Mountain area slope rock collapse geological disaster monitoring system and method

Abstract

The invention discloses a mountain side slope rock collapse geological disaster monitoring system and method, and relates to the technical field of geological disaster monitoring, the monitoring system realizes rock collapse geological disaster monitoring on a bedrock based on a vibration signal on the bedrock picked up by a vibration sensor. The vibration sensor is fixed to a bed rock through an anchor rod installed in an anchoring hole, a signal pickup surface of the vibration sensor is attached to the surface of the bed rock, and a coupling agent layer is arranged between the signal pickup surface and the surface; and a plurality of drainage holes which are positioned on the outer side of the signal pickup surface and wrap the signal pickup surface are formed in the bed rock. The monitoring method is realized based on the monitoring system. According to the scheme, ground disaster monitoring is realized based on the vibration signals, and the reliability of vibration signal pickup can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of geological disaster monitoring, and in particular to a system and method for monitoring geological disasters such as rock collapse on slopes in mountainous areas. Background Art

[0002] For the monitoring and prevention of geological disasters, the application of vibration sensors in the monitoring of rockfall on mountain slopes is crucial. This type of sensor and the monitoring network formed can timely capture the vibration signals generated by the impact and rolling of rockfalls. By processing the vibration signals and based on the processing results, valuable time can be effectively gained for early warning and emergency response.

[0003] In existing applications, sensors used for monitoring rockfall and collapse geological disasters on mountain slopes usually need to have excellent low-frequency performance. Commonly used sensors include accelerometers, vibration wave detectors, geophone detectors, etc. The specific installation location is based on geological survey results, such as identifying the rockfall location, main path, and accumulation location based on the rockfall trajectory imprints, rockfall accumulation area distribution, and mountain slope dangerous rock distribution found on site. The sensors are mainly installed below the location and distributed along the main path at intervals to capture the rock detachment signal as early as possible and reliably pick up the continuous impact signal during the rolling process. For the selection of specific installation locations, it is also necessary to consider installing them in locations where the rock is exposed and avoids the weathering layer, and in locations that can avoid natural interference (such as rainfall) and human interference (such as interference from transportation vehicles and other human production and life activities).

[0004] Regarding the specific implementation method, such as the technical solution provided by patent application No. CN202411079696.1, an anchor-type fixed vibration sensor is used to form a dot matrix network, and sensors are deployed at key locations in potential rockfall areas, specifically for sensing vibration signals when rockfall occurs. Regarding the specific method of fixing the vibration sensor on the rock mass, such as the technical solution provided by patent application No. CN201710302713.7, a sensor fastening device is provided on the mounting rod to complete the installation of the sensor at the end of the mounting rod.

[0005] Vibration signal detection has significant advantages in rock collapse geological disasters, including but not limited to: by picking up vibration signals, the geological disaster signals can be captured in a predictive and highly sensitive manner before the disaster can be observed by the naked eye; based on the fast propagation characteristics of vibration signals, geological disaster signals can be obtained in a timely manner; a single monitoring point has a wide coverage range, can cover the surface and deep positions of the rock mass at the same time, and locate the location of the occurrence; after installation, it is not easily affected by external environmental interference, and after a one-time installation, it is suitable for long-term and effective monitoring of areas that are difficult for humans to enter. Therefore, further optimizing the geological disaster monitoring method based on vibration signal detection is of positive significance to reducing the impact of geological disasters on humans and protecting the ecological environment. Summary of the Invention

[0006] In view of the problem of optimizing the geological disaster monitoring method based on vibration signal detection mentioned above, the present invention provides a geological disaster monitoring system and method for rock collapse on mountain slopes, which realizes geological disaster monitoring based on vibration signals and can effectively improve the reliability of vibration signal pickup.

[0007] In view of the above problems, a geological disaster monitoring system and method for rock collapse on mountain slopes provided by the present invention solve the problems through the following technical key points: A geological disaster monitoring system for rock collapse on mountain slopes, which realizes the monitoring of geological disasters of rock collapse on bedrock based on the vibration signals picked up by vibration sensors. In this system, the vibration sensors are fixed to the bedrock through anchor rods installed in the anchoring holes, the signal pickup surface of the vibration sensors is in contact with the surface of the bedrock, and a coupling agent layer is provided between the signal pickup surface and the surface. On the bedrock, a plurality of drainage holes are provided outside and surrounding the signal pickup surface.

[0008] In this solution, both the anchoring holes and the drainage holes are drill holes formed in the bedrock. The anchoring holes serve as the installation holes for the anchor rods on the bedrock, and further rigidly connect the vibration sensors to the bedrock through the anchor rods. The coupling agent layer is used to ensure the quality of the signals picked up by the vibration sensors from the bedrock, and is used to solve the problem that the vibration signals are transmitted from the anchoring glue layer and the anchor rods to the vibration sensors, resulting in poor pickup quality and signal distortion caused by interface reflection, etc., that is, the vibration sensors are in close contact with the bedrock through the coupling agent layer, and the coupling agent layer is used to improve the signal coupling quality between the bedrock and the signal pickup surface, so as to achieve the purpose of ensuring the signal pickup ability of the vibration sensors.

[0009] In such an application, this solution is further set to further include drainage holes outside and surrounding the signal pickup surface, and the drainage holes are used to improve the effective life of the coupling agent layer. Specifically: The coupling agent layer is a thin film structure formed between the vibration sensor and the bedrock by applying the coupling agent on the bedrock or the signal pickup surface and then pressing the vibration sensor onto the bedrock. Regarding the effective life of the coupling agent layer, water vapor is an important cause for accelerating the aging of the coupling agent layer (other causes include stress aging (including under various stresses, the coupling agent detaches from the coupling interface, affecting the coupling effect. Although it may not cause the performance aging of the coupling agent itself, such a situation is also considered an aging phenomenon that requires maintenance), thermal aging caused by temperature cycling, aging caused by ultraviolet radiation in sunlight, oxidation, corrosion aging, etc.). The main reason for the aging of the coupling agent caused by water vapor is that the coupling agent absorbs water, resulting in a decrease in the strength, softening, and swelling of the coupling agent. The aging of the coupling agent will lead to a significant deterioration of its coupling effect, affecting the reliability and life of the geological disaster monitoring system.

[0010] Among the existing optional coupling agents, although the performance of the coupling agent has been further optimized, for the coupling agent used in the monitoring of geological disasters of outdoor rock masses in mountainous areas, a coupling agent with low modulus, ultraviolet resistance, and resistance to damp-heat aging can be selected. However, the aging of the coupling agent is still the main cause of false alarms and failures of vibration sensors. From the perspective of engineering applications, the system for vibration monitoring on outdoor rock masses in mountainous areas to achieve geological disaster monitoring has problems such as high input and maintenance costs and great difficulties in input and maintenance. Therefore, engineers hope that the coupling agent has a longer anti-aging life. However, in traditional solutions, different from other vibration monitoring locations (such as bridges), for the anti-aging protection of the coupling agent, due to geographical location and installation location reasons, from the perspective of setting costs and maintainability, the protection of the coupling agent layer on mountain rock masses is not suitable for configuring air curtain protection (high cost and maintenance difficulty), gas-phase deposition layer covering protection (high implementation difficulty), molecular-level self-assembled film protection (poor reliability), etc.

