A measurement method for controlling the penetration error in long-distance tunnels

Abstract

A measurement method for controlling the penetration error in long-distance tunnels according to the present invention, based on the control measurement of the ground control network and the control measurement of the tunnel control network, combines gyro orientation measurement to improve the measurement accuracy of azimuth angles, etc., and extends the ground control network to the underground through borehole plumb point connection measurement, so that the accuracy of the measurement results meets the requirements, directly guides the construction, effectively controls the lateral penetration error of the tunnel, adopts ground borehole plumb point connection measurement at the shallow buried layer position close to the penetration surface in the long tunnel, and uses the underground gyro orientation measurement verification method to perform high-precision control point densification, ensuring the perfect penetration of the tunnel, ensuring the precise docking of the tunnel project, and precisely analyzing the measurement error.

Description

Technical Field

[0001] The present invention relates to the field of tunnel construction surveying, and particularly to a surveying method for controlling the penetration error of a long-distance tunnel. Background Art

[0002] The surveying method for controlling the penetration error of a tunnel is a very important technology in tunnel construction, which ensures that the tunnel can be accurately penetrated according to the design requirements.

[0003] However, for the existing methods of surveying the penetration error of a tunnel control, the comprehensive index analysis is insufficient, the surveying accuracy is lacking, and it is difficult to accurately analyze the surveying error.

[0004] Application Content

[0005] The purpose of the present application is to provide a surveying method for controlling the penetration error of a long-distance tunnel to solve the technical problems described in the background art.

[0006] The technical solution adopted by the present application is as follows:

[0007] A surveying method for controlling the penetration error of a long-distance tunnel, comprising the following steps:

[0008] S100: Ground control network control surveying: The ground control network is divided into a plane control network and a height control network;

[0009] S110: The ground plane control network adopts GPS satellite positioning surveying, and a total of 10 groups of control points are buried between the TBM starting hole and the exit hole according to the line direction;

[0010] S120: The mean square error σ of the baseline length of each grade GPS network is calculated by using the fixed error a and the proportional error b corresponding to the GPS network accuracy classification grade. The side length value D takes the actual average side length, and the mean square error of the baseline length is calculated according to the following formula:

[0011] In the formula: σ—mean square error of the baseline length, mm;

[0012] a—fixed error, mm;

[0013] b—proportional error coefficient, mm / km;

[0014] D—average side length, km;

[0015] S130: The height control network adopts second-class leveling surveying. The leveling surveying is carried out in a closed loop in both directions. The same type of instrument and turning point ruler support are used for the round-trip observation along the same leveling route;

[0016] S200: Tunnel control network control surveying: Laying out a traverse network: The traverse network is laid out in the form of a double traverse + cross double traverse;

[0017] S300: Gyro orientation measurement: Use precision wire control points and ground control points as known ground edges to perform gyro orientation observation of the tunnel edge; lay out an orientation edge in the tunnel, calculate the coordinate azimuth of the orientation edge in the tunnel based on the conversion calculation between the gyro azimuth and the coordinate azimuth, and compare it with the coordinate azimuth measured by the total station based on the underground control points to evaluate the reliability of the underground control wire orientation accuracy;

[0018] S400: Drilling point connection measurement: After the TBM excavates a certain distance in one direction, it will drill vertical holes on the surface into the tunnel to conduct connection measurement inside the tunnel and on the surface. The connection measurement adopts the one-well directional method to conduct connection observations on the ground and underground.

[0019] S410: Directional connection measurement of a well. When laying out the connection triangle above and below the well, the distance between the two suspended steel wires is greater than 5 meters; the angles r and r′ between the above-ground and underground well entry points and the two steel wires are both less than 1°; the ratio of the shortest distance between the above-ground and underground well entry points to the steel wires and the distance between the two steel wires is no more than 1.5; the steel wire diameter is 0.3mm, and a 10KG weight is hung, which is immersed in damping fluid. When observing, observations are made both above and below the well; the weight must be hung vertically, and the hole diameter is vertically downward when drilling;

[0020] S500: Tunnel penetration error analysis, based on drilling point analysis of tunnel plane penetration error, including: underground starting side orientation error analysis, lateral penetration error analysis of control points outside the tunnel, lateral penetration error analysis of wires inside the tunnel, lateral error analysis of drilling point tunnel, and tunnel elevation penetration error analysis.

