Measuring method of interval common point type double support wire net chain applied to shield tunnel

Abstract

The application discloses a kind of interval common point type double-branch guide line network chain measurement methods applied to shield tunnel, including step one, according to tunneling progress, according to design requirement, interval common point type double-branch guide line network chain is laid in hole;Step two, according to double-branch guide line network chain layout progress, guide line network chain section closed loop is divided, and the whole closed loop measurement path of guide line network chain is defined;Step three, intermediate station outside extension measurement and office calculation;Step four, when shield tunneling distance through face is set distance, double-branch guide line network chain whole closed measurement and office calculation;Step five, industry checking and calculating increase common reference point round trip measurement path plane coordinate result difference test.The application guarantees the precision of survey control guide line network, and to a certain extent, reduces the interference influence of related construction and measurement operation activities caused by limited space conditions, improves the efficient applicability, high-precision guarantee and low-cost saving of guide line network in long-distance, small-diameter shield tunnel.

Description

Measurement method for interval common-point double-branch traverse network chain applied to shield tunnels Technical Field

[0001] This invention relates to the field of measurement technology. More specifically, this invention relates to a measurement method for a spaced, common-point, double-branch traverse network applied to shield tunnels. Background Technology

[0002] With the ever-expanding scale of urban construction in China, the planning and construction of underground pipeline projects in the past can no longer meet the needs of contemporary urban development. As a result, urban underground utility tunnel projects have emerged in tandem with the planning and construction of urban underground rail transit projects, jointly forming a blueprint for underground engineering that serves the needs of modern urban development.

[0003] The second phase of a power tunnel project is an underground utility tunnel project with a construction length of approximately 2.1 km. The tunnel cross-section is circular with an inner diameter of 3.6 m (outer diameter of 4.1 m). Compared with underground urban rail transit projects, the tunnel cross-section of underground utility tunnel projects is smaller, resulting in poor visibility for underground surveying. Currently, the commonly used traditional network layout methods are double-branch traverse chains and branch traverse networks. The traditional double-branch traverse network layout method is difficult to avoid providing reliable spatial conditions for underground shield tunneling operations; the traditional branch traverse network layout method is more suitable for small-diameter shield tunnel structures, but its measurement accuracy cannot meet the requirements for long-distance shield tunnel construction.

[0004] A comprehensive predictive analysis of the implementation effects of traditional double-traverse and branch-traverse networks in the corresponding power tunnel engineering section 2 project reveals that neither of these traditional network layout methods can effectively address the spatial constraints and accuracy assurance issues encountered in the underground precision traverse layout and measurement of this project. To ensure the accuracy of the measurement control traverse network for long-distance, small-diameter shield tunnels, while simultaneously reducing the mutual interference between measurement and construction operations, this application presents a measurement method for a spaced, common-point double-branch-traverse network chain applied to long-distance, small-diameter shield tunnels. Summary of the Invention

[0005] One objective of this invention is to provide a measurement method for a spaced, common-point, double-branch traverse network chain applied to shield tunnels. This method combines the advantages of two traditional traverse networks and complements their shortcomings. While ensuring the accuracy of the measurement and control traverse network, it also reduces the interference between related construction and measurement operations caused by spatial constraints to a certain extent. This improves the efficiency, applicability, accuracy, and cost-effectiveness of the traverse network in long-distance, small-diameter shield tunnels.

[0006] To address the aforementioned technical problems, this invention provides a measurement method for a spaced, common-point, double-branch traverse network applied to shield tunnels, comprising the following steps:

[0007] Step 1: Based on the tunnel excavation progress, lay out the intermittent double-branch conductor network inside the tunnel according to the design requirements;

[0008] Step 2: Based on the deployment progress of the double-branch traverse network, divide the traverse network section closed loop and clarify the measurement path of the overall traverse network closed loop;

[0009] Step 3: Extended field surveying and office calculations at intermediate transfer stations;

[0010] Step 4: When the shield tunneling is at the set distance from the breakthrough face, perform overall closure measurement and office calculation of the double-branch traverse network;

[0011] Step 5: Industry verification includes checking the difference in the planar coordinate results of the round trip measurement path from the common benchmark point to control the accuracy of the connection.

[0012] Preferably, in step one, starting from the initial control point of the launching shaft, the tunnel boring machine (TBM) enters the tunnel from one side wall of the tunnel section according to the location of the initial control point and lays out a double-branch traverse network. Following the principle of first laying out synchronous double reference points on one side wall and then laying out common reference points on the other side wall, the TBM extends sequentially within the set control range of the traverse side lengths. The length of each side of the double-branch traverse network is 60~150m, and the ratio of adjacent side lengths is not greater than 2. The spacing between the synchronous double reference points is 1~3m according to the design requirements. The last point of the double-branch traverse network is laid out as a common reference point, within the set distance between the TBM tunneling and the breakthrough face.

[0013] Preferably, in step two, each pair of adjacent common reference points and synchronous double reference points form a local traverse network closed loop; according to the tunnel excavation direction, the synchronous double reference point closer to the large mileage direction is defined as reference point b, and the corresponding other is reference point a. The overall closed loop forward measurement path is formed by the starting control point, the adjacent reference point b, the adjacent common reference point, the next reference point b, the next common reference point, ... until the last common reference point; the overall closed loop return measurement path is formed by the last common reference point, the adjacent reference point a, the adjacent common reference point, the next reference point a, the next common reference point, ... until the starting control point; the round trip measurement path constitutes the overall closed loop measurement path of the double-branch traverse network.