[0011] To address the above problems, this solution is to set the drainage holes: On the one hand, the bedrock of mountain slopes usually has problems such as condensation caused by day-night temperature changes, seepage from above, and rainwater, resulting in a humid environment. When the inner side and edge of the coupling agent layer are in a humid environment for a long time, these water vapors will accelerate the hydrolysis reaction of the coupling agent layer, leading to premature aging of the coupling agent layer and affecting the signal pickup accuracy, reliability of the vibration sensor, and the maintenance frequency of the vibration sensor. In this solution, the drainage holes serve as the water seepage and evaporation channels on the periphery of the signal pickup surface on the bedrock. For the fitting surface on the bedrock that fits with the signal pickup surface, these drainage holes located on the periphery of the fitting surface can effectively reduce the humidity at the fitting surface position. By reducing the impact of moisture on the aging of the coupling agent layer, the purpose of enabling the coupling agent layer to have a reliable signal coupling ability for a long time, ensuring the signal pickup accuracy and reliability of the vibration sensor, and reducing the maintenance frequency of the vibration sensor can be achieved. On the other hand, although the drainage holes have a certain impact on the continuity of the bedrock, for the vibration signals from the side of the vibration sensor, compared with setting an annular groove surrounding the signal pickup surface on the bedrock outside the periphery of the signal pickup surface, there are still rock bridges (continuous bedrock parts) for the vibration signals to be transmitted to the fitting surface between the drainage holes. While optimizing the hydrolysis effect of the moisture on the coupling agent layer on the bedrock, this solution can still ensure that the vibration sensor can reliably pick up valuable vibration signals. For example, the drainage holes with a smaller diameter than the conventional anchor bolt holes (such as the anchor bolt holes with a diameter of 12 mm for an anchor bolt with a diameter of 10 mm) have a significantly smaller diameter than the wavelength of the vibration wave of the vibration signal. From the perspective of vibration wave energy loss, arranging drainage holes in the area within 30 cm from the fitting surface not only has an obvious effect of reducing the humidity of the fitting surface, but also has relatively little impact on the medium and low-frequency vibration signals (vibration wave signals with a frequency range of 2 Hz to 30 Hz). This frequency band range includes the core frequency band for monitoring rock collapse geological disasters, usually including characteristic signals such as the occurrence event, location, and energy of the geological disaster. Therefore, this solution can still reliably pick up valuable vibration signals. Compared with the medium and low-frequency vibration signals, the energy scattering of the drainage holes on the high-frequency signals will cause a certain amount of high-frequency attenuation. The high-frequency part of the vibration signal usually includes rock fracture signals and friction signals reflecting the precursors of rock collapse geological disasters. If it is necessary to introduce vibration signal monitoring above 50 Hz to expand the monitoring ability of the system, in specific applications, if the type of bedrock is suitable for obtaining drainage holes with a diameter of about 5 mm and good water permeability can be ensured for a long time through conventional drilling methods, the impact of these drainage holes on the pickup quality of high-frequency vibration signals can be ignored. At the same time, after removing the loose layer on the surface of the bedrock, such as the weathered layer, drainage holes with a diameter of 5 mm or even 3 mm and good water permeability can generally be drilled. Therefore, in specific applications, the monitoring system can be set to only pick up the core frequency band of the vibration signals in rock collapse geological disasters: vibration wave signals with a frequency range of 2 Hz to 30 Hz. When the rock mass at the installation position of the vibration sensor meets the conditions of reducing the diameter of the drainage holes (below 6 mm), increasing the spacing between the drainage holes, and the spacing between the drainage holes and the signal pickup surface (greater than 20 cm), vibration signal monitoring above 50 Hz can also be introduced to optimize the pickup ability of the system for the precursor signals of rock collapse geological disasters.

[0012] In a specific embodiment, a stepped hole is provided on the bedrock, and the anchoring hole is the hole section inside the stepped hole: the orifice of the anchoring hole is located on the step surface of the stepped hole; A fitting surface for coupling with the vibration sensor is provided on the step surface, and the fitting surface is a plane; The orifices of the drainage holes are all located on the step surface.

[0013] The above solution is a technical solution that processes the stepped hole and uses the stepped surface on the stepped hole as the surface on the bedrock for fitting with the vibration sensor. In this solution, the outer hole section of the stepped hole (the duct space outside the stepped surface) serves as the installation space for the vibration sensor on the bedrock, that is, the vibration sensor is installed to be embedded in the bedrock. Compared with directly installing the vibration sensor on the surface rock wall of the bedrock and exposing it outside the bedrock, the bedrock serves as a natural barrier for the installation space, making the installation space of the vibration sensor have a smaller temperature fluctuation to optimize the thermal aging problem of the coupling agent layer under temperature cycling. At the same time, the installation position of the vibration sensor can effectively avoid the direct influence of the water on the surface layer of the bedrock on the hydration of the coupling agent layer, further reducing the influence of the hydration of the coupling agent layer on the decline of its signal coupling performance. Setting the fitting surface as a plane aims to ensure the effective coupling area between the vibration sensor and the bedrock. With the signal pickup surface being a plane and the vibration sensor squeezing the coupling agent layer, each position on the signal pickup surface can form a large-area and rigid signal coupling relationship with the bedrock through the coupling agent layer that is tightly and evenly squeezed at each position, providing necessary conditions for the vibration sensor to effectively pick up weak but critical low-frequency signals. The position of the drain hole orifice is that the drain hole is processed in the stepped hole. The drain hole is located inside the outer hole section and sinks into the stepped hole. Compared with setting the drain hole on the periphery of the stepped hole, in this solution, the drain hole does not have a shallow hole section on the outermost surface layer of the bedrock. In this way, it can effectively avoid the infiltration of rainwater into the inside of the drain hole through the drain hole, resulting in the direct influence of the humidity of the rock mass in the fitting area of the vibration sensor on the bedrock by the rainwater.

[0014] Preferably, the stepped hole can be obtained by first drilling an anchor hole in the bedrock and then reaming the orifice position of the anchor hole. The distance between the stepped surface and the outermost surface of the bedrock is greater than 10 cm. The anchor rod is installed with a part exposed outside the stepped surface. The vibration sensor is squeezed against the fitting surface through the part of the anchor rod exposed outside the stepped surface. The hole section of the stepped hole outside the stepped surface is that the outer ends of the upper and lower hole walls are inclined downward relative to the inner ends. In this way, it can avoid the water droplets on the upper rock wall of the stepped hole from dripping into the inside of the stepped hole and enable the water in the stepped hole to flow out in time, further optimizing the anti-hydrolysis protection ability for the coupling agent layer.

[0015] In a specific embodiment, the axis of the drain hole is distributed on a cylindrical surface, and the axis of the cylindrical surface is coaxial with the axis of the anchor hole; The number of the cylindrical surfaces is greater than 1, and a plurality of drain holes are annularly arranged on each cylindrical surface.

[0016] In this solution, from a two-dimensional perspective, that is, the drainage holes are distributed on several rings with the center located on the axis of the anchoring hole, and from a three-dimensional perspective, that is, the drainage holes are distributed on several cylindrical surfaces with the axis coaxial with the anchoring hole. The number of the rings and the number of the cylindrical surfaces are greater than 1. By adopting such a solution, firstly, the anchoring hole can be used as a processing auxiliary hole when processing the drainage holes, so as to realize the processing of the drainage holes after the drilling equipment is constrained in the anchoring hole. Such a method can effectively reduce the drilling difficulty of the drainage holes for small-diameter drainage holes while realizing the efficient processing of the drainage holes. Secondly, the solution with the number of cylindrical surfaces greater than 1 and multiple drainage holes provided on each cylindrical surface aims at the following problem: adopting the multi-ring arrangement of the drainage holes, compared with setting the drainage holes on the same cylindrical surface, under the condition of similar drainage and moisture removal capabilities, the multi-ring shallow holes with shallower depth have the characteristics of having less influence on the propagation of vibration waves and being beneficial to ensuring the quality of vibration signal pickup compared with the single-ring deep hole.

[0017] In a specific embodiment, the anchor rod is anchored in the anchoring hole through an anchoring adhesive layer; The head end of the anchor rod extends relative to the anchoring hole. A sliding sleeve slidably connected to the anchor rod is arranged on the head end. A pressing plate is arranged at one end of the sliding sleeve close to the bedrock. The vibration sensor is connected to the side of the pressing plate close to the bedrock through a connecting bolt; It further includes a compression cap threadedly connected to the anchor rod. The compression cap applies a thrust towards the bedrock to the sliding sleeve, so that the vibration sensor is clamped between the bedrock and the pressing plate; A guiding groove parallel to the axis of the anchor rod is arranged on the anchor rod. A guiding rib is arranged on the inner side of the sliding sleeve. The guiding rib is embedded in the guiding groove.