[0021] Compared with the prior art, the advantages and positive effects of the present invention are as follows: on the basis of the ground control network control measurement and the tunnel control network control measurement, the gyro directional measurement is combined to improve the measurement accuracy of azimuth and other aspects, and the ground control network is extended to the underground through the drilling point connection measurement, so that the measurement result accuracy meets the requirements of the fourth-class conductor, directly guides the construction, and effectively controls the lateral penetration error of the tunnel. In the long tunnel, the shallow buried layer position close to the penetration surface is measured by ground drilling point connection measurement, and the underground gyro directional measurement verification method is used to encrypt the control points with high precision, so as to ensure the perfect penetration of the tunnel, ensure the accurate docking of the tunnel project, and accurately analyze the measurement errors. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0023] The structures, proportions, sizes, etc. illustrated in this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the conditions for the implementation of the present invention. Therefore, they do not have substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present invention.

[0024] Figure 1 It is a schematic diagram of the positions of traverse points in an embodiment of a measurement method for controlling the breakthrough error in a long-distance tunnel.

[0025] Figure 2 It is a schematic diagram of the positions of bench marks in an embodiment of a measurement method for controlling the breakthrough error in a long-distance tunnel.

[0026] Figure 3 It is a diagram showing the calculation relationship of instrument constants in an embodiment of a measurement method for controlling the breakthrough error in a long-distance tunnel.

[0027] Figure 4 It is a schematic diagram of the layout of gyroscopic sides in an embodiment of a measurement method for controlling the breakthrough error in a long-distance tunnel.

[0028] Figure 5 It is a schematic diagram of drilling and point dropping in an embodiment of a measurement method for controlling the breakthrough error in a long-distance tunnel.

[0029] Figure 6 It is a plan layout diagram of drill holes in the shallow-buried section in an embodiment of a measurement method for controlling the breakthrough error in a long-distance tunnel.

[0030] Figure 7 It is a schematic diagram of the selection and layout of ground points in an embodiment of a measurement method for controlling the breakthrough error in a long-distance tunnel. Detailed implementation manners

[0031] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0032] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation on the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0033] It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component, or there may be an intermediate component present at the same time. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. It should also be noted that unless otherwise clearly specified and limited, the terms "installation", "fixation", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0034] The present invention will be further explained below in conjunction with specific embodiments.

[0035] As shown in the attached Figure 1-7 description:

[0036] In one embodiment, a measurement method for controlling the penetration error in a long-distance tunnel includes the following steps:

[0037] S100: Control survey of the ground control network: The ground control network is divided into a plane control network and an elevation control network.

[0038] S110: The ground plane control network uses GPS satellite positioning measurement. A total of 10 groups of control points are buried at the TBM starting hole and the exit hole, etc. according to the line direction. The specific accuracy indexes are shown in Table 1-1:

[0039] Table 1-1 GPS network accuracy classification

[0040]

[0041] Specifically, for each level of plane control survey, the mean error of the weakest point position shall not be greater than ±5 cm, and the mean error of the weakest adjacent point position shall not be greater than ±3 cm.

[0042] S120: The standard deviation of baseline length σ for GPS networks of each level is calculated using the fixed error a and proportional error coefficient b corresponding to the accuracy classification level of the GPS network. The side length value D is taken as the actual average side length, and the standard deviation of baseline length shall be calculated according to the following formula:

[0043]

[0044] Where: σ — standard deviation of baseline length, mm;

[0045] a — fixed error, mm;

[0046] b — proportional error coefficient, mm / km;

[0047] D — average side length, km;

[0048] Specifically, the technical requirements for GPS measurement shall comply with the provisions of Table 1-2 below.

[0049] Table 1-2 Technical Requirements for GPS Measurement

[0050]

[0051] S130: The elevation control network adopts second-order leveling measurement. The leveling measurement is carried out along a closed loop route in both directions, and the same type of instrument and turning point supports are used for the round-trip observation along the same leveling route. The accuracy of the elevation control measurement results shall be in accordance with the second-level leveling measurement grade, and the accuracy indicators are shown in the following table:

[0052] Table 1-3 Accuracy Indicators of Leveling Measurement (mm)

[0053]

[0054]

[0055] Specifically, in the table, K is the length of the leveling route or the number of stations in a survey section, R is the length of the inspection survey section, with the unit of km, and L is the length of the closed loop route.

