two small cylinders, and correspondingly obtaining the upper and lower base points and the fitting diameter R of the small cylinder, and generating the rod space linear equation accordingly, making the actual diameter R' and the fitting diameter R for error comparison, and calculating the intersection of the planes п1 and п2 and the rod space linear equation if it is within the threshold range, obtaining the three-dimensional coordinates of the center of the upper and lower plane openings, and then converting them into two-dimensional coordinates to obtain the coordinates of the center of the pressure plate opening to determine the posture of the rod group. The present invention can achieve the effect of improving the opening accuracy of the pressure plate.

Description

Technical Field

[0001] The invention relates to the technical field of bridge engineering, and in particular to a method for batch detecting three-dimensional postures of pre-embedded rod groups of arch seats of large-span arch bridges. Background Art

[0002] Under the action of dead load and wind load, the chord of the arch foot section of the long-span arch bridge generates huge axial force and bending moment. Reasonable structural measures need to be set to ensure the reliability of force transmission. Generally, a fully pressure-bearing structure is adopted. A certain number of steel tie rods are embedded in the arch seat, and an anchor box with a pressure plate is set at the end of the arch foot chord (segment 0). When the segment is hoisted, the rod group needs to pass through all the reserved holes in the anchor box of segment 0. After the installation is completed, the first tensioning is carried out, and the second tensioning is carried out after the main arch ring is closed. Because the pressure plate needs to withstand huge axial pressure, the thickness is at least 15 cm. If the rod group and the hole do not match during on-site hoisting, it will not be able to be cut on site, and it needs to be returned to the factory for redoing, which consumes a lot of manpower and material resources. Therefore, how to obtain the three-dimensional posture of the embedded steel tie rods and then adjust the opening position of the pressure plate in time based on this has become a technical problem that needs to be solved urgently.

[0003] Therefore, it is an urgent problem for technical personnel in this field to propose a batch detection method for the three-dimensional posture of the embedded rod group of the arch seat of a large-span arch bridge to solve the problem that the existing technology cannot accurately obtain the opening position. Summary of the invention

[0004] In view of this, the present invention provides a method for batch detecting the three-dimensional posture of a pre-embedded rod group of an arch seat of a large-span arch bridge, which can achieve the effect of improving the opening accuracy of a pressure plate.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] A method for batch detecting three-dimensional postures of a large-span arch bridge arch seat embedded rod group comprises the following steps:

[0007] S1. Select the main site and sub-site based on the arch seat, set up the measurement and scanning device, build the central construction coordinate system, and encrypt the specific location;

[0008] S2, select the main site reference object and determine the coordinates, move and rotate other sites to make the coordinates of the same reference object consistent, obtain the transformation matrix K, repeat the operation to obtain the three-dimensional posture of the pole group with the coordinate information of the construction coordinate system;

[0009] S3, based on the design drawings, obtain the inclination angle of the arch seat, the coordinates of the plane center point and the horizontal distance, and obtain the normal vector n1 and the upper and lower planes п1 and п2 according to the geometric relationship;

[0010] S4, intercept the point cloud along the axial direction at the upper and lower planes п1 and п2 of the three-dimensional posture of the rod group obtained in S2, and fit the intercepted point cloud into two small cylinders; obtain the upper and lower base points and the fitting diameter R corresponding to the small cylinders, and obtain the straight line equation of the rod space;

[0011] S5. Take out the actual diameter R' of the pre-buried rod on site and compare the error with the fitted diameter R. When the error is within the threshold range, calculate the intersection of planes п1, п2 and the straight line equation of the rod space to obtain the three-dimensional coordinates of the center of the opening in the fitted upper and lower planes;

[0012] S6. Convert the three-dimensional coordinates of the center of the openings on the fitted upper and lower planes into two-dimensional coordinates to obtain the simulated coordinates of the center of the openings on the pressure plate, and compare them with the actual coordinates of the openings on the pressure plate to determine the position of the rod group.

[0013] The above method is optional, S1 includes: pasting no less than 3 black and white checkerboard targets on the front wall and side wall of the arch seat 1.5-2m above the ground, selecting 4 main sites and 4 secondary sites around the arch seat, and performing local encryption on the black and white checkerboard and pole group areas after the scanner scans.

[0014] In the above method, optionally, the reference objects selected in S2 include: the top surface and side surface of the abutment cap, the side surface of the junction pier and the fixed steel.

