GNSS-based Real-time Monitoring and Early Warning Device and Method for Tunnel Surface Displacement

Abstract

The present invention provides a GNSS-based real-time monitoring and early warning device and method for tunnel surface displacement. The GNSS-based real-time monitoring and early warning device for tunnel surface displacement includes a measurement module, a reference module and a data processing terminal, wherein a tunnel is provided with a plurality of tunnel sections along the length direction, and a plurality of monitoring points are evenly arranged on the tunnel section, and a measurement module is fixed to each monitoring point through a fixed structure, and the measurement module is used to measure the real-time displacement data of the tunnel surrounding rock; the reference module is fixed on the ground surface, and the input end of the real-time data processing terminal is connected to the output end of the measurement module and the reference module, and the data processing terminal corrects the data measured by the measurement module based on the data of the reference module, and monitors the tunnel surface displacement in real time based on the corrected data, and the present invention also provides a tunnel surface displacement real-time monitoring and early warning method. The present invention can realize real-time continuous full-section monitoring of the tunnel, and effectively improves the monitoring accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel displacement monitoring, and in particular to a GNSS-based real-time monitoring and early warning device and method for tunnel surface displacement. Background Art

[0002] Under deep mining conditions in coal mines, the mined coal rock mass is subjected to high static stress such as the deadweight of the overlying rock layer, tectonic stress, and mining stress, which can easily generate high stress on the surrounding rock of the tunnel, causing tunnel deformation, seriously threatening the stability of the surrounding rock of the tunnel, and affecting the smooth progress of coal mining. At present, the main methods for monitoring tunnel surface deformation are the cross point method and the sensor method. These two methods have the following defects and shortcomings:

[0003] (1) The monitoring timeliness is poor.

[0004] The monitoring of the cross-point method usually requires manual operation, including setting points and measuring, which is not only time-consuming and laborious, but also easily affected by human factors, such as errors, unstable monitoring frequency, etc. The setting of these points is usually limited. Therefore, this method cannot fully reflect the deformation of the entire roadway or tunnel, especially for the case of uneven deformation distribution or large local deformation. In addition, this method has large lags and uncertainties in data collection, updating and efficiency, and cannot provide real-time or continuous deformation data.

[0005] When using strain sensors for monitoring, existing products are limited in data collection frequency, resulting in the monitoring data being unable to meet real-time and accuracy requirements, which makes it somewhat insufficient in timely detection of deformation anomalies or emergency situations.

[0006] (2) The monitoring results are unreliable.

[0007] Strain sensors are usually a kind of precision electronic equipment, which is easily damaged by machinery or affected by factors such as electromagnetic interference. They need to be maintained and serviced, otherwise it will affect the normal operation of the monitoring system and the accuracy of the data. In addition, traditional strain sensors can only obtain the strain data of the tunnel, but cannot obtain the real displacement data of the tunnel surrounding rock.

[0008] (3) Poor environmental adaptability.

[0009] Due to the complexity of the tunnel environment, there may be geological structures such as faults, landslide zones or caves in the tunnel area, as well as high stress concentration or large-scale groundwater infiltration, which makes the surrounding rock extremely unstable and threatens the safety of personnel. There may be adverse conditions such as toxic gases, high temperatures or extreme humidity inside the tunnel, making it impossible for personnel to stay for a long time. Traditional monitoring equipment is difficult to effectively arrange and operate in a complex geological environment, which makes monitoring more difficult. Summary of the invention

[0010] In order to solve the problems in the prior art, the present invention provides a GNSS-based real-time monitoring and early warning device for tunnel surface displacement, and also provides a GNSS-based real-time monitoring and early warning method for tunnel surface displacement implemented based on the GNSS-based real-time monitoring and early warning device for tunnel surface displacement. Real-time monitoring and early warning of tunnel displacement based on the GNSS system can solve the problems of low timeliness and low monitoring accuracy in traditional tunnel monitoring methods, improve the safety and stability of underground tunnels, improve the real-time and accuracy of tunnel displacement monitoring, and effectively prevent the occurrence of tunnel surrounding rock accidents. The global positioning coverage and high-precision positioning capability of GNSS (Global Satellite Navigation System) are used to improve the comprehensiveness and accuracy of monitoring, and by constructing an intelligent tunnel detection model and early warning mechanism, the automatic collection, integration and analysis of monitoring data are realized, thereby improving the utilization value and application efficiency of monitoring data.

[0011] The present invention discloses a real-time monitoring and early warning device for tunnel surface displacement based on GNSS, comprising a measuring module, a reference module and a data processing terminal, wherein a plurality of tunnel sections are arranged along the length direction of the tunnel, a plurality of monitoring points are evenly arranged on the tunnel sections, a measuring module is fixed to each monitoring point through a fixed structure, and the measuring module is used to measure the real-time displacement data of tunnel surrounding rock; the reference module is fixed on the ground surface, the input end of the real-time data processing terminal is respectively connected to the output end of the measuring module and the reference module, the data processing terminal corrects the data measured by the measuring module based on the data of the reference module, and monitors the tunnel surface displacement in real time based on the corrected data, the measuring module comprises a GNSS receiving device and an acceleration detection device, the reference module adopts a GNSS receiver capable of receiving multiple satellite signals at the same time, the reference module is arranged on the ground surface and in an open area away from obstructions, the data processing terminal performs baseline solution and data adjustment according to the original data of the reference module, judges whether the reference module is displaced according to the adjustment result, and the original coordinates of the reference module are credible if no displacement occurs; if the reference module is displaced, the displacement amount is calculated according to the adjustment result, and the three-dimensional coordinate information of the reference module is updated.

