Method for determining tunnel rock mass stability advance support based on laser instrument

Abstract

The invention discloses a method for determining tunnel rock mass stability advance support based on a laser instrument, and relates to the technical field of tunnel rock mass stability analysis. The determination method comprises the following steps: firstly, determining a stress peak position and a protolith stress position by judging a stress environment; then identifying a tunnel surrounding rock structure, identifying lithology by using a laser instrument, constructing a rock stratum three-dimensional model, and analyzing a rock stratum damage degree; carrying out pre-treatment on the surface damage degrees of the rock stratums at the two sides; carrying out normalization treatment; comparing the surface damage degrees of the rock stratums at the top plate and the bottom plate; and finally, judging a support structure, judging support effectiveness according to a stress environment and an underground surrounding rock structure, and determining a support length. The invention provides a novel method for jointly determining a supporting structure by using a stress environment and a surrounding rock structure. The novel method is different from a rigid body limit equilibrium method, a numerical method, an analytical method and a reliability analysis method in the prior art. The method can ensure that the supporting structure meets the requirements of a mechanical foundation and actual engineering.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel rock mass stability analysis, and in particular to a method for determining advanced support for tunnel rock mass stability based on a laser instrument. Background Art

[0002] At present, in tunnel engineering, the stability of tunnel rock mass has always been an important issue. For the analysis of tunnel rock mass stability, numerical method, analytical method, rigid body limit equilibrium method and reliability analysis method are mainly used. The first three methods are the mainstream analysis methods at present. They are based on engineering practice experience and obtain results through statistical analysis. They are fast and easy to master. Due to the lack of rigor in the formulation of empirical formulas, these methods often cannot fully meet the actual engineering needs. In addition, these mainstream methods lack the overall analysis of stress environment, surrounding rock structure and support structure, and rely too much on precise and complex mathematical calculations, resulting in a large difference between theoretical assumptions and actual rock mass. Construction conditions that have a great impact on rock mass stability are difficult to reflect in the calculation; since the existing technology for the analysis of rock mass stability cannot meet the needs of comprehensive analysis of rock mass stability, it is necessary to propose a new rock mass stability analysis method and device. Therefore, in this paper, the laser instrument uses a laser spectrum device and a laser scanning device to intelligently identify the tunnel surrounding rock structure, construct a three-dimensional model of the rock layer and normalize the degree of surface damage. The effectiveness of the support structure is determined by analyzing the environment and surrounding rock structure. Summary of the invention

[0003] The purpose of the present invention is to provide a method for determining the advance support of tunnel rock stability based on laser instruments, which utilizes the analysis and processing results of the stress environment and the surrounding rock structure and the laser instrument modeling to jointly determine the support structure to ensure that the support structure meets the mechanical basis and actual engineering requirements.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A method for determining the stability of tunnel rock mass in advance based on laser instruments is characterized by intelligently identifying the tunnel surrounding rock structure through a laser spectrum device and a laser scanning device, constructing a three-dimensional model of the rock layer and normalizing the degree of surface damage, and determining the effectiveness of the support structure through analysis of the environment and surrounding rock structure. It includes the following steps in sequence:

[0006] Step 1: Based on rock stress monitoring and geological structure, clarify the stress environment of the rock formation around the tunnel, determine the location of the stress peak and the magnitude and location of the initial stress;

[0007] Step 2: Use laser scanning equipment to perform high-precision scanning of the rock formations around the tunnel to obtain 3D model data. With the help of geological information recognition algorithms and machine learning technology, the laser scanning data is processed and analyzed to obtain the thickness and lithology of the rock formations. Based on the identified rock formation information, a 3D model of the rock formation is constructed using computer-aided design software. The finite element analysis method is used to perform mechanical analysis on the 3D model, including the stress peak position, the rock formation surface damage degree analysis on the tunnel crown plate and both sides of the tunnel arch waist;

[0008] Step 3: Quantitatively evaluate the degree of surface loss of the rock strata on both sides of the tunnel vault plate and the tunnel waist. Use a unified evaluation standard to normalize the damage degree data to ensure data comparability. Compare and analyze the damage degrees on both sides of the vault plate and the waist to evaluate the stress environment and structural characteristics of the rock strata around the tunnel.