[0015] In the above method, optionally, the upper and lower planes п1 and п2 in S3 are obtained by: setting the vector n 1 Normalized, the expression is as follows:

[0016]

[0017] Among them, n 1 =(a 1 , 0, 1), β is the angle between the normal vector and the horizontal plane, and then the unit normal vector n is obtained 1 ', the point method is used to obtain the equation of the upper plane п1, and based on the fact that the upper and lower planes п1 and п2 are parallel and the distance between them is D, the equation of the lower plane п2 is obtained.

[0018] In the above method, optionally, the fitting of the rod space equation in S4 includes: obtaining the base point P1 (x 1 ,y 1 , z 1 ) and the base point P2(x 2 ,y 2 , z 2 ), we get the linear equation of the rod in space The rod space straight line corresponds one to one with the embedded rods.

[0019] In the above method, optionally, the error comparison in S5 includes: determining Is it true?

[0020] In the above method, optionally, the conversion of the three-dimensional coordinates into two-dimensional coordinates in S6 includes multiplying the three-dimensional coordinates with a matrix S, and the matrix S is expressed as follows:

[0021]

[0022] Among them, θ is the plane rotation angle, and the value is

[0023] It can be seen from the above technical solution that compared with the prior art, the present invention provides a method for batch detection of the three-dimensional posture of the embedded rod group of the arch seat of a large-span arch bridge. Compared with the traditional method of using a total station for discrete point measurement, the point cloud data of the embedded rod is more comprehensive, the opening accuracy of the pressure plate of the anchor box of section 0 is improved, the time required for measurement and the risk of returning to the factory for redoing are greatly reduced, and the economic benefits of construction are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0025] Figure 1 It is a flow chart of a method for batch detection of three-dimensional postures of pre-embedded rod groups in arch seats of a large-span arch bridge disclosed in the present invention;

[0026] Figure 2 This is a schematic diagram of the black and white grid target disclosed in the present invention;

[0027] Figure 3 It is a schematic diagram of the pre-embedded upper chord steel tie rod disclosed in the present invention;

[0028] Figure 4 It is a schematic diagram of point cloud processing disclosed in the present invention;

[0029] Figure 5 It is a schematic diagram of the rotation of the opening plane disclosed in the present invention;

[0030] Figure 6a A scan point cloud image of the main site disclosed in an embodiment of the present invention;

[0031] Figure 6b A point cloud image of a secondary site scan disclosed in an embodiment of the present invention;

[0032] Figure 7 The merged three-dimensional point cloud image disclosed in the embodiment of the present invention;

[0033] Figure 8 This is a schematic diagram of the opening of the anchor box pressure plate disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] In this application, relational terms such as first and second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. The terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of more restrictions, the elements defined by the sentence "comprise one..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0036] Reference Figure 1 As shown, the present invention discloses a method for batch detecting the three-dimensional posture of a group of pre-embedded rods in arch seats of a large-span arch bridge, comprising the following steps:

[0037] S1. Select the main site and sub-site based on the arch seat, set up the measurement and scanning device, build the central construction coordinate system, and encrypt the specific location;

[0038] S2, select the main site reference object and determine the coordinates, move and rotate other sites to make the coordinates of the same reference object consistent, obtain the transformation matrix K, repeat the operation to obtain the three-dimensional posture of the pole group with the coordinate information of the construction coordinate system;

[0039] S3, based on the design drawings, obtain the inclination angle of the arch seat, the coordinates of the plane center point and the horizontal distance, and obtain the normal vector n1 and the upper and lower planes п1 and п2 according to the geometric relationship;

[0040] S4, intercept the point cloud along the axial direction at the upper and lower planes п1 and п2 of the three-dimensional posture of the rod group obtained in S2, and fit the intercepted point cloud into two small cylinders; obtain the upper and lower base points and the fitting diameter R corresponding to the small cylinders, and obtain the straight line equation of the rod space;

[0041] S5. Take out the actual diameter R' of the pre-buried rod on site and compare the error with the fitted diameter R. When the error is within the threshold range, calculate the intersection of planes п1, п2 and the straight line equation of the rod space to obtain the three-dimensional coordinates of the center of the opening in the fitted upper and lower planes;

[0042] S6. Convert the three-dimensional coordinates of the center of the openings on the fitted upper and lower planes into two-dimensional coordinates to obtain the simulated coordinates of the center of the openings on the pressure plate, and compare them with the actual coordinates of the openings on the pressure plate to determine the position of the rod group.