[0056] S200: Control measurement steps for the tunnel control network: Layout the traverse network: The traverse network is laid out in the form of double traverses + cross double traverses, and the azimuth closure error The angular standard deviation is ±1.0″, the ranging standard deviation is ±2.0″, and the relative closing error of the total length is 1:110000.

[0057] Specifically, considering the small diameter of the tunnel boring machine (TBM) during tunneling and the influence of environmental factors such as temperature and humidity, the average side length of the traverse is laid out at about 300 meters, and the specific positions are as shown in the appendix Figure 1 as follows.

[0058] S210: Conduct in - tunnel traverse survey. When the number of observed directions is 2, the left - and - right angle observation method can be adopted without zeroing; when the number of observed directions is more than 2, the direction observation method is adopted.

[0059] Specifically, in the in - tunnel traverse distance measurement, reciprocal observations are made on the traverse sides, and meteorological corrections, multiplicative and additive constant corrections, and slope corrections are carried out according to meteorological elements.

[0060] The observation accuracy standard for in - tunnel traverse survey should meet the following table:

[0061] Table 2 - 1 Accuracy Requirements for In - Tunnel Traverse Survey

[0062]

[0063] Table 2 - 2 Technical Requirements for Horizontal Angle Direction Observation Method

[0064]

[0065]

[0066] Specifically, when the vertical angle of the observed direction exceeds the range of ±3°, the 2C difference of this direction can be compared with the same direction in adjacent survey rounds, and its value should meet the limit of 2C difference within one survey round in the table.

[0067] Table 2 - 3 Technical Requirements for Side - length Measurement

[0068]

[0069] Specifically, 1. One survey round is the process of measuring once with the total station in the left - hand position and once in the right - hand position; 2. The accuracy grade of the distance meter is classified as follows: Grade I, md ≤ 2mm; Grade II, 2mm ≤ md ≤ 5mm; Grade III, 5mm ≤ md ≤ 10mm, where md is the standard deviation of distance measurement per kilometer; 3. mD = a + b*D.

[0070] S220: Steps for traverse network adjustment: Calculate the angular error of closure of the traverse network, including: Calculate according to the left - and - right angle closure error; Calculate according to the traverse azimuth. The azimuth closure limit of the traverse network is observed using second - class traverse, and the azimuth closure error Correct the side lengths of the traverse network. The observed side lengths of the traverse are the distances between two points on the reference ellipsoid. According to the specification requirements, the observed distances should be corrected during the adjustment of the long - tunnel traverse.

[0071] Specifically, calculate according to the left - and - right angle closure error:

[0072]

[0073] Calculate according to the traverse azimuth

[0074]

[0075] Where: Δ—the difference between the sum of the left and right angles and 360°, (″);

[0076] f β —the azimuth closing error of the connecting traverse or closed traverse loop, (″);

[0077] N—the number of connecting traverses or closed traverse loops;

[0078] n—the number of interior angles of the connecting traverse or closed traverse loop;

[0079] S222: In the azimuth closing limit of the traverse, the closing limit of the traverse loop is calculated by the following formula:

[0080]

[0081] Where: m—the mean square error of angle measurement in the survey design (");

[0082] n—the number of interior angles of the traverse loop.

[0083] S224: In the side length correction of the traverse network, the length of the measured distance side reduced to the average elevation plane of the survey area or a specified elevation plane is calculated by the following formula:

[0084]

[0085] Where: D0—the length reduced to the average elevation plane or a selected elevation plane, m;

[0086] D—the horizontal distance between the instrument station and the target station on the average elevation plane, m;

[0087] H P —the average elevation of the survey area or a selected elevation, m;

[0088] H m —the average elevation of the two ends of the measured distance side, m;

[0089] R A —the radius of curvature of the normal section where the measured distance side is located, m;

[0090] The length of the measured distance side reduced to the reference ellipsoid is calculated by the following formula:

[0091]

[0092] Where: D1—the length reduced to the reference ellipsoid, m;

[0093] h m —the height difference between the geoid of the survey area and the reference ellipsoid, m;

[0094] The reduction of the length on the reference ellipsoid surface to the length on the Gaussian plane is calculated by the following formula:

[0095]

[0096] In the formula: D2—the length of the side on the Gaussian plane, m;

[0097] y m —the average abscissa of the two endpoints of the distance measuring side, m;

[0098] Δy—the difference in abscissas of the two endpoints of the distance measuring side, m;

[0099] R m —the average radius of curvature at the midpoint of the distance measuring side on the reference ellipsoid surface, m;

[0100] S226: The adjustment calculation of the in - tunnel traverse control network uses adjustment software and is adjusted according to the accuracy standard of the second - class traverse network. After adjustment, the adjusted coordinates and their mean errors of the traverse points, the position errors of the traverse points, the ellipsoid elements, the adjusted lengths and relative mean errors of the traverse sides, and the adjusted coordinate azimuths and their mean errors of the traverse sides are output.