[0018] In the above solution, the anchoring adhesive layer is used to ensure the anchoring stability of the anchor bolt in the anchoring hole. The structure formed by the pressing cap, the sliding sleeve and the pressing plate provides a thrust for the vibration sensor to firmly fit with the bedrock. The guiding groove and the guiding rib are used to realize the anti-rotation constraint of the sliding sleeve on the anchor bolt, aiming to achieve: when the vibration sensor is fixed on the pressing plate through the connecting bolt and the coupling agent is evenly applied on the signal pickup surface of the vibration sensor, during the process of rotating the pressing cap to push the vibration sensor towards the bedrock, the motion state of the vibration sensor is to always move towards the bedrock in a posture parallel to the fitting surface along the axis of the anchor bolt. In this way, it can effectively avoid the sliding of the vibration sensor relative to the bedrock, which may cause the bedrock to scrape the coupling agent, resulting in the influence on the distribution and content of the coupling agent on the signal pickup surface, and affecting the density, thickness, etc. of each position of the generated coupling agent layer. The connecting bolt is a fixing part for the vibration sensor and the pressing plate, and is used to firmly fix the position of the vibration sensor on the pressing plate. Specifically, since a thread cooperating with the pressing cap needs to be provided at the end of the anchor bolt, when the thread intersects with the guiding groove, the method of first machining the guiding groove and then machining the thread is adopted. In this way, the machining quality of the thread can be effectively guaranteed. Preferably, in order to obtain a coupling agent layer with the required thickness range, the pressing cap is tightened with a torque wrench, and after tightening to the torque threshold, a pressing cap connected to the anchor bolt by a thread and used as a locking nut is used to reinforce the anti-loosening of the pressing cap.

[0019] In a specific embodiment, the number of vibration sensors between the bedrock and the pressing plate is greater than or equal to 2.

[0020] This solution aims to achieve: for the monitoring of mountain slope rock collapse geological disasters, generally, multiple vibration signal pickup points need to be arranged. Each pickup point includes an anchor bolt and a vibration sensor coupled to the bedrock through the anchor bolt. This solution means that a single pickup point has two or more vibration sensors. For each signal pickup point, when it is set that each signal pickup point has two or more vibration sensors, the vibration sensors in the same signal pickup point have the characteristic of adjacent signal pickup positions. Therefore, these vibration sensors should have consistent signal pickup results. The above setting of the number of vibration sensors can not only optimize the vibration signal pickup redundancy ability of the signal pickup point, but also the vibration signal pickup difference can be used to judge the reliability of the vibration signals picked up by each vibration sensor. For example, for the common vibration signal pickup failure caused by the aging of the coupling agent layer, when the coupling agent layer of one vibration sensor ages significantly earlier than that of other vibration sensors, this phenomenon can be obtained through the signal difference picked up, so as to prompt the maintenance personnel to timely maintain the coupling agent layer.

[0021] In a specific embodiment, it further includes a protective cover installed on the bedrock through an anchor fitting. The protective cover includes a breathable cover fixed on the anchor fitting; It further includes a flexible sheet, the inner end of the flexible sheet is fixed on the anchor and / or the bedrock, the outer end of the flexible sheet is fixed on the breathable cover, and the flexible sheet is used to seal the gap between the breathable cover and the bedrock; Both the vibration sensor and the anchor rod are covered in the housing structure formed by the breathable cover and the flexible sheet.

[0022] In the above solution, the protective cover is used to form an isolation cover around the vibration sensor to prevent, for example, water flowing along the rock wall from flowing to the signal pickup surface position. At the same time, it partially shades the signal pickup surface position to reduce the impact of ultraviolet rays on the aging of the anchoring adhesive layer. At the same time, the semi-open isolation environment can not only reduce the impact of the gas-phase environment humidity on the coupling agent layer, but also reduce the impact caused by temperature fluctuations on the aging of the coupling agent layer. Specifically, the anchor is used as the anchoring structure of the breathable cover on the bedrock. After the breathable cover is fixed, a flexible sheet is used to seal the gap between the bedrock and the breathable cover to isolate the impact of the water body flowing along the bedrock rock wall on the inner space of the protective cover. The breathable cover is a housing structure provided with ventilation holes, which is used to enable gas convection between the inner space of the protective cover and the outside, so as to facilitate the control of the humidity of the installation environment of the vibration sensor. The breathable cover can be a standard prefabricated structure, and the flexible sheet can be a flexible sheet structure such as a waterproof cloth. After the installation of the breathable cover, the flexible sheet adjusts adaptively in shape to adapt to the gap style in the specific installation scenario. Therefore, the combination of the breathable cover and the flexible sheet enables the protective cover to be universal in various applications.

[0023] In a specific embodiment, the distance between the drain hole and the vibration sensor is 15 cm to 30 cm, the aperture of the drain hole is 4 mm to 6 mm, and the length of the drain hole is 8 cm to 15 cm.

[0024] In specific applications, a drainage hole arrangement that is closer to the vibration sensor and more densely surrounds the vibration sensor can more effectively reduce the impact of water vapor on the aging of the coupling agent layer. However, for the vibration signal that propagates along the bedrock and is picked up by the vibration sensor for rockfall geological disaster monitoring, the drain hole is equivalent to a near-field scattering hole for the vibration signal, and it has a relatively obvious impact on the signal acquisition quality of high-frequency vibration signals. The above-set aperture is much smaller than the wavelength of the target high-frequency vibration signal (200 Hz). Therefore, the impact of the Rayleigh scattering region caused by the drain hole aperture on the signal pickup quality can be accepted. The above-set spacing is used to control the impact of near-field strong scattering on the high-frequency signal acquisition quality. The above-set length of the drain hole is used to control the vibration coupling degree / vibration wave distortion between the signal pickup position of the vibration sensor and the bedrock. In specific applications, the distance between adjacent drain holes is greater than 20 cm to reduce the impact of the superposition of multi-hole heat dissipation on the high-frequency signal pickup quality. By adopting this solution, the signal pickup quality of the vibration signal can be effectively guaranteed.

[0025] This solution also relates to a method for monitoring geological disasters of rock collapses on mountain slopes. This method uses the monitoring system described in any of the above to implement the monitoring of geological disasters of rock collapses on bedrock, and the vibration sensor picks up vibration signals with a frequency lower than 200 Hz.

[0026] The monitoring method is a method for monitoring geological disasters of rock collapses on mountain slopes based on the monitoring system. In actual application, the high-frequency band of the rock fracture vibration signal, which is the precursor signal for monitoring rock collapse geological disasters, is usually less than 500 Hz. Since the drainage hole is relatively sensitive to the signal pickup quality of high-frequency vibration signals, the vibration sensor is set to pick up seismic waves with a frequency lower than 200 Hz as vibration signals. The specific frequency band range can be 2 Hz to 200 Hz. Such a vibration signal pickup scheme can not only ensure the signal pickup quality of each frequency band, but also cover the core frequency band commonly used in existing rock collapse geological disaster monitoring. If it is necessary to monitor vibration signals with a frequency higher than 200 Hz (such as 200 Hz to 500 Hz), a separate signal pickup point can be set in this system. Only anchor bolts are used to fix the vibration sensor to the bedrock under this signal pickup point, and signal coupling with the bedrock is achieved layer by layer through a coupling agent. Drainage holes are not set around the vibration signal pickup position on the bedrock.

[0027] In a specific embodiment, the anchor bolt is anchored in the anchor hole through an anchoring adhesive layer of an epoxy resin composite material filled with steel sand; The epoxy resin composite material is injected into the anchor hole by a vacuum negative pressure grouting method. The anchoring method of the anchor bolt is: sealing the orifice of the anchor hole and evacuating the anchor hole to remove air; injecting the epoxy resin composite material into the anchor hole that has completed evacuating air; inserting the anchor bolt into the epoxy resin composite material in the anchor hole.

[0028] In the above solution, an epoxy resin composite material modified with steel sand is used as the anchoring adhesive layer, aiming to reduce the influence of the installation of the anchor bolt on the attenuation of vibration signals (especially high-frequency signals in the frequency spectrum) and phase error from the perspective of impedance mismatch. The vacuum negative pressure grouting method is used to reduce the porosity of the anchoring adhesive layer. The porosity that can reach 10% under the traditional atmospheric pressure construction process can be controlled below 0.5%, enabling the anchor bolt to achieve an approximately void-free anchoring state, and achieving the purpose of reducing the influence of the anchor bolt anchoring on the fidelity of the high-frequency signals picked up by the vibration sensor.

[0029] In a specific embodiment, the setting method of the drainage hole and the vibration sensor is as follows: Confirm the signal source position of the vibration signal on the bedrock and the fitting position of the vibration sensor on the bedrock; According to the signal source position and the fitting position, set the drainage hole on the side of the fitting position away from the signal source position; The vibration sensor is installed after the drainage hole is machined, and the vibration sensor is installed as follows: Apply the coupling agent forming the coupling agent layer evenly on the signal pickup surface of the vibration sensor; Press the vibration sensor against the bedrock and provide a pushing force with a set threshold for the vibration sensor through the anchor bolt; Scrape off the coupling agent overflow that overflows to the outside of the signal pickup surface under the pushing around the vibration sensor; During the process of the monitoring system performing geological disaster monitoring, test the pickup quality of the vibration signal by actively knocking on the bedrock, and the active knocking includes active knocking under a set time plan and / or active knocking after experiencing extreme weather.

