Underground cavern surrounding rock displacement monitoring method and system based on self-locking compensation

Abstract

This invention relates to the field of geological monitoring technology and discloses a method and system for monitoring the displacement of surrounding rock in underground caverns based on self-locking compensation. It aims to solve the problem of poor accuracy in existing methods for monitoring the displacement of surrounding rock in underground caverns. The main components include: implanting self-locking anchors at the bottom of the borehole; implanting corresponding measuring point anchors at multiple measuring points within the borehole; and fixing the self-locking anchors using hydraulically driven flanges; connecting reference transmission rods to the self-locking anchors; connecting corresponding displacement transmission rods to the measuring point anchors; measuring the reference displacement corresponding to the reference transmission rod and the measured displacement of each measuring point corresponding to the displacement transmission rod; determining the displacement transmission coefficient corresponding to each measuring point under experimental conditions; and compensating the measured displacement based on the displacement transmission parameters and the reference displacement to obtain the true displacement of each measuring point. This invention improves the accuracy of monitoring the displacement of surrounding rock in underground caverns and is particularly suitable for underground engineering projects with overall settlement or tilting.

Description

Technical Field

[0001] This invention relates to the field of geological monitoring technology, specifically to a method and system for monitoring the displacement of surrounding rock in underground caverns based on self-locking compensation. Background Technology

[0002] Displacement monitoring of surrounding rock in underground caverns refers to observing displacement changes within the surrounding rock during tunnel or underground engineering excavation to capture the dynamic deformation process of the rock mass caused by stress distribution. Its core is measuring the displacement within the surrounding rock, thereby reflecting the deformation rate and stability of the rock mass. By monitoring the displacement of surrounding rock in underground caverns, stability assessments, collapse warnings, and construction guidance can be conducted, thus ensuring project safety and optimizing design.

[0003] Existing underground cavern surrounding rock displacement monitoring schemes primarily utilize self-locking anchors, multiple measuring point anchors, and a telescopic displacement transmission rod. The self-locking anchors are located at the bottom of the borehole, anchored in stable rock strata. The rock strata containing the self-locking anchors are absolutely stable, with zero displacement, serving as the absolute reference point for the entire system. Each measuring point anchor deforms synchronously with the rock mass, and its displacement reflects the rock mass movement at that depth. The self-locking anchors and each measuring point anchor are connected in series via a telescopic displacement transmission rod. The displacement transmission rod progressively amplifies the displacement of each anchor and transmits it to the borehole opening. Multiple borehole opening sensors measure the cumulative displacement of the transmission rod at each measuring point. When a displacement occurs at an anchor point, it pulls or pushes the transmission rod, causing a change in the borehole opening sensor readings. The displacement of each measuring point can then be inferred from the readings of the various borehole opening sensors. To calculate the displacement between any two measuring points, the difference between the corresponding borehole opening sensor readings can be calculated.

[0004] The reliability of the above scheme relies on the absolute stability of the rock stratum where the self-locking anchor is located, with zero displacement. However, in actual engineering projects, factors such as deep creep and groundwater, or the redistribution of surrounding rock stress after underground excavation, can cause actual displacement in the rock stratum where the self-locking anchor is located, with measured displacement deviations reaching 10% to 30%. Attempting to stabilize the reference point by increasing the anchoring depth or grouting reinforcement is not only costly but also has limited effectiveness. When the reference point corresponding to the self-locking anchor shifts, it drives the entire rod system to move, resulting in systematic errors in the displacement data of all measuring points. The cumulative monitoring method further amplifies these errors, leading to poor accuracy in displacement monitoring. For example, in the monitoring of a hydropower station tunnel, the reference point displacement reached 12mm, causing a cumulative error exceeding 15cm. Summary of the Invention

[0005] This invention aims to solve the problem of poor accuracy in existing underground cavern surrounding rock displacement monitoring methods, and proposes an underground cavern surrounding rock displacement monitoring method and system based on self-locking compensation.

[0006] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0007] In a first aspect, the present invention provides a method for monitoring the displacement of surrounding rock in underground caverns based on self-locking compensation, the method comprising:

[0008] After drilling and cleaning the surrounding rock of the underground cavern, self-locking anchors are implanted at the reference point at the bottom of the borehole, and corresponding measuring point anchors are implanted at multiple measuring points in the borehole. The self-locking anchors are then fixed using hydraulically driven wing plates.

