A Stability Analysis Method for Control Points in a Tunnel

Abstract

This invention relates to a stability analysis method for control points within a tunnel in the field of tunnel surveying technology, comprising the following steps: S1, establishing a traverse control network and a leveling network within the tunnel, and re-measuring the control points; S2, selecting a traverse point as the analysis point, comparing the two sets of horizontal angle data obtained after the re-measuring, and determining whether they meet the standards; S3, establishing a deviation constraint system for adjacent control points, including standards for side length difference, elevation difference, and relative accuracy standards for coordinate difference; S4, using two adjacent control points as two target points, comparing the deviation constraint system of these three control points pairwise, and comprehensively considering the judgment of horizontal angle difference, to determine the stability of the analysis point; this method can comprehensively analyze from multiple aspects, improving the accuracy of stability judgment.

Description

Technical Field

[0001] This invention relates to the field of tunnel measurement technology, and in particular to a method for stability analysis of control points within a tunnel. Background Technology

[0002] As is well known, in tunnel construction, traverse points, also called control points or benchmarks, and their control network and leveling network are two important measurement systems. Their function is to ensure that the tunnel construction and design meet the predetermined specifications and requirements. The leveling network is a measurement network used to control the tunnel elevation, while the control network is a geometric measurement network constructed through a series of measurement benchmarks. It is mainly used to determine the horizontal position and direction of the tunnel. If the control points are unstable, it may lead to measurement errors, which in turn affect the direction of tunnel excavation, causing the tunnel trajectory to deviate from the predetermined design, thus affecting the entire construction process. Therefore, only when the control points inside the tunnel remain stable can the measurement work be more efficient and accurate, thereby reducing the number of repeated checks and corrections and ensuring that the construction progress is not affected. For example, Chinese invention patent with announcement number CN111693021B discloses a method for checking traverse points inside a tunnel, which mainly uses adjustment calculations to determine whether the coordinates of the traverse points meet the requirements. The judgment method is relatively simple, the correction of measurement errors is limited, it is difficult to handle large-scale errors, and it cannot detect deviations in the construction process in a timely manner. Summary of the Invention

[0003] In order to overcome the shortcomings of the prior art and solve the existing technical problems, this invention discloses a stability analysis method for control points in tunnels, which can comprehensively analyze from multiple aspects and improve the accuracy of stability judgment.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A stability analysis method for control points within a tunnel includes the following steps: S1. Establishing a traverse control network and a leveling network within the tunnel, and re-measuring the control points to obtain two sets of side length data and two sets of elevation data between any two adjacent control points, two sets of three-dimensional coordinate data for any control point, and two sets of horizontal angle data with any control point as a corner point; S2. Selecting a control point as the analysis point, and using the two adjacent control points as the foresight and backsight points respectively, comparing the two sets of horizontal angle data obtained after re-measuring to obtain the horizontal angle difference, and determining whether the horizontal angle difference meets the standard; S3. Establishing a deviation constraint system between adjacent control points, including the side length difference standard. The standards for relative accuracy of elevation difference and coordinate difference are as follows: The side length difference standard involves comparing two sets of side length data obtained after remeasurement between two control points to obtain the side length difference, determining whether this difference meets the specified standard, and using the average of the two sets of side length data as the side length S of the two target points; the elevation difference standard involves comparing two sets of elevation data obtained after remeasurement between two control points to obtain the elevation difference, and determining whether this difference meets the specified standard; the relative accuracy standard for coordinate difference involves obtaining the three-dimensional coordinate increments ΔX, ΔY, and ΔZ of each control point after remeasurement of the three-dimensional coordinates of two control points, and calculating the relative accuracy of the coordinate difference between the two control points. , where △X ij, △Y ij, The difference in two-dimensional coordinate increments between adjacent target points i and j, ΔZ ij S4. The difference between the Z-direction coordinate increments of adjacent target points i and j; determine whether the relative accuracy of the coordinate difference meets the standard; S5. Take the two control points adjacent to the analysis point as two target points, compare the deviation constraint system of the three control points pairwise, and combine the judgment of the difference in horizontal angle to obtain the stability of the analysis point.

[0006] Furthermore, in S4, if the analysis point exceeds the limit with both target points but is within the limit with both target points, then the analysis point is an unstable point; if the analysis point is within the limit with one target point but exceeds the limit with the other target point, then the analysis point is a point to be observed; if the analysis point is within the limit with both target points, then the analysis point is a stable point.

[0007] Furthermore, the tunnel's conductor control network has two rows of control points.

[0008] Furthermore, the side length S is 200–500 m.

