A high-precision monitoring system and method for deformation and displacement of ultra-deep borehole rock mass

Abstract

This invention relates to a high-precision monitoring system and method for rock mass deformation and displacement in ultra-deep boreholes. The system includes: a monitoring tube with an opening at one end; a fixing structure outside the monitoring tube to fill the gap between the monitoring tube and the ultra-deep borehole, thus securing the monitoring tube; a monitoring structure inside the monitoring tube, comprising an array of displacement gauges and a piezometer at the other end of the monitoring tube, separated by a sealing structure; the array of displacement gauges being bent within the monitoring tube, with all nodes abutting against the inner wall of the monitoring tube; and an adjustment mechanism inside the monitoring tube, used to ballast the array of displacement gauges so that all nodes of the array of displacement gauges move against the inner wall of the monitoring tube. This invention can monitor large deformations of rock masses and, by combining external factors such as meteorology and hydrology, achieve high-precision monitoring of rock mass deformation and displacement.

Description

Technical Field

[0001] This invention belongs to the field of slope geological disaster prevention and control, and particularly relates to rock mass deformation monitoring technology, specifically to a high-precision monitoring system and method for ultra-deep hole rock mass deformation and displacement. Background Technology

[0002] Modern infrastructure construction is increasingly extending to mountainous areas with challenging terrain. During the construction and operation of highways, railways, tunnels, bridges, and dams, slope disaster prevention and control are becoming increasingly prominent issues. To quickly and efficiently manage slope disasters and develop effective slope remediation solutions, it is urgent to implement automated real-time monitoring systems for deep displacement and groundwater monitoring.

[0003] Currently, there are two main technical approaches for early warning and monitoring of slope deformation, especially rock mass deformation: "surface displacement monitoring" and "deep displacement monitoring." Compared to surface displacement monitoring, deep displacement monitoring can extend the borehole depth to the sliding surface and use sensor technology to measure the deformation and tilt of the borehole, thereby monitoring the deformation trend inside the landslide soil. It is more intuitive and accurate in some aspects.

[0004] Among them, there are many parameters that affect the deformation of deep rock masses. In addition to inherent factors such as topography, strata and lithology, and geological structure, there are also external factors such as meteorology and hydrology. It is necessary to combine multiple parameter information to achieve the requirements of high-precision monitoring. Therefore, it is especially necessary to monitor groundwater level, pore water pressure or fracture water pressure.

[0005] However, displacement monitoring or groundwater monitoring of deeper rock strata requires drilling, which is extremely costly and complex for large, deep strata (deformation depth exceeding 400m). Existing technologies only focus on monitoring geological hazards in shallow strata and installing single-type monitoring equipment in a single borehole, and have not yet been researched for large, deep strata and installing multiple monitoring devices in a single borehole. For example, CN108130896A discloses an ultra-deep borehole displacement monitoring device and its installation method, including a grouting steel pipe, an SAA device, and auxiliary devices. The entire device is installed inside the borehole, with an external cable pre-installed at the borehole opening to transmit monitoring data. First, the SAA device is installed inside a PVC pipe. Then, the grouting steel pipe, the PVC pipe with the SAA device already installed, and the auxiliary devices are installed section by section, extending side by side to the borehole opening. After grouting through the grouting steel pipe section at the bottom of the borehole, the ultra-deep borehole displacement monitoring device is formed. Although it can perform deep hole monitoring, the SAA device is directly fixed in the grouting body and is only suitable for slow, small deformations. If the displacement exceeds 10cm, the SAA will shear or the data will be abnormal. Furthermore, it cannot be combined with external factors such as meteorology and hydrology, that is, it cannot monitor groundwater level, pore water pressure or fracture water pressure, thus making the monitoring of rock mass unsatisfactory.

[0006] Therefore, how to develop a system for drilling and installing multiple monitoring devices and a device for accurately monitoring large deformations of rock masses for large, complex, and deep geological disaster bodies has become an urgent technical problem to be solved in this field. Summary of the Invention

[0007] To address the shortcomings of the existing technology, the present invention aims to provide a high-precision monitoring system and method for rock mass deformation and displacement in ultra-deep boreholes. By bending an array of displacement gauges and placing them inside the monitoring tube, it is possible to monitor large deformations of the rock mass. Furthermore, by rationally arranging the piezometers and combining them with external factors such as meteorology and hydrology, high-precision monitoring of rock mass deformation and displacement can be achieved.

[0008] To achieve the above-mentioned objectives, this invention provides a high-precision monitoring system for deformation and displacement of ultra-deep borehole rock masses, characterized in that it comprises:

[0009] The monitoring tube is used to extend into the ultra-deep hole of the rock mass, and the end of the monitoring tube corresponding to the opening of the ultra-deep hole is provided with an opening.

[0010] A fixing structure is provided outside the monitoring tube body. The fixing structure is used to fill the gap between the monitoring tube body and the ultra-deep hole to fix the monitoring tube body.

[0011] The monitoring structure located inside the monitoring tube includes an array of displacement gauges located in the middle of the monitoring tube and a piezometer located at the other end of the monitoring tube. The array of displacement gauges and the piezometer are separated by a sealing structure. The array of displacement gauges is bent inside the monitoring tube, and all nodes of the array of displacement gauges abut against the inner wall of the monitoring tube.