[0009] A reference transmission rod is connected to the self-locking anchor, and a corresponding displacement transmission rod is connected to each measuring point anchor.

[0010] The reference displacement of the reference point corresponding to the reference transmission rod and the measured displacement of the measuring point corresponding to each displacement transmission rod are measured by the corresponding orifice sensor.

[0011] Under experimental conditions, the displacement transfer coefficient corresponding to each measuring point is determined. Based on the corresponding displacement transfer parameters and the reference displacement, the measured displacement of each measuring point is compensated to obtain the true displacement of each measuring point.

[0012] Furthermore, the displacement of each measuring point is compensated based on the corresponding displacement transfer parameters and the reference displacement, including:

[0013] Determine whether the reference displacement is greater than the displacement threshold. If so, use the compensation calculation formula to compensate for the measured displacement of each measuring point. If not, take the measured displacement of each measuring point as the corresponding real displacement.

[0014] The compensation calculation formula is as follows:

[0015] ;

[0016] in, Indicates the first The true displacement of each measuring point Indicates the first The measured displacement of each measuring point Represents the reference displacement of the reference point. Indicates the first Displacement transfer coefficient at each measuring point.

[0017] Furthermore, the displacement transfer coefficients corresponding to each measuring point are determined under experimental conditions, including:

[0018] A test model corresponding to the surrounding rock of the underground cavern was constructed. Known displacements were applied to the corresponding measuring points on the test model. The reference displacements of the corresponding reference points on the test model were measured using self-locking anchors and a reference transfer rod, based on a borehole sensor. The measured displacements of the corresponding measuring points on the test model were then measured using measuring point anchors and a displacement transfer rod, based on a borehole sensor. The displacement transfer coefficients of the corresponding measuring points were calculated.

[0019] ;

[0020] in, Indicates the experimental model number 1 The measured displacement of each measuring point Indicates the experimental model number 1 The known displacement applied at each measuring point, This represents the reference displacement of the reference point corresponding to the test model.

[0021] Furthermore, the reference transmission rod and the displacement transmission rod are made of carbon fiber.

[0022] Furthermore, the self-locking anchor is secured using a hydraulically driven wing plate, including:

[0023] The hydraulic oil generated by the hydraulic pump is injected into the internal piston chamber of the self-locking anchor through the oil pipe. The hydraulic pressure drives the piston to move axially, converting the liquid pressure into radial extrusion force on the root of the flange. After being extruded, the root of the flange bends outward and undergoes plastic deformation. The barbs on the surface penetrate into the rock mass and forcibly interlock with the rock mass to form a mechanical interlock. The self-locking mechanism is used to maintain the prestress.

[0024] Furthermore, the surface of the wing plate is provided with tungsten steel particles to increase friction.

[0025] Furthermore, the method also includes:

[0026] The anchoring pressure of the self-locking anchor is measured in real time using a pressure sensor. When the anchoring pressure is less than the pressure threshold, the hydraulic pump is activated to replenish the pressure until the anchoring pressure is equal to the initial anchoring pressure.

[0027] Furthermore, the initial anchoring pressure of the self-locking anchor is 8 MPa, and the pressure threshold is 7.5 MPa.

[0028] Furthermore, the method also includes:

[0029] A fiber Bragg grating sensor is integrated into the self-locking anchor.

[0030] Determine whether the reference displacement measured by the corresponding aperture sensor is within a preset range. If not, use the fiber Bragg grating sensor to measure the wavelength offset of the fiber grating and calculate the reference displacement of the reference point based on the wavelength offset.

[0031] Secondly, the present invention provides a self-locking compensation-based underground cavern surrounding rock displacement monitoring system for implementing the self-locking compensation-based underground cavern surrounding rock displacement monitoring method as described in the first aspect, the system comprising:

[0032] Self-locking anchors are inserted at the reference point at the bottom of the borehole after drilling and cleaning the surrounding rock of the underground cavern.

[0033] Measuring point anchors are implanted at multiple measuring points within the borehole;

[0034] A wing plate that uses hydraulic drive to fix the self-locking anchor;

[0035] A reference transmission rod connected to the self-locking anchor;

[0036] Displacement transmission rods connected to the anchors at each measuring point;

[0037] The orifice sensor is used to measure the reference displacement of the reference point corresponding to the reference transmission rod and the measured displacement of the measuring point corresponding to each displacement transmission rod.