[0009] The normalization process specifically includes the following steps:

[0010] First, the data of the damage degree of each rock layer are collected, the state and number of cracks are analyzed, and the damage degree of the rock layer is converted into a function form represented by numerical values, so as to obtain the maximum and minimum values ​​of the damage degree a of the rock layer. The surface damage degree of the rock layer at the initial stress position is the maximum value, and the surface damage degree of the rock layer on both sides of the tunnel waist is the minimum value. Then, the original data of the damage degree of the rock layer at the initial stress position and the positions on both sides of the tunnel waist are linearly transformed, so that the eigenvalue is mapped to between [0,1], thereby eliminating the influence of the dimension on the final result and making different characteristics comparable. The transformation function is shown in formula (1):

[0011]

[0012] In formula (1), c is the value of the rock formation damage degree after normalization;

[0013] a is the original value of the rock damage degree;

[0014] a max 、a max are the maximum and minimum values ​​of the original values ​​of the rock formation loss degree, respectively;

[0015] Finally, the normalized rock surface damage degree data are obtained. The data are all infinite values ​​with a distribution interval of [0,1]. The larger the value, the smaller the rock surface damage degree, and the smaller the value, the greater the rock surface damage degree.

[0016] The zero mean normalization method can also be used, and the transformation function is shown in formula (2):

[0017]

[0018] Among them, u and e are the mean and variance of the original values ​​of the rock damage degree, respectively. This method normalizes the original values ​​of the rock damage degree to values ​​with a mean of 0 and a variance of 1.

[0019] Step 4: Determine the effectiveness of tunnel support by combining the tunnel stress environment and tunnel surrounding rock structure;

[0020] The steps are:

[0021] a. Determine whether the existing support method meets the support requirements;

[0022] b. Use thermal imaging analysis to obtain the degree of rock damage and instability, collect temperature changes in the form of infrared thermal imaging and two-dimensional temperature matrix, and analyze the degree of rock damage and instability through temperature changes. Compare the degree of damage and instability with the multiples of the tunnel size. The specific value of the multiples of the tunnel size is obtained based on the purpose of the underground space and the analysis of the rock lithology; if the degree of damage and instability is < the multiples of the tunnel size, it proves that the existing support is effective; if the degree of damage and instability is > the multiples of the tunnel size, it proves that the existing support is ineffective and the support method needs to be changed;

[0023] The infrared thermal imager used in the experiment can compensate for the radiation other than the infrared radiation from the rock surface. The compensation process can be expressed as follows:

[0024] Q mea =Q(T obj )×τ×ε+Q(T sur )×(l-ε)×τ+Q(T atm )×(l-τ) (3)

[0025] In formula (3), Q mea is the total radiation energy received by the thermal imager; Q(T) is the blackbody radiation energy at temperature T; T obj is the temperature of the target rock sample; T sur is the average temperature reflected from the surrounding environment to the rock sample; T atm is the average temperature of the atmosphere between the thermal imager and the rock sample; ε is the average emissivity of the rock sample surface within the spectral range of the thermal imager; τ is the average atmospheric penetration within the spectral range.

[0026] c. If the support structure is effective, the support is completed;

[0027] d. If the support structure fails, the support length and support density must be further determined.

[0028] In step one, geological surveys are conducted to collect information on strata, structures, and groundwater conditions, monitor rock formations, groundwater level changes, and ground stress, conduct non-destructive tests on rock formations, obtain data on the internal structure and stress distribution of rock formations, and finally use numerical analysis methods to determine the peak stress position of the rock formation and the size and position of the initial stress.

[0029] The laser instrument includes a housing, a built-in laser spectrometer, and a rotating laser scanning device. The rotating laser scanning device causes the laser device to rotate and scan, and the built-in laser spectrometer is located below the rotating device. In actual processes, the laser instrument is equipped with a telescopic rod and a placement frame. The front of the telescopic rod is connected to the laser instrument, and the rear is connected to the placement frame. The laser instrument detects the inner wall of the borehole by controlling the telescopic rod to extend and retract, thereby obtaining the lithology and thickness of the rock formation. The rate of the rotating laser scanning device matches the telescopic displacement rate of the telescopic rod. The digital camera is used to photograph the rock formation, and the time counter is used to control the scanning rate; the rotating laser scanning device can rotate in all directions.