[0012] Furthermore, the data processing terminal includes a processor, a storage module, a display module and a data transmission module, wherein the processor is used to monitor the tunnel surface displacement in real time, the storage module is used to store data information sent by the reference module and the measurement module and save calculation results, the display module is used to visualize the calculation results, and the data transmission module is used for data transmission between the data processing terminal and the reference module and the measurement module.

[0013] The present invention also provides a GNSS-based real-time monitoring and early warning method for tunnel surface displacement, comprising the following steps:

[0014] S101: receiving the global coordinates of each monitoring point on the tunnel surface, and establishing the number of each tunnel section and the measurement module number information;

[0015] S102: Based on the global coordinate information of the reference module, the global coordinates measured by the measurement module are corrected to obtain updated three-dimensional coordinate information of each monitoring point;

[0016] S103: Select the coordinates of the central axis position monitoring point of the installation surface of one of the tunnel sections as the local coordinate origin, generate data of each tunnel section, and determine the relative position of each tunnel section;

[0017] S105: Determine whether the three-dimensional coordinate information of each monitoring point has changed. If not, return to step S101. If yes, update the three-dimensional coordinate information of the monitoring point and receive the real-time acceleration information of the measurement module.

[0018] S107: Recording the single displacement amount, the deformation amount of the tunnel surface per unit time and the real-time acceleration information for each coordinate update;

[0019] S108: Establishing an early warning mechanism: Setting early warning signal characteristics, wherein the early warning signal characteristics include the total displacement and deformation speed of the tunnel, and generating early warning information to remind relevant personnel based on the early warning signal characteristic values.

[0020] Furthermore, after step S103 is executed, step S104 is further included: constructing a tunnel monitoring model according to the location characteristics and cross-section change characteristics of the tunnel section,

[0021] After step S105 is executed, step S106 is also included: reconstructing the tunnel monitoring model based on the monitoring points whose three-dimensional coordinate information has changed.

[0022] Furthermore, in step S104, the method for constructing a tunnel monitoring model according to the location characteristics and cross-section change characteristics of the tunnel section is:

[0023] If the tunnel section is in a straight line segment, the corresponding points of the adjacent tunnel sections are connected, and the triangulation method is used to construct a triangular surface network to generate a tunnel monitoring model;

[0024] If the tunnel section is at a corner, the three adjacent tunnel sections are taken as a tunnel section group, the local coordinates of the feature points at the corner are calculated, and the surface splicing technology is applied to realize the construction of the tunnel monitoring model.

[0025] Furthermore, if the tunnel section is at a corner, the tunnel monitoring model is constructed as follows:

[0026] The arc segments of the three lane sections at the lane corners are discretized uniformly into p feature points using the coordinates of the central axes of the three lane sections A, B, and C. , , Calculate the coordinates of the center of a circle of three points and radius R, with the center of the circle as the local coordinate origin, the coordinates of the feature points between the tunnel sections are calculated according to the azimuth α of each feature point; adjacent feature points are connected, and a triangulated network is constructed in the order of line-surface-body. The corners are connected using the surface splicing technology to generate a tunnel monitoring model.

[0027] Feature Points Coordinates The calculation formula is:

[0028]

[0029]

[0030]

[0031] in, .

[0032] Furthermore, in step S108, if any warning signal characteristic value is greater than a set threshold, the position of the measurement module is highlighted on the display end of the lane monitoring model to remind relevant personnel in a visual manner.

[0033] Furthermore, in step S108, the warning signal feature also includes a fractal dimension of the tunnel surface displacement, and the fractal dimension of the tunnel surface displacement is used to evaluate whether the tunnel surrounding rock surface deformation time series has state continuity.

[0034] Furthermore, the specific method of evaluating whether the deformation time series of the surrounding rock surface of the tunnel has state continuity through fractal dimension is as follows:

[0035] (1) Construct the relationship formula between fractal dimension and Hurst index H: ;

[0036] (2) Construct the regression equation of Hurst index H, and obtain the H value by the least squares regression equation. The method for obtaining Hurst index H is:

[0037] The Hurst index H is calculated using the repeated table range method, and the roadway surface displacement time series is divided into subsequences, each of which contains elements, is the subsequence number, is the sequence number of the element, and each element is recorded as:

[0038]

[0039] Normalized value of subsequence sample data for:

[0040]

[0041] in, is the mean of the subsequence sample data,

[0042] Establish a cumulative time series of roadway surface displacement :

[0043]

[0044] Calculate range , Standard Deviation , re-standardized range , the calculation formula is:

[0045]

[0046]

[0047]

[0048] make ,

[0049] Logarithmization is performed, and a least squares regression equation is established to obtain the value of the Hurst index H. The least squares regression equation is:

[0050]

[0051] in, is the range of the cumulative time series of the roadway surface displacement samples, is the standard deviation of the sample sequence, is a constant, is a constant Logarithmization, is the Hth power of the number of subsequences k, where H is the Hurst index; For The corresponding cumulative time series The ordinal number of

[0052] (3) Obtaining a value of the fractal dimension D based on the relationship between the fractal dimension and the Hurst exponent H;

[0053] (4) Based on the value of the fractal dimension D, the degree of continuity of the time series state of the deformation of the surrounding rock surface of the tunnel is evaluated.