[0038] The controller is used to determine the displacement transfer coefficient corresponding to each measuring point under test conditions, and to compensate for the measured displacement of each measuring point according to the corresponding displacement transfer parameters and the reference displacement, so as to obtain the true displacement of each measuring point.

[0039] The beneficial effects of this invention are as follows: The method and system for monitoring the displacement of surrounding rock in underground caverns based on self-locking compensation provided by this invention monitors the reference displacement of the reference point through a reference transmission rod and calibrates the displacement transmission coefficient corresponding to each measuring point. Displacement compensation is then performed on the measured displacement of each measuring point, eliminating the interference component generated by the reference displacement on the measured displacement, thus significantly improving the accuracy of monitoring the displacement of surrounding rock in underground caverns. Furthermore, the self-locking anchor is fixed by a hydraulically driven wing plate, ensuring that the self-locking anchor deforms synchronously with the surrounding rock, eliminating slippage errors, and improving the accuracy of reference point displacement monitoring, thereby further improving the accuracy of monitoring the displacement of surrounding rock in underground caverns. Finally, the independent and parallel monitoring of the measured displacement of each measuring point by multiple displacement transmission rods avoids the accumulation of displacement errors, further improving the accuracy of monitoring the displacement of surrounding rock in underground caverns. Attached Figure Description

[0040] Figure 1 A schematic flowchart of the method for monitoring the displacement of surrounding rock in underground caverns based on self-locking compensation provided in the embodiments;

[0041] Figure 2 A schematic diagram of the installation structure of the reference transmission rod and the displacement transmission rod provided for the embodiment;

[0042] Explanation of reference numerals in the attached figures:

[0043] A0 - Self-locking anchor; A1 - First measuring point anchor; A2 - Second measuring point anchor; An - nth measuring point anchor; L0 - Reference transmission rod; L1 - First displacement transmission rod; L2 - Second displacement transmission rod; Ln - nth displacement transmission rod. Detailed Implementation

[0044] The technical solution of the present invention is applicable to application scenarios that require displacement monitoring of the surrounding rock of underground caverns, and is especially suitable for underground projects with overall settlement or tilting.

[0045] Current underground cavern surrounding rock displacement monitoring schemes rely on unreliable static baseline assumptions, namely, that the displacement of the rock stratum containing the self-locking anchor at the bottom of the borehole is always zero. However, in actual engineering, the rock stratum containing the self-locking anchor is not absolutely stable. When the rock stratum containing the self-locking anchor displaces, it will cause the entire rod system to move, leading to errors in the measured displacement at each measuring point. Furthermore, the existing scheme's method of accumulating displacement monitoring at each measuring point using a single displacement transmission rod further contributes to the accumulation of errors, resulting in poor accuracy in displacement monitoring.

[0046] To improve the accuracy of displacement monitoring in underground caverns, this invention proposes a technical solution. In this invention, firstly, a self-locking anchor is implanted at the bottom of the borehole as a reference point and locked using a hydraulic flange. Measuring point anchors are then implanted at multiple measuring points at different depths within the borehole. Next, a reference transmission rod is connected to the self-locking anchor and extends to the borehole opening. For each measuring point anchor, a corresponding displacement transmission rod is independently connected and extends to the borehole opening, constructing a physical displacement transmission channel. The reference transmission rod and each displacement transmission rod operate in parallel and independently. Finally, the displacement of the reference transmission rod and each displacement transmission rod is measured using a corresponding borehole opening sensor to obtain the reference displacement of the reference point and the measured displacement of each measuring point. The measured displacement of each measuring point is then compensated based on the displacement transmission parameters calibrated by the experiment to obtain the true displacement of each measuring point. Because this invention compensates for the displacement of each measuring point, it eliminates the interference component of the reference displacement on the measured displacement, thereby improving the accuracy of underground cavern surrounding rock displacement monitoring. Furthermore, this invention uses a hydraulically driven wing plate to fix the self-locking anchor, ensuring that the self-locking anchor deforms synchronously with the surrounding rock, eliminating slippage errors, improving the accuracy of reference point displacement monitoring, and further improving the accuracy of underground cavern surrounding rock displacement monitoring. In addition, this invention uses multiple displacement transmission rods to independently and in parallel monitor the measured displacement of each measuring point, avoiding the accumulation of displacement errors, and further improving the accuracy of underground cavern surrounding rock displacement monitoring.

