A tunnel face deformation monitoring device and a monitoring method thereof

Abstract

The application discloses a tunnel surface deformation monitoring device and a monitoring method thereof, and belongs to the field of engineering measurement. The monitoring device comprises a laser scanner, the laser scanner is installed on a support and is fixedly installed through a supporting disc at the bottom of the support, and the supporting disc can be fixed on the ground through screws; a plurality of ranging units are arranged on a rotatable spherical surface of the laser scanner, the ranging units are arranged on the rotatable spherical surface according to a spiral line to form a ranging array, and the ranging direction is a spiral line of the spherical point. The three-dimensional model of the tunnel excavation surface is generated by adopting the surface monitoring method, the scanning model at each time is positioned in a three-dimensional graph, the differences of the several models can be compared, the abnormal deformation positions can be directly observed, the corresponding road main line stake numbers and positions are calculated from the model, the abnormal deformation positions are lofted on the spot to analyze the surrounding rock structure, and the tunnel deformation monitoring work is more rigorous and more accurate.

Description

Technical Field

[0001] This invention relates to the field of engineering surveying technology, and more specifically, to a surface deformation monitoring device and method for tunnels, suitable for monitoring tunnel deformation, including the observation and analysis of arch subsidence and perimeter convergence. Background Technology

[0002] Currently, 3D laser scanners are used for tunnel over-excavation and under-excavation measurement, replacing traditional tunnel cross-section inspection instruments. By replacing point measurement with surface measurement, they significantly improve the density and accuracy of tunnel cross-section measurements. 3D laser scanners are further divided into fixed and mobile types. Fixed types are mounted in a fixed position, similar to total stations or theodolites. Mobile types can be designed as backpacks for single-person use, or be vehicle-mounted or airborne. During movement, they require inertial systems to determine the equipment's attitude and GPS to determine its position; their structure is complex, their price is high, and their accuracy is lower than that of fixed types.

[0003] Tunnel deformation monitoring includes measuring arch settlement and peripheral convergence within the tunnel, and measuring surface settlement outside the tunnel. For deformation monitoring within the tunnel, total stations, precision levels, and convergence meters are mainly used. Currently, precision levels or total stations are primarily used to measure arch settlement, while the total station coordinate method is used to measure peripheral convergence. Total station three-dimensional coordinate measurements can simultaneously measure tunnel arch settlement and peripheral convergence, but the accuracy is lower than that of precision levels and convergence meters. To improve accuracy, multiple measurements are performed and the average value is taken. Combining precision level measurements of arch settlement with convergence meter measurements of peripheral convergence is also a commonly used method. Its advantages are high accuracy, but its disadvantages include the need for construction machinery such as loaders. When the tunnel is excavated to a certain height, a 3m leveling rod is insufficient, requiring a steel tape instead of a leveling rod in the precision leveling method, which reduces measurement accuracy. Furthermore, the need for construction machinery is also required for peripheral convergence, resulting in slow speed and low efficiency. The total station 3D coordinate measurement method directly measures the 3D coordinates of the observation point, and then calculates the settlement using the average elevation difference of multiple measurements. For peripheral convergence, the slope or horizontal distance is calculated from the coordinates of peripheral observation points obtained from multiple measurements to calculate the convergence value of peripheral points. This method is fast and efficient, but its accuracy is limited, requiring a high-precision total station with prism-free distance measurement or reflector-supporting distance measurement capabilities. In terms of point placement, the precision leveling and convergence meter method only requires the installation of a few expansion bolts, while the total station 3D coordinate method requires the installation of reflectors. Initial reflectors are easily covered by multiple applications of shotcrete, necessitating personnel to use construction machinery for cleaning.

[0004] The above methods are all point measurement methods, with a limited number of measurement points. They can only measure local arch settlement and surrounding convergence, and are prone to missing abnormal points of local deformation. They are insufficient in terms of measurement accuracy and precision. With the development of measuring instruments, production practice has put forward higher requirements for tunnel deformation monitoring.