[0014] Preferably, in step three, the intermediate station transfer extension measurement is carried out independently according to the closed loop of the local traverse network chain of the section, and the measurement is extended forward loop by loop, and the office calculation work is completed independently for the closed loop of the local traverse network chain of the section.

[0015] Preferably, when the station change control point is a synchronous double reference point, double traverse control measurement observation is carried out according to the measurement specifications corresponding to the traverse method; when the station change control point is a common reference point, closed traverse control measurement observation is carried out according to the measurement specifications corresponding to the double traverse method based on the local closed loop measurement path of the section.

[0016] Preferably, the closed-circuit distance verification and adjustment are the same as the traditional indoor calculations for double-traverse networks, and the azimuth angle verification and adjustment are specifically as follows:

[0017] First, based on the equal diagonal angles of the two diagonal triangles formed by the closed loop of the section, the actual angle values ​​measured in the field are checked, and the difference between the sums of the angles of the two triangles in the closed loop of the section is calculated. This difference is the azimuth closure difference Δi of the closed loop of the section. According to the standard formula... (seconds) Verify whether the angle closure difference Δi meets the specification requirements, where n is the number of angles of the conductor;

[0018] Secondly, the correction and adjustment of the azimuth angle are calculated. When △i=0, the correction △i'=0; when △i>0 or △i<0, the correction △i'=△i / n. The measured angle is adjusted to form the correction angle.

[0019] Preferably, in step four, the field closure measurement of the double-branch traverse network chain is carried out according to the relevant measurement specifications for double-traverse networks. The field closure angle measurement includes: the azimuth angle of the right wall includes the angle between the two traverse networks at all b reference points; the azimuth angle of the left wall includes the angle between all common reference points and two adjacent b reference points; the azimuth angle of the end of the measurement is the angle between the last common reference point and the adjacent a and b reference points; the azimuth angle of the right wall back measurement includes the angle between the two traverse networks at all a reference points; the azimuth angle of the left wall back measurement includes the angle between all common reference points and two adjacent a reference points; the azimuth angle of the closure end of the back measurement is the angle between the starting control point and the adjacent a and b reference points.

[0020] Preferably, the method for calculating the internal structure of the double-branch conductor network in step four includes:

[0021] First, based on the relationship of multiple diagonal triangles formed by the double-branch wire network chain, multiple common reference points are used as corner points to form angular relationships, and multiple formulas are transformed to form angular equation relationships;

[0022] Secondly, based on the indoor calculation method in step three, taking each closed loop as the basic unit, the angle equation relationship is transformed again to form the transformed equation relationship of all angles included in the outdoor closed angle measurement in step four.

[0023] Furthermore, after optimizing the definition of the azimuth angle in the deformed equation relationship, an optimized equation relationship is formed regarding the redefined variables;

[0024] Then, based on the optimized equation relationship, the actual angle values ​​of the field closure measurement are checked, and the overall azimuth closure difference ΔI of the double-branch traverse network is calculated according to the standard formula. (seconds) Verify whether the angle closure difference △I meets the specification requirements, where N is the number of angles of the conductor;

[0025] Finally, the overall azimuth correction is calculated and adjusted. When △I = 0, the correction △I' = 0; when △I > 0 or △I < 0, the correction △I' = △I / N. The correction angle is formed by adjusting each back-measured angle, forward-measured angle, azimuth of the back-measured closed end, and azimuth of the forward-measured head.

[0026] Preferably, in step five, the testing method is as follows:

[0027] First, calculate the difference in the planar coordinates of the round-trip measurement path from the common benchmark point;

[0028] Secondly, calculate the total length of the traverse wire for the local closed loop on both sides of the common reference point;

[0029] Next, the difference in the planar coordinates of the round-trip measurement path of the common benchmark point is checked according to the "relative closure error of the whole length" of the local closed loop of the related section to determine whether it is qualified.

[0030] Finally, all common reference points are inspected according to the above steps. If all inspections are qualified, it can be determined that the accuracy of the double-branch traverse network control network meets the set third-order accuracy requirements.

[0031] The present invention has at least the following beneficial effects:

[0032] 1. The measurement method of the interval common point double branch traverse network chain applied to shield tunnels in this application has closed adjustment constraints compared with traditional branch traverse, which improves the measurement control accuracy of the traverse network and can be applied to long-distance shield tunnel construction measurement.

[0033] 2. The measurement method of the interval common point double-branch traverse network chain applied to shield tunnels in this application optimizes the number of traverse network control points and the transmission path compared with the traditional double traverse network. It not only saves the cost of traverse network control point layout, but also effectively reduces the mutual interference between construction and measurement operations in small-diameter shield tunnels, and improves the operability of traverse network layout and measurement.

[0034] 3. The measurement method of the interval common point double-branch traverse network chain applied to shield tunnels proposed in this application is a method of sharing a reference point for the interval measurement path of closed measurement. Therefore, the internal verification can add a constraint condition for the difference of coordinate results of the measurement path of the common reference point, and provide multi-dimensional guarantee measures for the control of the accuracy of internal calculation.