[0047] The technical solutions in this embodiment will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0048] Figure 1 A flowchart illustrating a method for monitoring the displacement of surrounding rock in underground caverns based on self-locking compensation is shown. Please refer to [link / reference]. Figure 1 The method includes the following steps:

[0049] Step 1: After drilling and cleaning the surrounding rock of the underground cavern, self-locking anchors are implanted at the reference point at the bottom of the borehole. Corresponding measuring point anchors are implanted at multiple measuring points in the borehole, and the self-locking anchors are fixed by hydraulically driven wing plates.

[0050] In practical applications, the surrounding rock of the underground cavern is first drilled and then cleaned. Drilling and cleaning ensures the integrity and cleanliness of the borehole wall, providing a uniform stress interface for the anchor. Then, a self-locking anchor is inserted at the bottom of the borehole as a reference point, and the self-locking anchor is fixed by a hydraulically driven wing plate to form an anti-slip anchor. Finally, according to the monitoring requirements, measuring point anchors are inserted at multiple measuring points at different depths of the borehole.

[0051] Specifically, the self-locking anchor is fixed using a hydraulically driven wing plate, including:

[0052] The hydraulic oil generated by the hydraulic pump is injected into the internal piston chamber of the self-locking anchor through the oil pipe. The hydraulic pressure drives the piston to move axially, converting the liquid pressure into radial extrusion force on the root of the flange. After being extruded, the root of the flange bends outward and undergoes plastic deformation. The barbs on the surface penetrate into the rock mass and forcibly interlock with the rock mass to form a mechanical interlock. The self-locking mechanism is used to maintain the prestress.

[0053] In this embodiment, the wing plate surface is provided with tungsten steel particles to increase friction. After the wing plate is deformed by hydraulic drive, the tungsten steel particles on the surface are strongly embedded in the rock mass to form an anti-slip anchor, thereby ensuring that the self-locking anchor deforms synchronously with the surrounding rock, eliminating slip error and improving the accuracy of benchmark displacement monitoring.

[0054] In this embodiment, the method further includes: using a pressure sensor to measure the anchoring pressure of the self-locking anchor in real time; when the anchoring pressure is less than a pressure threshold, activating a hydraulic pump to replenish the pressure until the anchoring pressure equals the initial anchoring pressure.

[0055] Specifically, by measuring and replenishing pressure in real time, dynamic pressure compensation is achieved to maintain a constant embedding force on the flange, thereby offsetting the attenuation of anchoring force caused by rock creep or stress relaxation, ensuring long-term synchronous displacement between the reference point and the surrounding rock, and further improving the accuracy of reference point displacement monitoring. The initial anchoring pressure and pressure threshold of the self-locking anchor can be set according to the actual engineering conditions. In this embodiment, the initial anchoring pressure is 8 MPa, and the pressure threshold is 7.5 MPa. This ensures that the anchoring pressure is sufficient for the self-locking anchor to move synchronously with the surrounding rock, while preventing excessive anchoring pressure from crushing the rock mass and causing anchoring failure.

[0056] Step 2: Connect the reference transmission rod to the self-locking anchor and connect the corresponding displacement transmission rod to the anchor at each measuring point.

[0057] Please see Figure 2 The self-locking anchor A0 connects to the reference transmission rod L0 and extends to the borehole opening. Each measuring point anchor connects to its corresponding displacement transmission rod and extends to the borehole opening; that is, the first measuring point anchor A1 connects to the first displacement transmission rod L1 and extends to the borehole opening, the second measuring point anchor A2 connects to the second displacement transmission rod L2 and extends to the borehole opening, and the nth measuring point anchor An connects to the nth displacement transmission rod Ln and extends to the borehole opening, thus constructing a physical displacement transmission channel. Furthermore, each displacement transmission rod operates in parallel and independently. By independently and in parallel monitoring the displacement of each measuring point using multiple displacement transmission rods, the accumulation of displacement errors is avoided, further improving the accuracy of displacement monitoring of the surrounding rock in underground caverns.

[0058] In this embodiment, the reference transmission rod and the displacement transmission rod are made of carbon fiber to avoid displacement measurement errors caused by rod deformation; and the reference transmission rod and the displacement transmission rod have extremely low coefficients of thermal expansion (coefficient of thermal expansion is 0.5%). This is to suppress the rod's expansion and contraction errors caused by temperature and ensure the purity of displacement transmission.