[0054] Furthermore, the early warning mechanism is: according to the numerical range of the early warning signal characteristics, a corresponding early warning signal is generated, and the early warning signal includes: a first-level early warning signal, a second-level early warning signal and a third-level early warning signal.

[0055] When the total displacement of the lane at the monitoring point is less than or equal to the first displacement threshold or the deformation speed is less than or equal to the first speed threshold, the lane is monitored in real time, and the data processing terminal system sends out a first-level warning signal; when the total displacement of the lane at the monitoring point is greater than the first displacement threshold and less than or equal to the second displacement threshold, or the deformation speed is greater than the first speed threshold and less than or equal to the second speed threshold, the lane section position is located according to the measurement module number, and a second-level warning signal is sent out at the lane section position to remind the staff to check the relevant areas of the lane; when the total displacement of the lane at the monitoring point is greater than the second displacement threshold, or the deformation speed is greater than the second speed threshold, a third-level warning signal is sent out to the lane as a whole, and the lane section position is located according to the measurement module number, to warn the staff to take corresponding emergency measures.

[0056] at the same time,

[0057] When the fractal dimension When the fractal dimension is When the fractal dimension is , it means that the deformation of the tunnel has a time duration, and the system issues a second-level warning signal to remind relevant staff to be more vigilant and focus on the continuous deformation area; , indicating that the deformation of the tunnel is highly time-persistent, and the system issues a third-level early warning signal to remind relevant staff to take emergency measures immediately in the deformed area.

[0058] Compared with the prior art, the beneficial effects of the present invention are: by setting up multiple tunnel end faces in the tunnel and arranging multiple detection points on the tunnel end faces, it is possible to continuously monitor the entire cross-section in real time, and by correcting the detection information of the measurement module through the reference module, the monitoring accuracy can be further improved. By setting up a data processing terminal, the staff can remotely obtain the real-time data of the tunnel, which improves the safety of personnel monitoring. The present invention also has the following innovative features:

[0059] (1) The present invention can obtain the real displacement of the coal-rock tunnel, construct the three-dimensional position state of the tunnel in real time, and perform real-time continuous monitoring of the tunnel surface displacement.

[0060] The present invention uses a GNSS receiving device with high positioning accuracy, which can realize displacement monitoring with millimeter level or even higher accuracy, and can timely detect small displacement changes, making the monitoring data more timely and accurate. In addition, the GNSS system has the characteristics of global positioning coverage, which greatly improves the real-time, continuity and accuracy of monitoring. At the same time, by constructing a three-dimensional tunnel monitoring model, continuous full-section monitoring of the tunnel can be realized.

[0061] (2) The present invention can realize the monitoring of the entire life cycle of the tunnel, including from tunnel excavation construction to working face installation, mining, and then to working face withdrawal and closure, to ensure the safe and stable operation of the tunnel throughout its entire life cycle.

[0062] (3) The present invention can realize automatic collection, data processing, real-time monitoring and feedback of monitoring data, perform three-dimensional modeling based on the collected data, conduct visual management of the entire tunnel, and intelligently predict the tunnel status based on historical data, evaluate the tunnel risk status, provide response plans for decision makers, and improve decision-making efficiency and accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] In order to more clearly illustrate the present invention or the solutions in the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0064] Figure 1 This is a schematic structural diagram of the real-time monitoring and early warning device for tunnel surface displacement of the present invention;

[0065] Figure 2 This is a flow chart of the method for real-time monitoring of lane surface displacement of the present invention;

[0066] Figure 3 Constructing a flow chart for the laneway detection model of the present invention;

[0067] Figure 4 This is a schematic diagram of the arrangement of measurement modules on the end face of a tunnel according to an embodiment of the present invention.

[0068] Figure numerals: 1-surrounding rock, 2-measurement module. DETAILED DESCRIPTION

[0069] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs; the terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention; the terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of the present invention or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0070] Reference to "embodiments" in the present invention means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it mutually exclusive, independent, or alternative to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in the present invention may be combined with other embodiments.

[0071] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings.

[0072] like Figure 1 As shown, the present invention provides a GNSS-based real-time monitoring and early warning device for tunnel surface displacement, including a measuring module, a reference module and a data processing terminal, wherein a fixed base is fixed to the monitoring point on the surrounding rock surface of the tunnel by bolts, wherein a buckle is provided on the fixed base for connecting the fixed base with the measuring module, and the fixed base is fixed to the surrounding rock surface of the tunnel by bolts.

[0073] The measurement module of this example includes a GNSS receiver and an acceleration sensor. The GNSS receiver can be used to receive three-system eight-frequency signals, the three systems are China's Beidou satellite navigation system, the United States Global Positioning System and Russia's Global Satellite Navigation System, and the eight frequencies are the B1 / B2 / B3 bands of the Beidou satellite navigation system BDS, the L1 / L2 / L5 bands of the global positioning system GPS and the G1 / G2 bands of the global satellite navigation system GLONASS. The acceleration sensor can measure real-time acceleration and transmit it to the data processing terminal.

