Distributed optical fiber monitoring system for monitoring changing state of rock mass

Abstract

The application discloses a distributed optical fiber monitoring system for rock mass change state monitoring, and relates to the field of monitoring equipment, which is applied to an underground cavern and can simultaneously monitor axial and radial rupture signals of the underground cavern, so as to facilitate three-dimensional positioning of a seismic source of a rupture occurrence position. The distributed optical fiber monitoring system comprises a first optical fiber and a second optical fiber. The first optical fiber is arranged on a cavern wall of the underground cavern along an axial direction of the underground cavern, and can monitor the axial distributed rupture signals of the underground cavern; and the second optical fiber mainly comprises a circumferential optical fiber segment and a reversing transition segment. The circumferential optical fiber segment is arranged on the cavern wall along a cross-sectional profile of the cavern wall, and can monitor the radial distributed rupture signals of the underground cavern. It can be seen that the distributed optical fiber monitoring system can simultaneously monitor the axial and radial rupture signals of the underground cavern, realizes spatial monitoring of the underground cavern, and facilitates more accurate three-dimensional positioning of the seismic source of the rupture occurrence position.

Description

Technical Field

[0001] The invention belongs to the field of monitoring equipment, and in particular relates to a distributed optical fiber monitoring system for monitoring rock mass change status. Background Art

[0002] Due to the disturbance caused by engineering excavation, the original state of the rock mass is altered, including but not limited to temperature, strain, and rock fracture. This change in rock mass state directly impacts the safety of engineering construction and long-term operations. Effective monitoring and prediction of this change is a key measure to ensure engineering safety. Rock mass changes not only involve changes in deformation and rock fracture caused by stress field adjustments, such as surrounding rock collapse and rockbursts, but may also involve changes in the temperature field, such as water inrush and geological disposal of high-level radioactive waste. Rockburst, a typical example of rock mass fracture, is not only an extremely dangerous dynamic hazard, but also lacks equipment and analytical techniques for effective monitoring and prediction.

[0003] Rockbursts are caused by the sudden and violent release of accumulated elastic deformation energy in the rock mass due to external disturbances. Before rock failure occurs, only internal rock deterioration occurs, resulting in slight vibrations and sounds indiscernible to the human ear. Rock failures often occur within 24 hours of excavation, typically lasting one to two months, but sometimes exceeding a year. Severe events can be detected as earthquakes of magnitude 4 to 6, with intensities reaching 7 to 8. Therefore, monitoring and predicting rock failure based on the characteristics of vibration and sound generated before and during rock failure, determining its location, magnitude, and likely duration, and implementing appropriate preventive measures, can significantly reduce or eliminate casualties and property losses caused by rock failure.

[0004] Currently, on-site rockburst prediction primarily relies on predicting the location and likelihood of rockbursts through on-site monitoring during construction. These methods include microseismic (MS), acoustic emission (AE), drill cuttings, electromagnetic radiation (EMR), and distributed fiber optic monitoring. Distributed fiber optic monitoring uses optical fiber strips at monitoring points to detect rupture signals, such as vibration and sound, generated before and during rock rupture. However, these methods suffer from issues such as dispersed monitoring signals, difficulty in deployment, and low survival rates in complex geological environments.

[0005] For example, a Chinese utility model patent with authorization publication number CN212003266U discloses a rockburst monitoring system based on distributed fiber optic sensing. The system employs multiple armored optical cables installed along the top and supporting rock masses or retaining walls of a tunnel under construction or completed, or along the working face of a mountain or ore body under excavation. One end of each of the multiple armored optical cables is connected to a multi-channel, broadband, distributed fiber optic acoustic and strain sensing modulation and demodulation system, which is in turn connected to a real-time data recording and processing computer. Because deep underground tunnel chambers are typically excavated by blasting, the surrounding rock mass of the tunnel walls exhibits significant fluctuations. Using optical fiber strips for rockburst monitoring results in poor coupling between the optical fiber and the surrounding rock. Furthermore, in order for the optical fiber to couple with the surrounding rock, it is often necessary to bend the optical fiber significantly at the monitoring point, significantly reducing the fiber's survival rate. In addition, the above-mentioned patent adopts a linear layout along the tunnel axis and is not suitable for facilities with multiple staggered caverns, such as deep underground laboratories, underground factories and other projects; this is because optical fibers are more sensitive to deformation along their axial direction. This linear layout method can often only monitor rupture signals distributed along the tunnel axis, and cannot monitor rupture signals in directions other than the tunnel axis, making it difficult to achieve three-dimensional positioning of the earthquake source at the rupture location.

[0006] Therefore, there is an urgent need in this field for a distributed optical fiber monitoring system for monitoring rock mass change status to solve the above technical problems. Summary of the Invention

[0007] The present invention aims to address at least one of the technical problems existing in the prior art. To this end, the present invention provides a distributed fiber optic monitoring system for monitoring rock mass changes. This system, when applied to an underground cavern, can simultaneously monitor axial and radial fracture signals within the cavern, facilitating three-dimensional localization of the earthquake source at the fracture site.

[0008] The technical solution adopted by the present invention to solve the technical problem is: a distributed optical fiber monitoring system for monitoring rock mass change state, comprising a first optical fiber, wherein the first optical fiber is arranged on the wall of an underground cavern along the axial direction thereof;

[0009] Also included is a second optical fiber, wherein the second optical fiber includes a peripheral optical fiber segment and a switching transition segment;

[0010] The peripheral optical fiber segment is used to be arranged on the cavern wall along the cross-sectional profile thereof;

[0011] There are at least two circumferential optical fiber segments which can be arranged at intervals along the axial direction of the underground cavern. The circumferential optical fiber segments are sequentially connected end to end through the switching transition segment to make the optical path of the second optical fiber continuous.

[0012] Furthermore, the cavern wall includes a left cavern wall, a top cavern wall and a right cavern wall;

[0013] There are three or more first optical fibers, at least one of which is arranged on the left wall of the cave, at least one is arranged on the top wall of the cave, and at least one is arranged on the right wall of the cave.

[0014] Furthermore, the number of the first optical fibers is six;

[0015] One of them is used to be laid on the left wall of the cavern and is located at 1 / 3 of the height of the left wall of the cavern;

[0016] One of them is used to be laid on the left wall of the cavern and is located at 2 / 3 of the height of the left wall of the cavern;

[0017] One of them is used to be laid on the top wall of the cavern and is located at the position of 1 / 3 of the arc length of the top wall of the cavern;

[0018] One of them is used to be laid on the top wall of the cavern and is located at the position of 2 / 3 of the arc length of the top wall of the cavern;

[0019] One of them is used to be laid on the right wall of the cavern and is located at 1 / 3 of the height of the right wall of the cavern;

[0020] One of them is used to be laid on the right side wall of the cavern and is located at 2 / 3 of the height of the right side wall of the cavern.