[0030] In the above solution, the position of the signal source is the position where vibration signals may be generated, usually an area. In the monitoring of slope rock collapse disasters, according to the on-site geological exploration before the system layout, multiple areas can usually be determined on the slope. The fitting position is the position on the bedrock where it is suitable to install vibration sensors. After having the above two positions, the orientation of the signal source position relative to the fitting position can be confirmed, and further, under the guidance of this orientation, the setting orientation of the drainage hole relative to the fitting position can be confirmed. By using such means, the aim is to achieve: reducing the influence of the drainage hole on the quality of vibration signal pickup caused by directional shielding during the propagation of vibration signals in the bedrock. The setting method of the coupling agent layer aims to achieve: making use of the signal pickup surface being flatter than the bedrock surface to better control the amount of coupling agent applied and the thickness at each position, and before pressing the coupling agent onto the bedrock, cleaning the surface of the bedrock where it is to be fitted with the coupling agent. Specifically, a wire brush can be used to scrape and level the fitting surface, and then alcohol can be used to thoroughly remove dust. Controlling the pushing force aims to control the thickness of the formed coupling agent layer to avoid the coupling agent layer being too thick or too thin (the preferred setting is 0.2 mm - 0.3 mm). The specific threshold size needs to be set according to the size of the signal pickup surface of the sensor used and the specific coupling agent. Scraping the overflow of the coupling agent outside the signal pickup surface aims to achieve: preventing the formation of an elastic coupling layer around the periphery of the signal pickup surface. On the one hand, as a support layer between the bedrock and the vibration sensor, this elastic coupling layer is not conducive to ensuring an effective vibration signal propagation area between the vibration sensor and the bedrock. At the same time, from the perspectives of signal attenuation and parasitic vibration, it will also cause a certain degree of distortion of the picked-up vibration signals. On the other hand, it is easy for stress concentration to occur on the edge overflow, resulting in premature crack aging of the coupling agent layer due to crack propagation. On the other hand, it forms a water absorption channel and a water storage space together with the bedrock and the vibration sensor, significantly affecting the aging speed of the coupling agent layer. The active knocking can be carried out by hammering to confirm whether the vibration sensor can clearly and stably capture this part of the artificial vibration signal, and by comparing with the signal amplitude, waveform characteristics, and low-frequency response loss of the expected signal pickup result, detecting the signal coupling performance of the coupling agent layer and the performance of the vibration sensor itself. The knocking at the set time is to regularly verify the pickup performance of the vibration signal, and the knocking after experiencing extreme weather is to verify the pickup performance of the vibration signal after extreme environments.

[0031] The present invention has the following beneficial effects: On the one hand, in view of the problem that the bedrock of mountain slopes usually has moisture, when the inner side and the edge of the coupling layer are in a humid environment for a long time, it will cause the coupling layer to age prematurely, affecting the signal pickup accuracy, reliability of the vibration sensor, and the maintenance frequency of the vibration sensor. The drainage holes are set as the water seepage channel and evaporation channel on the periphery of the signal pickup surface on the bedrock. For the fitting surface on the bedrock that is used to fit with the signal pickup surface, these drainage holes located on the periphery of the fitting surface can effectively reduce the humidity at the fitting surface position. By reducing the influence of moisture on the aging of the coupling layer, the coupling layer can be enabled to have a reliable signal coupling ability for a long time, ensuring the signal pickup accuracy and reliability of the vibration sensor and reducing the maintenance frequency of the vibration sensor; On the other hand, although this solution has a certain impact on the continuity of the bedrock due to the drainage holes, for the vibration signals from the side of the vibration sensor, there are still rock bridges (continuous bedrock parts) between the drainage holes for the vibration signals to be transmitted to the fitting surface. While optimizing the hydrolysis effect of the moisture on the coupling layer on the bedrock, this solution can still ensure that the vibration sensor can reliably pick up valuable vibration signals. Description of the Drawings

[0032] Figure 1 is a cross-sectional view of a specific application embodiment of a mountain slope rockfall geological disaster monitoring system described in this solution; Figure 2 is Figure 1 a partial enlarged view of part A in Figure 3 is a partial schematic diagram of the system showing the opening method of the stepped hole, the fitting surface, and the setting method of the drainage hole on the stepped hole in a specific application embodiment of a mountain slope rockfall geological disaster monitoring system described in this solution.

[0033] The reference numerals in the drawings are respectively: 1, bedrock; 2, anchor rod; 3, vibration sensor; 4, flexible sheet; 5, ventilation cover; 6, anchoring adhesive layer; 7, coupling layer; 8, pressing plate; 9, guiding groove; 10, connecting bolt; 11, sliding sleeve; 12, pressing cap; 13, stepped hole; 14, anchoring hole; 15, fitting surface; 16, drainage hole; 17, anchor. Detailed Description of the Invention

[0034] The present invention will be further described in detail below in conjunction with the embodiments, but the present invention is not limited to the following embodiments: Embodiment 1:

[0035] As Figures 1 to 3As shown in the figure, a geological disaster monitoring system for rock collapse on mountain slopes. This monitoring system is based on the vibration signals picked up by the vibration sensor 3 on the bedrock 1 to achieve the monitoring of geological disasters of rock collapse on the bedrock 1. In this system, the vibration sensor 3 is fixed to the bedrock 1 through the anchor rod 2 installed in the anchor hole 14. The signal pickup surface of the vibration sensor 3 is in contact with the surface of the bedrock 1, and a coupling agent layer 7 is provided between the signal pickup surface and the surface. On the bedrock 1, a plurality of drainage holes 16 are provided outside the signal pickup surface and surrounding the signal pickup surface.

[0036] In this solution, both the anchor hole 14 and the drainage hole 16 are drill holes formed on the bedrock 1. The anchor hole 14 serves as the installation hole for the anchor rod 2 on the bedrock 1, and further rigidly connects the vibration sensor 3 to the bedrock 1 through the anchor rod 2. The coupling agent layer 7 is used to ensure the quality of the signals picked up by the vibration sensor 3 from the bedrock 1, and is used to solve the problem that the vibration signals are transmitted from the anchor glue layer 6 and the anchor rod 2 to the vibration sensor 3, resulting in poor pickup quality and signal distortion caused by interface reflection, etc., that is, the vibration sensor 3 and the bedrock 1 are in close contact through the coupling agent layer 7. The coupling agent layer 7 is used to improve the signal coupling quality between the bedrock 1 and the signal pickup surface. In this embodiment, silicone grease is used to achieve the purpose of ensuring the signal pickup ability of the vibration sensor 3 by maximizing the vibration energy transfer efficiency.

[0037] Before applying the silicone grease, the coupling surfaces of the bedrock 1 and the vibration sensor 3 that are in contact with each other are thoroughly cleaned and polished (only for the bedrock 1). For example, a cleaner is used to clean dust and oil stains (generally only for the vibration sensor 3), and compressed air is needed to blow and dry the coupling surface to ensure the good adhesion performance and durability of the coupling agent layer 7.

[0038] In such an application, this solution is further set to further include drainage holes 16 outside the signal pickup surface and surrounding the signal pickup surface. The drainage holes 16 are used to improve the effective life of the coupling agent layer 7. Specifically: The coupling agent layer 7 is a thin film structure formed between the vibration sensor 3 and the bedrock 1 by applying the coupling agent on the bedrock 1 or the signal pickup surface and then pressing the vibration sensor 3 onto the bedrock 1. Regarding the effective life of the coupling agent layer 7, water vapor is an important cause for accelerating the aging of the coupling agent layer 7 (others include stress aging (including under various stresses, the coupling agent detaches from the coupling interface, affecting the coupling effect. Although it may not cause the aging of the performance of the coupling agent itself, such a situation is also considered an aging phenomenon that requires maintenance), thermal aging caused by temperature cycling, aging caused by ultraviolet irradiation in sunlight, oxidation, corrosion aging, etc.). The main reason for the aging of the coupling agent caused by water vapor is that the coupling agent absorbs moisture, resulting in a decrease in the strength, softening, and swelling of the coupling agent. The aging of the coupling agent will lead to a serious deterioration of its coupling effect, affecting the reliability and life of the geological disaster monitoring system.