[0059] Step 3: Measure the reference displacement of the reference point corresponding to the reference transmission rod and the measured displacement of the corresponding measuring point of each displacement transmission rod using the corresponding orifice sensor.

[0060] It can be understood that each reference transmission rod and each displacement transmission rod corresponds one-to-one with an orifice sensor. Using the corresponding orifice sensor and based on a preset frequency, the reference displacement transmitted by the reference transmission rod and the measured displacement transmitted by each displacement transmission rod to its corresponding measuring point are measured. The measured displacement includes the actual displacement of the measuring point and the displacement error of the measuring point caused by the reference point displacement. The preset frequency can be set according to actual conditions, such as once per minute.

[0061] Step 4: Determine the displacement transfer coefficient corresponding to each measuring point under the test environment, and compensate the measured displacement of each measuring point according to the corresponding displacement transfer parameters and the reference displacement to obtain the true displacement of each measuring point.

[0062] In this embodiment, the displacement of each measuring point is compensated according to the corresponding displacement transfer parameters and the reference displacement, including:

[0063] If the reference displacement is greater than the displacement threshold, the measured displacement of each measuring point is compensated using the compensation calculation formula; otherwise, the measured displacement of each measuring point is taken as the corresponding true displacement.

[0064] It is understandable that when the surrounding rock as a whole shifts, the reference point will cause the entire rod system to move. At this time, the sensor reading of the measuring rod actually includes two parts: the actual displacement + the displacement caused by the rod system. In this embodiment, when the reference displacement is greater than the displacement threshold, it indicates that the reference point displacement has caused parasitic displacement at the measuring point. In this case, displacement compensation is performed using a compensation calculation formula. When the reference displacement is not greater than the displacement threshold, the small reference displacement is within the sensor error range, and compensation may introduce noise. This achieves the effect of ensuring accuracy while avoiding oversensitivity. The displacement threshold can be set according to the actual situation; for example, the displacement threshold can be 0.1 mm.

[0065] In this embodiment, the compensation calculation formula is as follows:

[0066] ;

[0067] in, Indicates the first The true displacement of each measuring point Indicates the first The measured displacement of each measuring point Represents the reference displacement of the reference point. Indicates the first Displacement transfer coefficient at each measuring point.

[0068] Specifically, by using the above compensation calculation formula, the interference component of the reference displacement is deducted from the measured displacement to obtain the true displacement of the measuring point, thereby avoiding systematic errors caused by the reference displacement and improving the accuracy of underground cavern surrounding rock displacement monitoring.

[0069] In this embodiment, the method for determining the displacement transfer coefficient includes:

[0070] A test model corresponding to the surrounding rock of the underground cavern was constructed. Known displacements were applied to the corresponding measuring points on the test model. The reference displacements of the corresponding reference points on the test model were measured using self-locking anchors and a reference transfer rod, based on a borehole sensor. The measured displacements of the corresponding measuring points on the test model were then measured using measuring point anchors and a displacement transfer rod, based on a borehole sensor. The displacement transfer coefficients of the corresponding measuring points were calculated.

[0071] ;

[0072] in, Indicates the experimental model number 1 The measured displacement of each measuring point Indicates the experimental model number 1 The known displacement applied at each measuring point, This represents the reference displacement of the reference point corresponding to the test model.

[0073] It is understood that this embodiment calibrates the displacement transfer coefficient through experiments. Specifically, an experimental model corresponding to the surrounding rock of the underground cavern is constructed, and an identical displacement monitoring system is installed in the experimental model. Then, on the [number]th [year] of the experimental model... Precise known displacement of each measuring point under mechanical loading For example, using hydraulic jacks to move rock blocks and simultaneously collecting data from the test model. Measured displacement at each measuring point Reference displacement of the reference point corresponding to the test model Then, the first step is calculated according to the above formula. Displacement transfer coefficient at each measuring point In practical applications, multiple repeated experiments can be conducted, and the average value can be taken.

[0074] In this embodiment, the method further includes: integrating a fiber Bragg grating sensor on the self-locking anchor; determining whether the reference displacement measured by the corresponding orifice sensor is within a preset range; if not, measuring the wavelength offset of the fiber Bragg grating using the fiber Bragg grating sensor, and calculating the reference displacement of the reference point based on the wavelength offset.