[0012] The adjustment mechanism is located inside the monitoring tube. The adjustment mechanism is located at the end of the array displacement gauge near the opening and ballasts the array displacement gauge so that all nodes of the array displacement gauge move against the inner wall of the monitoring tube.

[0013] The fixed structure includes grouting equipment and grouting pipe connected to the grouting equipment. The grouting pipe is located on the outside of the monitoring pipe along the axial direction of the monitoring pipe.

[0014] The monitoring tube is fitted with a grout stopper, the outer diameter of which is greater than or equal to the diameter of the ultra-deep hole, and the grout stopper corresponds to the position of the sealing structure.

[0015] The grouting equipment fills the space between the monitoring pipe and the rock mass with grout through the grouting pipe, and the grout deforms synchronously with the rock mass.

[0016] The monitoring tube includes a first monitoring tube and a second monitoring tube with an opening. The first monitoring tube and the second monitoring tube are fixed and sealed by a sleeve. The position of the sleeve corresponds to the position of the sealing structure. An array of displacement gauges is installed inside the first monitoring tube. The array of displacement gauges is located in a zigzag pattern inside the first monitoring tube. A piezometer is installed inside the second monitoring tube.

[0017] The initial tilt angle of each section of the array displacement gauge within the monitoring tube, relative to the outer diameter of the monitoring tube, satisfies the following formula:

[0018]

[0019] In the formula, H is the height of the array displacement gauge inside the monitoring tube, k is a predetermined coefficient, k∈(1,7.5), φ is the outer diameter of the monitoring tube, d is the thickness of the monitoring tube, n is the number of sections of the array displacement gauge, and α is the angle between a certain section of the array displacement gauge and the axis of the monitoring tube.

[0020] The system includes result output devices that are connected to an array-type displacement gauge and a piezometer, respectively. The result output devices are used to obtain the rock mass deformation and displacement within a predetermined time based on the monitoring results of the array-type displacement gauge and the piezometer.

[0021] The rock mass deformation and displacement within a predetermined time period are obtained based on the monitoring results of the array-type displacement gauge and the piezometer, specifically including:

[0022] Each array of displacement gauges monitors the acceleration along the X, Y, and Z axes respectively.

[0023] Based on the acceleration of each array displacement meter on the X-axis, Y-axis, and Z-axis respectively, the displacement of each array displacement meter on the X-axis, Y-axis, and Z-axis is obtained;

[0024] Based on the displacement of each array displacement gauge on the X-axis, Y-axis, and Z-axis, and the total number of times each array displacement gauge monitors within a predetermined time, the rock mass deformation within the predetermined time is obtained.

[0025] Based on the monitoring results of the piezometer, determine whether the rock mass deformation within the predetermined time period conforms to the predetermined trend.

[0026] The displacement of each array displacement meter along the X, Y, and Z axes is obtained based on the acceleration of each array displacement meter along the X, Y, and Z axes, satisfying the following formula:

[0027]

[0028] In the formula, the Z-axis is taken as the axial direction of the array displacement gauge, and G... xijFor the j-th monitoring of the acceleration on the X-axis by the array displacement meter in section i, G yij For the j-th monitoring of the acceleration on the Y-axis by the array displacement meter in section i, G zij For the j-th monitoring of the acceleration on the Z-axis by the array displacement meter in section i, X ij Let Y be the X-axis displacement of the i-th array displacement meter during the j-th monitoring time interval. ij Z represents the Y-axis displacement of the i-th array displacement meter during the j-th monitoring time interval. ij Let Z be the Z-axis displacement of the i-th array displacement meter during the j-th monitoring time interval;

[0029] The amount of rock mass deformation within a predetermined time period satisfies the following formula:

[0030]

[0031] In the formula, n is the number of sections of the array displacement gauge, m is the number of times the array displacement gauge monitors within a predetermined time, int() is the floor function, T is the predetermined time, t is the time interval between monitoring by the array displacement gauge, and ΔS is the amount of rock deformation within the predetermined time.

[0032] The result output device is connected to the piezometer via a first cable and to the array displacement meter via a second cable.

[0033] The first cable is installed outside the monitoring tube along the axial direction of the monitoring tube body, and passes through the end of the monitoring tube body away from the opening to connect with the piezometer. The first cable is sleeved inside the polyvinyl chloride tube.

[0034] The second cable is installed axially within the monitoring tube and connected to the end of the array displacement meter near the opening. The second cable is sleeved inside a cross-linked polyethylene pipe.

[0035] Secondly, the present invention also provides a method for monitoring the deformation and displacement of ultra-deep borehole rock mass using the above-mentioned system, comprising:

[0036] Ultra-deep holes were obtained by drilling at the pre-monitoring location;

[0037] The monitoring tube, equipped with a sealing structure and a piezometer, was lowered into the ultra-deep borehole.

[0038] The monitoring tube is fixed inside the ultra-deep hole using a fixing structure;

[0039] The array displacement gauge with the fixed adjustment mechanism is lowered along the axial direction of the monitoring tube, and the array displacement gauge is bent and installed inside the monitoring tube;

[0040] The overall deformation and displacement of the rock mass are obtained by monitoring the results of piezometers and array displacement gauges.