[0005] A search revealed that patent CN207798023U discloses a tunnel cross-section deformation monitoring system, including a main controller and multiple sub-monitoring devices installed inside the tunnel. The sub-monitoring devices are arranged along the length of the tunnel. Each sub-monitoring device includes a sub-controller that is communicatively connected to the main controller, a first laser ranging sensor, a second laser ranging sensor, and a memory. The first laser ranging sensor is used to monitor the displacement of the tunnel arch, and the second laser ranging sensor is used to monitor the displacement of the tunnel sidewalls. The sub-controller compares the monitored displacement values ​​of the tunnel arch with the set displacement values, and compares the monitored displacement values ​​of the tunnel sidewalls with the set displacement values, providing early warnings for construction. Patent CN113074653A discloses a tunnel cross-sectional deformation monitoring device. The mounting base includes an alarm unit, a processing unit, and multiple laser ranging units. Each laser ranging unit is equipped with multiple reflecting units located on the tunnel's inner wall, arranged radially along the tunnel. The laser ranging unit transmits measurement signals to the reflecting units and receives the reflected echo signals. The laser ranging unit then sends the echo signals to the processing unit, which calculates the distance value based on the echo signals. The processing unit uses the first calculated distance value as a reference value. It then calculates the difference between the subsequently calculated distance values ​​from the laser ranging units and the corresponding reference value. The processing unit determines whether the difference falls within the settlement range; if not, it sends an alarm signal to the alarm unit. While this solution also involves monitoring tunnel surface deformation, its practical effectiveness still needs further improvement. Summary of the Invention

[0006] 1. The technical problem that the invention aims to solve

[0007] To address the issues of low accuracy and easy loss of local deformation anomaly points in existing tunnel surface deformation monitoring technologies, this invention aims to provide a tunnel surface deformation monitoring device and method. This method employs laser scanning technology to make the monitoring more representative of the actual deformation of the tunnel excavation face, eliminating the drawback of missing local deformation anomalies in point measurements. Furthermore, it utilizes a three-light laser, estimating the moisture content change of the initial support concrete over different times by using the ratio of different laser reflection intensities on the initial support concrete surface, providing a reference for the mix design of the initial support concrete.

[0008] 2. Technical Solution

[0009] To achieve the above objectives, the technical solution provided by this invention is as follows:

[0010] The present invention discloses a surface deformation monitoring device for tunnels, comprising a laser scanner, which is mounted on a bracket and fixedly mounted by a support plate at the bottom of the bracket. The laser scanner has multiple sets of ranging units on its rotatable spherical surface, which are arranged in a radiating pattern to form a ranging array, with the ranging direction being the radiating line of the spherical point.

[0011] Furthermore, the ranging unit uses three different wavelengths of laser scanning, including a red laser ranging unit, a green laser ranging unit, and a blue laser ranging unit. The three laser ranging units are arranged alternately along the involute of the sphere, and each ranging unit has an independent number "address" to distinguish the different laser colors.

[0012] The surface deformation monitoring device of this invention operates on the same principle as a fixed 3D laser scanner, but differs in that it employs multiple sets of three-color laser scanning heads. Internally, it features electronically coded horizontal and vertical dials. Users can connect to the device via Bluetooth using a mobile app to view the horizontal and vertical angles after leveling. The 0-degree direction is defined by any end of the laser scanner's sphere's rotation axis. Alternatively, the app can be used to set the other end of the laser scanner's sphere's rotation axis to the horizontal 0-degree direction, with the vertical angle defined as 0 degrees when the axis is horizontal.

[0013] Furthermore, it also includes control point markers, which are spherical reflective surfaces with the coordinates of the three-dimensional coordinate point at the center of the sphere. The control point markers are targets for fixed 3D scanning scanners. The specific target rod and support are the same as the centering rod of a total station, except that the upper part is a reflective sphere. When using a total station to measure the three-dimensional coordinates of the sphere's center, it is not necessary to level and center it, and there is no bubble.