[0021] Furthermore, the distributed optical fiber monitoring system also includes a multi-channel optical fiber sensor regulator and a data processing terminal;

[0022] One end of each of the first optical fiber and the second optical fiber is used to extend to the excavation surface of the underground cavern, and each is provided with a light extinction device;

[0023] The other ends of the first optical fiber and the second optical fiber are optically connected to a multi-channel optical fiber sensing regulator via an outgoing optical fiber that can be arranged along the wall of the shaft;

[0024] The multi-channel optical fiber sensing regulator is communicatively connected to the data processing terminal.

[0025] Furthermore, the first optical fiber and / or the second optical fiber is optically connected to an integrated optical fiber sensor for collecting rupture signals in a key monitoring area;

[0026] The integrated optical fiber sensor includes a deformable body and a third optical fiber, wherein the third optical fiber includes a first optical fiber segment and a second optical fiber segment that are connected to each other;

[0027] The first optical fiber segment is arranged on the peripheral wall of the deformable body and is spirally wound at least once around the axial direction of the deformable body to form a first optical fiber coil;

[0028] The second fiber line segment comprises straight line segments arranged on the peripheral wall of the deformation body along the axial direction, the straight line segments are at least two and are uniformly distributed around the deformation body, each straight line segment is connected in sequence by an arc-shaped reversing segment, and the second fiber coil with continuous light paths is formed.

[0029] Further, the integrated optical fiber sensor further comprises a vibration conduction assembly.

[0030] The vibration conduction assembly is arranged at the bottom of the deformation body and is used for conducting the vibration generated by the rock mass rupture to the deformation body.

[0031] Further, the vibration conduction assembly comprises a rigid conduction sheet and a rigid vibration ball.

[0032] One side surface of the rigid conduction sheet is attached to the bottom surface of the deformation body.

[0033] The rigid vibration ball is arranged on the other side surface of the rigid conduction sheet, the rigid vibration ball is at least three and is arranged in a ring array with the extension line of the axial center line of the deformation body as the array center line.

[0034] Further, the integrated optical fiber sensor further comprises a protective shell, a fiber guide tube and a rock mass coupling component.

[0035] The deformation body is in a cylindrical shape.

[0036] The protective shell is arranged outside the deformation body, and the bottom of the vibration conduction assembly is at least partially exposed outside the protective shell.

[0037] The fiber guide tube comprises an inner guide tube and an outer guide tube; the inner guide tube is inserted into the protective shell along the axial direction of the deformation body; the outer guide tube is arranged outside the protective shell, and a partial tube segment of the outer guide tube is open and connected with one end of the inner guide tube.

[0038] The third fiber further comprises an entering fiber segment and an exiting fiber segment; the tail end of the entering fiber segment penetrates into the fiber guide tube from one end of the outer guide tube and penetrates out from the side of the inner guide tube, and is connected with the head end of the first fiber line segment; the head end of the exiting fiber segment is connected with the tail end of the second fiber line segment, and the tail end penetrates into the fiber guide tube from the side of the inner guide tube and penetrates out from the other end of the outer guide tube.

[0039] The rock mass coupling component is arranged at the bottom of the vibration conduction assembly and is used for coupling connection with the rock mass.

[0040] Further, the rock mass coupling component is a coupling cone head, and the coupling cone head is connected with the bottom of the vibration conduction assembly through the bottom surface.

[0041] Further, the rock mass coupling component includes a coupling base and a coupling connector;

[0042] The side surface of the coupling base is attached to the bottom of the vibration conduction assembly;

[0043] The coupling connector is arranged on the coupling base, and the at least partial connecting part of the coupling connector penetrates out from the other side surface of the coupling base;

[0044] The coupling connector is at least three, and is arranged in a ring array with the extension line of the deformation body axis as the array center line.

[0045] The beneficial effects of the present application are as follows:

[0046] (1) The distributed optical fiber monitoring system for monitoring the change state of rock mass provided by the present application, when monitoring the breakage signals such as vibration and sound generated before and during the rock mass breakage in the underground cavern, the first optical fiber is arranged on the cavern wall along the axial direction of the underground cavern, and can monitor the breakage signals distributed along the axial direction of the underground cavern; the second optical fiber is mainly composed of a circumferential optical fiber segment and a reversing transition segment, the circumferential optical fiber segment is arranged on the cavern wall along the cross-sectional profile of the cavern wall, and can monitor the breakage signals distributed along the radial direction of the underground cavern. It can be seen that the distributed optical fiber monitoring system can monitor the breakage signals in the axial and radial directions of the underground cavern at the same time, realize the spatial monitoring of the underground cavern, and facilitate more accurate three-dimensional positioning of the earthquake source of the breakage position.

[0047] (2) The distributed optical fiber monitoring system further includes a multi-channel optical fiber sensing adjustment instrument and a data processing terminal; the strain signals measured by the first optical fiber and the second optical fiber can be obtained at the same time through the multi-channel optical fiber sensing adjustment instrument, and sent to the data processing terminal; the strain signals can be analyzed and processed through the data processing terminal, which is beneficial to real-time feedback of the energy size and position distribution of the breakage event of the underground cavern in the excavation process, so as to predict the area where the rock burst or collapse disaster event may occur in advance according to the position information and energy information, so as to guide the staff to prevent and dispose in advance, and minimize the casualties and property losses caused by disaster events.

[0048] (3) By connecting an integrated fiber optic sensor to the first optical fiber and / or the second optical fiber, the integrated fiber optic sensor can be used to monitor the key monitoring areas in the underground cavern, thereby improving the monitoring effect of the distributed fiber optic monitoring system. When the deformable body of the integrated fiber optic sensor senses a rupture signal, it will deform, thereby causing the first fiber optic coil and the second fiber optic coil on the peripheral wall of the deformable body to deform, thereby realizing the monitoring of the rupture signal. Since the optical fiber can monitor the rupture signal along its axial direction, the first fiber optic coil that is spirally wound around the axial direction of the deformable body for at least one turn can effectively monitor the longitudinal and transverse strains perpendicular to the axial direction of the deformable body caused by vibration, while the second fiber optic coil that has two or more straight segments uniformly distributed around the circumference of the deformable body and arranged along the axial direction of the deformable body can effectively monitor the strain along the axial direction of the deformable body caused by vibration. It can be seen that the integrated fiber optic sensor can simultaneously obtain the components of the X, Y, and Z directions corresponding to the rupture signal, and has a good monitoring effect on rupture signals such as vibration and sound generated before and during the rupture.