[0035] 4. The measurement method of this application for the interval common-point double-branch traverse network chain applied to shield tunnels effectively combines the advantages of traditional double traverse networks and branch traverse networks, complementing the shortcomings of both traditional traverse network applications. Traverse measurement at intermediate stations can be advanced ring by ring according to the segmented interval traverse network chain; for the first 150m of the tunnel, the entire double-branch traverse network chain is used for closed traverse measurement. This flexible network layout and measurement mode effectively improves the efficiency of traverse measurement operations, saving valuable time for controlling the progress, quality, and safety of shield tunneling.

[0036] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0037] Figure 1 is a schematic diagram showing the division of the closed loop in the double-branch conductor network and the clear measurement path of the overall closed loop.

[0038] Figure 2 is a schematic diagram of the extended measurement and data processing analysis of intermediate transfer stations;

[0039] Figure 3 is a schematic diagram of the overall closure measurement and indoor calculation analysis of the double-branch conductor network;

[0040] Figure 4 is a schematic diagram of the verification and analysis of the difference between the coordinate results of the round-trip measurement path of the common benchmark point.

[0041] In the diagram: K1 and K2: Starting control points of the launching shaft; Z1, Z2, Zn: Common reference points; Y1, Y2, Yn: Synchronous dual reference points; O1, O2, On: Diagonal points of the triangular network diagram of the closed loop of the interval segment; ∠Y1-b, ∠Y2-b, ∠Yn-b: Azimuth angles of the right side wall of the shield tunnel; ∠Z1-1, ∠Z2-1: Azimuth angles of the left side wall of the shield tunnel; ∠Zn: Azimuth angle of the end of the forward measurement; ∠Y1-a, ∠Y2-a, ∠Yn-a: Azimuth angles of the right side wall of the shield tunnel; ∠Z1-2, ∠Z2-2: Azimuth angles of the left side wall of the shield tunnel; ∠K1: Azimuth angle of the closed end of the forward measurement; △D1, △D2: Difference values ​​between the calculated coordinates of the forward and backward measurement paths of the common reference points. Detailed Implementation

[0042] To better understand the purpose, structure, and function of this invention, the invention will be further described in detail below with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0043] It should be noted that, unless otherwise specified, the experimental methods described in the following embodiments are all conventional methods, and the reagents and materials described are all commercially available unless otherwise specified. In the description of this invention, the terms "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0044] To address the challenges of spatial constraints and ensuring control accuracy in long-distance, small-diameter shield tunnel applications using traditional double-traverse traverse networks and single-traverse traverse networks, the specific difficulties are as follows: Double-traverse traverse networks offer advantages such as high control accuracy, but their numerous and densely packed traverse points occupy a significant portion of the tunnel's operational space, increasing interference with other construction activities. They are generally more suitable for shield tunnels with long distances and large diameters. Single-traverse traverse networks, lacking self-closing mechanisms, suffer from lower measurement and control accuracy. However, they have fewer traverse points and flexible deployment, minimizing interference with other construction activities within the shield tunnel. They are generally more suitable for shield tunnels with short distances and small diameters. To combine the advantages of two traditional traverse networks and complement their shortcomings, while ensuring the accuracy of the measurement and control traverse network and reducing the interference between related construction and measurement activities caused by spatial constraints, this invention provides a measurement method for a spaced, common-point, double-branch traverse network chain applied to long-distance, small-diameter shield tunnels, thereby addressing the deficiencies of existing technologies.

[0045] This application discloses a measurement method for a spaced, common-point, double-branch traverse network chain applied to long-distance, small-diameter shield tunnels. The specific operation steps are as follows:

[0046] Measurement preparation → Based on the tunnel boring machine (TBM) progress, lay out the intermittent double-branch traverse network in the tunnel as required → Based on the double-branch traverse network layout progress, divide the traverse network section closed loop and clarify the measurement path of the overall closed loop of the traverse network → Field extension measurement and office calculation at intermediate stations → When the TBM is 150m away from the breakthrough face, perform overall closed measurement and office calculation of the double-branch traverse network → Verify the difference between the coordinate results of the round trip measurement path of the common benchmark point.

[0047] Starting from the initial control point of the launching shaft, the tunnel boring machine (TBM) enters the tunnel from one side wall and lays out a double-branch traverse network, based on the location of the starting point. Following the principle of first laying out synchronous double reference points on one side wall and then common reference points on the other side wall, the network extends sequentially within a range of 60-150m in length. This double-branch traverse network essentially consists of two branch traverses. The overall double-branch traverse network follows the same path, sharing a reference point intermittently. Non-shared reference points are laid out synchronously on the same tunnel side wall at intervals of 1-3m. Each pair of adjacent common reference points and synchronous double reference points forms a local closed loop of the traverse network. The final point of the double-branch traverse network is laid out as a common reference point, within 150m of the tunnel boring machine's progress from the breakthrough face. The mid-term station transfer extension measurement and internal calculation are controlled by extending the local closed loop of the double-branch traverse network chain. When the shield tunneling is 150m away from the breakthrough face, the overall control of the double-branch traverse network chain closure measurement and internal calculation is carried out. The internal verification also includes the comparison of the coordinate results of the round trip measurement path of the common benchmark point to ensure the breakthrough accuracy control of the last 150m shield tunnel excavation.

[0048] As shown in Figures 1 to 4, the present invention provides a measurement method for a spaced, common-point, double-branch conductor network chain applied to shield tunnels, which specifically includes the following steps.