[0101] Specifically, during the adjustment process, if there are multiple iterations and non - convergence, or other prompts indicating that the adjustment cannot continue, first check whether there are incorrect data in the plane observation file and correct it in a timely manner. If the a posteriori unit weight mean error in the adjustment result is significantly too large, it should be considered that there may be gross errors in the observed values, and the traverse loops with large closing errors should be re - measured and supplemented. Repeated observations and calculations are carried out until all accuracy indicators of the adjustment result meet the specification requirements.

[0102] S230: In - tunnel leveling control survey: A fixed and stable leveling point is set at the tunnel entrance and connected with the leveling points near the ground as the starting point of the tunnel leveling survey. A leveling point is set every about 2 km in the tunnel. Due to the deep water accumulation in the tunnel and the large vibration caused by the operation of the formation trains, the wire point brackets on both sides of the segment are used as leveling points for measurement. The leveling point location map is as attached Figure 2 as shown.

[0103] Specifically, S232: Observation steps for in - tunnel leveling survey: The in - tunnel leveling survey adopts the second - class leveling observation method. The observation sequence for each survey station is as follows: For odd - numbered stations, it is "back - front - front - back", and for even - numbered stations, it is "front - back - back - front". For the forward and backward measurements of a survey section, the number of survey stations is an even number; otherwise, the zero - point difference correction should be added. When turning from the forward measurement to the backward measurement, the two leveling rods should be interchanged and the instrument should be reset.

[0104] The main technical requirements for leveling survey are as follows:

[0105]

[0106]

[0107] The observation requirements for leveling at each survey station are as follows:

[0108]

[0109] S234: Steps for leveling network adjustment: The accidental mean square error per kilometer of leveling measurement can be calculated by the following formula:

[0110]

[0111] Where: Δ—the discrepancy between the round-trip height differences of a survey section, mm;

[0112] R—the length of a survey section, km;

[0113] n—the number of survey sections

[0114] S236: Leveling measurement is adjusted using adjustment software. The total mean square error per kilometer of the elevation network is calculated from the closing error of the leveling network. The results of the adjustment software include approximate elevations, statistical data of the measured height differences of survey sections, adjusted elevation values and their precisions, adjusted height difference values and their precisions, overall information of the elevation control network, etc. The presence of gross errors in the observed values is judged by the magnitude of the closing error, and data that do not meet the precision requirements are re-measured and supplemented.

[0115] S300: Gyroscopic orientation measurement: Using precise traverse control points, with the ground control points as the known ground sides, gyroscopic orientation observations are carried out on the tunnel's orientation sides; a single orientation side is laid out in the tunnel, and based on the conversion calculation between the gyroscopic azimuth and the coordinate azimuth, the coordinate azimuth of the orientation side in the tunnel is solved and compared with the coordinate azimuth measured by a total station using the underground control points to evaluate the reliability of the orientation precision of the underground control traverse.

[0116] Specifically, the gyroscopic orientation measurement includes the following steps: S310: Conduct gyroscopic orientation observations on the known ground side for ≥3 sets of measurements to determine the instrument constant; conduct gyroscopic orientation observations on the underground orientation side for ≥3 sets of measurements to determine the gyroscopic azimuth of the orientation side; return to the known ground side for gyroscopic orientation observations for ≥3 sets of measurements. The results of the two measurements on the known ground side are used to check the instrument stability (instrument constant) and precision to ensure the accuracy and reliability of the gyroscopic orientation results.

[0117] S320: Calculation of the coordinate azimuth of the underground orientation side: The instrument constant Δ is directly measured based on the azimuth of the control point.

[0118] Specifically, for the measurement of the instrument constant, the gyroscope axis, the collimation axis of the total station telescope, and the optical axis represented by the zero graduation line of the observation eyepiece graticule usually do not lie in the same vertical plane. Therefore, the stable position of the gyroscope axis usually does not coincide with the geographical meridian, and the included angle between the two is called the instrument constant, generally denoted by Δ. If the gyroscope meridian is located east of the geographical meridian, Δ is positive; otherwise, it is negative. The instrument constant Δ can be directly measured based on the azimuth of the control point, and the relationship between the two is as shown in the appendix Figure 3 as follows.