[0030] The built-in laser spectroscopy device includes a laser source, a focusing mirror, a reflector and a grating. The laser source releases photons when particles transition from a high energy level to a low energy level. These photons return to the working material under the reflector of the resonant cavity, triggering more transitions of the same nature, thereby generating radiation of the same frequency, direction and phase. Through the feedback amplification of the resonant cavity, these radiations are continuously enhanced, and eventually form a powerful laser beam output; the focusing mirror improves the ability of the edge beam to be incident on the detector and increases the energy of the laser; the reflector is used for imaging, focusing and diffusion. Refraction passes through the lens and irradiates the laser on the rock surface. The grating is used as an output coupler in the laser to control the output power of the laser and the direction of the output beam.

[0031] In step 3, select Min-Max normalization processing and scale the anchor data for support to the interval [0,1]. The process is: old_min = min(date), old_max = max(date), date = (date-old_min) / (old_max-old_min). The anchor data for support is selected in the interval of rock surface damage degree after normalization processing. Place.

[0032] In step 4, the infrared thermal imager obtains the infrared radiation energy projected by the rock to the thermal imager detector, and then converts it into an electrical signal through the relationship between radiation energy and temperature to determine the instability of the rock mass, and compares it with the degree of instability. When the support fails, change its support method.

[0033] The laser scanning device includes a laser transmitter, a thermal imager, a rotatable cylindrical filter, a receiver, a time counter and a digital camera. The laser transmitter is used to emit infrared lasers, while the rotatable cylindrical filter increases the area of ​​laser scanning so that the laser can be reflected back after scanning the rock surface. The receiver is used to receive the scanning rate, while the digital camera is used to photograph the rock formation. The time counter controls the scanning rate, and when the thermal imager scans the tunnel rock formation through the digital camera, the degree of rock damage and instability is analyzed through temperature changes. The laser scanning device can rotate in all directions.

[0034] A system for identifying underground surrounding rock structures, including a computer, a data transmission line and a laser instrument. After the laser instrument collects excited rock photons, the data acquisition device has some basic data processing functions, such as amplification, calibration and calibration. The data acquisition device supports real-time data transmission. It is transmitted to the computer through a network connection or wireless communication. The data is processed on the computer, and infrared thermal images and spectral images of the rock are generated by visualization, and analyzed and compared with the data in the database. The lithology, spectral characteristics, etc. are displayed on the computer.

[0035] Compared with the prior art, the present invention brings the following beneficial technical effects:

[0036] The laser instrument of the present invention uses a laser spectrum device and a laser scanning device to intelligently identify the tunnel surrounding rock structure, construct a three-dimensional model of the rock layer and normalize the degree of surface damage. The purpose is to eliminate the dimensional influence between various evaluation criteria and determine the effectiveness of the support structure by analyzing the environment and surrounding rock structure.

[0037] The laser instrument comprises a housing, a thermal imager, a built-in laser spectrum device, and a rotating laser scanning device. The rotating laser scanning device enables the laser device to rotate and scan, and the built-in laser spectrum device is located below the rotating device.

[0038] The built-in laser spectrometer includes a laser source, a focusing mirror, a reflector, and a grating. The laser source releases photons when particles transition from a high energy level to a low energy level. These photons return to the working material under the reflector of the resonant cavity, triggering more transitions of the same nature, thereby generating radiation of the same frequency, direction, and phase. Through the feedback amplification of the resonant cavity, these radiations are continuously enhanced, and eventually form a powerful laser beam output; the focusing mirror improves the ability of the edge beam to be incident on the detector and increases the energy of the laser; the reflector is used for imaging, focusing, and diffusion. Refraction passes through the lens and irradiates the laser on the rock surface. The grating is used as an output coupler in the laser to control the output power of the laser and the direction of the output beam.