[0049] (4) Based on the monitoring method implemented by the distributed optical fiber monitoring system, the deformation field and temperature field of the monitored cavern rock mass obtained synchronously are three-dimensional distributions, which can more realistically reflect the deformation field state and temperature field differences in different parts of the cavern space morphology.

[0050] The technical effects brought about or directly produced by other technical features of the present invention will be described in detail in the subsequent specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a schematic diagram of the implementation structure of the present invention;

[0052] Figure 2 This is a schematic diagram of the structure of an integrated optical fiber sensor according to one embodiment of the present invention;

[0053] Figure 3 This is an analysis diagram of the monitoring rupture signal when the optical fiber is wound;

[0054] Figure 4 yes Figure 3 Schematic diagram of the optical fiber unfolding state in the winding arrangement;

[0055] Figure 5 is based on Figure 3 The relationship diagram between the local coordinate system n-axis and the global coordinate system;

[0056] Figure 6 This is a schematic diagram of the structure of another embodiment of the integrated optical fiber sensor of the present invention;

[0057] Figure 7This is a schematic diagram of the structure of another embodiment of the integrated optical fiber sensor of the present invention;

[0058] Marked in the figure are: underground cavern 1, cavern wall 11, first optical fiber 2, second optical fiber 3, peripheral optical fiber segment 31, reversing transition segment 32, multi-channel optical fiber sensor regulator 4, data processing terminal 5, deformable body 100, entering optical fiber segment 210, first optical fiber coil 220, second optical fiber coil 230, straight segment 231, arc-shaped reversing segment 232, lead-out optical fiber segment 240, vibration conduction component 300, rigid conduction sheet 310, rigid vibration ball 320, protective shell 400, optical fiber guide tube 500, inner guide tube 510, outer guide tube 520, coupling cone head 600, coupling base 710, coupling connector 720. DETAILED DESCRIPTION

[0059] The present invention will be further described below with reference to the accompanying drawings and embodiments. The same reference numerals in the accompanying drawings represent components with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise indicated.

[0060] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "head", "tail", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate directions or positions, and dimensional relationships based on the directions or position relationships shown in the accompanying drawings, are only for the convenience of description, and do not indicate or imply that the device or component referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0061] When used to describe a numerical range, terms like "about" and "approximately" generally refer to a range within ±10%. For example, "approximately 100 mm" generally refers to 90-110 mm. When referring to a quantity, the term "plurality" generally refers to three or more. For example, "a plurality" generally refers to three or more. The expression "consisting primarily of" should be interpreted as including components not mentioned in the sentence. The term "and / or" simply describes an association between related objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone. The term "communication connection" refers to the communication between connected devices through the transmission of signals. It can be divided into wired and wireless connections. Wired connections typically include cables, optical fibers, and other connections; wireless connections typically include radio, Bluetooth, infrared, NFC, and other connections. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0062] like Figure 1 As shown, a distributed optical fiber monitoring system for monitoring rock mass change status includes a first optical fiber 2 and a second optical fiber 3;

[0063] The first optical fiber 2 is arranged along the axial direction of the underground cavern 1 on the cavern wall 11 thereof to monitor fracture signals distributed along the axial direction of the underground cavern 1. The first optical fiber 2 is generally fixed to the cavern wall 11 by an adhesive such as cement, or by a fixing member such as a wire clip. The number of first optical fibers 2 arranged is generally selected according to monitoring needs, and multiple optical fibers are usually arranged according to the required optical fiber resolution.

[0064] The second optical fiber 3 is fixed on the chamber wall 11 in the same manner as the first optical fiber 2; the second optical fiber 3 includes a peripheral optical fiber segment 31 and a reversing transition segment 32;

[0065] The peripheral optical fiber segment 31 is arranged along the cross-sectional profile of the cavern wall 11 to monitor fracture signals distributed radially along the underground cavern 1. The peripheral optical fiber segment 31 is generally arranged perpendicular to the axial direction of the underground cavern 1, and is routed sequentially along the height direction of the left cavern wall, the arc length direction of the cavern ceiling, and the height direction of the right cavern wall. Because the cavern ceiling is curved, the radius of the curved arc of the peripheral optical fiber segment 31 during the transition from the left cavern wall to the cavern ceiling, and from the cavern ceiling to the right cavern wall, must be greater than 20 times the diameter of the bare optical fiber.

[0066] There are at least two circumferential optical fiber segments 31 and they can be arranged at intervals along the axial direction of the underground cavern 1. The circumferential optical fiber segments 31 are connected end to end in sequence through the reversing transition segment 32 to make the optical path of the second optical fiber 3 continuous; the more circumferential optical fiber segments 31 there are, the higher the monitoring accuracy will be, but it will lead to signal acquisition redundancy. Therefore, the specific number of circumferential optical fiber segments 31 can usually be determined based on comprehensive consideration of factors such as monitoring effect requirements, the minimum curvature of the reversing transition segment 32, production cost, and production difficulty; the reversing transition segment 32 is usually smoothly connected to the circumferential optical fiber segment 31, and the curvature of the reversing transition segment 32 must meet the requirement of basically not affecting the signal transmission of the optical fiber. It is usually required that the arc radius of the reversing transition segment 32 is greater than 20 times the diameter of the bare optical fiber.

[0067] This distributed fiber optic monitoring system is mainly used to be deployed in the underground cavern 1 to monitor the fracture signals such as vibration and sound generated before and during the rock fracture. It can simultaneously monitor the axial and radial fracture signals of the underground cavern 1, realize the spatial monitoring of the underground cavern, and facilitate more accurate three-dimensional positioning of the fracture location.

[0068] To detect high-precision rupture signals, the spacing between optical fibers should typically be equal to or close to their resolution, which is pre-set based on the desired monitoring performance. The spacing between optical fibers refers to the spacing between two adjacent first optical fibers 2 and / or the spacing between two adjacent peripheral optical fiber segments 31. If the spacing between optical fibers is too large, the following drawbacks may occur: incomplete signal acquisition, lower monitoring accuracy, and increased data sparsity. If the spacing between optical fibers is too small, the following drawbacks may occur: redundant signal acquisition, wasted resources, and the need for increased computing and storage resources to process and store this redundant information. Therefore, the spacing between optical fibers is typically limited to 1 to 5 meters.