[0074] The measuring module is installed on the surface of the tunnel surrounding rock and is used to measure the real-time deformation data of the tunnel surrounding rock, including real-time three-dimensional coordinates and real-time acceleration.

[0075] The reference module includes a GNSS receiver, which is installed on the surface. The selected position should have a wide and unobstructed view and can receive multiple satellite signals at the same time to receive the positioning error of the receiving device, improve the positioning accuracy, and obtain real-time data.

[0076] The data processing terminal includes a processor, a storage module, a display module, and a data transmission module. The processor is used to run a predetermined computer program, process received data, and generate calculation results; the storage module is used to store computer programs, received data, and save calculation results; the display module is used to visualize calculation results; and the data transmission module is used to transmit data between the measurement module, the reference module, and the storage module of the data processing terminal. The computer program in this example is used to execute the real-time monitoring and early warning method of the roadway surface displacement.

[0077] The device of the present invention can receive raw data from each reference module and measurement module in the monitoring area, determine the three-dimensional coordinates of each reference module and measurement module, and transmit the three-dimensional coordinates to the data processing terminal through the network.

[0078] Preferably, the data processing terminal performs baseline solution and data adjustment based on the original data of the reference module, and determines whether the reference station has been displaced based on the adjustment result. If no displacement has occurred, the original coordinates of the reference module are credible; if the reference module has been displaced, the displacement amount is calculated based on the adjustment result, and the three-dimensional coordinates of the reference station are updated.

[0079] The measurement module collects data, and the data processing center performs real-time differential calculations based on the differential correction data of the base station and the data collected by the measurement module according to the principle of relative positioning to obtain accurate three-dimensional coordinates of the measurement station and update the stored three-dimensional coordinates of the measurement module.

[0080] In this example, several tunnel sections are set up along the length of the tunnel, and multiple monitoring points are arranged in each tunnel section. The tunnel sections can be set at different intervals according to different monitoring accuracies, such as 1m, 5m, 10m, etc. In order to improve the continuity of measurement between tunnel sections, monitoring points can be set at the midpoints of two sections on the central axis of the four faces of the tunnel. Use 1, 2, 3, ... to number each tunnel section one by one, number the installed measurement modules, and mark the numbers of the measurement modules at special points; special points can be tunnel corners, central axis points on both sides, and central axis points of the bottom and top plates, etc.

[0081] like Figure 4 As shown, as an embodiment of the present invention, this example takes a rectangular tunnel as an example, and sets a monitored tunnel section every 2m along the length direction of the tunnel monitoring section. The number of tunnel end faces in this example is the minimum number 3 for illustration. 16 monitoring points are arranged on each tunnel section, which are located at the corner points of the rectangular tunnel, the center axis points of both sides, the center axis points of the bottom plate and the top plate, and the midpoint of the selected point. Drill holes at the selected monitoring points, use expansion bolts to pass through the four limit holes on the fixed base to fix the base on the surrounding rock 1, so that the fixed base is tightly connected to the surface of the surrounding rock 1, and then connect the measurement module 2 to the buckle on the fixed base to achieve the installation of the measurement module 2.

[0082] In this example, the reference module is installed on the ground of the tunnel in the monitoring area, away from obstructions such as high buildings, mountains, trees, etc., and with a wide open sky area within the field of view, and avoiding undulating areas on the surface, to ensure that a sufficient number of satellite signals can be effectively received. Multiple reference modules can be set according to the length of the tunnel to improve the availability and fault tolerance of the system.

[0083] The reference module imports known precise coordinates , using the received satellite signals to calculate its true position. By measuring the propagation time difference of satellite signals and the Doppler effect, the position of the base station relative to the satellite system can be determined. The base module generates differential correction data from its own measured position information and other related information (such as clock calibration, atmospheric delay correction, etc.). The differential correction data is used to correct the positioning error of the receiving device and improve the positioning accuracy.

[0084] The measurement module receives navigation signals from satellites in orbit, including the position, speed, and time of the satellites. It determines the distance by measuring the signal propagation time from the satellite to the receiving station. It performs baseline calculation on the three-dimensional position direction based on the satellite data received by the GNSS receiver, thereby obtaining the spatial position data and three-dimensional displacement information of the monitoring station with an accuracy of millimeters. The measurement module transmits the data to the data processing terminal via a wireless connection (4G, Wi-Fi, Bluetooth, etc.).

[0085] like Figure 2 and Figure 3 As shown, the method for real-time monitoring of the tunnel surface displacement by the data processing terminal in this example is:

[0086] Step S101: receiving the global coordinates of each monitoring point on the tunnel surface, and establishing each tunnel section number and measurement module number information.

[0087] In this example, the measurement modules that have completed the initial positioning are numbered. In this example, the measurement modules in the same section are grouped together to number the tunnel sections, and the three-dimensional coordinates corresponding to each measurement module are determined to quickly locate the tunnel section position where displacement occurs. In this example, the measurement module in the middle of the tunnel floor of the No. 1 tunnel section is the No. 1 measurement module, and the corresponding coordinate number is , and number them sequentially until the 16th measurement module is .