[0039] At present, the identification method of the support structure is mainly based on the judgment of the ultimate state of bearing capacity and the ultimate state of deformation. However, at this stage, more and more tunnel stress environment and surrounding rock structure are taken into consideration to jointly determine the support structure. This method not only follows the principles of safety, economy, rationality and stability of the support structure, but also realizes the overall analysis of the three factors affecting the stability of the rock mass. Therefore, the support structure can be judged quickly and accurately. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The present invention will be further described below in conjunction with the accompanying drawings:

[0041] Figure 1 Flow chart of the method of the present invention;

[0042] Figure 2 is a cross-sectional view of the laser instrument of the present invention;

[0043] In the figure:

[0044] 1. Rotatable cylindrical filter, 2. Time counter, 3. Receiver, 4. CCD camera, 5. Laser transmitter, 6. Rotating device, 7. Focusing lens, 8. Thermal imager, 9. Reflector, 10. Grating, 11. Laser source. DETAILED DESCRIPTION

[0045] The present invention proposes a method for determining the advanced support of tunnel rock mass stability based on a laser instrument. In order to make the advantages and technical solutions of the present invention clearer and more specific, the flow chart of the present invention is as follows: Figure 1 The present invention will be further described below in conjunction with specific embodiments.

[0046] Step 1: Based on rock stress monitoring and geological structure, clarify the stress environment of the rock formation around the tunnel, determine the location of the stress peak and the magnitude and location of the initial stress;

[0047] Step 2: Use laser scanning equipment to perform high-precision scanning of the rock formations around the tunnel to obtain 3D model data. With the help of geological information recognition algorithms and machine learning technology, the laser scanning data is processed and analyzed to obtain the thickness and lithology of the rock formations. Based on the identified rock formation information, a 3D model of the rock formation is constructed using computer-aided design software. The finite element analysis method is used to perform mechanical analysis on the 3D model, including the stress peak position, the rock formation surface damage degree analysis on the tunnel crown plate and both sides of the tunnel arch waist;

[0048] Step 3: Quantitatively evaluate the degree of surface loss of the rock strata on both sides of the tunnel vault plate and the tunnel waist. Use a unified evaluation standard to normalize the damage degree data to ensure data comparability. Compare and analyze the damage degrees on both sides of the vault plate and the waist to evaluate the stress environment and structural characteristics of the rock strata around the tunnel.

[0049] The normalization process specifically includes the following steps:

[0050] First, the data of the damage degree of each rock layer are collected, the state and number of cracks are analyzed, and the damage degree of the rock layer is converted into a function form represented by numerical values, so as to obtain the maximum and minimum values ​​of the damage degree a of the rock layer. The surface damage degree of the rock layer at the initial stress position is the maximum value, and the surface damage degree of the rock layer on both sides of the tunnel waist is the minimum value; then, the original data of the damage degree of the rock layer at the initial stress position and the positions on both sides of the tunnel waist are linearly transformed, so that the eigenvalue is mapped to between [0,1], thereby eliminating the influence of the dimension on the final result and making different characteristics comparable. The transformation function is shown in formula (1):

[0051]

[0052] In formula (1), c is the value of the rock formation damage degree after normalization;

[0053] a is the original value of the rock damage degree;

[0054] a max 、a max are the maximum and minimum values ​​of the original values ​​of the rock formation loss degree, respectively;

[0055] Finally, the normalized rock surface damage degree data are obtained. The data are all infinite values ​​with a distribution interval of [0,1]. The larger the value, the smaller the rock surface damage degree, and the smaller the value, the greater the rock surface damage degree.

[0056] The zero mean normalization method can also be used, and the transformation function is shown in formula (2):

[0057]

[0058] Among them, u and e are the mean and variance of the original values ​​of the rock damage degree, respectively. This method normalizes the original values ​​of the rock damage degree to values ​​with a mean of 0 and a variance of 1.

[0059] Step 4: Determine the effectiveness of tunnel support by combining the tunnel stress environment and tunnel surrounding rock structure;

[0060] The steps are:

[0061] a. Determine whether the existing support method meets the support requirements;

[0062] b. Use thermal imaging analysis to obtain the degree of rock damage and instability, collect temperature changes in the form of infrared thermal imaging and two-dimensional temperature matrix, and analyze the degree of rock damage and instability through temperature changes. Compare the degree of damage and instability with the multiples of the tunnel size. The specific value of the multiples of the tunnel size is obtained based on the purpose of the underground space and the analysis of the rock lithology; if the degree of damage and instability is < the multiples of the tunnel size, it proves that the existing support is effective; if the degree of damage and instability is > the multiples of the tunnel size, it proves that the existing support is ineffective and the support method needs to be changed;

[0063] The infrared thermal imager used in the experiment can compensate for the radiation other than the infrared radiation from the rock surface. The compensation process can be expressed as follows:

[0064] Q mea =Q(T obj )×τ×ε+Q(T sur )×(l-ε)×τ+Q(T atm )×(l-τ) (3)

[0065] In formula (3), Q mea is the total radiation energy received by the thermal imager; Q(T) is the blackbody radiation energy at temperature T; T obj is the temperature of the target rock sample; T sur is the average temperature reflected from the surrounding environment to the rock sample; T atm is the average temperature of the atmosphere between the thermal imager and the rock sample; ε is the average emissivity of the rock sample surface within the spectral range of the thermal imager; τ is the average atmospheric penetration within the spectral range.