[0041] Compared with existing technologies, this invention, by bending the array displacement gauges installed within the monitoring tube, avoids the shearing of the array displacement gauges or abnormal data when the displacement caused by rock deformation is too large. Therefore, it can continue to monitor the rock mass even when it has significant deformation. Furthermore, by rationally arranging the piezometers, it can monitor groundwater level, pore water pressure, or fissure water pressure. Thus, when monitoring rock mass deformation and displacement, it can combine external factors such as meteorology and hydrology to achieve high-precision monitoring of rock mass deformation and displacement.

[0042] In addition, by setting a sealed structure, the monitoring tube can be divided into multiple independent installation spaces, allowing multiple monitoring devices to be buried in the same borehole without crosstalk between them. This reduces the number of boreholes, greatly lowers construction costs, and makes signal transmission and observation more convenient. Attached Figure Description

[0043] The above and other objects, features, and advantages of this disclosure will become readily apparent upon reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of the invention are illustrated by way of example and not limitation, and like or corresponding reference numerals denote like or corresponding parts, wherein:

[0044] Figure 1 This is a schematic diagram illustrating a high-precision monitoring system for deformation and displacement of ultra-deep borehole rock mass according to an embodiment of the present invention;

[0045] Figure 2 This is a partial schematic diagram showing the opening according to an embodiment of the present invention;

[0046] Figure 3 This is a partial schematic diagram showing an array-type displacement gauge and an adjustment mechanism according to an embodiment of the present invention;

[0047] Figure 4 This is a flowchart illustrating a method for monitoring deformation and displacement of rock masses in ultra-deep holes according to an embodiment of the present invention.

[0048] Explanation of reference numerals in the attached drawings: 1-Monitoring pipe, 10-Ultra-deep hole, 21-Array displacement gauge, 22-Pyrometer, 23-Sealing structure, 24-Magnetometer, 3-Adjustment mechanism, 41-Grouting pipe, 42-Grouting stop plug, 51-First cable, 52-Second cable, 6-Grouting body, 71-Safety rope, 72-Wire rope. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. Identical components are denoted by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "upper," and "lower" used in the following description refer to directions in the drawings; the terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component; the term "connection" includes "direct connection" or "indirect connection"; and the component designations themselves, such as "first," "second," etc., are only used to distinguish the described objects and have no sequential or technical meaning.

[0050] See Figures 1 to 3 As shown, the present invention provides a high-precision monitoring system for deformation and displacement of ultra-deep borehole rock mass, comprising:

[0051] Monitoring tube 1 is used to extend into the ultra-deep hole 10 of the rock mass. The end of the monitoring tube 1 corresponding to the opening of the ultra-deep hole 10 is provided with an opening.

[0052] A fixing structure is provided outside the monitoring tube body 1. The fixing structure is used to fill the gap between the monitoring tube body 1 and the ultra-deep hole 10 to fix the monitoring tube body 1.

[0053] The monitoring structure located inside the monitoring tube 1 includes an array displacement gauge 21 located in the middle of the monitoring tube 1 and a piezometer 22 located at the other end of the monitoring tube 1. The array displacement gauge 21 and the piezometer 22 are separated by a sealing structure 23. The array displacement gauge 21 is bent inside the monitoring tube 1, and all nodes of the array displacement gauge 21 abut against the inner wall of the monitoring tube 1.

[0054] An adjustment mechanism 3 is located inside the monitoring tube 1. The adjustment mechanism 3 is located at one end of the array displacement meter 21 near the opening and is used to ballast the array displacement meter 21 so that all nodes of the array displacement meter 21 move against the inner wall of the monitoring tube 1. In addition, the other end of the array displacement meter 21 is provided with its built-in magnetometer 24. The magnetometer 24 is fixed against the sealing structure and is used as a judgment criterion for monitoring the array displacement meter.

[0055] The adjustment mechanism 3 is a gravity loading device. To ensure the gravity loading device is fixed in one position and to prevent its lifespan and position from being affected by gravity over a long period, the monitoring system may also include a steel wire rope 72. One end of the steel wire rope 72 is located at the opening at the upper end of the monitoring tube 1, and the other end is connected to the gravity loading device. The gravity loading device is an object with a predetermined weight, which can be determined based on the weight of the array displacement gauge and / or the coefficient of friction inside the monitoring tube. The array displacement gauge 21, bent and installed inside the monitoring tube 1, is zigzag in shape. The array displacement gauge 21 uses an advanced micromechanical accelerometer sensor. Based on microelectromechanical systems technology, it is manufactured on a common silicon wafer substrate using microfabrication technology to create a system integrating mechanical parts, sensor actuators, and electronic components. It consists of multiple subarrays connected in series. Each subarray comprises seven MEMS accelerometer segments and one microprocessor segment, with a length of 50cm or 30cm. The monitoring tube 1 is a seamless steel pipe with a diameter of 76mm and a thickness of 5mm.