[0043] Further, see Figure 2 As shown, S1 includes: pasting no less than 3 black and white checkerboard targets on the front wall and side wall of the arch seat at 1.5-2m from the ground, selecting 4 main sites and 4 auxiliary sites around the arch seat, and performing local encryption on the black and white checkerboard and pole group areas after the scanner scans.

[0044] Specifically, the black and white checkerboard targets are named Q1, Q2, and Q3, and their coordinates are: Q1(x Q1 ,y Q1 , z Q1 )、Q2(x Q2 ,y Q2 , z Q2 )、Q3(x Q3 ,y Q3 , z Q3 ), the main site layout requirement is that the distance to the scanned object is less than 50m and greater than 5m, the secondary site is less than 30m and greater than 5m from the scanned object, the scanner leveling requirement is that the error is no more than 5", the resolution is set to 3.1mm, the scanning angle α and range are set to cover all pole group areas, and the encryption value is 1.6mm.

[0045] Furthermore, the reference objects selected in S2 include: the top surface and side surface of the abutment, the side surface of the junction pier and the fixed steel.

[0046] Specifically, take the main site 1 as the reference site, and the reference coordinates are D 承顶主1 , D 承侧主1 , D 交侧主1 , D 型钢主1 By moving and rotating the same reference object in station 2, it can be aligned with D 承顶主1 , D 承侧主1 , D 交侧主1 , D 型钢主1 The same is obtained, thus obtaining the transformation matrix K = [dx, dy, dz, Rz]. All the point cloud data obtained by scanning at site 2 are then transformed by matrix K and unified with site 1 in the same coordinate system. Repeating this operation can make the scanned point clouds of all sites in the same coordinate system. The coordinates of targets Q1, Q2, and Q3 measured in step 1 are brought into the scanned point cloud to obtain a three-dimensional point cloud with coordinate information of the construction coordinate system.

[0047] Further, see Figure 3 As shown, the upper and lower planes п1 and п2 in S3 are obtained by: setting the vector n 1 Normalized, the expression is as follows:

[0048]

[0049] Among them, n 1 =(a 1 , 0, 1), β is the angle between the normal vector and the horizontal plane, and then the unit normal vector n is obtained 1 ', the point method is used to obtain the equation of the upper plane п1, and based on the fact that the upper and lower planes п1 and п2 are parallel and the distance between them is D, the equation of the lower plane п2 is obtained.

[0050] Specifically, due to We can get n 1 The three-dimensional coordinate expression of ' is:

[0051] The equation of plane п1 obtained by the point method is:

[0052] The simplified expression is as follows:

[0053] Therefore, the equation of the lower plane п2 is:

[0054]

[0055] Further, see Figure 4 As shown in the figure, the intercept length of the point cloud in S4 is 4 cm, and the base point P1 (x 1 ,y 1 , z 1 ) and the base point P2(x 2 ,y 2 , z 2 ), we get the linear equation of the rod in space The rod space straight line corresponds one to one with the embedded rods.

[0056] Furthermore, the error comparison in S5 includes: judging Is it true?

[0057] Further, see Figure 5 As shown, the conversion of the three-dimensional coordinates in S6 into two-dimensional coordinates includes multiplying the three-dimensional coordinates with the matrix S, and the matrix S is expressed as follows:

[0058]

[0059] Among them, θ is the plane rotation angle, and the value is

[0060] In a specific embodiment, the black and white checkerboard target data obtained according to S1 are Q1: (8285.712, 13.884, 474.629), Q2: (8284.582, -23.516, 474.840), Q3: (8267.886, -12.625, 492.2518), and the point cloud images scanned by the main site and the secondary site are as follows: Figure 6a and Figure 6b As shown, the three-dimensional point cloud obtained after S2 merging is as follows Figure 7 As shown, after step S3β=40.76, a 1 =0.861959, OP1: (8277.9361, 0, 488.427), D = 1.5, after unitization n 1 '=(0.757451,0,0.652892), we can get the plane equation п1: 0.757451·x+0.652892·z=6589.021, п2: 0.757451·x+0.652892·z=6590.521. In the example, there are 25 steel rods, so there are 25 straight line equations. This article only gives one example. The cylinder base point P1: (8866.2579,-9.2209,490.3352), P2: (8867.2277,-9.2249,489.4851), and the straight line equation is obtained The model calculated the simulated diameter R = 131.5mm, the measured diameter R' = 132.3mm, ε = 0.8mm < 3mm, and it is considered that the above steps are properly operated and the error is within the controllable range. The three-dimensional coordinates of the center of the upper and lower plane openings are calculated to be O1: (8278.162, 11.682, 490.462), O2: (8278.041, 10.806, 490.603), which are converted into two-dimensional coordinate data: O1': (6160.104, -9.224), O2': (6160.103, -9.618), and the final opening result is as follows Figure 8 shown.