[0009] Furthermore, the standard for horizontal angle error is no more than 3″; the standard for side length error is no more than 2mD=2(a+bD), in mm, where a is the fixed error in the nominal accuracy of total station distance measurement, in mm, b is the proportional coefficient in the nominal accuracy of total station distance measurement, in mm / km, and D is the distance measurement length, in km; the standard for elevation error is... The unit is mm; the relative accuracy standard for the difference in coordinates is no more than 1 / 50000.

[0010] Furthermore, the re-measurement equipment includes a total station, a prism, and a level.

[0011] By employing the technical solution described above, the present invention has the following beneficial effects:

[0012] The stability analysis method for control points in tunnels disclosed in this invention comprehensively judges the stability of control points by re-measuring control points in the tunnel control network and leveling network, utilizing the relative accuracy of differences in horizontal angles, side lengths, elevations, and coordinates, as well as the deviation relationship with adjacent control points. This makes the analysis more comprehensive and the judgment more accurate. In particular, the method of judging the relative accuracy of coordinate differences has a significantly improved correction capability compared to traditional adjustment calculation methods. More importantly, it can accurately reflect the individual changes of each control point, facilitating timely adoption of targeted corrective measures. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the conductor control network inside the tunnel. Detailed Implementation

[0014] The technical solution of the present invention will now be described with reference to the accompanying drawings in the embodiments of the present invention.

[0015] Combined with appendix Figure 1 The stability analysis method for control points within the tunnel includes the following steps:

[0016] Step 1: Establish the traverse control network and leveling network within the tunnel, and re-measure the control points. This will yield two sets of side length data and two sets of elevation data between any two adjacent control points, two sets of three-dimensional coordinate data for any control point, and two sets of horizontal angle data with any control point as the corner point. As needed, the traverse control network within the tunnel has two rows of control points, as shown in the attached diagram. Figure 1 As shown, it is capable of symmetrical measurement. When re-measuring, a total station and a prism are generally used, and a level is used to assist in elevation measurement.

[0017] Step 2: Select a control point as the analysis point. Using the two adjacent control points as the foresight and backsight points respectively, compare the two sets of horizontal angle data obtained after the remeasurement to obtain the horizontal angle difference. Determine whether this horizontal angle difference meets the standard; see attached. Figure 1 As shown, assuming the analysis point is point B, the foresight point and the backsight point are points A and C respectively, the difference in horizontal angles is the difference between the two ∠ABC. The standard for the difference in horizontal angles is not more than 3″. If it is met, it is considered qualified; otherwise, it is considered unqualified.

[0018] Step 3: Establish a deviation limitation system for adjacent control points, including standards for side length difference, elevation difference, and relative accuracy standards for coordinate difference.

[0019] The side length difference standard is obtained by comparing two sets of side length data obtained after remeasurement between two control points. The side length difference standard is not more than 2mD=2(a+bD), in mm, where a is the fixed error in the nominal accuracy of total station ranging, in mm, b is the proportional coefficient in the nominal accuracy of total station ranging, in mm / km, and D is the distance measured, in km. It is then determined whether the side length difference meets the limit standard, and the average of the two sets of side length data is taken as the side length S of the two target points. The side length S is generally 200-500m.

[0020] The elevation difference standard is obtained by comparing two sets of elevation data obtained after re-measuring two control points. The elevation difference standard is as follows: The unit is mm. That is, when D is 1km, the value of D is taken as 1, and it is determined whether the elevation difference meets the limiting standard.

[0021] The relative accuracy standard for the difference in coordinates is based on the fact that after re-measuring the three-dimensional coordinates of two control points, the three-dimensional coordinate increments ΔX, ΔY, and ΔZ of each control point can be obtained, and the relative accuracy of the difference in coordinates between the two control points can be calculated.

[0022]

[0023] Wherein, △X ij, △Y ij, The difference in two-dimensional coordinate increments between adjacent control points i and j, in meters, is ΔZ. ij The difference in Z-direction coordinate increments between adjacent target points i and j is expressed in meters. The relative accuracy of the coordinate difference is judged to meet the standard, which is no more than 1 / 50000.