[0014] Furthermore, it also includes a data processing system on a PC and an APP system installed on a mobile phone. The laser scanner has a data communication device, which connects to the mobile APP via Bluetooth interface. The mobile APP is used to set the functions of the laser scanner. The data processing system imports data using a memory card reader or downloads data using the mobile APP. It uses the center three-dimensional coordinates of the control point markers for each measurement and the measurement time to generate a three-dimensional measured model of the tunnel cross section at major time points.

[0015] This invention also provides a method for monitoring surface deformation in tunnels. Multiple sets of the aforementioned surface deformation monitoring devices are installed simultaneously on both the left and right sides along the length of the tunnel. Measurements are taken from both sides simultaneously. The construction equipment travels through the middle. The monitoring device on the left side only covers the right half, and the monitoring device on the right side only covers the left half. During data processing, the left side takes the half-tunnel data model scanned from the left side, and the right side takes the half-tunnel data model scanned from the right side. The overlap between the left and right sides is not less than 0.3m. The models are then spliced ​​together into a whole using control point markers.

[0016] The 3D coordinate model is generated using a dedicated app for post-processing. The app first uses the 3D coordinates of the center of several control point marker spheres, and then uses the relative point cloud data measured by the 3D scanner (based on arbitrary horizontal and vertical angles and the measured slope distance when the scanner is set up). It uses the horizontal, vertical angles, and slope distance measured by the 3D coordinates of the control point markers, plus the radius of the control point marker sphere and the 3D coordinates of the control point markers to inversely calculate the 3D coordinates of the phase center of the scanner and the azimuth angle in the 0 direction (0 degrees for horizontal and vertical angles). Then, it corrects the actual azimuth angle and slope distance of the measured point cloud data to calculate the actual 3D coordinates of the point cloud data to generate the model.

[0017] Furthermore, the three primary color laser ranging units are arranged alternately, and each ranging unit has an independent number "address" to distinguish different laser colors. By using laser beams of different colors to measure the intensity of reflected signals from nearby three-dimensional coordinate points under the same weather conditions, the moisture level of the initial support concrete is distinguished. The actual recorded point cloud data includes the color code of the ranging unit's laser beam and the code of the reflected signal intensity. The water content of the concrete is calculated by using the amount of reflection and absorption of different colors of the laser beam to analyze the location and range of multiple grouting operations, thereby distinguishing the surface monitoring model.

[0018] Models generated by different colors have different refractive indices for different colors under the same meteorological conditions, resulting in different measured slope distances. Meteorological corrections can be made using slope distances measured at the same point using different colors. Automatic weather recorders can be installed inside the tunnel to record changes in temperature, air pressure, and humidity of the air inside the tunnel at different times. The software APP performs meteorological corrections on the slope distances measured by different colors and then takes the average value to improve the accuracy of the measurement.

[0019] Furthermore, by using the coordinates of control point markers for redirection, models from different times are superimposed, and the intersection of the models represents the deformation at different locations. The system is configured to display deformation exceeding the allowable range to facilitate data analysis by technicians.

[0020] 3. Beneficial effects

[0021] Compared with the prior art, the technical solution provided by this invention has the following advantages:

[0022] The surface deformation monitoring method of this invention adopts a three-dimensional surface deformation monitoring approach, which differs from the conventional point measurement method using total station coordinates or precision level with convergence meters. The drawback of point measurement methods is the limited density of measurement points; the displacement and convergence of a few points cannot represent the entirety of the tunnel excavation face deformation, and point measurement methods are prone to missing areas of abnormal deformation. Sometimes, localized deformation anomalies are crucial, indicating that the surrounding rock grade or stress condition in that area differs from other areas. This invention uses a surface monitoring method to generate a three-dimensional model of the tunnel excavation face surface. Each scanned model is positioned within a three-dimensional graphic, allowing for comparison of the differences between several models (the model generated by the intersection of the three-dimensional models). This provides a direct view of areas of abnormal deformation. The corresponding road mainline station number and location are then calculated from the model, and the abnormal deformation areas are laid out on-site for surrounding rock structure analysis, making tunnel deformation monitoring more rigorous and accurate. Attached Figure Description