[0119] S322: Azimuth calculation. According to the appendix Figure 3 to calculate the coordinate azimuth of the underground orientation side:

[0120] α ab = T ab - γ0 = T ab陀 + Δ - γ0

[0121] Since Δ = T AB - T AB陀 = α AB + γ A - T AB陀

[0122] We get α ab = α AB +(T ab陀 - T AB陀 )+(γ A - γ0)

[0123] = α AB +(T ab陀 - T AB陀 ) - δ γ

[0124] From δ γ =(γ A - γ0) being the difference in the convergence angle of the meridians between the ground and underground survey stations, calculated according to δ γ = u(Y A - Y a ). [εδ is in seconds, μ = 32.3tanφ (s / km)]

[0125] In the above formula: α AB --- Coordinate azimuth of the ground control side; --- Local latitude; T AB陀 --- Gyro azimuth of the ground control side; T ab陀 --- Gyro azimuth of the underground side to be measured; Y A --- Abscissa of the ground setting station (in km); Y a --- Abscissa of the underground setting station (in km).

[0126] S324: Gyroscopic side layout. According to the tunnel length and curve elements, a total of 6 gyroscopic sides are laid out, with one layout every 1.5 - 2 km, as shown in the appendix. Figure 4 as shown.

[0127] Specifically, the mileage and numbers of the gyroscopic theodolite traverse points are as follows:

[0128] Gyroscope installation point Mileage Loop number Remarks Y8 28761.938 1673 Installed Y12 27567.822 2674 Installed Y19 25414.930 4455 Installed Y25 23618.514 5950 Installed Y31 21695.238 7547 Installed Y37 19313.000 9094 Not started

[0129] S330: When the gyroscopic orientation error and angular measurement error of the direction traverse satisfy the following formula, the gyroscopic side can be regarded as a strengthened side to participate in the adjustment model. The formula is as follows:

[0130]

[0131] In the formula, m a — the mean error of a single gyroscopic orientation; m β — the mean error of traverse angle measurement; n — the number of survey stations.

[0132] Specifically, the gyroscopic orientation azimuth can be used as a vertical strong side for the adjustment of the connecting traverse according to the situation. Generally, it is corrected to half of the difference between the gyroscopic azimuth and the traverse azimuth.

[0133] S400: Borehole plumb point connection survey: After the TBM drives unidirectionally for a certain distance, a vertical borehole is drilled from the ground surface to the tunnel, and the connection survey inside and outside the tunnel is carried out. The connection survey adopts the one - shaft orientation method to conduct connection observations on the ground and underground.

[0134] Specifically, the TBM drives unidirectionally for 11.8 km and passes through four shallow - buried strata within the mileage range of 20 + 560 - 19 + 000. To better control the tunneling through accuracy of the tunnel, it is planned to drill a vertical borehole from the ground surface to the tunnel near the shallow - buried section at the mileage of 20 + 543, and conduct the connection survey inside and outside the tunnel. Along the tunnel center line direction at the mileage of 20 + 543 in the shallow - buried section, two vertical boreholes are drilled vertically 90° underground at an interval of 14 m. The drilling depth is about 12.4 m, and the drilling diameter is about 10 - 15 cm. The connection survey adopts the one - shaft orientation method to conduct connection observations on the ground and underground.

[0135] S410: One - shaft orientation connection survey. When arranging the connection triangles above and below the shaft, the distance between the two suspended steel wires should be as long as possible, and the distance between the two steel wires should be at least greater than 5 meters; the angles r and r′ between the in - well and out - well entry points and the two steel wires should both be less than 1°; the ratio of the shortest distance from the in - well and out - well entry points to the steel wires to the distance between the two steel wires should not exceed 1.5; the steel wires should be 0.3mm in diameter, with a 10KG weight suspended, and the weight should be immersed in damping fluid (waste engine oil). When observing, it should be ensured that the observations are carried out simultaneously above and below the shaft; when suspending the weight, it must be vertical, and when drilling, ensure that the hole diameter is vertically downward. (Before observation, check the distance between the steel wires above and below the shaft, and the difference should be less than 1mm)

[0136] Specifically, for the determination of the one - shaft orientation dropping point position, the main equipment configuration for TBM tunneling includes: determination of the above - ground point position and determination of the underground point position.