[0088] S102: Based on the global coordinate information of the reference module, the global coordinates measured by the measurement module are corrected to obtain updated three-dimensional coordinate information of each monitoring point.

[0089] S103: Select the coordinates of the central axis position monitoring point of the installation surface of one of the tunnel sections as the local coordinate origin, generate data for each tunnel section, and determine the relative position of each tunnel section.

[0090] In this example, the coordinates of the first measurement module are is the local coordinate origin , establish the local coordinate system of the tunnel, determine the basic position data of each section, and determine the relative position between the tunnel sections. The local coordinate conversion formula is:

[0091]

[0092] in, are local coordinates, is the local origin coordinate, is the corresponding global coordinate.

[0093] The three-dimensional coordinate system in space has three basis vectors, namely the unit vector , converting GNSS three-dimensional global coordinates into localized local coordinates to build a three-dimensional lane monitoring model, are local coordinate unit vectors respectively. The unit vectors of the new and old coordinate systems can be converted by the following formula:

[0094]

[0095] In the formula is the coordinate transformation coefficient matrix, is the global coordinate unit vector, is the local coordinate unit vector, The value of is 1, 2, 3.

[0096] The formula for converting GNSS global coordinates into local coordinates is:

[0097]

[0098] In the formula, is the local coordinate vector, is the global coordinate vector, is the transformation vector of the two coordinate origins,

[0099] From the conversion relationship, we can know that:

[0100]

[0101] That is, the global coordinates are converted to local coordinates:

[0102]

[0103] S105: Determine whether the three-dimensional coordinate information of each monitoring point has changed. If not, return to step S101. If yes, update the three-dimensional coordinate information of the monitoring point and receive the real-time acceleration information of the measurement module.

[0104] S107: Record the single displacement amount, the deformation amount of the tunnel surface per unit time and the real-time acceleration information for each coordinate update.

[0105] S108: Establish an early warning mechanism: Set early warning signal characteristics, including the total displacement and deformation speed of the lane, and generate early warning information to remind relevant personnel based on the early warning signal characteristic value. In this example, relevant personnel can be reminded by indicator lights, buzzers, PC terminals, mobile terminal information, etc.

[0106] Preferably, this example constructs a lane monitoring model and displays the lane monitoring model in real time through a display module, so that monitoring personnel can obtain the real-time displacement status of the lane more intuitively and conveniently.

[0107] Therefore, after executing step S103, this example further includes step S104: constructing a tunnel monitoring model according to the location characteristics and cross-section change characteristics of the tunnel section.

[0108] After step S105 is executed, step S106 is also included: reconstructing the tunnel monitoring model for the monitoring points whose three-dimensional coordinate information has changed.

[0109] In step S108, if any warning signal characteristic value is greater than a set threshold, the position of the measurement module is highlighted on the display end of the lane monitoring model to remind relevant personnel in a visual manner.

[0110] The preferred embodiments of the present invention are described in detail below.

[0111] In step S104, the method for constructing a tunnel monitoring model according to the location characteristics and cross-section change characteristics of the tunnel section is:

[0112] If the tunnel section is in a straight line segment, the corresponding points of the adjacent tunnel sections are connected, and the triangulation method is used to construct a triangular surface network to generate a tunnel monitoring model;

[0113] If the tunnel section is at a corner, the three adjacent tunnel sections are taken as a tunnel section group, the local coordinates of the feature points at the corner are calculated, and the surface splicing technology is applied to realize the construction of the tunnel monitoring model.

[0114] Preferably, if the tunnel section is at a corner, the tunnel monitoring model is constructed as follows:

[0115] The arc segments of the three lane sections A, B, and C at the lane corners are discretized uniformly into p feature points, 48 ​​feature points in this example, and then the arc segments of the three lane sections A, B, and C are discretized uniformly into p feature points. , , Calculate the coordinates of the center of a circle of three points and radius R, with the center of the circle as the local coordinate origin, the coordinates of the feature points between the tunnel sections are calculated according to the azimuth α of each feature point; adjacent feature points are connected, and a triangulated network is constructed in the order of line-surface-body. The corners are connected using the surface splicing technology to generate a tunnel monitoring model.

[0116] Feature Points Coordinates The calculation formula is:

[0117]

[0118]

[0119]

[0120] is the sequence number of the feature point,

[0121] In this example, if the tunnel section is in a straight line segment, during the monitoring process, due to local displacement and deformation of the tunnel, the processing method for the situation where multiple tunnel end faces are not straight lines is as follows:

[0122] The measurement module updates the coordinates at a fixed signal receiving frequency, connects adjacent lane monitoring points, and constructs a triangulated network in the order of line-surface-body. For the unchanged segments between lane feature points, the adjacent feature points are connected and the triangulated network is constructed using Delaunay triangulation. For the changed segments between lane feature points, Bézier surfaces and Bézier surface splicing are used to realize model construction and generate a local lane monitoring model.