[0039] Among the existing optional coupling agents, although the performance of the coupling agent has been further optimized, the coupling agent with low modulus, ultraviolet resistance, and heat and humidity aging resistance can be selected for the monitoring of geological disasters of outdoor rock masses in mountainous areas. However, the aging of the coupling agent is still the main reason for false alarms and failures of the vibration sensor 3. From the perspective of engineering applications, the system for vibration monitoring on outdoor rock masses in mountainous areas to achieve geological disaster monitoring has problems of high investment and maintenance costs and great difficulties in investment and maintenance. Therefore, engineering personnel hope that the coupling agent has a longer aging resistance life. However, in traditional solutions, different from other vibration monitoring locations (such as bridges), due to geographical location and installation location reasons, from the perspective of setting costs and maintainability, the protection of the coupling agent layer 7 on mountain rock masses is not suitable for configuring air curtain protection (high cost and maintenance difficulty), vapor deposition layer covering protection (high implementation difficulty), molecular self-assembled film protection (poor reliability), etc.

[0040] To address the above problems, this solution is to set the drain hole 16: On the one hand, the bedrock 1 of mountain slopes usually has problems of condensation, seepage from above, rainwater, etc. caused by day-night temperature changes. When the inner side and edge of the coupling agent layer 7 are in a humid environment for a long time, these water vapors will accelerate the hydrolysis reaction of the coupling agent layer 7, resulting in premature aging of the coupling agent layer 7 and affecting the signal pickup accuracy, reliability of the vibration sensor 3, and the maintenance frequency of the vibration sensor 3. In this solution, the drain hole 16 serves as a water seepage channel and evaporation channel for the water body on the periphery of the signal pickup surface on the bedrock 1. For the fitting surface 15 on the bedrock 1 that is used to fit with the signal pickup surface, these drain holes 16 located on the periphery of the fitting surface 15 can effectively reduce the humidity at the position of the fitting surface 15. By reducing the influence of moisture on the aging of the coupling agent layer 7, the purpose of enabling the coupling agent layer 7 to have a reliable signal coupling ability for a long time, ensuring the signal pickup accuracy and reliability of the vibration sensor 3, and reducing the maintenance frequency of the vibration sensor 3 is achieved; On the other hand, although the continuity of the bedrock 1 is affected by the drainage holes 16 to some extent, for the vibration signals from the side of the vibration sensor 3, compared with setting a ring groove surrounding the signal pickup surface on the bedrock 1 outside the periphery of the signal pickup surface, there are still rock bridges (continuous parts of the bedrock 1) between the drainage holes 16 for the vibration signals to be transmitted to the joint surface 15. While optimizing the hydrolysis effect of the moisture on the coupling agent layer 7 on the bedrock 1, this solution can still ensure that the vibration sensor 3 can reliably pick up valuable vibration signals. For example, the drainage holes 16 with a smaller diameter than that of the conventional anchor rod 2 holes (such as the anchor rod 2 holes with a diameter of 12 mm for an anchor rod 2 with a diameter of 10 mm) have a significantly smaller diameter than the wavelength of the vibration wave of the vibration signal. From the perspective of vibration wave energy loss, arranging the drainage holes 16 in the area within 30 cm from the joint surface 15 not only has an obvious effect of reducing the humidity of the joint surface 15, but also has relatively little influence on the medium and low-frequency vibration signals (vibration wave signals of 2 Hz to 30 Hz). This frequency band range includes the core frequency band for rockfall geological disaster monitoring, usually including characteristic signals such as geological disaster occurrence events, locations, and energies. Therefore, this solution can still reliably pick up valuable vibration signals. Compared with the medium and low-frequency vibration signals, the energy scattering of the drainage holes 16 on the high-frequency signals will cause a certain amount of high-frequency attenuation. The high-frequency part of the vibration signal usually includes rock fracture signals and friction signals reflecting the precursors of rockfall geological disasters. If it is necessary to introduce vibration signal monitoring above 50 Hz to expand the monitoring ability of the system, in specific applications, if the type of the bedrock 1 is suitable for obtaining drainage holes 16 with a diameter of about 5 mm and good water permeability can be ensured for a long time through conventional drilling methods, the influence of these drainage holes 16 on the pickup quality of high-frequency vibration signals can be ignored. At the same time, after removing the loose layer on the surface of the bedrock 1, such as the weathered layer, drainage holes 16 with a diameter of 5 mm or even 3 mm and good water permeability can generally be drilled for a long time. Therefore, in specific applications, the monitoring system can be set to only pick up the core frequency band of the vibration signals in rockfall geological disasters: vibration wave signals of 2 Hz to 30 Hz. When the rock mass at the installation position of the vibration sensor 3 meets the conditions of reducing the diameter of the drainage holes 16 (below 6 mm), increasing the spacing between the drainage holes 16, and the spacing between the drainage holes 16 and the signal pickup surface (greater than 20 cm), vibration signal monitoring above 50 Hz can also be introduced to optimize the pickup ability of the system for the precursor signals of rockfall geological disasters.

[0041] In this embodiment, regarding the installation position of the vibration sensor 3 on the bedrock 1, based on geological exploration, historical rockfall records, and topography and geomorphology (steep cliffs, grooves, toe accumulation areas), the most likely rockfall initiation areas, main movement paths, and accumulation areas are identified, and the approximate installation position of the vibration sensor 3 on the bedrock 1 is determined according to the identification results. For key areas of geological disaster monitoring, such as initiation areas and around human activity ranges, vibration signal pickup points are densely arranged. To reduce the attenuation of vibration signals during transmission in the bedrock 1, the specific location selection of the vibration sensor 3 should preferably avoid loose rock formations. If there is no such natural exposed surface of the bedrock 1, the method of removing the loose surface layer of the bedrock 1 and then installing the vibration sensor 3 is adopted to ensure the quality of vibration signal pickup.

[0042] The anchoring method of the anchor rod 2 can be as follows: Drill an anchoring hole 14 slightly larger than the diameter of the anchor rod 2, and the specific depth is determined according to the strength of the bedrock 1. Then, use compressed air to clean the dust in the anchoring hole 14, and then inject the anchoring glue by the negative pressure perfusion method. Then, insert the anchor rod 2, and after the anchor rod 2 is stable, install the vibration sensor 3 that is signal-coupled with the bedrock 1 through the coupling agent layer 7.

[0043] The vibration sensor 3 is preferably a multi-axis sensor to better adapt to multi-directional vibration signals.

[0044] For the azimuth of the vibration signal source whose direction can be clearly defined, to ensure the quality of signal pickup, it is preferably to process the plane of the bedrock 1 (the fitting surface 15 in Embodiment 2) that is coupled with the signal pickup surface as follows: After the vibration sensor 3 is coupled to it, the sensitive axis of the vibration sensor 3 points to the azimuth of the vibration signal source.

[0045] After the setup of this system is completed, verify whether this system can meet the requirements of vibration signal pickup by manually knocking.

[0046] Preferably, after the drainage hole 16 is processed and the dust inside the drainage hole is removed, a metal mesh is used to cover the orifice of the drainage hole 16. The metal mesh enables the drainage hole 16 to still be in communication with the outside through its mesh holes. At the same time, the metal mesh can be used to reduce the cavity resonance of the drainage hole 16, which is beneficial to ensuring the signal pickup quality of the vibration sensor 3.

[0047] Preferably, the coupling surface on the bedrock for coupling with the vibration sensor 3 is generally perpendicular to the anchor rod 2. To reduce the influence of the drainage hole 16 on the signal pickup quality and improve the waterproof and anti-aging performance of the coupling agent layer 7, when drilling the drainage hole 16, the drainage hole 16 is drilled as an inclined hole inclined relative to the anchoring hole 14, and specifically: the orifice of the drainage hole 16 is farther from the anchoring hole 14 than the bottom of the hole relative to the bottom of the hole.

[0048] Embodiment 2:

[0049] This embodiment is further refined on the basis of embodiment 1: The bedrock 1 is provided with a step hole 13, and the anchor hole 14 is a hole section inside the step hole 13: the opening of the anchor hole 14 is located on the step surface of the step hole 13; The step surface is provided with a fitting surface 15 for coupling with the vibration sensor 3, and the fitting surface 15 is a plane; The openings of the drainage holes 16 are all located on the step surface.