[0049] Step 1: Measurement Preparation

[0050] The preparatory work mainly includes the requirements for instrumentation, personnel allocation, and the installation of traverse control points. Instrumentation requirements: one precision total station, two sets of ordinary prisms and bases, and one tripod; Personnel requirements: one operator and two target setters; Traverse control point installation: The traverse control points will be installed using wall-mounted forced centering brackets, which can be fixed to the shield tunneling shaft wall and tunnel segment walls using expansion bolts.

[0051] Step 2: Based on the tunnel excavation progress, install the intermittent, double-branch conductor network inside the tunnel as required.

[0052] The starting control points in the launching shaft are generally arranged diagonally. According to the distribution of the starting control points in the launching shaft and the tunnel entrance shown in Figure 1, the first entry guide wire network chain edge point is selected on the right side wall of the shield tunnel according to the tunneling direction. Following the principle of simultaneous and parallel deployment of two traverse chains, the first traverse chain entering the tunnel should be set up with synchronous double reference points, with the distance between the two reference points within the range of 1-3m. Depending on the progress of the tunnel boring machine (TBM), the next traverse chain should be deployed on the left side wall of the TBM, and its control point should be set up as a common reference point. This process continues, with the control points of the two traverse chains deployed sequentially along the tunnel boring direction. The length of each traverse chain should ideally be controlled within the range of 60-150m. In curved sections, adjustments should be made based on the visibility conditions to ensure uniform traverse chain lengths and that the ratio of adjacent lengths is not greater than 2. Within 150m before the TBM tunnel breakthrough, the last point of this interval-based, common-point traverse chain should be deployed, and this last point should be set up as a common reference point. Each pair of adjacent common reference points and synchronous double reference points should form a local traverse chain closed loop, meeting the requirement that 4-6 points of the two traverse chains must form a local closed loop. Based on the characteristics of the common-point double-branch conductor network and the location of the shield tunneling 150m from the breakthrough face, the standard layout of the common-point double-branch conductor network should be properly adjusted.

[0053] Step 3: Based on the deployment progress of the double-branch conductor network, divide the conductor network into closed loop sections and determine the measurement path for the overall closed loop of the conductor network.

[0054] As shown in Figure 1, when the double-branch traverse network is laid to the first common reference point, the four reference control points K1, Y1a, Y1b, and Z1 form the first local traverse network closed loop, which is divided into section I. When the double-branch traverse network is laid to the second common reference point, the four reference control points Z1, Y2a, Y2b, and Z2 form the second local traverse network closed loop, which is divided into section II. This process continues until the nth common reference point is laid within 150m of the tunnel boring machine from the breakthrough face, at which point the last traverse network closed loop is divided into section n.

[0055] The tunnel excavation direction is defined as the major mileage direction. The synchronous dual reference points are divided into two relative position reference points: a minor mileage reference point and a major mileage reference point, as shown in Figure 1. The minor mileage reference point is uniformly defined as reference point a, and the major mileage reference point is defined as reference point b. The overall closed-loop forward measurement path is determined as "starting point K1 → major mileage reference point Y1b → common reference point Z1…major mileage reference point Ynb → common reference point Zn", as shown in Figure 1 with blue arrows pointing to the traverse. The overall closed-loop return measurement path is determined as "starting point K1 ← minor mileage reference point Y1a ← common reference point Z1…minor mileage reference point Yna ← common reference point Zn", as shown in Figure 1 with black arrows pointing to the traverse. These forward and return measurement paths constitute the overall closed-loop measurement path of the dual-branch traverse network.

[0056] Step 4: Field extension surveying and office calculations at intermediate transfer stations

[0057] Traditionally, traverse surveying at intermediate switching stations in a double-traverse network involves angle and distance measurements based on a predetermined survey path. However, in a double-branch traverse network, the field extension surveying at intermediate switching stations is conducted independently as a closed loop within each section, extending forward loop by loop. The office calculations for each section's closed loop are also completed independently.

[0058] Field extension measurement methods:

[0059] 1) When the station change control point is a synchronous double reference point, since it is impossible to form a local closed loop, double traverse control measurement and observation shall be carried out in accordance with the relevant measurement specifications of the traverse method.

[0060] 2) When the station change control point is a common reference point, closed traverse control measurement observation is carried out according to the relevant measurement specifications of the double traverse method based on the local closed loop measurement path of the section. As shown in Figure 2: for the closed loop of section I, the measurement path is K1→Y1b→Z1→Y1a→K1; for the closed loop of section II, the measurement path is Z1→Y2b→Z2→Y2a→Z1; for the closed loop of section n, the measurement path is Zn-1→Ynb→Zn→Yna→Zn-1.

[0061] As shown in Figure 2, taking the closed-loop field survey of section I as an example, the main contents of measuring azimuth and measuring traverse side lengths are as follows:

[0062] The azimuth measurement includes: ∠Y1aK1Y1b, ∠K1Y1aZ1, ∠Y1aZ1Y1b, and ∠Z1Y1bK1.

[0063] The measurement of traverse side lengths includes: traverse side K1-Y1a, traverse side Y1a-Z1, traverse side Z1-Y1b, and traverse side K1-Y1b.