[0075] It is understandable that when the reference displacement is not within the preset range, the reference displacement rod is determined to be broken. In this case, the reference displacement is measured using a fiber Bragg grating sensor integrated on the self-locking anchor. Specifically, the Bragg wavelength of the fiber Bragg grating in the fiber Bragg grating sensor will linearly shift with the strain applied externally. By precisely measuring the wavelength shift, the absolute displacement of the self-locking anchor can be calculated, thereby obtaining the reference displacement. The relevant calculation method is existing technology and will not be elaborated in this embodiment. By integrating a fiber Bragg grating sensor, the reference displacement failure caused by the breakage of the reference displacement rod can be avoided, improving the accuracy and reliability of the reference displacement, and further improving the accuracy of underground cavern surrounding rock displacement monitoring.

[0076] In summary, the self-locking compensation-based method for monitoring the displacement of surrounding rock in underground caverns provided in this embodiment monitors the reference displacement of the reference point using a reference transfer rod and calibrates the displacement transfer coefficient corresponding to each measuring point. Displacement compensation is then performed on the measured displacement of each measuring point, eliminating the interference component caused by the reference displacement on the measured displacement, thus significantly improving the accuracy of monitoring the displacement of surrounding rock in underground caverns. Furthermore, the hydraulically driven wing plate fixes the self-locking anchors, ensuring that the self-locking anchors deform synchronously with the surrounding rock, eliminating slippage errors and improving the accuracy of reference point displacement monitoring, thereby further enhancing the accuracy of monitoring the displacement of surrounding rock in underground caverns. Finally, the independent and parallel monitoring of the measured displacement of each measuring point using multiple displacement transfer rods avoids the accumulation of displacement errors, further improving the accuracy of monitoring the displacement of surrounding rock in underground caverns.

[0077] Based on the above technical solution, this embodiment also provides a self-locking compensation-based underground cavern surrounding rock displacement monitoring system. The system implementing the self-locking compensation-based underground cavern surrounding rock displacement monitoring method of this embodiment includes:

[0078] Self-locking anchors are inserted at the reference point at the bottom of the borehole after drilling and cleaning the surrounding rock of the underground cavern.

[0079] Measuring point anchors are implanted at multiple measuring points within the borehole;

[0080] A wing plate that uses hydraulic drive to fix the self-locking anchor;

[0081] A reference transmission rod connected to the self-locking anchor;

[0082] Displacement transmission rods connected to the anchors at each measuring point;

[0083] The orifice sensor is used to measure the reference displacement of the reference point corresponding to the reference transmission rod and the measured displacement of the measuring point corresponding to each displacement transmission rod.

[0084] The controller is used to determine the displacement transfer coefficient corresponding to each measuring point under test conditions, and to compensate for the measured displacement of each measuring point according to the corresponding displacement transfer parameters and the reference displacement, so as to obtain the true displacement of each measuring point.

[0085] It is understood that the underground cavern surrounding rock displacement monitoring system based on self-locking compensation described in this embodiment is a system used to implement the underground cavern surrounding rock displacement monitoring method based on self-locking compensation described in the embodiment. As the system disclosed in the embodiment corresponds to the method disclosed in the embodiment, the description is relatively simple. For relevant parts, please refer to the description of the method. It will not be repeated here.