[0056] This invention improves upon existing technology by bending the array displacement gauge 21 within the monitoring tube 1. This avoids the shearing of the array displacement gauge 21 or abnormal data when the displacement caused by rock deformation is too large, thus enabling continuous monitoring of the rock mass even with significant deformation. Furthermore, by rationally arranging the piezometers 22, groundwater level, pore water pressure, or fracture water pressure can be monitored. This allows for high-precision monitoring of rock mass deformation and displacement by incorporating external factors such as meteorology and hydrology. Additionally, the sealing structure 23 divides the monitoring tube 1 into multiple independent installation spaces, allowing multiple monitoring devices to be installed in the same borehole without crosstalk. This reduces the number of boreholes required, significantly lowers construction costs, and makes signal transmission and observation more convenient.

[0057] In this embodiment, to ensure accurate monitoring of the rock mass by the array displacement gauge 21 housed within the monitoring tube 1, a fixing structure is used to secure the monitoring tube 1 within the ultra-deep borehole 10. In practical applications, the fixing structure may include grouting equipment and a grouting pipe 41 connected to the grouting equipment. The grouting pipe 41 is positioned axially along the outside of the monitoring tube 1. The grouting equipment, through the connected grouting pipe 41, fills the space between the monitoring tube 1 and the rock mass (the inner wall of the ultra-deep borehole 10) with grout 6 or concrete, and the monitoring tube 1 is secured after the grout 6 has solidified. By securing the monitoring tube 1, the entire system remains stationary, preventing movement that could affect monitoring, thereby improving monitoring accuracy and extending its service life. Furthermore, when filling the space between the monitoring pipe 1 and the ultra-deep borehole 10 with grouting equipment using grouting material 6 or concrete, it is necessary to fully consider the deformation coordination between the grouting material 6 and the surrounding rock mass. Since the grouting material 6 is a cement slurry prepared according to actual needs, depending on the strength of the rock mass, a predetermined amount of soil can be added to the cement slurry to form a cement-soil slurry. The solidified cement-soil slurry deforms synchronously with the surrounding rock mass. In this embodiment, to achieve synchronous deformation, the strength of the cement-soil slurry and the surrounding rock mass can be made the same or approximately the same. Preferably, the strength of the cement-soil slurry and the surrounding rock mass is the same. That is, by using the cement slurry with a predetermined amount of soil added as the grouting material 6, this embodiment ensures that the grouting material 6 has the same deformation and displacement effect when the system monitors rock mass deformation, thereby improving the accuracy of the system's monitoring of rock mass deformation and displacement.

[0058] When grouting the area between the ultra-deep borehole 10 and the monitoring tube 1, to prevent the grout 6 from affecting the piezometer 22 inside the monitoring tube 1, a corresponding structure can be set up so that the piezometer 22 is not affected when monitoring the water level inside the ultra-deep borehole 10. In one application scenario, a flexible grout stopper 42 can be fitted over the monitoring tube 1. The outer diameter of the grout stopper 42 is slightly larger than or equal to the diameter of the ultra-deep borehole 10, and the grout stopper 42 corresponds to the position of the sealing structure 23. By setting the grout stopper 42, the ultra-deep borehole 10 can be divided into two parts corresponding to the inside of the monitoring tube 1, so that the piezometer 22 located at the bottom of the ultra-deep borehole 10 is not affected by the grout 6, and can accurately monitor the water level inside the ultra-deep borehole 10. In another application scenario, the bottom of the monitoring tube 1 is provided with an annular flexible bag, which corresponds to the sealing structure 23. The flexible bag is provided with multiple grouting holes in an annular shape. The other end of the grouting pipe 41, which is connected to the grouting equipment, extends into the flexible bag. When the grouting equipment injects grout 6 into the flexible bag through the grouting pipe 41 and the flexible bag is filled, the outer diameter of the flexible bag is greater than or equal to the diameter of the ultra-deep hole 10, thereby dividing the ultra-deep hole 10 into two parts corresponding to the inside of the monitoring tube 1 (two parts separated by the sealing structure 23). The grouting holes on the flexible bag are located in the upper part corresponding to the array displacement gauge 21. In this embodiment, when the grouting equipment injects grout into the ultra-deep hole 10 and the monitoring tube 1, the grout 6 first fills the flexible bag to a full state. Then, the grout 6 is continuously injected into the flexible bag. The subsequent grout 6 will enter the area between the ultra-deep hole 10 and the monitoring tube 1 through the grouting holes. Due to the isolation effect of the flexible bag, the injected grout 6 is prevented from reaching the lower part corresponding to the piezometer 22.

[0059] The number of grouting pipes 41 can be selected according to the actual scenario. In one application scenario, only one grouting pipe 41 is set, which is arranged on the outside along the axial direction of the monitoring pipe body 1. When grouting is required, the grouting body 6 is delivered through this grouting pipe 41. In another application scenario, four grouting pipes 41 can be used, which are evenly arranged around the outside of the monitoring pipe body 1. The four grouting pipes 41 can complete the grouting operation between the ultra-deep hole 10 and the monitoring pipe body 1 more quickly and evenly. In addition, when using a grouting plug, the structure of the grouting pipe 41 can also be selected according to the actual scenario. In one application scenario, the grouting pipe 41 is provided with several grouting holes at predetermined intervals. During grouting, the grouting body 6 is delivered to the area between the ultra-deep hole 10 and the monitoring pipe body 1 through the grouting holes. In another application scenario, the grouting pipe 41 extends from the opening of the monitoring pipe body 1 to the grout plug 42, and several grouting holes are spirally distributed on the pipe wall of the grouting pipe 41. The grouting holes are arranged in a spiral pattern. By using separate grouting holes, the grouting body 6 can be evenly inserted into the area between the ultra-deep hole 10 and the monitoring pipe 1 along the grouting pipe 41. This avoids the structural strength of the grouting pipe 41 being damaged when multiple grouting holes are set circumferentially at the same position.