[0023] Figure 1 This is a side view of the surface deformation monitoring device used in this invention;

[0024] Figure 2 This is a front view of the surface deformation monitoring device used in this invention;

[0025] Figure 3 This is a schematic diagram of the installation and arrangement of the surface deformation monitoring device in the tunnel according to the present invention.

[0026] Explanation of the labels in the diagram:

[0027] 1. Distance measuring unit; 11. Red laser distance measuring unit; 12. Green laser distance measuring unit; 13. Blue laser distance measuring unit; 2. Rotatable spherical surface; 3. Bracket; 4. Support plate; 5. Fixing screws; 6. Control point markers. Detailed Implementation

[0028] To further understand the content of this invention, a detailed description of the invention will be provided in conjunction with the accompanying drawings.

[0029] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] The present invention will be further described below with reference to embodiments.

[0031] Example

[0032] Combination Figures 1-3 As shown, this embodiment of a tunnel surface deformation monitoring device includes a laser scanner. The laser scanner is mounted on a bracket 3 and fixedly mounted via a support plate 4 at the bottom of the bracket 3. The support plate 4 can be fixed to the ground with screws. Multiple ranging units 1 are provided on the rotatable spherical surface 2 of the laser scanner. The ranging units 1 are arranged in a radial pattern on the rotatable spherical surface 2 to form a ranging array. The ranging direction is the radiating line from the center of the sphere, i.e., a straight line outward from the center of the sphere. The laser scanner has a controller, including a CPU, memory, a quartz resonator, a Bluetooth communication module, a rechargeable lithium battery, and a clock. The CPU can control the rotation of the scanner, scanning ranging, and data storage.

[0033] The surface deformation monitoring device also includes control point marker 6, which is a spherical reflective surface with the coordinates of its center three-dimensional coordinate point. The device also includes a data processing system on a PC and an app system installed on a mobile phone. The laser scanner contains a data communication device and a rechargeable battery. The laser scanner connects to the mobile app via Bluetooth using the data communication device, and the app is used to configure the laser scanner's functions. The data processing system imports data using a memory card reader or downloads data using the mobile app. Using the center three-dimensional coordinates of control point marker 6 and the measurement time for each measurement, it generates a three-dimensional measured model of the tunnel cross-section at various time points. The data communication device has three green indicator lights: a battery capacity indicator (flashing red and green alternately when less than 5%), a memory card remaining space indicator (flashing red and green alternately when less than 10%), and a data acquisition indicator (flashing green during data acquisition, indicating that data is being written to the memory card and the card should not be removed). The rechargeable batteries are insertable, and two batteries can be inserted. The system uses the upper battery first. When the upper battery's power is low, the indicator light will flash. When the power is below 5%, it will automatically switch to the lower battery. The user then replaces the upper battery, alternating between the two. When the lower battery's power is low, the indicator light flashes, and when it is below 5%, it will automatically switch to the upper battery. The user must ensure that at least one battery is fully charged. There is also a power indicator on the battery. When the battery is fully charged above 75%, the indicator light is green; 50% to 75% is yellow-green; 25% to 50% is orange; 5% to 25% is red; and when it is below 5%, the indicator light is off, and the user must replace the battery.