[0069] Specifically, the second optical fiber 3 is laid out on the cavern wall 11 as follows: cement or a wire clip is used to vertically lay the second optical fiber 3 close to the wall surface of the left side wall of the cavern, and it is laid all the way to the top of the left side wall of the cavern, and then it is bent upward in an arc shape with a radius greater than 20 times the diameter of the bare optical fiber, and continues to extend upward along the top of the left side wall of the cavern close to the wall surface to transition to the cavern top wall, and then it is bent again and laid out axially perpendicular to the underground cavern 1 along the cavern top wall until it extends to the top of the right side wall of the cavern, and then it is laid downward along the wall surface of the right side wall of the cavern, extending It extends to the bottom of the right side wall of the cavern to form a circumferential optical fiber segment 31; then, it is bent to form a reversing transition segment 32 that changes the direction of the second optical fiber 3. Then, a circumferential optical fiber segment 31 is laid out with the bottom of the right side wall of the cavern as the starting point and the bottom of the left side wall of the cavern as the end point. The second optical fiber 3 is bent in this way until it is laid to the excavation surface. The distance between any two adjacent circumferential optical fiber segments 31 should be less than or equal to the resolution of the optical fiber; taking the resolution set to 2m as an example, the distance between any two adjacent circumferential optical fiber segments 31 should be 2m.

[0070] The first optical fiber 2 and the second optical fiber 3 of the distributed optical fiber monitoring system are generally not laid on the bottom surface of the underground cavern 1 in order to prevent construction disturbance from reducing the survival rate of the optical fiber and to prevent too many construction noise signals from being monitored.

[0071] In order to improve the monitoring effect, Figure 1 As shown, in some embodiments of the present invention, the cave wall 11 includes the left wall of the cave, the top wall of the cave and the right wall of the cave; there are three or more first optical fibers 2, at least one of which is used to be arranged on the left wall of the cave, at least one is used to be arranged on the top wall of the cave, and at least one is used to be arranged on the right wall of the cave.

[0072] In some embodiments of the present invention, both the first optical fiber 2 and the second optical fiber 3 are armored optical fibers. Armored optical fibers can enhance the survival rate of optical fibers in complex geological environments. The armor is usually made of corrosion-resistant and aging-resistant materials, preferably rubber.

[0073] For example Figure 1 As shown, in some embodiments of the present invention, there are six first optical fibers 2. One is arranged on the left side wall of the cavern at 1 / 3 of its height; one is arranged on the left side wall at 2 / 3 of its height; one is arranged on the top wall of the cavern at 1 / 3 of its arc length; one is arranged on the top wall of the cavern at 2 / 3 of its arc length; one is arranged on the right side wall of the cavern at 1 / 3 of its height; and one is arranged on the right side wall at 2 / 3 of its height. This even arrangement of the first optical fibers 2 improves the accuracy of the fiber-optic monitoring signal. Two first optical fibers 2 are arranged on the same cavern wall, and the signal data monitored by these two first optical fibers 2 can complement and verify each other. Taking a 6-meter-high underground cavern 1 as an example, to accurately monitor rupture signals, the first optical fibers 2 are arranged in this manner, with a resolution of approximately 2 meters.

[0074] For example Figure 1 As shown, in some embodiments of the present invention, the distributed optical fiber monitoring system further includes a multi-channel optical fiber sensor regulator 4 and a data processing terminal 5;

[0075] One end of the first optical fiber 2 and the second optical fiber 3 are both used to extend to the excavation surface of the underground cavern 1, and are both provided with a light extinction device; the light extinction device is used to eliminate the reflected signal of the first optical fiber 2 and the second optical fiber 3 close to the excavation surface end;

[0076] The other ends of the first optical fiber 2 and the second optical fiber 3 are optically connected to the multi-channel optical fiber sensor regulator 4 through lead-out optical fibers that can be laid along the wall of the shaft;

[0077] The multi-channel fiber optic sensor regulator 4 is used to simultaneously acquire the strain signals measured by the first optical fiber 2 and the second optical fiber 3. The multi-channel fiber optic sensor regulator 4 can be of various types, preferably a quantitative acoustic data acquisition system based on optical phase and amplitude demodulation developed by FEBUS Optics of France, model TV155. The multi-channel fiber optic sensor regulator 4 is communicatively connected to the data processing terminal 5.

[0078] The data processing terminal 5 is used to analyze and process the strain signal, which is conducive to real-time feedback of the energy size and position distribution of the rupture event of the underground cavern 1 during the excavation process, so that based on the position information and energy information, the area where the rock burst event may occur can be predicted in advance, thereby guiding the staff to carry out reinforcement treatment in advance and minimize the casualties and property losses caused by the rock burst; the data processing terminal 5 can be a smart phone, a tablet computer, a computer or a server; the data processing terminal 5 can analyze and process the strain signal in various ways, such as: Reference 1 (Song Guangdong. Research on microseismic signal acquisition and identification and earthquake source location based on optical fiber sensing [D]. China University of Mining and Technology (Beijing), 2019.) and Reference 2 (Luo B, Trainor-Guitton W, The method described in E, et al. Horizontally orthogonal distributed acoustic sensing array for earthquake-and ambient-noise-based multichannel analysis of surface waves [J]. Geophysical Journal International, 2020, 222(3): 2147-2161.).

[0079] Based on the above distributed optical fiber monitoring system, when the rock mass in the monitored area is broken, local stress concentration occurs in the rock mass, thereby inducing the occurrence of microseismic events. The optical fiber arranged on the wall 11 of the cavern monitors the seismic waves of these microseismic signals and transmits them to the multi-channel optical fiber sensing conditioning instrument 4, and at the same time, transmits them to the data processing terminal 5 in real time. The data processing terminal 5 can calculate the spatial coordinate position and the time of the rupture event according to the difference between the first arrival of the P wave and the S wave of the same microseismic signal at different monitoring points of the optical fiber. At the same time, according to the amplitude of the monitored rupture signal, the energy of the microseismic event can also be judged. Subsequently, the data processing terminal 5 can present the rupture position and energy information in real time, so as to judge the area where rock burst may occur and make early warning in time, so that the staff can reinforce the area where rock burst may occur.