[0060] The monitoring system of this embodiment, by bending the array displacement gauges 21 inside the monitoring tube 1, that is, by tilting each section of the array displacement gauges 21 inside the monitoring tube 1, can avoid the shearing of the array displacement gauges 21 or abnormal data when the displacement caused by rock deformation is too large. At the same time, to avoid the measurement range not meeting the predetermined requirements due to excessive tilt angle of each section of the array displacement gauges 21, a suitable tilt angle can be set. Preferably, the tilt angle of each section of the array displacement gauges 21 is between 0° and 60°, thereby ensuring that the monitoring system of this embodiment can continue to monitor the rock mass even when the rock mass has large deformation. When the array displacement gauges 21 are bent and installed, the initial tilt angle of each section of the array displacement gauges 21 inside the monitoring tube 1 and the outer diameter of the monitoring tube 1 satisfy the following formula:

[0061]

[0062] In the formula, H is the height of the array displacement gauge located in the monitoring tube, k is a predetermined coefficient, k∈(1,7.5), which can be obtained by the length of a single section of the array displacement gauge and the outer diameter of the monitoring tube, or by the conventional experience of those skilled in the art, φ is the outer diameter of the monitoring tube, d is the thickness of the monitoring tube, n is the number of sections of the array displacement gauge, and α is the angle between a certain section of the array displacement gauge and the axis of the monitoring tube.

[0063] In this embodiment, after monitoring the deformation and displacement of the rock mass using the array displacement gauge 21 and the piezometer 22, the collected data can be sent to a processor for processing to complete the monitoring of the rock mass deformation and displacement. In practical applications, the monitoring system may include a result output device connected to the array displacement gauge 21 and the piezometer 22 respectively. The result output device is used to obtain the rock mass deformation and displacement within a predetermined time based on the monitoring results of the array displacement gauge 21 and the piezometer 22. Specifically, the result output device can first calculate the rock mass deformation within the predetermined time based on the monitoring results of the array displacement gauge 21, and then compare the calculated rock mass deformation with the monitoring results of the piezometer 22 to determine whether the calculation result conforms to the predetermined trend. For example, if the initial water level monitored by the piezometer 22 is 'a', and the water level after the predetermined time is 'b' (b > a), and the calculated rock mass deformation is larger, it indicates that the calculated result conforms to the predetermined trend. The judgment result can also be obtained through calculation. By statistically analyzing multiple sets of actual rock mass deformation and water level changes within the monitoring area, and then performing fitting calculations, the relationship between rock mass deformation and water level can be obtained. Based on the relationship between rock mass deformation and water level, it can be determined whether the calculated structure is correct.

[0064] Specifically, the output device obtains the rock mass deformation and displacement within a predetermined time period based on the monitoring results of the array displacement gauge 21 and the piezometer 22, including:

[0065] Each array of displacement gauges monitors the acceleration along the X, Y, and Z axes respectively.

[0066] Based on the acceleration of each array displacement meter on the X-axis, Y-axis, and Z-axis respectively, the displacement of each array displacement meter on the X-axis, Y-axis, and Z-axis is obtained;

[0067] Based on the displacement of each array displacement gauge on the X-axis, Y-axis, and Z-axis, and the total number of times each array displacement gauge monitors within a predetermined time, the rock mass deformation within the predetermined time is obtained.

[0068] Based on the monitoring results of the piezometer, determine whether the rock mass deformation within the predetermined time period conforms to the predetermined trend.

[0069] The displacement of each array displacement meter along the X, Y, and Z axes is obtained based on the acceleration of each array displacement meter along the X, Y, and Z axes, satisfying the following formula:

[0070]

[0071] In the formula, the Z-axis is taken as the axial direction of the array displacement gauge, and G... xij For the j-th monitoring of the acceleration on the X-axis by the array displacement meter in section i, G yijFor the j-th monitoring of the acceleration on the Y-axis by the array displacement meter in section i, G zij For the j-th monitoring of the acceleration on the Z-axis by the array displacement meter in section i, when j=1, G xi0 Let G be the acceleration on the X-axis of the i-th array displacement meter when it is initially located inside the monitoring tube (the array displacement meter is tilted inside the monitoring tube after deployment, at which point no displacement has occurred). yi0 Let G be the acceleration on the Y-axis of the i-th array displacement meter when it is initially located inside the monitoring tube. zi0 Let X be the acceleration on the Z-axis of the i-th array displacement meter when it is initially located inside the monitoring tube. ij Let Y be the X-axis displacement of the i-th array displacement meter during the j-th monitoring time interval. ij Z represents the Y-axis displacement of the i-th array displacement meter during the j-th monitoring time interval. ij Let Z be the Z-axis displacement of the i-th array displacement meter during the j-th monitoring time interval;

[0072] The amount of rock mass deformation within a predetermined time period satisfies the following formula:

[0073]

[0074] In the formula, n is the number of sections of the array displacement gauge, m is the number of times the array displacement gauge monitors within a predetermined time, int() is the floor function, T is the predetermined time, t is the time interval between monitoring by the array displacement gauge, and ΔS is the amount of rock deformation within the predetermined time.