[0123] In step S108, the tunnel monitoring model in this example outputs the results to the display terminal to form a visual interface. The PC client and mobile client are set up to visualize and display the monitored tunnel displacement in real time and record the single displacement amount. , the deformation of the tunnel surface per unit time is also called the deformation speed , real-time acceleration In this example, the changing trend of the lane displacement can be presented on the display terminal in the form of variable-time charts, curves, etc.

[0124] Preferably, the early warning mechanism established in this example is based on the total displacement of the lane , deformation speed , fractal dimension It is the characteristic value of the early warning signal. When any characteristic value of the early warning signal reaches or exceeds the set threshold, a corresponding alarm signal will be generated. The alarm signal will be notified in the form of a pop-up window on the PC client and in the form of an alarm ring on the mobile client, reminding relevant personnel to take necessary emergency measures.

[0125] In this example, the cumulative displacement of the three-direction coordinate data of each monitoring point is the total displacement of the tunnel. Use the Euclidean norm to measure:

[0126]

[0127] The cumulative displacement in each direction is recorded, and the deformation speed of the tunnel surrounding rock per unit time is calculated. ,

[0128]

[0129] Where T is the unit time, which can be set to 1h, 2h, 5h, 24h, etc.

[0130] The storage module records the surface deformation data of the tunnel surrounding rock in each time period and evaluates the safety of the tunnel based on the early warning mechanism.

[0131] Preferably, this example also builds an early warning model to predict deformation trends, evaluate the risk status of the tunnel, provide response plans for decision makers, and improve decision-making efficiency and accuracy. The early warning model in this example is established using a trend algorithm. By recording the deformation data of the tunnel surrounding rock surface over a period of time, it calculates whether the deformation time series of the tunnel surrounding rock surface has state continuity.

[0132] In this example, the trend algorithm calculates the relationship between the fractal dimension D of the roadway surface displacement and the Hurst index H according to the deformation characteristics of the roadway to predict the evolution characteristics of the roadway surface displacement. When 1.0<D<1.5, the deformation time series of the roadway surrounding rock surface has state continuity. The closer D is to 1.0, the higher the degree of time continuity of the series.

[0133] The specific method of evaluating whether the deformation time series of the surrounding rock surface of the tunnel has state continuity through fractal dimension is as follows: ;

[0134] (2) Construct the regression equation of Hurst index H, and obtain the H value by the least squares regression equation. The method for obtaining Hurst index H is:

[0135] The Hurst index H is calculated using the repeated table range method, and the roadway surface displacement time series is divided into subsequences, each of which contains elements, is the subsequence number, is the sequence number of the element, and each element is recorded as:

[0136]

[0137] Normalized value of subsequence sample data for:

[0138]

[0139] in, is the mean of the subsequence sample data,

[0140] Establish a cumulative time series of roadway surface displacement :

[0141]

[0142] Calculate range , Standard Deviation , re-standardized range , the calculation formula is:

[0143]

[0144]

[0145]

[0146] make ,

[0147] Logarithmization is performed, and a least squares regression equation is established to obtain the value of the Hurst index H. The least squares regression equation is:

[0148]

[0149] in, is the range of the cumulative time series of the roadway surface displacement samples, is the standard deviation of the sample sequence, is a constant, is a constant Logarithmization, is the Hth power of the number of subsequences k, where H is the Hurst index; For The corresponding cumulative time series The ordinal number of

[0150] (3) Obtaining a value of the fractal dimension D based on the relationship between the fractal dimension and the Hurst exponent H;

[0151] (4) Based on the value of the fractal dimension D, the degree of continuity of the time series state of the deformation of the surrounding rock surface of the tunnel is evaluated.

[0152] Preferably, this example adopts a three-level warning mechanism. According to the numerical range of the warning signal feature, a corresponding warning signal is generated, and the warning signal includes: a first-level warning signal, a second-level warning signal and a third-level warning signal.

[0153] In this case, the first-level warning signal is a green warning signal, the second-level warning signal is a yellow warning signal, and the third-level warning signal is a red warning signal.

[0154] Green warning signal: When the tunnel is in normal use and the deformation is within a safe range, the deformation warning system sends a continuous monitoring signal, the tunnel monitoring model has no special display on the display terminal, and the warning signal is green;

[0155] Yellow warning signal: When abnormal deformation occurs somewhere in the tunnel, the deformation warning system sends out a yellow warning signal and locates the abnormal deformation location in real time. The tunnel monitoring model highlights the abnormal location on the display terminal to remind the staff to check the relevant areas of the tunnel;

[0156] Red warning signal: When the deformation of the tunnel exceeds the safety threshold, the deformation warning system sends a red signal. The tunnel monitoring model highlights the abnormal tunnel as a whole on the display terminal, and sends an alarm message to the mobile terminal to remind relevant staff to take emergency measures immediately.

[0157] In this example, the early warning mechanism is:

[0158] When the total displacement of the lane at the monitoring point is less than or equal to the first displacement threshold or the deformation speed is less than or equal to the first speed threshold, the lane is monitored in real time, and the data processing terminal system sends out a first-level warning signal; when the total displacement of the lane at the monitoring point is greater than the first displacement threshold and less than or equal to the second displacement threshold, or the deformation speed is greater than the first speed threshold and less than or equal to the second speed threshold, the lane section position is located according to the measurement module number, and a second-level warning signal is sent out at the lane section position to remind the staff to check the relevant areas of the lane; when the total displacement of the lane at the monitoring point is greater than the second displacement threshold, or the deformation speed is greater than the second speed threshold, a third-level warning signal is sent out to the lane as a whole, and the lane section position is located according to the measurement module number, to warn the staff to take corresponding emergency measures.