[0080] As shown in Figure 2 , Figure 6 or Figure 7 , in some embodiments of the present application, an integrated optical fiber sensor for collecting rupture signals in the key monitoring area is optically connected to the first optical fiber 2 and / or the second optical fiber 3. The integrated optical fiber sensor can be provided with one, two or more as needed. When more than two integrated optical fiber sensors are arranged, because the integrated optical fiber sensor is connected to the first optical fiber 2 and / or the second optical fiber 3, the specific connection position of the optical fiber section will be determined in advance according to the actual needs. The collected signals on each section of the first optical fiber 2 and / or the second optical fiber 3 can be displayed and data can be obtained from the data processing terminal 5 in real time, so the signal monitored by the integrated optical fiber sensor at which position can be judged according to the arrangement position of the integrated optical fiber sensor on the optical fiber. Therefore, the position of the optical fiber will be accurately calibrated before formal monitoring. The specific method is as follows: first, connect the optical fiber with the multi-channel optical fiber sensing conditioning instrument 4, and measure the length of a certain position of the optical fiber. Knock the position, and the vibration caused by the knocking will be highlighted on the data processing terminal 5 after being processed by the multi-channel optical fiber sensing conditioning instrument 4. The amplitude and other information of the knocking position can be highlighted on the data processing terminal 5, so that the position can be calibrated as the measured length on the data processing terminal 5.

[0081] The area that needs to be monitored in the underground cavern 1 is usually determined according to the construction requirements, which generally includes the rock mass near the entrance of the underground cavern 1, the area where structural deformation occurs in the underground cavern 1, the area where the rock layer is relatively thin in the underground cavern 1, and the area where there are many fractures in the underground cavern 1, etc.

[0082] The integrated optical fiber sensor includes a deformation body 100 and a third optical fiber, and the third optical fiber includes a first optical fiber section and a second optical fiber section which are in communication with each other.

[0083] The deformable body 100 is a component that will produce elastic deformation under the action of a load (such as vibration); the deformable body 100 is usually made of an elastic material, preferably made of rubber; the deformable body 100 is usually a regular columnar structure, preferably a cylindrical structure, to ensure that it can produce a deformation that is adapted to the vibration magnitude, vibration frequency and vibration direction under the action of vibration, thereby ensuring the monitoring effect;

[0084] A first optical fiber segment is disposed on the peripheral wall of the deformable body 100 and is helically wound at least once around the axial direction of the deformable body 100 to form a first optical fiber coil 220. Because the optical fiber can monitor fracture signals along its axial direction, and each turn of the first optical fiber coil 220 is approximately perpendicular to the axial direction of the deformable body 100, the first optical fiber coil 220 can effectively monitor longitudinal and transverse strains perpendicular to the axial direction of the deformable body 100 caused by vibration. The greater the number of turns of the first optical fiber coil 220 and the smaller the spacing between adjacent turns, the better the monitoring effect. The specific number of turns of the first optical fiber coil 220 and the spacing between adjacent turns can generally be determined based on a comprehensive consideration of factors such as the actual monitoring effect requirements, production cost, production difficulty, and the amount of signal collection.

[0085] The second optical fiber segment includes a straight segment 231 arranged on the peripheral wall of the deformable body 100 along the axial direction thereof. There are at least two straight segments 231 and they are evenly distributed around the circumference of the deformable body 100. The straight segments 231 are connected end to end in sequence through the arc-shaped reversing segment 232 to form a second optical fiber coil 230 with a continuous optical path. The arc-shaped reversing segment 232 is usually smoothly connected to the straight segment 231, and the curvature of the arc-shaped reversing segment 232 must be such that it does not substantially affect the signal transmission of the optical fiber. The straight segments 231 can effectively monitor the strain along the axial direction of the deformable body 100 caused by vibration. The more straight segments 231 there are, the higher the monitoring accuracy is, but this will lead to signal acquisition redundancy. Therefore, the specific number of straight segments 231 can usually be determined based on a comprehensive consideration of factors such as the monitoring effect requirements, the minimum curvature of the arc-shaped reversing segment 232, the production cost, the production difficulty, and the amount of signal collection.

[0086] The integrated fiber optic sensor can simultaneously detect the X, Y, and Z components of the fracture signal, effectively monitoring vibration and sound signals generated before and during rock fracture. The theoretical basis for simultaneous fiber optic monitoring of fracture signal components in three mutually perpendicular directions is as follows:

[0087] Combined with Figure 3 、 Figure 4 and Figure 5 Analyze the crack signal components that can be monitored when the optical fiber is wound. Figure 3 Point P is any position on the optical fiber, α is the winding angle, corresponding to Figure 2In the embodiment, the tilt angle of the front projection of the first optical fiber coil 220 corresponds to Figure 3 The angle between the axial direction of the optical fiber and the tangent line of the deformed body at point A; AA′ is the optical fiber winding section, e x 、e y 、e z are the strains of the X, Y, and Z components caused by vibration at the optical fiber location. They are actual quantities and are calculated according to formulas 1 to 5. Because the only strain actually obtained during the monitoring process is the axial strain of the optical fiber, e x 、e y 、e z The three component strains can be obtained by calculating the winding angle α and the following other parameters. is the axial strain of the optical fiber at point P, P-lmn is the local coordinate system of point P, n direction is the axial direction of the optical fiber winding section, θ is the rotation angle, θ nx is the angle between the n-axis in the local coordinate system P-lmn coordinate system and the x-axis in the global coordinate system. Similarly: θ ny is the angle between the n-axis in the local coordinate system P-lmn and the y-axis in the global coordinate system, θ nz is the angle between the n-axis in the local coordinate system P-lmn coordinate system and the z-axis in the global coordinate system.

[0088] Depend on Figure 3 、 Figure 4 and Figure 5 It can be deduced that the axial strain of the optical fiber at point P is The relationship with the three strain components is:

[0089]

[0090] Three coefficients R that affect the axial strain of optical fiber nx 、R ny 、R nz They are:

[0091]

[0092] θ nx ,θ ny ,θ nz The relationship with the winding angle α is:

[0093]

[0094] Where: R nx 、R ny 、R nz Represents the direction cosines between the n-axis and the x-, y-, and z-axes respectively; r is the fiber winding radius. Figure 2 or Figure 6 or Figure 7In the embodiment, r is equal to the radius of the deformable body 100. k is Figure 3 h is the length of the AP segment in the fiber optic unfolded state of the winding setting; h is the height of point P in the fiber optic unfolded state of the winding setting.

[0095] Formula 2 can be expressed in matrix form as:

[0096]

[0097] It can be shortened to:

[0098] E=GE0...(Formula 5);

[0099] Where: E is the axial strain matrix of the winding optical fiber; G is R nx 、R ny 、R nz E0 is the actual three-component strain e of the optical fiber in the winding setting. x 、e y 、e z The matrix formed.