Claims

1. A method for monitoring the displacement of surrounding rock in underground caverns based on self-locking compensation, characterized in that, The method includes: After drilling and cleaning the surrounding rock of the underground cavern, self-locking anchors are implanted at the reference point at the bottom of the borehole, and corresponding measuring point anchors are implanted at multiple measuring points in the borehole. The self-locking anchors are then fixed using hydraulically driven wing plates. A reference transmission rod is connected to the self-locking anchor, and a corresponding displacement transmission rod is connected to each measuring point anchor. The reference displacement of the reference point corresponding to the reference transmission rod and the measured displacement of the measuring point corresponding to each displacement transmission rod are measured by the corresponding orifice sensor. Under experimental conditions, the displacement transfer coefficient corresponding to each measuring point is determined. Based on the corresponding displacement transfer coefficient and the reference displacement, the measured displacement of each measuring point is compensated to obtain the true displacement of each measuring point. The displacement of each measuring point is compensated based on the corresponding displacement transfer coefficient and the reference displacement, including: Determine whether the reference displacement is greater than the displacement threshold. If so, use the compensation calculation formula to compensate for the measured displacement of each measuring point. If not, take the measured displacement of each measuring point as the corresponding real displacement. The compensation calculation formula is as follows: ； in, Indicates the first The true displacement of each measuring point Indicates the first The measured displacement of each measuring point Represents the reference displacement of the reference point. Indicates the first Displacement transfer coefficient at each measuring point; Determine the displacement transfer coefficient corresponding to each measuring point under experimental conditions, including: A test model corresponding to the surrounding rock of the underground cavern was constructed. Known displacements were applied to the corresponding measuring points on the test model. The reference displacements of the corresponding reference points on the test model were measured using self-locking anchors and a reference transfer rod, based on a borehole sensor. The measured displacements of the corresponding measuring points on the test model were then measured using measuring point anchors and a displacement transfer rod, based on a borehole sensor. The displacement transfer coefficients of the corresponding measuring points were calculated. ； in, Indicates the experimental model number 1 The measured displacement of each measuring point Indicates the experimental model number 1 The known displacement applied at each measuring point, This represents the reference displacement of the reference point corresponding to the test model.

2. The method for monitoring the displacement of surrounding rock in underground caverns based on self-locking compensation according to claim 1, characterized in that, The reference transmission rod and displacement transmission rod are made of carbon fiber.

3. The method for monitoring the displacement of surrounding rock in underground caverns based on self-locking compensation according to claim 1, characterized in that, The self-locking anchor is secured using a hydraulically driven wing plate, including: The hydraulic oil generated by the hydraulic pump is injected into the internal piston chamber of the self-locking anchor through the oil pipe. The hydraulic pressure drives the piston to move axially, converting the liquid pressure into radial extrusion force on the root of the flange. After being extruded, the root of the flange bends outward and undergoes plastic deformation. The barbs on the surface penetrate into the rock mass and forcibly interlock with the rock mass to form a mechanical interlock. The self-locking mechanism is used to maintain the prestress.

4. The method for monitoring the displacement of surrounding rock in underground caverns based on self-locking compensation according to claim 3, characterized in that, The wing plate surface is provided with tungsten steel particles to increase friction.

5. The method for monitoring the displacement of surrounding rock in underground caverns based on self-locking compensation according to claim 3, characterized in that, The method further includes: The anchoring pressure of the self-locking anchor is measured in real time using a pressure sensor. When the anchoring pressure is less than the pressure threshold, the hydraulic pump is activated to replenish the pressure until the anchoring pressure is equal to the initial anchoring pressure.

6. The method for monitoring the displacement of surrounding rock in underground caverns based on self-locking compensation according to claim 5, characterized in that, The initial anchoring pressure of the self-locking anchor is 8 MPa, and the pressure threshold is 7.5 MPa.

7. The method for monitoring the displacement of surrounding rock in underground caverns based on self-locking compensation according to claim 1, characterized in that, The method further includes: A fiber Bragg grating sensor is integrated into the self-locking anchor. Determine whether the reference displacement measured by the corresponding aperture sensor is within a preset range. If not, use the fiber Bragg grating sensor to measure the wavelength offset of the fiber grating and calculate the reference displacement of the reference point based on the wavelength offset.

8. A self-locking compensation-based underground cavern surrounding rock displacement monitoring system, characterized in that, For implementing the method for monitoring the displacement of surrounding rock in underground caverns based on self-locking compensation as described in any one of claims 1 to 7, the system comprises: After drilling and cleaning the surrounding rock of the underground cavern, self-locking anchors are inserted at the reference point at the bottom of the borehole. Measuring point anchors are implanted at multiple measuring points within the borehole; A wing plate that uses hydraulic drive to fix the self-locking anchor; A reference transmission rod connected to the self-locking anchor; Displacement transmission rods connected to the anchors at each measuring point; The orifice sensor is used to measure the reference displacement of the reference point corresponding to the reference transmission rod and the measured displacement of the measuring point corresponding to each displacement transmission rod. The controller is used to determine the displacement transfer coefficient corresponding to each measuring point under test conditions, and to compensate for the measured displacement of each measuring point based on the corresponding displacement transfer coefficient and the reference displacement, so as to obtain the true displacement of each measuring point.

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