[0075] By using an array of displacement gauges 21 with an inclination angle between 0 and 60 degrees to monitor a predetermined position within the tube 1, and by using the above formula to accurately calculate the large deformation displacement of the rock mass, and then using the monitoring results of the piezometer 22 to assist in the judgment of the calculated results, the high-precision monitoring of rock mass deformation displacement in this embodiment is further improved.

[0076] When performing comprehensive analysis and calculation of the monitoring results of the array displacement gauge 21 and the piezometer 22 through the result output device, it is also necessary to set up corresponding cables to connect the result output device with the array displacement gauge 21 and the piezometer 22 for signal transmission. In one application scenario, both the array displacement gauge 21 and the piezometer 22 are connected to wireless transmission modules, and the result output device is also equipped with a wireless receiving module that matches the wireless transmission modules. The result output device completes the real-time acquisition of the monitoring results of the array displacement gauge 21 and the piezometer 22 through the wireless receiving module, and analyzes and calculates the deformation and displacement of the rock mass after the acquisition is completed. In another application scenario, the result output device is connected to the piezometer 22 via a first cable 51 and to the array displacement meter 21 via a second cable 52. The first cable 51 is axially positioned outside the monitoring tube 1 and passes through the end of the monitoring tube 1 furthest from the opening, connecting to the piezometer 22. The first cable 51 is sleeved inside a polyvinyl chloride (PVC) pipe. The second cable 52 is axially positioned inside the monitoring tube 1 and connects to the end of the array displacement meter 21 closest to the opening. The second cable 52 is sleeved inside a cross-linked polyethylene (XLPE) pipe. By positioning the first cable 51 outside the monitoring tube 1, the interference of the first cable 51 with the array displacement meter 21 when it runs inside the monitoring tube 1 can be avoided, thus preventing the array displacement meter 21 from having low monitoring accuracy. In addition, by placing the first cable 51 inside the polyvinyl chloride pipe, corrosion damage to the first cable 51 can be avoided when it is directly exposed to the grouting body 6 and the ultra-deep hole 10, thereby improving the service life of the first cable 51.

[0077] To facilitate the installation of the sealing structure 23 and the piezometer 22 within the monitoring tube 1, the structure of the monitoring tube 1 can be selected. In practical applications, the monitoring tube 1 may include a first monitoring tube and a second monitoring tube with openings. The first and second monitoring tubes are fixed and sealed by a sleeve, the position of which corresponds to the position of the sealing structure 23. An array-type displacement gauge 21 is installed inside the first monitoring tube, and a piezometer 22 is installed inside the second monitoring tube. By setting the monitoring tube 1 into two parts, the sealing structure 23 can be easily installed inside the first and / or second monitoring tubes, and the piezometer 22 can be installed inside the second monitoring tube. Furthermore, after installing the sealing structure 23 and the piezometer 22, it is also convenient to connect the first and second monitoring tubes to form a complete sealed unit. The sealing structure 23 is a pre-cast cement grout, mainly used to prevent concrete / grout 6 from entering the SAA equipment and affecting the monitoring accuracy when grouting is performed between the ultra-deep hole 10 and the monitoring tube 1 using the grouting pipe 41.

[0078] See Figure 4As shown, the present invention also provides a method for monitoring the deformation and displacement of ultra-deep borehole rock mass using the above-described system, comprising:

[0079] Ultra-deep hole 10 (diameter 130 mm, depth 480 m) was obtained by drilling at the pre-monitoring location;

[0080] The monitoring tube 1, which is equipped with a sealing structure 23 and a piezometer 22, is lowered into the ultra-deep hole 10;

[0081] The monitoring tube 1 is fixed inside the ultra-deep hole 10 by a fixing structure;

[0082] The array displacement meter 21 of the fixed adjustment mechanism 3 is lowered along the axial direction of the monitoring tube 1, and the array displacement meter 21 is bent and installed inside the monitoring tube 1.

[0083] The overall deformation and displacement of the rock mass are obtained by monitoring the results of the piezometer 22 and the array displacement meter 21.

[0084] This invention also provides a construction method for a high-precision monitoring system for deformation and displacement of ultra-deep borehole rock mass, which includes the following steps:

[0085] S1. Drilling: Drilling holes at the pre-construction location. A 480m ultra-deep hole was obtained.

[0086] S2. Installation of monitoring tube 1: Drill a hole in the lower side wall of monitoring tube 1 to obtain... The side wall hole allows the piezometer 22 to be installed inside the lower end of the monitoring tube 1. One end of the first cable 51 is then connected to the piezometer 22, while the other end of the first cable 51 is placed outside the main tube. A PVC pipe is installed outside the first cable. A grout stop plug 42 is installed 18-20m away from the bottom of the ultra-deep hole 10. One end of the grouting pipe 41 is inserted from the top of the ultra-deep hole 10 until the bottom end of the grouting pipe 41 is inserted into the grout stop plug 42. Then the bottom end of the monitoring pipe 1 is inserted into the bottom of the ultra-deep hole 10.