[0100] Based on formulas 1 to 5, the strain E0 of the optical fiber monitoring point in the three components can be calculated according to the collected optical fiber axial strain E. It can be seen from formulas 1 to 5 that the three strain components generated by the optical fiber receiving the rupture signal are related to the winding angle α. When α increases, e z The weight increases, and e x and e y The component strain decreases, and when α decreases, e z The weight decreases, and e x and e y The component increases. Therefore, in order to be able to monitor the three more obvious strain component signals at the same time. Therefore, the present invention adopts two different winding methods to set the optical fiber segment on the deformable body 100, that is, one is a first optical fiber segment, which is set on the peripheral wall of the deformable body 100 and spirally wound around the axial direction of the deformable body 100 for at least one circle to form a first optical fiber coil 220; the other is a second optical fiber segment, which includes a straight line segment 231 set on the peripheral wall of the deformable body 100 along the axial direction of the deformable body 100, and there are at least two straight line segments 231 and they are evenly distributed around the circumference of the deformable body 100. The straight line segments 231 are connected end to end in sequence through the arc-shaped reversing segment 232 to form a second optical fiber coil 230 with a continuous optical path; the winding angle α of the straight line segment 231 is 90°, and the e monitored by it is z Component reaches its maximum value; when the winding angle α of the first optical fiber coil 220 is close to 0°, the monitored e x and e y The component is close to the maximum value.

[0101] like Figure 2 、 Figure 6 or Figure 7 As shown, in some embodiments of the present invention, the first optical fiber coil 220 is positioned below the second optical fiber coil 230, with the first optical fiber coil 220 wound from bottom to top. This arrangement not only provides a compact structure but also helps ensure the continuity of the optical path of the third optical fiber, thereby ensuring monitoring sensitivity and accuracy. The winding angle α of the first optical fiber coil 220 should be minimized. The winding length can be determined based on actual measurement requirements and the size of the deformable body 100, typically around 1 meter.

[0102] In some embodiments of the present invention, an integrated fiber optic sensor vibration transmission assembly 300 is provided at the bottom of the deformable body 100 and is used to transmit vibrations generated by rock fractures to the deformable body 100, thereby improving monitoring sensitivity and accuracy. The vibration transmission assembly 300 can be made of a variety of materials, typically a rigid material, preferably a solid metal.

[0103] For example Figure 2 、 Figure 6 or Figure 7 As shown, in some embodiments of the present invention, the vibration conducting component 300 includes a rigid conducting sheet 310 and a rigid vibration ball 320;

[0104] One side of the rigid conductive sheet 310 is attached to the bottom surface of the deformable body 100 and is used to evenly transmit vibration energy to the deformable body 100. The rigid conductive sheet 310 is generally a sheet-shaped member adapted to fit the bottom surface of the deformable body 100 and is typically made of a rigid material, preferably a metal material such as a steel sheet. The rigid conductive sheet 310 also prevents direct contact between the rigid vibration ball 320 and the deformable body 100, thereby preventing the loss or weakening of vibration energy due to friction.

[0105] The rigid vibration balls 320 are arranged on the other side surface of the rigid conductive sheet 310. There are at least three rigid vibration balls 320 and they are distributed in a circular array with the extension line of the axis of the deformable body 100 as the center line of the array. Since the rigid vibration balls 320 have a regular shape and high dimensional accuracy, they can accurately transmit vibrations. Moreover, the rigid vibration balls 320 have high hardness and rigidity, which can reduce energy loss in the process of transmitting vibrations. In addition, the rigid vibration balls 320 distributed in a plurality of circular arrays can ensure that they can uniformly transmit the rupture signal. Therefore, when the rigid vibration balls 320 are affected by external vibrations, only a small elastic deformation will occur, and they will quickly recover and generate vibration waves. These vibration waves will propagate along the rigid vibration balls 320, thereby accurately and efficiently transmitting the rupture signal to the rigid conductive sheet 310. The rigid vibration balls 320 are usually made of rigid materials, preferably made of metal materials, such as steel balls made of steel.

[0106] In order to simplify the structure and ensure good vibration conduction effect, in some embodiments of the present application, the number of rigid vibration balls 320 is preferably set to three or four.

[0107] In order to effectively reduce the loss of vibration energy at the connection part of the rigid vibration ball 320 and the rigid conduction sheet 310, and improve the connection effect, in some embodiments of the present application, the rigid vibration ball 320 and the rigid conduction sheet 310 are preferably in surface contact, that is, an arc-shaped groove is arranged on the other side surface of the rigid conduction sheet 310, and the local part of the rigid vibration ball 320 is embedded in the arc-shaped groove to form an arc-shaped surface matching connection.

[0108] Again as shown in Figure 2 , Figure 6 or Figure 7 In some embodiments of the present application, the integrated optical fiber sensor further comprises a protective shell 400, an optical fiber guide tube 500, and a rock mass coupling component;

[0109] The deformation body 100 is in a cylindrical shape;

[0110] The protective shell 400 covers the deformation body 100, and the bottom of the vibration conduction assembly 300 is at least partially exposed outside the protective shell 400; the protective shell 400 is mainly used for protecting the sensor parts installed inside, and reducing external interference on the integrated optical fiber sensor; the protective shell 400 is usually made of metal material, and can be in various structures, and is usually a cylindrical or inverted conical shell;

[0111] The optical fiber guide tube 500 comprises an inner guide tube 510 and an outer guide tube 520; the inner guide tube 510 is inserted into the protective shell 400 along the axial direction of the deformation body 100; the outer guide tube 520 is arranged outside the protective shell 400, and a local tube segment thereof is open and connected with one end of the inner guide tube 510;

[0112] The third optical fiber further comprises an entering optical fiber segment 210 and an exiting optical fiber segment 240; the tail end of the entering optical fiber segment 210 penetrates into the optical fiber guide tube 500 from one end of the outer guide tube 520, and penetrates out from the side of the inner guide tube 510, and is connected with the head end of the first optical fiber segment; the head end of the exiting optical fiber segment 240 is connected with the tail end of the second optical fiber segment, and the tail end thereof penetrates into the optical fiber guide tube 500 from the side of the inner guide tube 510, and penetrates out from the other end of the outer guide tube 520;

[0113] The rock mass coupling component is arranged at the bottom of the vibration conduction assembly 300, and is used for coupling connection with the rock mass; the rock mass coupling component can be various, such as a screw, a bolt, an anchor rod, a connecting seat, etc.; the specific structure of the rock mass coupling component can be selected according to the different flatness of the chamber wall, so as to ensure that the integrated optical fiber sensor can be fully coupled with the surrounding rock of the chamber, and the monitoring effect is optimal.