[0064] 3) The intermediate station extension measurement work takes the closed loop of the section as the basic unit and extends the measurement forward segment by segment. The control point of the closed loop of the (n-1)th section has been determined, and the control point of the closed loop of the next section n is extended for measurement. The specific plan is to start the measurement control point of the closed loop of the 1st section as the starting measurement control point, and carry out traverse control measurement for the extended control point of the closed loop of the 2nd section of the next section. And so on. When the intermediate station extension measurement reaches the nth section and has not reached the 150m range before the breakthrough, the intermediate station measurement control work can start from the control point of the closed loop of the (n-1)th section and carry out traverse control measurement for the extended control point of the closed loop of the nth section. Before the intermediate station extension measurement work begins, the known starting section closed loop control point should be checked and its stability should be verified to meet the relevant specification accuracy requirements. Only after the accuracy verification is qualified can the traverse control measurement be carried out for the unknown extension control point of the next section.

[0065] Internal calculation methods:

[0066] The traditional work of calculating the internal parameters of a double-traverse network mainly includes checking whether the azimuth and closure distance exceed the limits. Only if the limits are not exceeded can the relevant data adjustment be carried out, the coordinate azimuth and coordinate increment be calculated, and finally the plane coordinates of each control point be calculated.

[0067] Based on the characteristics of the field extension measurements at intermediate substations in this double-branch traverse network, the office calculations are similarly checked and adjusted separately for each local closed-loop measurement data. The local closed-loop diagram of this double-branch traverse network is not a conventional quadrilateral diagram; as shown in Figure 1, two measurement sides intersect, forming two diagonal triangular network diagrams. Compared with traditional double-traverse network office calculations, the main difference in the office calculations for this double-branch traverse network lies in the different azimuth angle verification and adjustment principles, while the closed-loop distance verification and adjustment principles are the same. The azimuth angle verification and adjustment principles are described in detail below:

[0068] Taking the closed-loop field measurement data of section I as an example, as shown in Figure 2, △K1Y1aO1 and △Z1Y1bO1 are diagonal triangles, so the two triangles have an equal diagonal relationship. The theoretical relationship formula is as follows:

[0069] ∠Y1aK1Y1b+∠K1Y1aZ1=∠Y1aZ1Y1b+∠Z1Y1bK1(Formula 1)

[0070] 1) Verification of azimuth closure error during intermediate station extension measurement

[0071] According to the equation relationship in formula (I) above, the actual angle values ​​measured in the field are checked, and the azimuth closure error Δi is calculated:

[0072] △i = (measured ∠Y1aK1Y1b + measured ∠K1Y1aZ1) - (measured ∠Y1aZ1Y1b + measured ∠Z1Y1bK1) (Formula 2)

[0073] According to the relevant requirements of the "Code for Surveying and Mapping of Urban Rail Transit Engineering", the calculation results of the intermediate transfer station extension survey in this invention are set according to the technical requirements of third-order precision traverse network surveying. Based on the standard formula... (seconds) Verify whether the angle closure difference Δi in the above formula meets the specification requirements, where n is the number of angles of the conductor, and in this example n equals 4.

[0074] 2) Calculation and adjustment of azimuth correction for intermediate station extension measurements

[0075] a. When △i = 0, the correction △i' = 0;

[0076] b. When △i > 0 or △i < 0, the correction △i' = △i / n, where n is the number of angles of the conductor. In this example, n equals 4. Based on the above formula (II), the calculation formulas for the angle corrections in each direction are as follows:

[0077] Calculation of angle correction within the left parenthesis: Correction ∠Y1aK1Y1b = Measured ∠Y1aK1Y1b - △i / 4

[0078] Correction: ∠K1Y1aZ1 = Measured ∠K1Y1aZ1 - △i / 4

[0079] Calculation of angle correction within the right parenthesis: Correction ∠Y1aZ1Y1b = Measured ∠Y1aZ1Y1b + △i / 4

[0080] Correction: ∠Z1Y1bK1 = Measured ∠Z1Y1bK1 + △i / 4

[0081] Step 5: When the shield tunneling is 150m from the breakthrough face, perform overall closure measurement and office calculation of the double-branch traverse network.

[0082] According to the "Code for Surveying and Mapping of Urban Rail Transit Engineering", all traverse control points within 150m before the shield tunnel breakthrough should be checked by closed-loop measurement. As shown in Figure 3, the method for field closed-loop measurement and office calculation of double-branch traverse network is described in detail below.

[0083] Field closure measurement method:

[0084] Based on the measurement path of the complete closed loop of the double-branch traverse network determined in step 3, the control measurement of the complete closed traverse network is carried out in accordance with the relevant measurement specifications for double-traverse networks. The detailed content of the field closed angle measurement and distance measurement is listed below:

[0085] The azimuth angles of the right side wall include: ∠Y1-b, ∠Y2-b, ∠Yn-b

[0086] The azimuth angles of the left side wall include: ∠Z1-1, ∠Z2-1

[0087] Azimuth of the measuring end: ∠Zn

[0088] The azimuth angles measured on the right side wall include: ∠Y1-a, ∠Y2-a, ∠Yn-a

[0089] The azimuth angles measured on the left side wall include: ∠Z1-2, ∠Z2-2

[0090] Return measurement of the azimuth angle at the closed end: ∠K1

[0091] The lengths of the conductor sides, in sequence, include: conductor side K1-Y1b, conductor side Y1b-Z1, conductor side Z1-Y2b, conductor side Y2b-Z2, conductor side Z2-Ynb, and conductor side Ynb-Zn.