[0050] The above scheme is a technical scheme in which the step hole 13 is processed and the step surface on the step hole 13 is used as the surface on the bedrock 1 for fitting with the vibration sensor 3. In this scheme, the outer hole section of the step hole 13 (the channel space outside the step surface) is used as the installation space of the vibration sensor 3 on the bedrock 1, that is, the vibration sensor 3 is installed to be embedded in the bedrock 1. Compared with directly installing the vibration sensor 3 on the surface rock wall of the bedrock 1 and exposing it to the outside of the bedrock 1, the bedrock 1 serves as a natural barrier for the installation space, so that the installation space of the vibration sensor 3 has smaller temperature fluctuations, so as to optimize the thermal aging problem of the coupling agent layer 7 under temperature cycle. At the same time, the setting position of the vibration sensor 3 can effectively avoid the direct influence of the surface water of the bedrock 1 on the hydration of the coupling agent layer 7, and further reduce the influence of the hydration of the coupling agent layer 7 on the degradation of its signal coupling performance. The fitting surface 15 is set as a plane, Under the condition of ensuring the effective coupling area between the vibration sensor 3 and the bedrock 1, and cooperating with the planar signal pickup surface and the vibration sensor 3 squeezing the coupling agent layer 7, each position of the signal pickup surface can form a large-area, rigid signal coupling relationship with the bedrock 1 through the coupling agent layer 7 that is tightly and evenly squeezed at each position, so as to provide the necessary conditions for the vibration sensor 3 to effectively pick up weak but critical low-frequency signals. The position of the orifice of the drainage hole 16 is that the drainage hole 16 is processed in the step hole 13, the drainage hole 16 is located on the inner side of the outer hole section, and the drainage hole 16 sinks into the step hole 13. Compared with setting the drainage hole 16 on the periphery of the step hole 13, the drainage hole 16 in this scheme does not have a shallow hole section located on the outermost surface of the bedrock 1. In this way, it can effectively avoid rainwater from infiltrating into the inner side of the drainage hole 16 through the drainage hole 16, resulting in the humidity of the rock mass in the area where the vibration sensor 3 is attached on the bedrock 1 being directly affected by rainwater.

[0051] Preferably, the stepped hole 13 can be obtained by first drilling an anchoring hole 14 in the bedrock 1 and then expanding the diameter of the orifice of the anchoring hole 14. The distance from the stepped surface to the outermost surface of the bedrock 1 is greater than 10 cm. The anchor rod 2 is installed so that a part of it is exposed outside the stepped surface. The vibration sensor 3 is pressed against the joint surface 15 through the part of the anchor rod 2 exposed outside the stepped surface. The hole section of the stepped hole 13 outside the stepped surface is such that the outer ends of the upper and lower side walls are inclined downward relative to the inner ends. In this way, it is possible to prevent the water droplets on the rock wall of the upper side of the stepped hole 13 from dripping into the inside of the stepped hole 13 and enable the water in the stepped hole 13 to flow out in time, so as to further optimize the anti-hydrolysis protection ability of the coupling agent layer 7.

[0052] Embodiment 3:

[0053] This embodiment is further refined on the basis of Embodiment 1: The axes of the drain holes 16 are distributed on a cylindrical surface, and the axis of the cylindrical surface is coaxial with the axis of the anchoring hole 14; The number of the cylindrical surfaces is greater than 1, and a plurality of drain holes 16 are annularly arranged on each cylindrical surface.

[0054] In this solution, from a two-dimensional perspective, that is, the drain holes 16 are distributed on several rings with the axis of the anchoring hole 14 as the center, and from a three-dimensional perspective, that is, the drain holes 16 are distributed on several cylindrical surfaces with axes coaxial with the anchoring hole 14. The number of the rings and the number of the cylindrical surfaces are greater than 1. By adopting such a solution, first, the anchoring hole 14 can be used as a processing auxiliary hole when processing the drain holes 16, so as to realize the processing of the drain holes 16 after the drilling equipment is constrained in the anchoring hole 14. Such a method can effectively reduce the drilling difficulty of the drain holes 16 with a small diameter while realizing the efficient processing of the drain holes 16. Secondly, the solution that the number of the cylindrical surfaces is greater than 1 and a plurality of drain holes 16 are provided on each cylindrical surface aims at the following problem: compared with arranging the drain holes 16 on the same cylindrical surface, in the case of similar drainage and dehumidification capabilities, the multi-ring shallow holes with a shallower depth have the characteristics of having less influence on the propagation of vibration waves and being beneficial to ensuring the quality of vibration signal pickup compared with the single-ring deep hole.

[0055] Embodiment 4:

[0056] This embodiment is further refined on the basis of Embodiment 1: The anchor rod 2 is anchored in the anchoring hole 14 through the anchoring adhesive layer 6; The head end of the anchor rod 2 extends out relative to the anchoring hole 14. A sliding sleeve 11 slidably connected to the anchor rod 2 is provided on the head end. A pressing plate 8 is provided at one end of the sliding sleeve 11 close to the bedrock 1. The vibration sensor 3 is connected to the side of the pressing plate 8 close to the bedrock 1 through a connecting bolt 10; It further includes a compression cap 12 threadedly connected to the anchor bolt 2. The compression cap 12 applies a thrust to the imaging bedrock 1 by means of the sliding sleeve 11, so that the vibration sensor 3 is clamped between the bedrock 1 and the pressing plate 8; A guiding groove 9 parallel to the axis of the anchor bolt 2 is provided on the anchor bolt 2, and guiding ribs are provided on the inner side of the sliding sleeve 11, and the guiding ribs are embedded in the guiding groove 9.

[0057] In the above solution, the anchoring adhesive layer 6 is used to ensure the anchoring stability of the anchor bolt 2 in the anchoring hole 14. The compression cap 12 forms a structure with the sliding sleeve 11 and the pressing plate 8 to provide a thrust for the vibration sensor 3 to firmly fit with the bedrock 1. The guiding groove 9 and the guiding ribs are used to realize the anti-rotation constraint of the sliding sleeve 11 on the anchor bolt 2, aiming to achieve: when the vibration sensor 3 is fixed to the pressing plate 8 through the connecting bolt 10 and the coupling agent is evenly applied on the signal pickup surface of the vibration sensor 3, during the process of rotating the compression cap 12 to push the vibration sensor 3 towards the bedrock 1, the motion state of the vibration sensor 3 is to always move along the direction of the axis of the anchor bolt 2 and parallel to the fitting surface 15 towards the bedrock 1. In this way, it can effectively avoid the sliding of the vibration sensor 3 relative to the bedrock 1 causing the bedrock 1 to scrape the coupling agent, resulting in the influence on the distribution and content of the coupling agent on the signal pickup surface, affecting the density, thickness, etc. of each position of the generated coupling agent layer 7. The connecting bolt 10 is a fixing member for the vibration sensor 3 and the pressing plate 8, and is used to firmly fix the position of the vibration sensor 3 on the pressing plate 8. Specifically, since a thread for cooperating with the compression cap 12 needs to be provided at the end of the anchor bolt 2, when the thread intersects with the guiding groove 9, the method of first machining the guiding groove 9 and then machining the thread is adopted. In this way, the machining quality of the thread can be effectively guaranteed. Preferably, in order to obtain the coupling agent layer 7 within the required thickness range, the compression cap 12 is tightened with a torque wrench, and after tightening to the torque threshold, another compression cap 12 threadedly connected to the anchor bolt 2 and used as a locking nut is used to reinforce the anti-loosening of the compression cap 12.

[0058] Embodiment 5:

[0059] This embodiment is further refined on the basis of Embodiment 4: The number of vibration sensors 3 between the bedrock 1 and the pressing plate 8 is greater than or equal to 2.

[0060] This solution aims to achieve the following: For the monitoring of geological disasters such as rock collapses on mountain slopes, it is generally necessary to deploy multiple vibration signal pickup points. Each pickup point includes an anchor rod 2 and a vibration sensor 3 coupled to the bedrock 1 through the anchor rod 2. In this solution, a single pickup point has two or more vibration sensors 3. For each signal pickup point, when it is set to have two or more vibration sensors 3, since the vibration sensors 3 at the same signal pickup point have the characteristic of adjacent signal pickup positions, these vibration sensors 3 should have consistent signal pickup results. The above setting of the number of vibration sensors 3 can not only optimize the vibration signal pickup redundancy ability of the signal pickup point, but also the vibration signal pickup difference can be used to judge the reliability of the vibration signals picked up by each vibration sensor 3. For example, for the common vibration signal pickup failure caused by the aging of the coupling agent layer 7, when the coupling agent layer 7 of one vibration sensor 3 ages significantly earlier than that of other vibration sensors 3, this phenomenon can be obtained through the signal difference picked up to prompt the maintenance personnel to timely maintain the coupling agent layer 7.