[0034] Furthermore, ranging unit 1 employs three different wavelengths of laser scanning, including a red laser ranging unit 11, a green laser ranging unit 12, and a blue laser ranging unit 13. These three laser ranging units are arranged along an involute curve of the sphere, alternating between red, green, and blue. Each ranging unit 1 has an independent "address" number to distinguish it from the different laser colors. By using laser beams of different colors to measure the intensity of reflected signals from nearby three-dimensional coordinate points under the same weather conditions, the moisture content of the initial support concrete is distinguished. The actual recorded point cloud data includes the color coding of the laser beams from the ranging units and the coding of the reflected signal intensity. In post-processing, the water content of the concrete is calculated using the amount of reflection and absorption of different colored relative laser beams to analyze the location and range of multiple grouting operations. This allows for the differentiation of the surface monitoring model, such as the model after the first grouting, the model after the second grouting, etc., eliminating the misinterpretation of the concrete surface model differences caused by grouting as subsidence or convergence, ensuring that the monitoring results match the actual situation.

[0035] In this embodiment, the laser scanning ranging accuracy of the surface deformation monitoring device is 100m ± 1mm, with a ranging speed of 10,000 to 100,000 times per second. The spherical body rotates at an angular velocity of 1 to 30 degrees per second under the action of a stepper motor. The ranging speed and the maximum angular velocity of the motor are designed according to different needs. Devices with higher accuracy have larger maximum scanning ranging speed and angular velocity, but require higher system hardware configuration. The rotation range is 0 to 180 degrees. The ranging units 1 are arranged along the spherical surface in a gradually expanding pattern. The spacing of the expanding patterns and the density of the ranging units 1 are determined by the scanning accuracy. Each ranging unit 1 corresponds to a cache address, and the scanned three-dimensional relative coordinates are directly stored in the cache. At the same time, the CPU immediately writes the cached data into memory after each scanning and ranging measurement. Data transfer and scanning and ranging should be synchronized to prevent data loss. This device has very high requirements for data processing speed. The scanning and rotation speed and the point density of the ranging units 1 are determined according to the required accuracy, and at the same time, the requirements for hardware operating speed are higher, and the manufacturing cost is also higher.

[0036] This embodiment also provides a method for monitoring surface deformation in tunnels. Multiple sets of the aforementioned surface deformation monitoring devices are installed simultaneously on both sides of the tunnel's length. Specifically, six sets of surface deformation monitoring devices are fixed to the tunnel floor using screws. The three-dimensional coordinates of control point marker 6 are measured using a total station. In straight tunnels, control point marker 6 and the fixed point of the laser scanner's support plate 4 can be spaced 20m apart. For tunnels with small-radius circular curves, to ensure accuracy, they can be spaced 10m apart. The placement of the laser scanner and control point marker 6 does not necessarily have to be based on whole-meter data; the placement should be determined based on the actual site conditions and should not be affected by the construction equipment. Measurements are taken simultaneously on both sides, with the construction equipment traveling from the middle. The left monitoring device only obscures the right half, and the right monitoring device only obscures the left half. During data processing, the left side uses the half-tunnel data model scanned from the left, and the right side uses the half-tunnel data model scanned from the right, with an overlap of at least 0.3m. The models are then pieced together using the control point marker 6.

[0037] To prevent displacement of control point marker 6, it needs to be connected to other control points inside the tunnel or to control points outside the tunnel for weekly joint measurements. After each joint measurement, the control point data is stored in the data processing system, which is installed on a PC. Each surface deformation monitoring device has a unique device number and a built-in insertable flash memory card. Data is exported from the memory card every week. Remove the memory card containing data and replace it with a blank card. Note that the card must not be removed during data acquisition. During data acquisition, the indicator light will flash; wait until the indicator light stops flashing before removing and inserting the card.