[0137] For the determination of the above - ground point position, according to the shallow - buried section data and the tunnel center - line data provided by the construction, conduct a field survey of the visibility between terrains.

[0138] Specifically, select the section with mileage stake numbers 20 + 526 to 20 + 546 as the position for drilling and dropping points in the shallow - buried section. The selection and layout of the above - ground points are as shown in the appendix Figure 7 as follows

[0139] Specifically, in order to ensure that the included angles of the connection triangles above and below the ground meet the specification requirements, two sets of drilling plan data are designed according to different in - well entry points, and the second set of data is preferentially selected. As shown in the following table

[0140]

[0141]

[0142] Specifically, for the determination of the underground point position: after determining the above - ground drilling point position, considering the tunnel visibility and environmental problems, the underground observation points are selected in the same way as above - ground. In the mileage direction of the near - well point, select a suitable position to determine the underground survey station position.

[0143] S420: Observation and calculation of one - shaft orientation connection survey. The one - shaft orientation observation uses a 0.5 - second Leica total station, and three independent observations are carried out, with 6 sets of observations each time for checking. After there are no problems, take the average value. Set up a station at the near - well point on the ground, sight one direction, and observe the included angle and distance between the set - up station and the reflectors on GS1 and GS2 on the ground. Set up a station at the underground traverse point, sight one direction, and observe the included angle and distance between the set - up station and the reflectors on GS1 and GS2 underground. The limit requirements for angle observation refer to the tunnel traverse observation standard.

[0144] Specifically, after the observation is completed, the adjustment software is used to process the measurement data. Analyze and retest the data that does not meet the requirements of the one-shaft orientation connection triangle, and control the posterior mean square error of unit weight of the adjustment result not to exceed 2.5″.

[0145] S500: Analysis of tunnel breakthrough errors, analysis of tunnel plane breakthrough errors based on borehole plumb points, including: analysis of the azimuth error of the underground starting side, the lateral breakthrough mean square error of the out-of-tunnel control points, the lateral breakthrough mean square error of the in-tunnel traverse, and the lateral error of the tunnel using borehole plumb points; analysis of the elevation breakthrough error of the tunnel.

[0146] S510: Analysis of the azimuth error of the underground starting side: The formula for calculating the azimuth of the underground starting side is:

[0147] α DX1-DX2 =α DS2-DS1 +φ - α + β' + φ' ± 4×180°

[0148] In the formula: φ is the angle between the starting side and the long side; α is the interior angle of the triangle corresponding to side b; β' is the interior angle of the triangle corresponding to side b'; φ' is the angle between side b' and the traverse side DX1 - DX2.

[0149] The error of the azimuth angle α DX1-DX2 in addition to including the errors of each angle used in the calculation, there is also the throwing error θ. According to the error propagation law, the total orientation error is:

[0150]

[0151] Assume that the angular measurement mean square error is 1″, the plumb point error is 1mm, the lengths of the ground connection triangle sides are a = 8m, b = 9m, c = 6m respectively, and the lengths of the underground connection triangle sides are a' = 7.2m, b' = 8, c' = 6.001m respectively. Then there is:

[0152]

[0153] The distance from the starting side to the tunnel breakthrough point is 1700m. Then the maximum lateral coordinate error caused by the orientation azimuth difference is:

[0154]

[0155] S520: Analysis of the lateral breakthrough mean square error of the out-of-tunnel control points: The results of the out-of-tunnel control points adopt the E-level GNSS control network result table provided by the design institute. The tunnel lateral breakthrough error caused by GPS control measurement errors can be estimated by the following method:

[0156]

[0157] In the formula, m j 、m c——Y coordinate error of GPS control points at the inlet and outlet; L j 、L c ——Length from GPS control points at the inlet and outlet to the breakthrough plane; m aj 、m ac ——Azimuth mean square error of GPS connection sides at the inlet and outlet; θ, φ——Angles between the lines connecting the control points at the inlet and outlet to the breakthrough plane and the tangent of the breakthrough point line.