[0066] c. If the support structure is effective, the support is completed;

[0067] d. If the support structure fails, the support length and support density must be further determined.

[0068] In step one, geological surveys are conducted to collect information on strata, structures, and groundwater conditions, monitor rock formations, groundwater level changes, and ground stress, conduct non-destructive tests on rock formations, obtain data on the internal structure and stress distribution of rock formations, and finally use numerical analysis methods to determine the peak stress position of the rock formation and the size and position of the initial stress.

[0069] like Figure 2As shown, the laser instrument 14 includes a housing, a built-in laser spectrometer, and a rotating laser scanning device. The rotating laser scanning device causes the laser device to rotate and scan, and the built-in laser spectrometer is located below the rotating device 6. In the actual process, the laser instrument is equipped with a telescopic rod and a placement frame. The front of the telescopic rod is connected to the laser instrument, and the rear is connected to the placement frame. The borehole inner wall detection of the laser instrument is carried out by controlling the telescopic rod to extend and retract, thereby obtaining the lithology and thickness of the rock formation. The speed of the rotating laser scanning device matches the telescopic displacement rate of the telescopic rod. The digital camera is used to photograph the rock formation, and the time counter is used to control the scanning rate; the rotating laser scanning device can rotate in all directions.

[0070] The built-in laser spectroscopy device includes a laser source 11, a focusing mirror 7, a reflector 9 and a grating 10. The laser source releases photons when particles transition from a high energy level to a low energy level. These photons return to the working material under the reflector of the resonant cavity, triggering more transitions of the same nature, thereby generating radiation of the same frequency, direction and phase. Through the feedback amplification of the resonant cavity, these radiations are continuously enhanced, and eventually form a powerful laser beam output; the focusing mirror improves the ability of the edge beam to be incident on the detector and increases the energy of the laser; the reflector is used for imaging, focusing and diffusion. Refraction passes through the lens and irradiates the laser on the rock surface. The grating is used as an output coupler in the laser to control the output power of the laser and the direction of the output beam.

[0071] In step 3, select Min-Max normalization processing and scale the anchor data for support to the interval [0,1]. The process is: old_min = min(date), old_max = max(date), date = (date-old_min) / (old_max-old_min). The anchor data for support is selected in the interval of rock surface damage degree after normalization processing. Place.

[0072] In step 4, the infrared thermal imager obtains the infrared radiation energy projected by the rock to the thermal imager detector, and then converts it into an electrical signal through the relationship between radiation energy and temperature to determine the instability of the rock mass, and compares it with the degree of instability. When the support fails, change its support method.

[0073] The laser scanning device includes a laser transmitter 5, a thermal imager 8, a rotatable cylindrical filter 1, a receiver 3, a time counter 2 and a digital camera 4. The laser transmitter is used to emit infrared laser, and the rotatable cylindrical filter increases the area of ​​laser scanning so that the laser can be reflected back after scanning the rock surface. The receiver is used to receive the scanning rate, and the digital camera is used to photograph the rock formation. The time counter controls the scanning rate, and when the thermal imager scans the tunnel rock formation through the digital camera, the degree of rock damage and instability is analyzed through temperature changes. The laser scanning device can rotate in all directions.

[0074] A system for identifying underground surrounding rock structures, including a computer, a data transmission line and a laser instrument. After the laser instrument collects excited rock photons, the data acquisition device has some basic data processing functions, such as amplification, calibration and calibration. The data acquisition device supports real-time data transmission. It is transmitted to the computer through a network connection or wireless communication. The data is processed on the computer, and infrared thermal images and spectral images of the rock are generated by visualization, and analyzed and compared with the data in the database. The lithology, spectral characteristics, etc. are displayed on the computer.