[0114] The incoming fiber segment 210 and the outgoing fiber segment 240 are typically protected by a protective casing; the casing is typically made of a corrosion-resistant and aging-resistant material, preferably rubber. The optical fiber guide tube 500, primarily composed of an inner guide tube 510 and an outer guide tube 520, guides the incoming and outgoing fibers, facilitates optical connections with other optical fibers and / or other integrated optical fiber sensors, and protects these fiber segments from external influences. Inserting the inner guide tube 510 axially within the protective housing 400 makes the entire integrated optical fiber sensor compact and facilitates installation within the deformable body 100. The tail end of the incoming fiber segment 210 exits through the side of the inner guide tube 510, facilitating direct connection with the first optical fiber segment wrapped around the deformable body 100. The tail end of the outgoing fiber segment 240 enters the optical fiber guide tube 500 through the side of the inner guide tube 510, facilitating direct connection with the second optical fiber segment wrapped around the deformable body 100. This reduces the number of optical fiber segments required for connection and improves monitoring accuracy. The exposed connection ends of the incoming optical fiber segment 210 and the outgoing optical fiber segment 240 are respectively passed through the two end pipe openings of the external guide tube 520, which facilitates the connection of the integrated optical fiber sensor with other optical components during use and facilitates maintenance.

[0115] In some embodiments of the present invention, the bottom of the protective shell 400 is open, the deformable body 100 is arranged in the protective shell 400 and is fixed in a compressed state between the inner top surface of the protective shell 400 and the vibration conduction component 300, and the exposed part of the vibration conduction component 300 is exposed through the opening at the bottom of the protective shell 400.

[0116] For the vibration conduction component 300, which is mainly composed of a rigid conduction sheet 310 and a rigid vibration ball 320, when the rupture signal is transmitted to the rigid vibration ball 320, it will cause multiple evenly distributed rigid vibration balls 320 to vibrate. Subsequently, the rigid vibration ball 320 will evenly distribute the rupture signal to the deformable body 100 through the rigid conduction sheet 310, thereby causing the deformable body 100 to produce a uniform deformation corresponding to the rupture signal. The deformation of the deformable body 100 causes the first optical fiber coil 220 and the second optical fiber coil 230 to deform, causing the optical signal inside the optical fiber to change, and finally restore the rupture signal, thereby realizing the monitoring of the rupture signal.

[0117] In order to further facilitate the use and maintenance of the integrated optical fiber sensor, Figure 2 、 Figure 6 or Figure 7As shown, in some embodiments of the present invention, the inner guide tube 510 and the outer guide tube 520 are perpendicular to each other, and the middle tube section of the outer guide tube 520 is open and connected to one end of the inner guide tube 510 to form a "T"-shaped optical fiber guide tube 500.

[0118] For example Figure 6 As shown, in some embodiments of the present invention, the rock coupling component of the integrated fiber optic sensor is a coupling cone 600, which is connected to the bottom of the vibration transmission assembly 300 through its bottom surface. The coupling cone 600 has a conical structure, and its tip facilitates insertion into the surrounding rock of the cavern and enables sufficient coupling with the surrounding rock to effectively transmit the fracture signal. When the fracture signal is transmitted to the coupling cone 600, it causes the vibration transmission assembly 300 to vibrate. This integrated fiber optic sensor is particularly suitable for use in caverns with large wall contours, such as those excavated by blasting.

[0119] In order to further improve the monitoring effect, Figure 6 As shown, in some embodiments of the present invention, the coupling cone 600 and the deformation body 100 remain coaxial.

[0120] For example Figure 7 As shown, in some embodiments of the present invention, the rock coupling component of the integrated fiber optic sensor includes a coupling base 710 and a coupling connector 720. One side of the coupling base 710 is attached to the bottom of the vibration transmission assembly 300. The coupling connector 720 is mounted on the coupling base 710, with at least a portion of its connection portion protruding from the other side of the coupling base 710. There are at least three coupling connectors 720, arranged in a circular array with the extension of the axis of the deformable body 100 as the array centerline. The coupling base 710 is used to install, support, and transmit vibrations to the integrated fiber optic sensor. The coupling connector 720 is connected to the surrounding rock of the cavern through the coupling connector 720 to ensure full contact between the coupling base 710 and the rock mass, thereby enhancing the transmission of the fracture signal. The coupling connector 720 can be a screw, bolt, or the like. This integrated fiber optic sensor not only has good coupling with the surrounding rock, but also requires a low drilling depth, making installation easier. It is particularly suitable for use in caverns with relatively flat walls, such as those excavated by TBMs (full-face hard rock tunnel boring machines).

[0121] The distributed optical fiber monitoring system for monitoring rock mass change status provided by the present invention is applied to an underground cavern 1, and can monitor fracture signals during the construction process and realize fracture source location and source energy intensity acquisition; the distributed optical fiber monitoring system has the advantages of simple deployment, long-distance monitoring, high sensitivity, large capacity, low cost, all-weather, full-space sound wave / vibration perception, etc., and overcomes the problems of relatively scattered monitoring signals of a single bare optical fiber, great deployment difficulty, and low survival rate in complex geological environments. It can be used in complex and deep buried complex environments, and effectively monitor fracture signals such as vibration and sound generated before and during the fracture. It can prevent and monitor rock fractures generated during the excavation of deep-buried high-stress underground cavern projects, and ensure the safe and smooth construction of deep-earth projects.

[0122] The distributed fiber optic monitoring system for monitoring rock mass change status provided by the present invention has a spatial distance resolution as low as less than 1m, and can identify signal frequencies in the range of 1 to 2000Hz. Its capacity is determined by the multi-channel fiber optic sensor regulator 4. The internal storage can currently reach 4TB, and the external storage can be increased indefinitely, thereby enabling long-term monitoring.

[0123] The description of various embodiments of the present invention is presented herein for illustrative purposes only and is not intended to be exhaustive or limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terms used herein are selected to best explain the principles of the embodiments, practical applications, or technological advancements, or to enable others skilled in the art to understand the embodiments disclosed herein, as compared to commercially available technology.

[0124] In this article, various embodiments of the present invention may be presented in the form of ranges. It should be understood that the description in range form is merely for convenience and brevity and should not be construed as a hard limit to the scope of the invention. Therefore, the description of a range should be considered to specifically disclose all possible sub-ranges and individual values ​​within the range. For example, a description of a range such as from 1 to 6 should be considered to specifically disclose sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as individual values ​​within the range, such as 1, 2, 3, 4, 5, 6, which has nothing to do with the width of the range.

[0125] It should be understood that certain features of the invention described in the context of separate embodiments for the sake of clarity may also be provided in combination in a single embodiment. Conversely, various features of the invention described in the context of a single embodiment for the sake of brevity may also be provided individually or in any suitable subcombination, or in any other described embodiment of the invention, where appropriate. Certain features described in the context of various embodiments are not considered essential features of those embodiments unless the embodiment would not function without those features.