[0158] Specifically, for the out-of-hole control points m j = 1.9194 cm, m c = 2.1175 cm,

[0159] L j = 1639.66 m, L c = 274.76 m, m aj = 0.141″

[0160] m ac = 0.8″, θ = 82°, φ = 20°, through data calculation:

[0161]

[0162] M 洞外 = 2.85 cm

[0163] S530: Analysis of the lateral breakthrough mean square error of the in-hole traverse: According to the in-hole plane control survey design, draw the traverse plane layout diagram according to the scale, and estimate according to the following formula:

[0164]

[0165] In the formula: m β —Mean square error of angle measurement in the control network design; R X —Vertical distance from each point of the control network to the breakthrough plane; d y —Projection length of each side of the control network on the breakthrough plane; —Relative mean square error of the control network design.

[0166] Specifically, according to the technical requirements of the second-class traverse survey in the hole, the average side length of the tunnel is calculated as 300 m respectively to calculate the lateral breakthrough error in the hole. The mean square error of angle measurement m β = 1.8″, relative mean square error of side length Measured and calculated on the cad drawing Then there is:

[0167]

[0168] M 洞内 = 2.8 cm

[0169] Therefore, the through error of the cross double wires in the tunnel is as follows:

[0170]

[0171] S540: Analysis of the lateral error of the tunnel by drilling and dropping points: Considering the GPS control survey outside the tunnel, the lateral through error of the tunnel in the guiding inside the tunnel, and the azimuth error of the starting side, the lateral through error of the tunnel:

[0172]

[0173] Specifically, substituting the above errors into the formula, we get:

[0174]

[0175] M = 28 CM

[0176] From the above results, it can be seen that the through error of the tunnel mainly depends on the starting azimuth difference of the dropped points. If the starting azimuth

[0177]

[0178] Then the through error of the tunnel is:

[0179]

[0180] M = 8.7 CM

[0181] To ensure a smooth through, a gyroscope can be used to check the starting azimuth of the dropped points, and the difference between the gyro azimuth and the underground coordinate azimuth angle is controlled within 15″.

[0182] S550: Analysis of the elevation through error of the tunnel:

[0183] Calculation of the elevation through error of the tunnel:

[0184] The mean square error of the elevation through error caused by the elevation control survey errors inside and outside the tunnel should be calculated according to the following formula:

[0185]

[0186] In the formula, m Δ —— The accidental mean square error per kilometer of leveling (mm); L—— The length of the elevation route outside or inside the tunnel (Km).

[0187] Specifically, the tunnel is leveled according to the second-class leveling, the accidental mean square error per kilometer of leveling is 2 mm, the length of the elevation route outside the tunnel is taken as 21 KM, and the length of the elevation route inside the tunnel is taken as 12 KM. The mean square error of the elevation through error of the tunnel:

[0188]

[0189] M = 16.73 mm

[0190] According to the specification requirements, the maximum allowable error is taken as twice the mean error, and the predicted through error of the tunnel elevation is 33.46 mm.

[0191] In this embodiment, based on the control survey of the ground control network and the tunnel control network, the gyro orientation measurement is combined to improve the measurement accuracy of the azimuth angle, etc. The ground control network is extended to the underground through the connection measurement of drilling and point dropping, so that the accuracy of the measurement results meets the requirements, directly guiding the construction, effectively controlling the transverse through error of the tunnel. In the shallow buried layer position near the through surface in the long tunnel, the connection measurement of ground drilling and point dropping and the underground gyro orientation measurement verification method are used for high-precision control point densification to ensure the perfect through of the tunnel, ensure the precise docking of the tunnel project, and accurately analyze the measurement error.

[0192] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered by the protection scope of the present invention.