[0061] Embodiment 6:

[0062] This embodiment is further refined on the basis of Embodiment 1: It further includes a protective cover installed on the bedrock 1 through the anchor fixture 17. The protective cover includes a breathable cover 5 fixed on the anchor fixture 17; It further includes a flexible sheet 4. The inner end of the flexible sheet 4 is fixed on the anchor fixture 17 and / or the bedrock 1, and the outer end of the flexible sheet 4 is fixed on the breathable cover 5. The flexible sheet 4 is used to block the gap between the breathable cover 5 and the bedrock 1; The vibration sensor 3 and the anchor rod 2 are both covered in the housing structure formed by the breathable cover 5 and the flexible sheet 4.

[0063] In the above solution, the protective cover is used to form an isolation cover around the vibration sensor 3 to prevent, for example, the flowing water along the rock wall from flowing to the signal pickup surface position. At the same time, it partially shades the signal pickup surface position to reduce the impact of ultraviolet rays on the aging of the anchoring adhesive layer 6. Meanwhile, the semi-open isolation environment can not only reduce the impact of the gas-phase environment humidity on the coupling agent layer 7, but also reduce the impact caused by temperature fluctuations on the aging of the coupling agent layer 7. Specifically, the anchor 17 serves as the anchoring structure of the ventilation cover 5 on the bedrock 1. After the ventilation cover 5 is fixed, a flexible sheet 4 is used to seal the gap between the bedrock 1 and the ventilation cover 5 to isolate the impact of the water body flowing along the rock wall of the bedrock 1 on the inner space of the protective cover. The ventilation cover 5 is a housing structure provided with ventilation holes, which is used to enable gas convection between the inner space of the protective cover and the outside, so as to facilitate the control of the humidity of the installation environment of the vibration sensor 3. The ventilation cover 5 can be a standard prefabricated structure, and the flexible sheet 4 can be a flexible sheet structure such as a waterproof cloth. After the installation of the ventilation cover 5, the flexible sheet 4 adaptively adjusts its shape to adapt to the gap style in the specific installation scenario. Therefore, the combination of the ventilation cover 5 and the flexible sheet 4 enables the protective cover to be universal in various applications.

[0064] In this embodiment, the ventilation cover 5 is made of a steel protective cage.

[0065] Embodiment 7:

[0066] This embodiment is further refined on the basis of Embodiment 1: The distance between the drain hole 16 and the vibration sensor 3 is 15 cm to 30 cm, the aperture of the drain hole 16 is 4 mm to 6 mm, and the length of the drain hole 16 is 8 cm to 15 cm.

[0067] In specific applications, the arrangement of the drain holes 16 that is closer to the vibration sensor 3 and more densely wraps around the vibration sensor 3 can more effectively reduce the impact of water vapor on the aging of the coupling agent layer 7. However, for the vibration signals that propagate along the bedrock 1 and are picked up by the vibration sensor 3 for rockfall geological disaster monitoring, the drain holes 16 are equivalent to near-field scattering holes for the vibration signals, and they have a relatively obvious impact on the signal acquisition quality of high-frequency vibration signals. The above-set aperture is much smaller than the wavelength of the target high-frequency vibration signal (200 Hz). Therefore, the impact of the Rayleigh scattering region caused by the aperture of the drain holes 16 on the signal pickup quality can be accepted. The above-set spacing is used to control the impact of near-field strong scattering on the high-frequency signal acquisition quality, and the above-set length of the drain holes 16 is used to control the vibration coupling degree / vibration wave distortion between the signal pickup position of the vibration sensor 3 and the bedrock 1. In specific applications, the spacing between adjacent drain holes 16 is greater than 20 cm to reduce the impact of the superposition of multi-hole heat dissipation on the high-frequency signal pickup quality. By adopting this solution, the signal pickup quality of the vibration signals can be effectively guaranteed.

[0068] Example 8:

[0069] This solution provides a method for monitoring rockfall geological disasters on mountain slopes. This method uses the monitoring system described in any of the above embodiments to monitor rockfall geological disasters on the bedrock 1, and the vibration sensor 3 picks up vibration signals with a frequency lower than 200 Hz.

[0070] The monitoring method is a method for monitoring rockfall geological disasters on mountain slopes based on the monitoring system. In actual applications, the high-frequency band of the rock fracture vibration signal, which is a precursor signal for rockfall geological disaster monitoring, is usually less than 500 Hz. Since the drain holes 16 are relatively sensitive to the signal pickup quality of high-frequency vibration signals, the vibration sensor 3 is set to pick up seismic waves with a frequency lower than 200 Hz as vibration signals. The specific frequency band range can be 2 Hz to 200 Hz. Such a vibration signal pickup scheme can not only guarantee the signal pickup quality of each frequency band but also cover the core frequency bands commonly used in existing rockfall geological disaster monitoring. If it is necessary to monitor vibration signals with a frequency higher than 200 Hz (such as 200 Hz to 500 Hz), a separate signal pickup point can be set in this system. Only the anchor rod 2 is used to fix the vibration sensor 3 to the bedrock 1 under this signal pickup point, and the signal coupling with the bedrock 1 is achieved through the coupling agent layer 7, and no drain holes 16 are arranged around the vibration signal pickup position on the bedrock 1.

[0071] Example 9:

[0072] This embodiment is further refined on the basis of Example 8: The anchor rod 2 is anchored in the anchor hole 14 through an anchoring glue layer 6 made of an epoxy resin composite material filled with steel sand; The epoxy resin composite material is injected into the anchoring hole 14 by a vacuum negative pressure grouting method. The anchoring method of the anchor rod 2 is as follows: sealing the orifice of the anchoring hole 14 and evacuating the air in the anchoring hole 14; injecting the epoxy resin composite material into the anchoring hole 14 that has completed air evacuation; inserting the anchor rod 2 into the epoxy resin composite material in the anchoring hole 14.

[0073] In the above solution, the epoxy resin composite material modified with steel sand is used as the anchoring adhesive layer 6, aiming to reduce the influence of the installation of the anchor rod 2 on the attenuation of vibration signals (especially high-frequency signals in the frequency spectrum) and phase errors from the perspective of impedance mismatch. The vacuum negative pressure grouting method is used to reduce the porosity in the anchoring adhesive layer 6, and the porosity that can reach 10% under the traditional atmospheric pressure construction process can be controlled below 0.5%, so that the anchor rod 2 reaches an approximately void-free anchoring state, achieving the purpose of reducing the influence of the anchoring of the anchor rod 2 on the fidelity of the high-frequency signals picked up by the vibration sensor 3.

[0074] Example 10: This example is further refined on the basis of Example 1: The setting method of the drainage hole 16 and the vibration sensor 3 is as follows: Confirm the signal source position of the vibration signal on the bedrock 1 and the fitting position of the vibration sensor 3 on the bedrock 1; According to the signal source position and the fitting position, the drainage hole 16 is set on the side of the fitting position away from the signal source position; The vibration sensor 3 is installed after the drainage hole 16 is processed. The vibration sensor 3 is installed as follows: Evenly apply the coupling agent forming the coupling agent layer 7 on the signal pickup surface of the vibration sensor 3; Press the vibration sensor 3 against the bedrock 1, and provide a pushing force with a set threshold value for the vibration sensor 3 through the anchor rod 2; Scrape off the coupling agent overflow that overflows to the outside of the signal pickup surface around the vibration sensor 3 under the pushing; During the process of the monitoring system performing geological disaster monitoring, test the pickup quality of the vibration signal by actively knocking on the bedrock 1. The active knocking includes active knocking under a set time plan and / or active knocking after experiencing extreme weather.