[0061] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can refer to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system or system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can refer to the partial description of the method embodiment. The system and system embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without creative work.

[0062] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for batch detection of three-dimensional posture of pre-embedded rod groups of arch seats of large-span arch bridges, characterized in that: The following steps are involved: S1. Select the main site and sub-site based on the arch seat, set up the measurement and scanning device, build the central construction coordinate system, and encrypt the specific location; S2, select the main site reference object and determine the coordinates, move and rotate other sites to make the coordinates of the same reference object consistent, obtain the transformation matrix K, repeat the operation to obtain the three-dimensional posture of the pole group with the coordinate information of the construction coordinate system; S3, based on the design drawings, obtain the inclination angle of the arch seat, the coordinates of the plane center point and the horizontal distance, and obtain the normal vector n1 and the upper and lower planes п1 and п2 according to the geometric relationship; S4, intercept the point cloud along the axial direction at the upper and lower planes п1 and п2 of the three-dimensional posture of the rod group obtained in S2, and fit the intercepted point cloud into two small cylinders; obtain the upper and lower base points and the fitting diameter R corresponding to the small cylinders, and obtain the straight line equation of the rod space; S5. Take out the actual diameter R' of the pre-buried rod on site and compare the error with the fitted diameter R. When the error is within the threshold range, calculate the intersection of planes п1, п2 and the straight line equation of the rod space to obtain the three-dimensional coordinates of the center of the opening in the fitted upper and lower planes; S6. Convert the three-dimensional coordinates of the center of the openings on the fitted upper and lower planes into two-dimensional coordinates to obtain the simulated coordinates of the center of the openings on the pressure plate, and compare them with the actual coordinates of the openings on the pressure plate to determine the position of the rod group.

2. The method for batch detecting the three-dimensional posture of the pre-embedded rod group of the arch seat of a long-span arch bridge according to claim 1 is characterized in that: S1 specifically includes: sticking no less than 3 black and white checkerboard targets on the front wall and side wall of the arch 1.5-2m above the ground, selecting 4 main sites and 4 secondary sites around the arch, and performing local encryption on the black and white checkerboard and pole group areas after the scanner scans.

3. The method for batch detecting the three-dimensional posture of the pre-embedded rod group of the arch seat of a long-span arch bridge according to claim 1 is characterized in that: The reference objects selected in S2 include: the top surface and side surface of the abutment, the side surface of the junction pier and the fixed steel.

4. The method for batch detecting the three-dimensional posture of the pre-embedded rod group of the arch seat of a long-span arch bridge according to claim 1 is characterized in that: The upper and lower planes п1 and п2 in S3 are obtained by normalizing the vector n1, and the expression is as follows: Where n1 = (a1, 0, 1), β is the angle between the normal vector and the horizontal plane, and then we get the unit normal vector n1'. The point method is used to obtain the equation of the upper plane п1. Based on the fact that the upper and lower planes п1 and п2 are parallel and the distance between them is D, we get the equation of the lower plane п2.

5. The method for batch detecting the three-dimensional posture of the pre-embedded rod group of the arch seat of a long-span arch bridge according to claim 1 is characterized in that: The fitting of the rod space equation in S4 includes: obtaining the upper base point P1 (x1, y1, z1) of cylinder 1 at the upper plane of the rod and the lower base point P2 (x2, y2, z2) of cylinder 2 at the lower plane, and obtaining the rod space straight line equation The rod space straight line corresponds one to one with the embedded rods.

6. The method for batch detecting the three-dimensional posture of the pre-embedded rod group of the arch seat of a long-span arch bridge according to claim 1 is characterized in that: Error comparison in S5 includes: Is it true? 7. The method for batch detecting the three-dimensional posture of the pre-embedded rod group of the arch seat of a long-span arch bridge according to claim 4 is characterized in that: The conversion of the three-dimensional coordinates into two-dimensional coordinates in S6 includes multiplying the three-dimensional coordinates by the matrix S. The matrix S is expressed as follows: Among them, θ is the plane rotation angle, and the value is

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