[0087] S3. Grouting inside the hole: Inject concrete from the upper end of the grouting pipe 41 until grout comes out from the upper end of the grouting pipe 41. The concrete fills the space between the grouting pipe 41 and the side wall of the ultra-deep hole 10.

[0088] S4 and SAA equipment installation: (For) The second cable 52 above the SAA device (array displacement gauge 21) is installed and extends to the upper end of the monitoring tube 1. A gravity loading device (adjustment mechanism 3) is installed between the second cable 52 and the SAA device. The SAA device, the gravity loading device and the second cable 52 extend from the upper end of the ultra-deep hole 10 to the bottom of the ultra-deep hole 10.

[0089] Before step S1, there is also step S0, SAA equipment installation: the SAA equipment is pre-connected to the second cable 52, the SAA equipment and the second cable 52 are connected by a connector and glued together.

[0090] Before step S0, a seamless steel pipe processing step is included: according to design requirements, a monitoring tube body 1 with a diameter of 76mm is manufactured using seamless steel pipe, and the first monitoring tube body and the second monitoring tube body are connected by... Seamless steel sleeves are connected to form a whole, forming monitoring tube 1.

[0091] The first cable 51 has one end located at the pipe hole at the upper end of the monitoring tube 1, and the other end is electrically connected to the piezometer 22.

[0092] Along Safety ropes 71 are installed along the entire length of the SAA equipment. Their purpose is to allow for mechanical lifting to retrieve the equipment should design requirements not be met during installation. SAA equipment.

[0093] The monitoring system also includes a controller, which is electrically connected to the gravity loading device; the controller is electrically connected to the gravity loading device via a second cable 52.

[0094] The specific installation and construction process of this invention is as follows:

[0095] (1) Processing of seamless steel pipes:

[0096] According to design requirements, it is manufactured using seamless steel pipes. Seamless steel pipes are used as monitoring pipe body 1.

[0097] (2) SAA equipment installation:

[0098] SAA equipment is manufactured in a factory and transported to the construction site. First, it... The PEX conduit is fitted into the AWG14 cable, and the interface is connected with the matching connector and glued together to form a whole.

[0099] (3) Drilling:

[0100] Drilling should be carried out using a 1000m drilling rig (model: XY-4), with a hole diameter of not less than 130mm. The maximum permissible deviation in hole depth is ±2‰, and correction must be performed every 50m of drilling. The hole inclination should not exceed 2° every 100m, and correction must be performed every 50m of drilling. The hole wall should be kept flat and free of gourd-like shapes to ensure the smooth operation of the inclination measuring equipment inside the hole. Drilling with steel pellets is prohibited in intact bedrock to ensure a smooth hole wall.

[0101] (4) Seamless steel pipe installation:

[0102] First, a drilling rig is used to drill a hole with a diameter of 130mm. Drill a hole 15m from the bottom of the borehole on the seamless steel pipe (monitoring pipe body 1). Drill a hole (sidewall hole) and insert the piezometer 22 through the hole. The piezometer 22 is connected to an external cable inside the seamless steel pipe. A PVC pipe is used to install a grout stop plug 42 at a distance of 18-20m from the bottom of the borehole. The grouting steel pipe extends from the borehole opening into the grout stop plug 42. Seamless steel pipes and The PVC pipe extends from the opening of the borehole to the bottom of the borehole. Seamless steel pipe connection adopts Seamless steel sleeve thread connection.

[0103] (5) Grouting inside the borehole:

[0104] The grouting mix ratio is cement:water = 1:0.6~0.8:. Grout is injected through the grouting steel pipe until grout oozes out of the borehole. The grout body 6 is expelled from the grouting hole and fills the gap between the grouting steel pipe and the borehole. Cement grout is also present inside the grouting steel pipe. The grouting pressure is between 0.8 and 2.0.

[0105] (6) Installation of SAA monitoring equipment

[0106] Externally mount the AWG14 cable on the top of the SAA equipment and extend it to the orifice. Inside the PEX conduit, between the AWG14 cable and... A gravity loading device is installed between the SAA equipment, and the SAA equipment, gravity loading device, and AWG14 cable extend from the borehole opening to the bottom of the hole.

[0107] The preferred embodiments of the present invention have been described above to make the spirit of the present invention clearer and easier to understand, and are not intended to limit the present invention. All modifications, substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope summarized by the appended claims.