[0159] at the same time,

[0160] When the fractal dimension When the fractal dimension is When the fractal dimension is , it means that the deformation of the tunnel has a time duration, and the system issues a second-level warning signal to remind relevant staff to be more vigilant and focus on the continuous deformation area; , indicating that the deformation of the tunnel is highly time-persistent, and the system issues a third-level early warning signal to remind relevant staff to take emergency measures immediately in the deformed area.

[0161] The first displacement threshold in this example is , the second displacement threshold is , the first speed threshold in this example is , the second speed threshold is Of course, the various thresholds in this example are not limited to the values ​​in this embodiment and can be set according to requirements.

[0162] Compared with the prior art, the present invention has the following innovative features:

[0163] (1) The present invention can realize real-time continuous full-section monitoring.

[0164] The present invention adopts a GNSS receiving device with high positioning accuracy, can realize displacement monitoring with millimeter level or even higher accuracy, can timely detect small displacement changes, can realize real-time displacement monitoring of tunnels, and make monitoring data more timely and accurate. In addition, the GNSS system has the characteristics of global positioning coverage, which greatly improves the real-time, continuity and accuracy of monitoring. At the same time, by constructing a three-dimensional tunnel monitoring model, continuous full-section monitoring of the tunnel is realized. The present invention can obtain the real displacement of the coal and rock tunnel, construct the three-dimensional position state of the tunnel in real time, and perform real-time and continuous monitoring of the surface displacement of the tunnel.

[0165] (2) The present invention can realize the full life cycle monitoring of the tunnel.

[0166] The present invention can realize the whole life cycle monitoring of the tunnel, from tunnel excavation construction to working face installation, mining, and then to working face withdrawal and closure. The present invention can monitor the surface displacement of the tunnel in real time to ensure the safe and stable operation of the tunnel throughout its whole life cycle.

[0167] (3) The present invention can assist monitoring personnel in making intelligent decisions in lanes.

[0168] The present invention can realize automatic collection, data processing, real-time monitoring and feedback of monitoring data, perform three-dimensional modeling based on the collected data, conduct visual management of the entire tunnel, and intelligently predict the tunnel status based on historical data, evaluate the tunnel risk status, provide response plans for decision makers, and improve decision-making efficiency and accuracy.

[0169] The specific implementation modes described above are preferred implementation modes of the present invention, and are not intended to limit the specific implementation scope of the present invention. The scope of the present invention includes but is not limited to the specific implementation modes, and all equivalent changes made according to the present invention are within the protection scope of the present invention.

Claims

1. A GNSS-based real-time monitoring and early warning device for tunnel surface displacement, characterized in that: It includes a measurement module, a reference module and a data processing terminal, wherein: Several tunnel sections are arranged along the length direction of the tunnel, and multiple monitoring points are evenly arranged on the tunnel sections. A measuring module is fixed to each monitoring point through a fixed structure, and the measuring module is used to measure the real-time displacement data of the tunnel surrounding rock; The reference module is fixed on the ground surface, the input end of the data processing terminal is connected to the output end of the measurement module and the reference module respectively, the data processing terminal corrects the data measured by the measurement module based on the data of the reference module, and monitors the displacement of the tunnel surface in real time based on the corrected data, The measurement module includes a GNSS receiving device and an acceleration detection device. The reference module uses a GNSS receiver that can simultaneously receive multiple satellite signals. The reference module is set on the surface of the earth in an open area away from obstructions. The data processing terminal performs baseline solution and data adjustment based on the original data of the reference module, and determines whether the reference module is displaced based on the adjustment result. If no displacement occurs, the original coordinates of the reference module are credible; if the reference module is displaced, the displacement amount is calculated based on the adjustment result, and the three-dimensional coordinate information of the reference module is updated. The data processing terminal constructs a tunnel monitoring model based on the location characteristics and cross-section change characteristics of the tunnel section. If the tunnel section is in a straight line segment, the corresponding points of the adjacent tunnel sections are connected, and the triangulation method is used to construct a triangular surface network to generate a tunnel monitoring model; If the tunnel section is at a corner, the three adjacent tunnel sections are used as a tunnel section group, the local coordinates of the feature points at the corner are calculated, and the surface splicing technology is applied to realize the construction of the tunnel monitoring model. The specific construction method is as follows: The arc segments of the three lane sections A, B, and C at the lane corners are discretized uniformly into p feature points. , , Calculate the coordinates of the center of a circle of three points and radius R, with the center of the circle as the local coordinate origin, the coordinates of the feature points between the tunnel sections are calculated according to the azimuth α of each feature point; adjacent feature points are connected, and a triangulated network is constructed in the order of line-surface-body. The corners are connected using the surface splicing technology to generate a tunnel monitoring model. Feature Points Coordinates The calculation formula is: in, .