[0092] The measured conductor side lengths are as follows: conductor side Zn-Yna, conductor side Yna-Z2, conductor side Z2-Y2a, conductor side Y2a-Z1, conductor side Z1-Y1a, and conductor side Y1a-K1.

[0093] Internal calculation methods:

[0094] Based on the aforementioned field closure measurement data and the relevant requirements of the "Urban Rail Transit Engineering Surveying Specification," relevant calculations and adjustments were performed according to the traditional double-traverse network closed-loop data processing steps. The main difference between this invention and the traditional double-traverse network data processing method lies in the principle of azimuth angle closure error constraint adjustment; other steps and contents are basically the same. The principle of azimuth angle verification and adjustment for the overall closed traverse control measurement of this double-branch traverse network chain is described below:

[0095] As shown in Figure 3, the following angular relationship exists:

[0096] 1) The theoretical relationship of angles formed by common reference point Z1 as corner points is as follows:

[0097] ∠Z1-1=∠Y1bZ1Y2a+∠Y2aZ1Y2b

[0098] ∠Z1-2=∠Y1bZ1Y2a+∠Y1aZ1Y1b

[0099] From the above two equations, we can derive the following equation: ∠Z1-2-∠Y1aZ1Y1b =∠Z1-1-∠Y2aZ1Y2b (Formula 3)

[0100] Similarly, taking the common reference point Z2 as the corner point, the following angle equation can be derived according to formula (III):

[0101] ∠Z²-2-∠Y²aZ²Y²b=∠Z²-1-∠YnaZ²Ynb (Formula 4)

[0102] 2) Based on the calculation method described in step 4 above, and according to the principle of equality in formula (I), taking the closed loop of segments I, II, and n as the basic unit, the following equation relationship can be derived:

[0103] ∠Y1aZ1Y1b+∠Y1-b=∠K1+∠Y1-a (Formula 5)

[0104] ∠Y2aZ2Y2b+∠Y2-b=∠Y2aZ1Y2b+∠Y2-a (Formula Six)

[0105] ∠Zn+∠Yn-b=∠YnaZ2Ynb+∠Yn-a (Formula 7)

[0106] Based on formulas (III) to (VII), by summing the variables on the left and right sides of the formulas respectively, the following equation relationship can be obtained:

[0107] (∠Z1-2+∠Z2-2)+(∠Y1-b+∠Y2-b+∠Yn-b)+∠Zn=

[0108] (∠Z1-1+∠Z2-1)+(∠Y1-a+∠Y2-a+∠Yn-a)+∠K1(Formula 8)

[0109] 3) The actual traverse measurement section is generally longer than that shown in Figure 3. The variables in the above formula (viii) are redefined and optimized as follows:

[0110] Definition 1: The sum of the azimuth angles measured from the left side wall on the left side of the equation (∠Z1-2+∠Z2-2)= Retest

[0111] Definition 2: The sum of the azimuth angles measured from the right side wall on the left side of the equation (∠Y1-b+∠Y2-b+∠Yn-b) = Forward test

[0112] Definition 3: The sum of the azimuth angles measured from the left wall on the right side of the equation (∠Z1-1+∠Z2-1)= Forward test

[0113] Definition 4: The sum of the azimuth angles measured from the right side wall on the right side of the equation (∠Y1-a + ∠Y2-a + ∠Yn-a) = Retest

[0114] Substituting the redefined variables into the above equation yields the following equation:

[0115] Retesting+ Forward measurement + ∠Zn = Forward test + Return test + ∠K1 (Formula Nine)

[0116] 4) Overall azimuth closure error check of the double-branch conductor network

[0117] According to the equation relationship in formula (IX) above, the actual angle value of the field closure measurement is checked, and the azimuth closure difference △I is calculated:

[0118] △I = (actual measurement) Return testing + actual testing Forward measurement + ∠Zn) - (actual measurement) Previous test + actual test (Return test + Actual test ∠K1) (Formula 10)

[0119] According to the requirements of the "Urban Rail Transit Engineering Surveying Specifications", the calculation results of the overall closed-loop measurement of the double-branch traverse network chain in this invention are set and verified according to the technical requirements of third-order precision traverse network measurement. Based on the standard formula... (seconds) Verify whether the angle closure difference △I in the above formula meets the specification requirements, where N is the number of angles of the conductor; in this example, N is equal to twice the number of local interval closed loops, that is, N=2n, where n is the number of local closed loops in the entire double-branch conductor network chain segment.

[0120] 5) Calculation and adjustment of the overall azimuth correction of the double-branch traverse network

[0121] a. When △I = 0, the correction △I' = 0;

[0122] b. When △I > 0 or △I < 0, the correction △I' = △I / N, where N is the number of angles of the conductor; according to the above formula (x), the calculation formula for the angle correction in each direction is as follows:

[0123] Calculation of azimuth angle correction within the left bracket: Corrected ∠Zx (return measurement) = Actual ∠Zx (return measurement) - △I / N

[0124] Correction: ∠Yx forward measurement = Actual ∠Yx forward measurement - △I / N

[0125] Correction: ∠Zn = Measured ∠Zn - △I / N

[0126] Wherein, “∠Zx back measurement” represents any back measurement angle of the left side wall, and “∠Yx forward measurement” represents any forward measurement angle of the right side wall.