[0075] Parts not described in the present invention can be implemented by referring to the existing technology.

[0076] It should be noted that any equivalent method or obvious variation method made by those skilled in the art under the guidance of this specification should be within the protection scope of the present invention.

Claims

1. A method for determining the advanced support of tunnel rock mass stability based on laser instrument, characterized in that The tunnel surrounding rock structure is intelligently identified through laser spectroscopy and laser scanning devices, a three-dimensional model of the rock formation is constructed and the degree of surface damage is normalized. The effectiveness of the support structure is determined through analysis of the environment and surrounding rock structure. The following steps are included in sequence: Step 1: Based on rock stress monitoring and geological structure, clarify the stress environment of the rock formation around the tunnel, determine the location of the stress peak and the magnitude and location of the initial stress; Step 2: Use laser scanning equipment to perform high-precision scanning of the rock formations around the tunnel to obtain 3D model data. With the help of geological information recognition algorithms and machine learning technology, the laser scanning data is processed and analyzed to obtain the thickness and lithology of the rock formations. Based on the identified rock formation information, a 3D model of the rock formation is constructed using computer-aided design software. The finite element analysis method is used to perform mechanical analysis on the 3D model, including the stress peak position, the rock formation surface damage degree analysis on the tunnel crown plate and both sides of the tunnel arch waist; Step 3: Quantitatively evaluate the degree of surface loss of the rock strata on both sides of the tunnel vault plate and the tunnel waist. Use a unified evaluation standard to normalize the damage degree data to ensure data comparability. Compare and analyze the damage degrees on both sides of the vault plate and the waist to evaluate the stress environment and structural characteristics of the rock strata around the tunnel. The normalization process specifically includes the following steps: First, the data of the damage degree of each rock layer are collected, the state and number of cracks are analyzed, and the damage degree of the rock layer is converted into a function form represented by numerical values, so as to obtain the maximum and minimum values ​​of the damage degree a of the rock layer. The surface damage degree of the rock layer at the initial stress position is the maximum value, and the surface damage degree of the rock layer on both sides of the tunnel waist is the minimum value; then, the original data of the damage degree of the rock layer at the initial stress position and the positions on both sides of the tunnel waist are linearly transformed, so that the eigenvalue is mapped to between [0,1], thereby eliminating the influence of the dimension on the final result and making different characteristics comparable. The transformation function is shown in formula (1): In formula (1), c is the value of the rock formation damage degree after normalization; a is the original value of the rock damage degree; a max 、a max are the maximum and minimum values ​​of the original values ​​of the rock formation loss degree, respectively; Finally, the normalized rock surface damage degree data are obtained. The data are all infinite values ​​with a distribution interval of [0,1]. The larger the value, the smaller the rock surface damage degree, and the smaller the value, the greater the rock surface damage degree. The zero mean normalization method can also be used, and the transformation function is shown in formula (2): Among them, u and e are the mean and variance of the original values ​​of the rock damage degree, respectively. This method normalizes the original values ​​of the rock damage degree to values ​​with a mean of 0 and a variance of 1. Step 4: Determine the effectiveness of tunnel support by combining the tunnel stress environment and tunnel surrounding rock structure; The steps are: a. Determine whether the existing support method meets the support requirements; b. Use thermal imaging analysis to obtain the degree of rock damage and instability, collect temperature changes in the form of infrared thermal imaging and two-dimensional temperature matrix, and analyze the degree of rock damage and instability through temperature changes. Compare the degree of damage and instability with the multiples of the tunnel size. The specific value of the multiples of the tunnel size is obtained based on the purpose of the underground space and the analysis of the rock lithology; if the degree of damage and instability is < the multiples of the tunnel size, it proves that the existing support is effective; if the degree of damage and instability is > the multiples of the tunnel size, it proves that the existing support is ineffective and the support method needs to be changed; The infrared thermal imager used in the experiment can compensate for the radiation other than the infrared radiation from the rock surface. The compensation process can be expressed as follows: Q mea =Q(T obj )×τ×ε+Q(T sur )×(l-ε)×τ+Q(T atm )×(l-τ) (3) In formula (3), Q mea is the total radiation energy received by the thermal imager; Q(T) is the blackbody radiation energy at temperature T; T obj is the temperature of the target rock sample; T sur is the average temperature reflected from the surrounding environment to the rock sample; T atm is the average temperature of the atmosphere between the thermal imager and the rock sample; ε is the average emissivity of the rock sample surface within the spectral range of the thermal imager; τ is the average atmospheric penetration within the spectral range. c. If the support structure is effective, the support is completed; d. If the support structure fails, the support length and support density must be further determined.