2. The GNSS-based real-time monitoring and early warning device for tunnel surface displacement according to claim 1 is characterized in that: The data processing terminal includes a processor, a storage module, a display module and a data transmission module, wherein the processor is used to monitor the displacement of the tunnel surface in real time, the storage module is used to store the data information sent by the reference module and the measurement module and save the calculation results, the display module is used to visualize the calculation results, and the data transmission module is used for data transmission between the data processing terminal and the reference module and the measurement module.

3. A method for real-time monitoring and early warning of tunnel surface displacement, implemented based on the GNSS-based real-time monitoring and early warning device for tunnel surface displacement according to claim 1 or 2, characterized in that: The steps include: S101: receiving the global coordinates of each monitoring point on the tunnel surface, and establishing the number of each tunnel section and the measurement module number information; S102: Based on the global coordinate information of the reference module, the global coordinates measured by the measurement module are corrected to obtain updated three-dimensional coordinate information of each monitoring point; S103: Select the coordinates of the central axis position monitoring point of the installation surface of one of the tunnel sections as the local coordinate origin, generate data of each tunnel section, and determine the relative position of each tunnel section; S105: Determine whether the three-dimensional coordinate information of each monitoring point has changed. If not, return to step S101. If yes, update the three-dimensional coordinate information of the monitoring point and receive the real-time acceleration information of the measurement module. S107: Recording the single displacement amount, the deformation amount of the tunnel surface per unit time and the real-time acceleration information for each coordinate update; S108: Establishing an early warning mechanism: Setting early warning signal characteristics, wherein the early warning signal characteristics include the total displacement and deformation speed of the tunnel, and generating early warning information to remind relevant personnel based on the early warning signal characteristic values.

4. The method according to claim 3, characterized in that: After step S103 is executed, step S104 is also included: constructing a tunnel monitoring model according to the location characteristics and cross-section change characteristics of the tunnel section, After step S105 is executed, step S106 is also included: reconstructing the tunnel monitoring model based on the monitoring points whose three-dimensional coordinate information has changed.

5. The method according to claim 4, characterized in that: In step S108, if any warning signal characteristic value is greater than a set threshold, the position of the measurement module is highlighted on the display end of the lane monitoring model to remind relevant personnel in a visual manner.

6. The method according to any one of claims 3 to 5, characterized in that: In step S108, the warning signal feature also includes the fractal dimension of the tunnel surface displacement, and the fractal dimension of the tunnel surface displacement is used to evaluate whether the deformation time series of the tunnel surrounding rock surface has state continuity.

7. The method according to claim 6, characterized in that: The specific method of evaluating whether the deformation time series of the surrounding rock surface of the tunnel has state continuity through fractal dimension is as follows: (1) Construct the relationship formula between fractal dimension and Hurst index H: ; (2) Construct the regression equation of Hurst index H, and obtain the H value by the least squares regression equation. The method for obtaining Hurst index H is: The Hurst index H is calculated using the repeated table range method, and the tunnel surface displacement time series is divided into subsequences, each of which contains elements, is the subsequence number, is the sequence number of the element, and each element is recorded as , Normalized value of subsequence sample data for: in, is the mean of the subsequence sample data, Establish a cumulative time series of roadway surface displacement : Calculate range , Standard Deviation , re-standardized range , the calculation formula is: make , Logarithmization is performed, and a least squares regression equation is established to obtain the value of the Hurst index H. The least squares regression equation is: in, is the range of the cumulative time series of the roadway surface displacement samples, is the standard deviation of the sample sequence, is a constant, is a constant Logarithmization, is the Hth power of the number of subsequences k, where H is the Hurst index; For The corresponding cumulative time series The ordinal number of (3) Obtaining a value of the fractal dimension D based on the relationship between the fractal dimension and the Hurst exponent H; (4) Based on the value of the fractal dimension D, the degree of continuity of the time series state of the deformation of the surrounding rock surface of the tunnel is evaluated.

8. The method according to claim 7, characterized in that The warning mechanism is: according to the numerical range of the warning signal characteristics, a corresponding warning signal is generated, and the warning signal includes: a first-level warning signal, a second-level warning signal and a third-level warning signal. When the total displacement of the lane at the monitoring point is less than or equal to the first displacement threshold or the deformation speed is less than or equal to the first speed threshold, the lane is monitored in real time, and the data processing terminal system sends out a first-level warning signal; when the total displacement of the lane at the monitoring point is greater than the first displacement threshold and less than or equal to the second displacement threshold, or the deformation speed is greater than the first speed threshold and less than or equal to the second speed threshold, the lane section position is located according to the measurement module number, and a second-level warning signal is sent out at the lane section position to remind the staff to check the relevant areas of the lane; when the total displacement of the lane at the monitoring point is greater than the second displacement threshold, or the deformation speed is greater than the second speed threshold, a third-level warning signal is sent out to the lane as a whole, and the lane section position is located according to the measurement module number, to warn the staff to take corresponding emergency measures. at the same time, When the fractal dimension When the fractal dimension is When the fractal dimension is , it means that the deformation of the tunnel has a time duration, and the system issues a second-level warning signal to remind relevant staff to be more vigilant and focus on the continuous deformation area; , indicating that the deformation of the tunnel is highly time-persistent, and the system issues a third-level early warning signal to remind relevant staff to take emergency measures immediately in the deformed area.

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