Claims

1. A high-precision monitoring system for deformation and displacement of ultra-deep borehole rock mass, characterized in that, include: The monitoring tube is used to extend into the ultra-deep hole of the rock mass, and the end of the monitoring tube corresponding to the opening of the ultra-deep hole is provided with an opening. A fixing structure is provided outside the monitoring tube body. The fixing structure is used to fill the gap between the monitoring tube body and the ultra-deep hole to fix the monitoring tube body. The monitoring structure located inside the monitoring tube includes an array of displacement gauges located in the middle of the monitoring tube and a piezometer located at the other end of the monitoring tube. The array of displacement gauges and the piezometer are separated by a sealing structure. The array of displacement gauges is bent inside the monitoring tube, and all nodes of the array of displacement gauges abut against the inner wall of the monitoring tube. The tilt angle of each section of the array of displacement gauges is between 0° and 60°. An adjustment mechanism is located inside the monitoring tube. The adjustment mechanism is located at one end of the array displacement gauge near the opening and ballasts the array displacement gauge so that all nodes of the array displacement gauge move against the inner wall of the monitoring tube. The other end of the array displacement gauge is equipped with its built-in magnetometer, which is fixed against the sealing structure. The system includes result output devices connected to an array-type displacement gauge and a piezometer, respectively. These output devices are used to obtain the rock mass deformation and displacement within a predetermined time period based on the monitoring results from the array-type displacement gauge and the piezometer. Specifically, this includes: Each array of displacement gauges monitors the acceleration along the X, Y, and Z axes respectively. Based on the acceleration of each array displacement gauge on the X, Y, and Z axes, the displacement of each array displacement gauge on the X, Y, and Z axes is obtained; based on the displacement of each array displacement gauge on the X, Y, and Z axes, and the total number of times each array displacement gauge monitors within a predetermined time, the rock mass deformation within a predetermined time is obtained; based on the monitoring results of the piezometer, it is determined whether the rock mass deformation within the predetermined time conforms to the predetermined trend.

2. The system as described in claim 1, characterized in that, The fixed structure includes grouting equipment and grouting pipe connected to the grouting equipment. The grouting pipe is located on the outside of the monitoring pipe along the axial direction of the monitoring pipe.

3. The system as described in claim 2, characterized in that, The monitoring tube is fitted with a grout stopper. The outer diameter of the grout stopper is greater than or equal to the diameter of the ultra-deep hole, and the position of the grout stopper corresponds to that of the sealing structure.

4. The system as described in claim 2 or 3, characterized in that, The grouting equipment fills the space between the monitoring pipe and the rock mass with grout through the grouting pipe, and the grout deforms synchronously with the rock mass.

5. The system as described in claim 1, characterized in that, The monitoring tube includes a first monitoring tube and a second monitoring tube with an opening, and the first monitoring tube and the second monitoring tube are fixed and sealed by a sleeve. The position of the sleeve corresponds to the position of the sealing structure. An array of displacement gauges is installed in the first monitoring tube in a zigzag pattern. A piezometer is installed in the second monitoring tube.

6. The system as described in claim 1, characterized in that, The initial tilt angle of each section of the array displacement gauge within the monitoring tube, relative to the outer diameter of the monitoring tube, satisfies the following formula: In the formula, H is the height of the array displacement gauge inside the monitoring tube, k is a predetermined coefficient, k∈(1,7.5), φ is the outer diameter of the monitoring tube, d is the thickness of the monitoring tube, n is the number of sections of the array displacement gauge, and α is the angle between a certain section of the array displacement gauge and the axis of the monitoring tube.

7. The system as described in claim 6, characterized in that, Based on the acceleration of each array displacement gauge along the X, Y, and Z axes, the displacement of each array displacement gauge along the X, Y, and Z axes is obtained, satisfying the following formula: In the formula, the Z-axis is taken as the axial direction of the array displacement gauge, and G... xij For the j-th monitoring of the acceleration on the X-axis by the array displacement meter in section i, G yij For the j-th monitoring of the acceleration on the Y-axis by the array displacement meter in section i, G zij For the j-th monitoring of the acceleration on the Z-axis by the array displacement meter in section i, X ij Let Y be the X-axis displacement of the i-th array displacement meter during the j-th monitoring time interval. ij Z represents the Y-axis displacement of the i-th array displacement meter during the j-th monitoring time interval. ij Let Z be the Z-axis displacement of the i-th array displacement meter during the j-th monitoring time interval; The amount of rock mass deformation within a predetermined time period satisfies the following formula: In the formula, n is the number of sections of the array displacement gauge, m is the number of times the array displacement gauge monitors within a predetermined time, int() is the floor function, T is the predetermined time, t is the time interval between monitoring by the array displacement gauge, and ΔS is the amount of rock deformation within the predetermined time.

8. The system as described in claim 1, characterized in that, The output device is connected to the piezometer via the first cable and to the array displacement meter via the second cable. The first cable is installed outside the monitoring tube along the axial direction of the monitoring tube body, and passes through the end of the monitoring tube body away from the opening to connect with the piezometer. The first cable is sleeved inside the polyvinyl chloride tube. The second cable is installed axially within the monitoring tube and connected to the end of the array displacement meter near the opening. The second cable is sleeved inside a cross-linked polyethylene pipe.

9. A method for monitoring the deformation and displacement of ultra-deep borehole rock mass using a high-precision monitoring system for ultra-deep borehole rock mass deformation and displacement as described in any one of claims 1-8, characterized in that, include: Ultra-deep holes were obtained by drilling at the pre-monitoring location; The monitoring tube, equipped with a sealing structure and a piezometer, was lowered into the ultra-deep borehole. The monitoring tube is fixed inside the ultra-deep hole using a fixing structure; The array displacement gauge with the fixed adjustment mechanism is lowered along the axial direction of the monitoring tube, and the array displacement gauge is bent and installed inside the monitoring tube; The overall deformation and displacement of the rock mass are obtained by monitoring the results of piezometers and array displacement gauges.

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