[0075] In the above solution, the position of the signal source is the position where vibration signals may be generated, which is usually an area. In the monitoring of slope rock collapse geological disasters, according to the on-site geological exploration before the system layout, multiple areas can usually be determined on the slope. The fitting position is the position on the bedrock 1 where the vibration sensor 3 is suitable for installation. After having these two positions, the orientation of the signal source position relative to the fitting position can be confirmed, and further, under the guidance of this orientation, the setting orientation of the drainage hole 16 relative to the fitting position can be confirmed. By using such means, the aim is to achieve: reducing the influence of the drainage hole 16 on the quality of vibration signal pickup caused by directional shielding during the propagation of vibration signals in the bedrock 1. The setting method of the coupling agent layer 7 aims to achieve: taking advantage of the fact that the signal pickup surface is flatter than the surface of the bedrock 1 to better control the amount of coupling agent applied and make the thickness uniform at each position, and before pressing the coupling agent against the bedrock 1, cleaning the surface of the bedrock 1 at the position where it fits with the coupling agent. Specifically, a wire brush can be used to scrape and level the fitting surface 15, and then alcohol can be used to thoroughly remove dust. The control of the pushing force aims to control the thickness of the formed coupling agent layer 7 to avoid the coupling agent layer 7 being too thick or too thin (the preferred setting is 0.2 mm - 0.3 mm). The specific threshold size needs to be set according to the size of the signal pickup surface of the sensor used and the specific coupling agent. Scraping the overflow of the coupling agent outside the signal pickup surface aims to achieve: avoiding the formation of an elastic coupling layer around the signal pickup surface. On the one hand, as a support layer between the bedrock 1 and the vibration sensor 3, this elastic coupling layer is not conducive to ensuring an effective vibration signal propagation area between the vibration sensor 3 and the bedrock 1. At the same time, from the perspective of signal attenuation and parasitic vibration, it will also cause a certain degree of distortion of the picked-up vibration signals. On the other hand, it is easy to cause premature crack aging of the coupling agent layer 7 due to stress concentration occurring on the edge overflow, resulting in crack propagation. On the other hand, it forms a water absorption channel and a water storage space with the bedrock 1 and the vibration sensor 3, significantly affecting the aging speed of the coupling agent layer 7. The active knocking can be carried out by hammering to confirm whether the vibration sensor 3 can clearly and stably capture this part of the artificial vibration signal, and by comparing with the signal amplitude, waveform characteristics, and low-frequency response loss of the expected signal pickup result, detecting the signal coupling performance of the coupling agent layer 7 and the performance of the vibration sensor 3 itself. The knocking at the set time is to regularly verify the pickup performance of the vibration signal, and the knocking after experiencing extreme weather is to verify the pickup performance of the vibration signal after extreme environments.

[0076] The above content is a further detailed description of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific embodiments of the present invention are only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention belongs, other embodiments obtained without departing from the technical solution of the present invention should all be included within the protection scope of the present invention.

Claims

1. A geological disaster monitoring system for rock collapse on mountain slopes. This monitoring system realizes the monitoring of geological disasters of rock collapse on bedrock (1) based on the vibration signals picked up by vibration sensors (3). It is characterized in that, In this system, the vibration sensor (3) is fixed to the bedrock (1) through a rock bolt (2) installed in an anchoring hole (14), the signal pickup surface of the vibration sensor (3) is in contact with the surface of the bedrock (1), and a coupling agent layer (7) is provided between the signal pickup surface and the surface; On the bedrock (1), a plurality of drainage holes (16) are provided outside the signal pickup surface and surrounding the signal pickup surface.

2. The geological disaster monitoring system for rock collapse of mountain slopes according to claim 1, characterized in that, A stepped hole (13) is provided on the bedrock (1), and the anchoring hole (14) is the hole section inside the stepped hole (13): the orifice of the anchoring hole (14) is located on the step surface of the stepped hole (13); A fitting surface (15) for coupling with the vibration sensor (3) is provided on the step surface, and the fitting surface (15) is a plane; The orifices of the drainage holes (16) are all located on the step surface.

3. A geological disaster monitoring system for rock collapse on mountain slopes according to claim 1 or 2, characterized in that, The axes of the drainage holes (16) are distributed on a cylindrical surface, and the axis of the cylindrical surface is coaxial with the axis of the anchoring hole (14); The number of the cylindrical surfaces is greater than 1, and a plurality of drainage holes (16) are annularly arranged on each cylindrical surface.

4. A geological disaster monitoring system for rock collapse on mountain slopes according to claim 1, characterized in that, The rock bolt (2) is anchored in the anchoring hole (14) through an anchoring adhesive layer (6); The head end of the rock bolt (2) extends relative to the anchoring hole (14), a sliding sleeve (11) slidably connected to the rock bolt (2) is provided on the head end, a pressing plate (8) is provided at one end of the sliding sleeve (11) close to the bedrock (1), and the vibration sensor (3) is connected to the side of the pressing plate (8) close to the bedrock (1) through a connecting bolt (10); It further includes a compression cap (12) threadedly connected to the rock bolt (2), and the compression cap (12) applies a thrust towards the bedrock (1) to the sliding sleeve (11), so that the vibration sensor (3) is clamped between the bedrock (1) and the pressing plate (8); A guiding groove (9) parallel to the axis of the rock bolt (2) is provided on the rock bolt (2), and guiding ridges are provided on the inner side of the sliding sleeve (11), and the guiding ridges are embedded in the guiding groove (9).

5. A geological disaster monitoring system for rock collapses on mountain slopes according to claim 4, characterized in that, The number of vibration sensors (3) between the bedrock (1) and the pressing plate (8) is greater than or equal to 2.

6. The geological disaster monitoring system for rock collapse of mountain slopes according to claim 1, characterized in that, It further includes a protective cover installed on the bedrock (1) through an anchor (17), and the protective cover includes a breathable cover (5) fixed to the anchor (17); It further includes a flexible sheet (4), the inner end of the flexible sheet (4) is fixed to the anchor (17) and / or the bedrock (1), the outer end of the flexible sheet (4) is fixed to the breathable cover (5), and the flexible sheet (4) is used to seal the gap between the breathable cover (5) and the bedrock (1); The vibration sensor (3) and the rock bolt (2) are both covered in the housing structure surrounded by the breathable cover (5) and the flexible sheet (4).

7. A geological disaster monitoring system for rock collapse on mountain slopes according to claim 1, characterized in that, The distance between the drainage hole (16) and the vibration sensor (3) is 15 cm to 30 cm, the aperture of the drainage hole (16) is 4 mm to 6 mm, and the length of the drainage hole (16) is 8 cm to 15 cm.

8. A geological disaster monitoring method for rock collapses on mountain slopes, characterized in that, This method uses the monitoring system described in any one of claims 1 to 7 to realize the monitoring of geological disasters of rock collapse on the bedrock (1), and the vibration sensor (3) picks up vibration signals with a frequency lower than 200 Hz.

9. A method for monitoring geological disasters of rock collapses on mountain slopes according to claim 8, characterized in that, The anchor rod (2) is anchored in the anchor hole (14) through an anchoring adhesive layer (6) of an epoxy resin composite material filled with steel sand; The epoxy resin composite material is injected into the anchor hole (14) by a vacuum negative pressure grouting method. The anchoring method of the anchor rod (2) is as follows: closing the orifice of the anchor hole (14) and evacuating the anchor hole (14) to exhaust air; injecting the epoxy resin composite material into the anchor hole (14) that has completed evacuating air; inserting the anchor rod (2) into the epoxy resin composite material in the anchor hole (14).

10. A method for monitoring geological disasters of rock collapses on mountain slopes according to claim 8, characterized in that, The setting method of the drain hole (16) and the vibration sensor (3) is as follows: Confirm the signal source position of the vibration signal on the bedrock (1) and the fitting position of the vibration sensor (3) on the bedrock (1); According to the signal source position and the fitting position, the drain hole (16) is set on one side of the fitting position away from the signal source position; The vibration sensor (3) is installed after the drain hole (16) is processed. The vibration sensor (3) is installed by the following method: Evenly apply the coupling agent forming the coupling agent layer (7) on the signal pickup surface of the vibration sensor (3); Press the vibration sensor (3) against the bedrock (1), and provide a pushing force with a set threshold for the vibration sensor (3) through the anchor rod (2); Scrape off the coupling agent overflow that overflows to the outside of the signal pickup surface around the vibration sensor (3) under the pushing; During the process of the monitoring system performing geological disaster monitoring, test the pickup quality of the vibration signal by actively knocking on the bedrock (1). The active knocking includes active knocking under a set time plan and / or active knocking after experiencing extreme weather.

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