2. The method for determining the advanced support of tunnel rock mass stability based on a laser instrument according to claim 1 is characterized in that: In step one, geological surveys are conducted to collect information on strata, structures, and groundwater conditions, monitor rock formations, groundwater level changes, and ground stress, conduct non-destructive tests on rock formations, obtain data on the internal structure and stress distribution of rock formations, and finally use numerical analysis methods to determine the peak stress position of the rock formation and the size and position of the initial stress.

3. According to claim 1, a method for determining the advanced support of tunnel rock mass stability based on a laser instrument is characterized in that: the laser instrument includes a shell, a built-in laser spectrum device, and a rotating laser scanning device. The rotating laser scanning device causes the laser device to rotate and scan, and the built-in laser spectrum device is located below the rotating device. In the actual process, the laser instrument is equipped with a telescopic rod and a placement frame. The front of the telescopic rod is connected to the laser instrument, and the rear is connected to the placement frame. The borehole inner wall detection of the laser instrument is carried out by controlling the telescopic rod to extend and retract, thereby obtaining the rock lithology and thickness of the rock formation. The speed of the rotating laser scanning device matches the telescopic displacement rate of the telescopic rod. The digital camera is used to shoot the rock formation, and the time counter is used to control the scanning rate; the rotating laser scanning device can rotate in all directions.

4. The method for determining the advanced support of tunnel rock mass stability based on a laser instrument according to claim 2 is characterized in that: The built-in laser spectroscopy device includes a laser source, a focusing mirror, a reflector and a grating. The laser source releases photons when particles transition from a high energy level to a low energy level. These photons return to the working material under the reflector of the resonant cavity, triggering more transitions of the same nature, thereby generating radiation of the same frequency, direction and phase. Through the feedback amplification of the resonant cavity, these radiations are continuously enhanced, and eventually form a powerful laser beam output; the focusing mirror improves the ability of the edge beam to be incident on the detector and increases the energy of the laser; the reflector is used for imaging, focusing and diffusion. Refraction passes through the lens and irradiates the laser on the rock surface. The grating is used as an output coupler in the laser to control the output power of the laser and the direction of the output beam.

5. The method for determining the advanced support of tunnel rock mass stability based on a laser instrument according to claim 1 is characterized in that: In step 3, select Min-Max normalization processing and scale the anchor data for support to the interval [0,1]. The process is: old_min = min(date), old_max = max(date), date = (date-old_min) / (old_max-old_min). The anchor data for support is selected in the interval of rock surface damage degree after normalization processing. Place.

6. The method for determining the advanced support of tunnel rock mass stability based on a laser instrument according to claim 1 is characterized in that: In step 4, the infrared thermal imager obtains the infrared radiation energy projected by the rock to the thermal imager detector, and then converts it into an electrical signal through the relationship between radiation energy and temperature to determine the instability of the rock mass, and compares it with the degree of instability. When the support fails, change its support method.

7. The laser scanning device includes a laser transmitter, a thermal imager, a rotatable cylindrical filter, a receiver, a time counter and a digital camera. The laser transmitter is used to emit infrared lasers, while the rotatable cylindrical filter increases the area of ​​laser scanning so that the laser can be reflected back after scanning the rock surface. The receiver is used to receive the scanning rate, while the digital camera is used to photograph the rock formation. The time counter controls the scanning rate, and when the thermal imager scans the tunnel rock formation through the digital camera, the degree of rock damage and instability is analyzed through temperature changes. The laser scanning device can rotate in all directions.

8. A system for identifying underground surrounding rock structures, including a computer, a data transmission line and a laser instrument. After the laser instrument collects excited rock photons, the data acquisition device has some basic data processing functions, such as amplification, calibration and calibration. The data acquisition device supports real-time data transmission. It is transmitted to the computer through a network connection or wireless communication. The data is processed on the computer, and infrared thermal images and spectral images of the rock are generated by visualization, and analyzed and compared with the data in the database. The lithology, spectral characteristics, etc. are displayed on the computer.

Images