[0038] In specific use, follow Figure 2The setup is as shown. Control point marker 6 is a spherical reflective surface, and the coordinates of the sphere's center are shown in the diagram. The three-dimensional coordinates of control point marker 6 are measured by adding the measured slope distance to the sphere's radius (a fixed length), and then calculating the three-dimensional coordinates using horizontal and vertical angles. The surface deformation monitoring device and control point marker 6 are fixed to the base using expansion bolts pre-embedded in the tunnel floor or on the invert arch. Tilting is not considered during installation, and precise verticality is not required. After installation, the three-dimensional coordinates of the sphere's center are measured and calculated using a total station and input into the data processing system. Six laser scanners and control point marker 6 operate repeatedly in a continuous flow. As the excavation length of the tunnel face increases, deformation near the tunnel entrance stabilizes and no longer requires monitoring. Control point marker 6 and the surface deformation monitoring device are then removed, moved to the end near the tunnel face, and reinstalled, repeating the cycle. The surface deformation monitoring device's data communication components include a power switch, a wireless Bluetooth interface, and a storage card slot. The mobile app for the surface deformation monitoring device allows users to configure the device, including synchronizing the clock with the phone's standard time, setting the data sampling interval, viewing and downloading 3D coordinate data from the memory card, and managing the remaining memory card space. The app flashes when the memory card space is less than 10%. If no data is being collected or stored, the memory card can be removed and replaced with a blank card. Alternatively, data can be downloaded to the phone's memory using the app, and then the data on the memory card can be cleared using the app. However, this method is more demanding on the phone's speed due to the large data volume and long download times. Data includes the device number and the time of each data collection session. The data processing system imports data using a memory card reader or downloads data using the app. It generates 3D measured models of the tunnel cross-section at various time points using the center 3D coordinates of control point marker 6 and the measurement time. The coordinates of control point marker 6 are used for redirection, and the models from different times are superimposed. The difference (intersection) of the models represents the deformation at different locations. The system can be configured to display deformation exceeding the allowable range in red or other colors to facilitate data analysis by technicians. Of course, models can also be generated even if the sampling time is not a whole number of points, using computer interpolation algorithms.

[0039] Solution to the impact of construction machinery and equipment: Since measurements are taken simultaneously on the left and right sides, and the construction equipment travels from the middle, the left laser scanner only obscures the right half, while the right laser scanner only obscures the left half. During data processing, the left side uses the half-tunnel data model scanned from the left; conversely, the right side uses the half-tunnel model scanned from the right, with an overlap of at least 0.3m. The models are then pieced together using control point markers (6). In practical use, the left half of the tunnel can also be used from the left, and the right half from the right, to ensure accuracy. This is because the error in tunnel scanning distance measurement increases with the distance between the target and the scanning head. Other fixed obstacles in the tunnel, such as ventilation ducts and water pipes, can be easily removed.

[0040] This method employs a three-dimensional surface deformation monitoring approach, unlike the conventional point measurement methods using total stations or precision levels with convergence meters. Point measurement methods have the drawback of limited point density; the displacement and convergence of a few points cannot represent the entirety of tunnel excavation face deformation, and anomalies are easily missed. Sometimes, localized deformation anomalies are crucial, indicating that the surrounding rock grade or stress condition differs from other areas. This embodiment uses a surface monitoring method to generate a three-dimensional model of the tunnel excavation face. Each scanned model is positioned within a three-dimensional graphic, allowing for comparison of the differences between several models (the intersection of the three-dimensional models generates the model), providing a direct view of anomalies. The corresponding road mainline station number and location are then calculated from the model, and the anomaly areas are laid out on-site for surrounding rock structure analysis, making tunnel deformation monitoring more rigorous and accurate.

[0041] In this embodiment, the monitoring device directly scans the 3D model, and then uses the actual 3D coordinates and elevations of the scanned marker points to reposition the 3D model. The actual center coordinates of the marker spheres are obtained by measuring the 3D coordinates of the center of all marker points after the total station is leveled and oriented at the measurement control points. Since the center coordinates cannot be directly measured, a prism-free measurement with an added constant (the radius of the marker point is a constant) is used for distance measurement. The average of the leftmost and rightmost horizontal angles of the marker sphere is used as the horizontal azimuth angle of the marker sphere center, and the average of the vertical angles of the top and bottom of the marker sphere is used as the vertical angle of the marker point center to calculate the 3D coordinates of the marker point center. The post-processing software (APP) calculates the coordinates of the center of the scanned sphere using the coordinates of adjacent control points, adding the radius of the scanning distance measurement unit and the center of the sphere to the calculation.