[0127] Calculation of azimuth angle correction within the right parenthesis: Correction ∠Zx (forward measurement) = Measured ∠Zx (forward measurement) + △I / N

[0128] Correction of ∠Yx backtesting = Actual measurement of ∠Yx backtesting + △I / N

[0129] Correction: ∠K1 = Measured ∠K1 + △I / N

[0130] Wherein, “∠Zx forward measurement” represents any forward measurement angle of the left side wall, and “∠Yx return measurement” represents any return measurement angle of the right side wall.

[0131] Step 6: Verification of the difference between the plane coordinate results of the round trip measurement path from the common benchmark point.

[0132] According to the above step 5 of the office calculation process, the common benchmark point participates in two calculations based on the forward and reverse measurement paths, ultimately outputting two separate results: the forward-measured plane coordinates and the reverse-measured plane coordinates. A certain difference exists between these two plane coordinate results. To further verify that the above step 5 office calculation results meet the relevant specifications, and based on the requirement that the difference between the plane coordinates of the forward and reverse measurement paths of the common benchmark point should meet the local closed loop constraint condition of the double-branch traverse network link section, the difference between the coordinates of the forward and reverse measurement paths of the common benchmark point is further verified according to the "total relative closure error" technical requirements stipulated in the "Urban Rail Transit Engineering Surveying Specification". The verification method is as follows:

[0133] 1) Calculation of the difference between the plane coordinate results of the round trip measurement path from the common benchmark point

[0134] As shown in Figure 4, taking the common reference point Z1 as an example, assuming the forward coordinate calculation result of Z1 is (X1-1, Y1-1) and the backward coordinate calculation result is (X1-2, Y1-2), and letting the difference between the forward and backward coordinate results of the common reference point Z1 be (△X1, △Y1), the following equation relationship can be established:

[0135] △X1=|X1-1-X1-2|,△Y1=|X1-1-X1-2| (Formula 11)

[0136] Therefore, the formula for calculating the difference △D1 between the plane coordinate results of the round-trip measurement path of the Z1 common reference point is as follows:

[0137] (Formula 12)

[0138] 2) Calculate the total length of the traverse wire for the local closed loop on both sides of the common reference point.

[0139] As shown in Figure 4, the total length of the traverse line of the local closed loop in section I of the Z1 common reference point in the small mileage direction and the total length of the traverse line of the local closed loop in section II of the large mileage direction are calculated as follows:

[0140] ∑ Total length of the closed loop in section I = L(K1-Y1b) + L(Y1b-Z1 forward) + L(Z1 back-Y1a) + L(Y1a-K1) (Formula XIII)

[0141] The total length of the closed loop in section II = L(Z1 forward - Y2b) + L(Y2b - Z2 forward) + L(Z2 return - Y2a) + L(Y2a - Z1 return) (Formula XIV)

[0142] 3) The difference in the planar coordinates of the round-trip measurement path for the Z1 common benchmark point is verified by the "relative closure error of the whole length" of the local closed loop of the relevant section.

[0143] According to the requirements of the "Urban Rail Transit Engineering Surveying Specification", the standard for verifying the difference between the forward and reverse coordinate results of the Z1 common benchmark point in this invention is set as the technical requirement for third-order precision traverse network surveying, that is, according to the "limit of no more than 1 / 35000 for the relative closure error of the whole length" in the specification, the verification is carried out, and the verification calculation formula is as follows:

[0144] f(relative closure error of the entire length of segment I) = △D1 / ∑(the total length of the closed loop of segment I) ≤ 1 / 35000 (Formula XV)

[0145] f (relative closure error of the entire length of segment II) = △D1 / ∑ total length of the closed loop of segment II ≦1 / 35000 (Formula XVI)

[0146] Evaluation of inspection results: When the results of the plane coordinates of the round-trip measurement path of the Z1 common benchmark point are poorly tested and the requirements of formulas (xv) and (xvi) above are met, it indicates that the Z1 common benchmark point is qualified.

[0147] Other common reference points are verified in the same way as described above. When all common reference points pass the verification, the accuracy of the double-branch traverse chain control network can be determined to meet the set third-order accuracy requirements.

[0148] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. It can be applied to various fields suitable for the present invention, and other modifications can be easily implemented by those skilled in the art. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and examples shown and described herein.

Claims

1. A measurement method for a spaced, common-point, double-branch traverse network applied to shield tunnels, characterized in that, The process includes the following steps: Step 1: Based on the tunnel excavation progress, lay out a double-branch traverse network with intermittent common points within the tunnel according to design requirements; Step 2: Based on the progress of the double-branch traverse network layout, divide the traverse network section into closed loops and clarify the measurement path for the overall closed loop of the traverse network; Step 3: Extend field measurements and perform office calculations at intermediate stations; Step 4: When the shield tunneling is at a set distance from the breakthrough face, perform overall closed-loop measurements and perform office calculations for the double-branch traverse network; Step 5: Verify the difference between the plane coordinate results of the round-trip measurement path of the common reference point in the industry calculations to control the breakthrough accuracy; In Step 1, starting from the initial control point of the launching shaft, select one side wall of the shield tunnel section to enter the tunnel and lay out the double-branch traverse network according to the location of the initial control point. Following the principle of first laying out synchronous double reference points on one side wall and common reference points on the other side wall, extend the network sequentially within the set control range of traverse side lengths. The side length of each double-branch traverse network is 60~150m, and... The ratio of adjacent side lengths is no greater than 2; the spacing between the synchronous double reference points is 1-3m according to design requirements; the last point of the double-branch traverse network is set as a common reference point, located within a set distance from the tunnel face during shield tunneling; in step two, each pair of adjacent common reference points and the synchronous double reference points form a local traverse network closed loop; according to the tunnel excavation direction, the synchronous double reference point closer to the large mileage direction is defined as reference point b, and the corresponding other one is reference point a. The overall closed loop forward measurement path is formed by the starting control point, the adjacent reference point b, the adjacent common reference point, the next reference point b, the next common reference point... until the last common reference point; the overall closed loop return measurement path is formed by the last common reference point, the adjacent reference point z, the adjacent common reference point, the next reference point a, the next common reference point... until the starting control point; the round trip measurement path constitutes the overall closed loop measurement path of the double-branch traverse network.