[0024] Step 4: Using the two control points adjacent to the analysis point as two target points, compare the deviation constraint system of these three control points pairwise, and combine the judgment of the horizontal angle difference to determine the stability of the analysis point. That is, even if the horizontal angle difference of the analysis point meets the standard, it is still necessary to continue the analysis and judgment of the deviation constraint system. For the three points A, B, and C, pairwise comparison analysis needs to be performed on each of the three standards: the side length difference standard, the elevation difference standard, and the relative accuracy standard of the coordinate difference difference. If the analysis point B exceeds the limit with both target points A and C, it does not meet the standard, while the two target points AC meet the limit, it proves that the analysis point B exceeds the limit with both target points A and C. If only point B moves, then analysis point B is an unstable point under this standard. If analysis point B is within limits with one target point A but exceeds limits with another target point C, then analysis point B is an observation point, and its condition needs to be determined based on the situation between the two target points A and C. Point C will then be used as the analysis point for further analysis. If analysis point B is within limits with both target points A and C, then analysis point B is a stable point under this standard. It should be noted that when performing pairwise comparisons, points A and C cannot be directly measured. Instead, they can be indirectly determined by first measuring A and B1, then measuring B1 and C, to determine whether points A and C exceed limits or are within limits under each standard.

[0025] The comprehensive analysis is more thorough and the judgment is more accurate. In particular, the method for judging the relative accuracy of coordinate differences has a significantly improved correction capability compared to the traditional adjustment calculation method. More importantly, it can accurately reflect the individual changes of each traverse point, which facilitates timely adoption of targeted corrective measures.

[0026] The parts of this invention not described in detail are prior art. It will be apparent to those skilled in the art that this invention is not limited to the details of the above exemplary embodiments, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the above embodiments should be regarded as exemplary and non-limiting in all respects. The scope of this invention is defined by the appended claims rather than the foregoing description. Therefore, it is intended to include all changes that fall within the meaning and scope of the equivalents of the claims within this invention, and no reference numerals in the claims should be regarded as limiting the content of the claims.

Claims

1. A stability analysis method for control points within a tunnel, characterized by: Includes the following steps: S1. Establish a traverse control network and a leveling network inside the tunnel, and re-measure the control points to obtain two sets of side length data and two sets of elevation data between any two adjacent control points, two sets of three-dimensional coordinate data of any control point, and two sets of horizontal angle data with any control point as the corner point. S2. Select a control point as the analysis point, and take the two control points adjacent to the analysis point as the foresight point and the backsight point, respectively. Compare the two sets of horizontal angle data obtained after the remeasurement to obtain the horizontal angle difference, and determine whether the horizontal angle difference meets the standard. S3. Establish a deviation limit system for two adjacent control points, including the standard for side length difference, the standard for elevation difference, and the relative accuracy standard for the difference in coordinates. The side length difference standard is to compare the two sets of side length data obtained after remeasurement between two control points to obtain the side length difference, determine whether the side length difference meets the limit standard, and take the average of the two sets of side length data as the side length S of the two target points. The elevation difference standard is to compare two sets of elevation data obtained after re-measurement between two control points to obtain the elevation difference, and then determine whether the elevation difference meets the specified standard. The relative accuracy standard for the difference in coordinates is based on the fact that after re-measuring the three-dimensional coordinates of two control points, the three-dimensional coordinate increments ΔX, ΔY, and ΔZ of each control point can be obtained, and the relative accuracy of the difference in coordinates between the two control points can be calculated. , where △X ij, △Y ij, △Z is the difference in the two-dimensional coordinate increments between adjacent control points i and j. ij The difference in Z-direction coordinate increments between adjacent control points i and j; determine whether the relative accuracy of the coordinate difference meets the specified standard; S4. Using two control points adjacent to the analysis point as two target points, compare the deviation limits of these three control points pairwise, and combine the judgment of the difference in horizontal angle to determine the stability of the analysis point. If the analysis point exceeds the limit with both target points, but is within the limit with both target points, then the analysis point is an unstable point. If the analysis point is within the limit with one target point, but exceeds the limit with the other target point, then the analysis point is a point to be observed. If the analysis point is within the limit with both target points, then the analysis point is a stable point.

2. The stability analysis method for control points within a tunnel according to claim 1, characterized in that: The tunnel's internal traverse control network has two rows of control points.

3. The stability analysis method for control points within a tunnel according to claim 1, characterized in that: The side length S is 200-500m.

4. The stability analysis method for control points within a tunnel according to claim 1, characterized in that: The standard for horizontal angle error is no more than 3″; the standard for side length error is no more than 2(a+bD), in mm, where a is the fixed error in the nominal accuracy of total station distance measurement, in mm, b is the proportional coefficient in the nominal accuracy of total station distance measurement, in mm / km, and D is the distance measurement length, in km; the standard for elevation error is... The unit is mm; the relative accuracy standard for the difference in coordinates is no more than 1 / 50000.

5. The stability analysis method for control points within a tunnel according to claim 1, characterized in that: The equipment used for the re-measurement includes a total station, a prism, and a level.

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