[0126] All publications, patents, and patent applications mentioned herein are incorporated herein by reference in their entirety, to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated as being incorporated herein by reference. In addition, the citation or identification of any reference herein should not be construed as an admission that such reference is available as prior art to the present invention. To the extent that section headings are used, such headings should not be construed as necessarily limiting.

Claims

1. A distributed optical fiber monitoring system for monitoring rock mass change status, comprising a first optical fiber (2), wherein the first optical fiber (2) is arranged on the wall (11) of an underground cavern (1) along the axial direction thereof; Its characteristics are: It also includes a second optical fiber (3), the second optical fiber (3) including a peripheral optical fiber segment (31) and a switching transition segment (32); The peripheral optical fiber segment (31) is used to be arranged on the cavern wall (11) along the cross-sectional profile thereof; There are at least two circumferential optical fiber segments (31) which can be arranged at intervals along the axial direction of the underground cavern (1), and the circumferential optical fiber segments (31) are sequentially connected end to end via the reversing transition segment (32) so that the optical path of the second optical fiber (3) is continuous; An integrated optical fiber sensor for collecting rupture signals in a key monitoring area is optically connected to the first optical fiber (2) and / or the second optical fiber (3), and the integrated optical fiber sensor comprises a deformable body (100), a third optical fiber, and a vibration transmission component (300); The third optical fiber includes a first optical fiber segment and a second optical fiber segment that are connected to each other; The first optical fiber segment is arranged on the peripheral wall of the deformable body (100) and is spirally wound at least once around the axial direction of the deformable body (100) to form a first optical fiber coil (220); The second optical fiber segment comprises a straight segment (231) arranged on the peripheral wall of the deformable body (100) along the axial direction thereof, the straight segments (231) being at least two and evenly distributed around the circumference of the deformable body (100), the straight segments (231) being connected end to end in sequence via an arc-shaped reversing segment (232) to form a second optical fiber coil (230) with a continuous optical path; The vibration conduction component (300) is arranged at the bottom of the deformable body (100) and is used to conduct vibration generated by rock mass fracture to the deformable body (100).

2. The distributed optical fiber monitoring system for monitoring rock mass change status according to claim 1, characterized in that: The cavern wall (11) includes a left cavern wall, a top cavern wall, and a right cavern wall; There are three or more first optical fibers (2), at least one of which is arranged on the left wall of the cave, at least one of which is arranged on the top wall of the cave, and at least one of which is arranged on the right wall of the cave.

3. The distributed optical fiber monitoring system for monitoring rock mass change status according to claim 2, characterized in that: There are six first optical fibers (2); One of them is used to be laid on the left wall of the cavern and is located at 1 / 3 of the height of the left wall of the cavern; One of them is used to be laid on the left wall of the cavern and is located at 2 / 3 of the height of the left wall of the cavern; One of them is used to be laid on the top wall of the cavern and is located at the position of 1 / 3 of the arc length of the top wall of the cavern; One of them is used to be laid on the top wall of the cavern and is located at the position of 2 / 3 of the arc length of the top wall of the cavern; One of them is used to be laid on the right wall of the cavern and is located at 1 / 3 of the height of the right wall of the cavern; One of them is used to be laid on the right side wall of the cavern and is located at 2 / 3 of the height of the right side wall of the cavern.

4. The distributed optical fiber monitoring system for monitoring rock mass change status according to any one of claims 1 to 3, characterized in that: It also includes a multi-channel optical fiber sensor regulator (4) and a data processing terminal (5); One end of the first optical fiber (2) and the second optical fiber (3) are both used to extend to the excavation surface of the underground cavern (1), and are both provided with a light extinction device; The other ends of the first optical fiber (2) and the second optical fiber (3) are optically connected to a multi-channel optical fiber sensing regulator (4) via an outgoing optical fiber that can be laid along the wall of the shaft; The multi-channel optical fiber sensing regulator (4) is communicatively connected to the data processing terminal (5).

5. The distributed optical fiber monitoring system for monitoring rock mass change status according to claim 4, characterized in that: The vibration conduction component (300) comprises a rigid conduction sheet (310) and a rigid vibration ball (320); One side surface of the rigid conductive sheet (310) is attached to the bottom surface of the deformable body (100); The rigid vibration balls (320) are arranged on the other side surface of the rigid conductive sheet (310), and there are at least three rigid vibration balls (320) distributed in a ring array with the extension line of the axis of the deformable body (100) as the array center line.

6. The distributed optical fiber monitoring system for monitoring rock mass change status according to claim 4, characterized in that: The integrated optical fiber sensor further comprises a protective housing (400), an optical fiber guide tube (500), and a rock coupling component; The deformed body (100) is cylindrical; The protective shell (400) is arranged outside the deformable body (100), and the bottom of the vibration conduction component (300) is at least partially exposed outside the protective shell (400); The optical fiber guide tube (500) comprises an inner guide tube (510) and an outer guide tube (520); the inner guide tube (510) is inserted into the protective shell (400) along the axial direction of the deformable body (100); the outer guide tube (520) is arranged outside the protective shell (400), and a partial tube section thereof is opened and connected to one end of the inner guide tube (510); The third optical fiber also includes an entry optical fiber segment (210) and an exit optical fiber segment (240); the tail end of the entry optical fiber segment (210) passes through the optical fiber guide tube (500) from one end of the outer guide tube (520), passes through the side of the inner guide tube (510), and is connected to the head end of the first optical fiber segment; the head end of the exit optical fiber segment (240) is connected to the tail end of the second optical fiber segment, and its tail end passes through the optical fiber guide tube (500) from the side of the inner guide tube (510), and passes through the other end of the outer guide tube (520); The rock mass coupling component is arranged at the bottom of the vibration conduction component (300) and is used for coupling with the rock mass.

7. The distributed optical fiber monitoring system for monitoring rock mass change status according to claim 6, characterized in that: The rock mass coupling component is a coupling cone head (600), and the coupling cone head (600) is connected to the bottom of the vibration conduction component (300) through its bottom surface.

8. The distributed optical fiber monitoring system for monitoring rock mass change status according to claim 6, characterized in that: The rock mass coupling component comprises a coupling base (710) and a coupling connector (720); One side surface of the coupling base (710) is attached to the bottom of the vibration conduction component (300); The coupling connector (720) is arranged on the coupling base (710), and at least part of its connecting portion passes through the other side surface of the coupling base (710); There are at least three coupling connectors (720), which are distributed in a ring array with the extension line of the axis of the deformable body (100) as the array center line.

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