2. The measurement method for a spaced, common-point, double-branch traverse network applied to a shield tunnel as described in claim 1, characterized in that, In step three, the intermediate station transfer extension measurement is carried out independently according to the closed loop of the local traverse network chain of the section, and the measurement is extended forward loop by loop. The internal calculation work is completed independently for the closed loop of the local traverse network chain of the section.

3. The measurement method for a spaced, common-point, double-branch traverse network applied to a shield tunnel as described in claim 2, characterized in that, When the station change control point is a synchronous double reference point, double traverse control measurement and observation shall be carried out in accordance with the measurement specifications corresponding to the traverse method; when the station change control point is a common reference point, closed traverse control measurement and observation shall be carried out in accordance with the measurement specifications corresponding to the double traverse method based on the local closed loop measurement path of the section.

4. The measurement method for a spaced, common-point, double-branch traverse network applied to a shield tunnel as described in claim 2, characterized in that, The verification and adjustment of the closed loop are the same as the traditional indoor calculations for double-traverse networks. The azimuth verification and adjustment specifically involve: First, based on the equal diagonal angles of the two diagonal triangles formed by the closed loop of the section, verifying the actual angle values ​​measured in the field. Calculate the difference between the sums of the angles of the two triangles in the closed loop of the section; this difference is the azimuth closure difference Δi of the closed loop, calculated according to the standard formula. First, check whether the angle closure difference Δi meets the specification requirements, where n is the number of angles of the conductor; second, calculate and adjust the azimuth correction. When Δi = 0, the correction Δi' = 0; when Δi > 0 or Δi < 0, the correction Δi' = Δi / n. Adjust the measured angle to form the correction angle.

5. The measurement method for a spaced, common-point, double-branch traverse network applied to a shield tunnel as described in claim 1, characterized in that, In step four, the field closure measurement of the double-branch traverse network chain is carried out according to the relevant measurement specifications for double-traverse networks. The field closure angle measurement includes: the azimuth angle of the right wall includes the angle between the two traverse networks at all b reference points; the azimuth angle of the left wall includes the angle between all common reference points and two adjacent b reference points; the azimuth angle of the end of the measurement is the angle between the last common reference point and the adjacent a and b reference points; the azimuth angle of the right wall back measurement includes the angle between the two traverse networks at all a reference points; the azimuth angle of the left wall back measurement includes the angle between all common reference points and two adjacent a reference points; the azimuth angle of the closure end of the back measurement is the angle between the starting control point and the adjacent a and b reference points.

6. The measurement method for a spaced, common-point, double-branch traverse network applied to a shield tunnel as described in claim 5, characterized in that, In step four, the indoor calculation method for the double-branch traverse network includes: First, based on the multiple diagonal triangle relationships formed by the double-branch traverse network, multiple common reference points are used as corner points to form angular relationships, and multiple formulas are transformed into angular equations; Second, based on the indoor calculation method in step three, each closed loop is used as a basic unit, and the angular equations are transformed again to form the deformed equations for all angles included in the field closed angle measurement in step four; Third, the azimuth angles of the deformed equations are optimized and defined to form optimized equations about the redefined variables; Then, based on the optimized equations, the actual angle values ​​of the field closed measurement are checked, and the overall azimuth angle closure difference ΔI of the double-branch traverse network is calculated according to the standard formula. , seconds, verify whether the angle closure difference △I meets the specification requirements, where N is the number of angles of the conductor; finally, calculate and adjust the overall azimuth correction. When △I=0, the correction △I'=0; when △I>0 or △I<0, the correction △I'=△I / N. Adjust the azimuth of each back-measured angle, forward-measured angle, back-measured closed end azimuth, and forward-measured end azimuth to form the correction angle.

7. The measurement method for a spaced, common-point, double-branch traverse network applied to a shield tunnel as described in claim 6, characterized in that, In step five, the inspection method is as follows: First, calculate the difference in the plane coordinates of the forward and backward measurement paths of the common reference point; second, calculate the total length of the traverse for the local closed loops on both sides of the common reference point; third, inspect the difference in the plane coordinates of the forward and backward measurement paths of the common reference point according to the "total relative closure difference" of the local closed loops of the related sections to determine whether it is qualified; finally, inspect all common reference points according to the above steps. If all inspections are qualified, it can be determined that the accuracy of the double-branch traverse network control network meets the set third-order accuracy requirements.

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