[0193] Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A method for measuring the penetration error of a long-distance tunnel, characterized in that: The following steps are involved: S100: Ground control network control measurement: The ground control network is divided into plane control network and elevation control network; S110: The ground plane control network adopts GPS satellite positioning measurement, and 10 groups of control points are buried between the TBM starting tunnel and the exit tunnel according to the route direction; S120: The mean error σ of the baseline length of each level of GPS network is calculated using the fixed error a and proportional error b corresponding to the GPS network accuracy classification level. The side length value D takes the actual average side length. The mean error of the baseline length is calculated as follows: Where: σ—mean error of baseline length, mm; a—fixed error, mm; b—proportional error coefficient, mm / km; D—average side length, km; S130: The elevation control network adopts second-class leveling. The leveling is carried out in round trips along the same leveling route using the same type of instruments and turning point scales. S200: Tunnel control network control measurement: wire network layout: double wire + cross double wire form to lay out the wire network; S300: Gyro orientation measurement: Use precision wire control points and ground control points as known ground edges to perform gyro orientation observation of the tunnel edge; lay out an orientation edge in the tunnel, calculate the coordinate azimuth of the orientation edge in the tunnel based on the conversion calculation between the gyro azimuth and the coordinate azimuth, and compare it with the coordinate azimuth measured by the total station based on the underground control points to evaluate the reliability of the underground control wire orientation accuracy; S400: Drilling point connection measurement: After the TBM excavates a certain distance in one direction, it will drill vertical holes on the surface into the tunnel to conduct connection measurement inside the tunnel and on the surface. The connection measurement adopts the one-well directional method to conduct connection observations on the ground and underground. S410: Directional connection measurement of a well. When laying out the connection triangle above and below the well, the distance between the two suspended steel wires is greater than 5 meters; the angles r and r′ between the above-ground and underground well entry points and the two steel wires are both less than 1°; the ratio of the shortest distance between the above-ground and underground well entry points to the steel wires and the distance between the two steel wires is no more than 1.5; the steel wire diameter is 0.3mm, and a 10KG weight is hung, which is immersed in damping fluid. When observing, observations are made both above and below the well; the weight must be hung vertically, and the hole diameter is vertically downward when drilling; S500: Tunnel penetration error analysis, based on drilling point analysis of tunnel plane penetration error, including: underground starting side orientation error analysis, lateral penetration error analysis of control points outside the tunnel, lateral penetration error analysis of wires inside the tunnel, lateral error analysis of drilling point tunnel, and tunnel elevation penetration error analysis.

2. The method for measuring the penetration error of a long-distance tunnel according to claim 1, characterized in that: Step S200 also includes: S210: Conducting in-tunnel wire measurement, when the number of observation directions is 2, adopting the left and right angle observation method, which may not be zeroed; when the number of observation directions is greater than 2, adopting the direction observation method: S220: Traverse network adjustment steps: Calculation of mean error in traverse network angle measurement, including: calculation based on left and right angle closure error; calculation based on traverse azimuth; traverse azimuth closure tolerance, using second-class traverse for observation; Calculated by the closure difference between the left and right angles: Calculated by the azimuth of the wire: Where: Δ—the difference between the sum of the left and right angles and 360°, and the unit of Δ is "; f β —Azimuth closure error of the attached conductor or closed conductor loop, f β The unit is "; N—number of attached wires or closed wire loops; n—the number of internal angles of the attached conductor or closed conductor loop; S230: In-tunnel leveling control measurement: a fixed and stable leveling point is set at the tunnel entrance and connected with the leveling point near the ground as the starting point of the tunnel leveling measurement. A leveling point is set every 2 km in the tunnel. Due to the deep water accumulation in the tunnel and the large vibration caused by the running of the marshalling train, the conductor point brackets on both sides of the segment are used as leveling points for measurement.

3. The method for measuring the penetration error of a long-distance tunnel according to claim 1, characterized in that: Step S300 also includes: S310: Perform gyro orientation observation on the known side on the ground to determine the instrument constant; perform gyro orientation observation on the underground orientation side to determine the gyro azimuth of the orientation side; return to the known side on the ground to perform gyro orientation observation, and check the instrument stability and accuracy based on the two ground known side measurement results to ensure that the gyro orientation results are accurate and reliable; S320: Calculation of the azimuth of the underground directional edge coordinates: directly measure the instrument constant Δ based on the azimuth of the control point; S330: When the gyro orientation error of the directional wire and the wire angle measurement error satisfy the following formula, the gyro edge can be regarded as a reinforcement edge to participate in the adjustment model: Where m a — gyro orientation error; m β —Traverse angle measurement error; n—number of measuring stations.

4. The method for measuring the penetration error of a long-distance tunnel according to claim 1, characterized in that: Step S400 also includes: S420: one-well directional connection measurement observation and calculation, one-well directional observation uses a 0.5-second Leica total station, conducts three independent observations, and observes 6 rounds each time for verification. After no problem, the average is taken, and a station is set up near the well point on the ground, looking back in one direction, observing the angle and distance between the station and the reflectors on the ground GS1 and GS2; a station is set up on the underground wire point, looking back in one direction, observing the angle and distance between the station and the reflectors on the underground GS1 and GS2. After the observation is completed, the measurement data is processed using adjustment software.

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