[0042] The present invention and its embodiments have been described above illustratively. This description is not restrictive and is merely one embodiment of the present invention, and is not actually limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A method for monitoring surface deformation of a tunnel, characterized in that: A surface deformation monitoring device is adopted, which includes a laser scanner. The laser scanner is mounted on a bracket (3) and fixedly installed by a support plate (4) at the bottom of the bracket (3). Multiple sets of ranging units (1) are provided on the rotatable spherical surface (2) of the laser scanner. The ranging units (1) are arranged in a radiating line on the rotatable spherical surface (2) to form a ranging array. The ranging direction is the radiating line of the spherical point. The ranging unit (1) uses three different wavelengths of laser scanning, including a red laser ranging unit (11), a green laser ranging unit (12), and a blue laser ranging unit (13). The three laser ranging units are arranged alternately along the involute of the sphere. Each ranging unit (1) has an independent number "address" to distinguish different laser colors. It also includes control point markers (6), which are spherical reflective surfaces with the coordinates of the three-dimensional coordinate point at the center of the sphere. It also includes a data processing system on a PC and an APP system installed on a mobile phone. The laser scanner has a data communication device. The laser scanner uses the Bluetooth interface of the data communication device to connect to the mobile APP. The mobile APP is used to set the functions of the laser scanner. The data processing system imports data using a memory card reader or downloads data using the mobile APP. It uses the center three-dimensional coordinates of multiple control point markers (6) and the measurement time of each measurement. The APP system then uses the known spherical radius plus the measured slope distance and the measured angle to calculate the three-dimensional coordinates of the phase center of the surface scanner and the azimuth of each control point, also known as resection. Then, it uses the three-dimensional coordinates of the phase center of the surface scanner and the azimuth of the control point to calculate all the collected point cloud data, including the relative slope distance and horizontal and vertical angles of the surface scanner, which are arbitrarily set up, to generate a three-dimensional measured coordinate point cloud surface model of the tunnel cross section at major time points. The method for monitoring surface deformation of the tunnel is as follows: Multiple sets of surface deformation monitoring devices are installed simultaneously on the left and right sides along the length of the tunnel. Measurements are taken simultaneously on both sides. The construction equipment travels from the middle. The monitoring device on the left side only covers the right half, and the monitoring device on the right side only covers the left half. When processing the data, the left side takes the half-tunnel data model scanned on the left side, and the right side takes the half-tunnel data model scanned on the right side. The overlap between the left and right sides is not less than 0.3m. The model is spliced ​​into a whole using control point markers (6).

2. The method for monitoring surface deformation of a tunnel according to claim 1, characterized in that: The three primary color laser ranging units are arranged alternately, and each ranging unit (1) has an independent number "address" to distinguish different laser colors. The relative strength of the reflected signals from similar three-dimensional coordinate points is used to measure the distance under the same meteorological conditions to distinguish the moisture level of the initial support concrete. The actual recorded point cloud data includes the laser beam color code of the ranging unit and the code of the reflected signal intensity. The water content of the concrete is calculated by using the amount of reflection and absorption of different hues of laser beams by the concrete to analyze the position and range of multiple grouting, thereby distinguishing the surface monitoring model.

3. The method for monitoring surface deformation of a tunnel according to claim 1, characterized in that: Redirecting is performed using the coordinates of control point markers (6), and models from different times are superimposed. The intersection of the models is the deformation of different parts. The system is set to display the deformation exceeding the allowable range to facilitate data analysis by technicians.

4. The method for monitoring surface deformation of a tunnel according to claim 1, characterized in that: For sampling times that are not at the top of the hour, a computer-generated interpolation algorithm is used to generate the model.

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