Slope deep deformation monitoring device based on optical fiber strain measurement and use method

Abstract

The invention relates to the technical field of side slope detection, in particular to a side slope deep deformation monitoring device based on optical fiber strain measurement, which comprises a PVC (polyvinyl chloride) pipe, a plurality of groups of microgrooves are formed in the outer surface of the PVC pipe, tight-buffered optical fibers are embedded in each group of microgrooves, and a hot melt adhesive-based covering layer wraps the outside of the PVC pipe in a hot melt manner. The tight-buffered optical fiber is fixed by the hot melt adhesive-based covering layer, and a temperature measurement node is arranged at the end part of the tight-buffered optical fiber, so that the defects that the traditional optical fiber monitoring means are easily influenced by the environment, the burying efficiency is low and the monitoring precision is not high are overcome, and single horizontal displacement monitoring in the traditional monitoring means is expanded to three-dimensional displacement in the rock-soil body; the method has wide application in geological disaster monitoring.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of slope detection, in particular to a slope deep deformation monitoring device based on optical fiber strain measurement and a use method thereof. BACKGROUND

[0002] The core basis of slope engineering and geological disaster warning lies in accurately grasping the deformation behavior of rock-soil mass. The deep displacement monitoring of rock-soil mass can directly reflect the formation and development of potential slip surface and reveal the shear deformation accumulation process, which is one of the most sensitive indicators for slope instability warning. Continuous and high-resolution horizontal displacement field data are crucial for evaluating overall stability, predicting slip range and speed, and timely starting disaster prevention and mitigation measures. Therefore, realizing high-precision and automated horizontal displacement monitoring of multiple key monitoring drill holes is a key requirement for improving slope safety management level and disaster warning capability.

[0003] Currently, traditional point-type devices rely on manual operation and can only obtain low-resolution discrete point data in a single drill hole. Moreover, they cannot achieve simultaneous monitoring of horizontal and vertical displacement in multiple holes. The operation is time-consuming and inefficient, and it is difficult to meet real-time and high-frequency monitoring requirements. Although quasi-distributed fiber sensing can achieve certain online monitoring, its spatial resolution is limited by the number and density of gratings, making it difficult to form a continuous displacement curve at the millimeter level. Therefore, it cannot meet the demand for truly three-dimensional deformation automated collaborative monitoring of multiple holes. To solve the above technical problems, a slope deep deformation monitoring device based on optical fiber strain measurement and a use method thereof are provided. SUMMARY

[0004] To solve the technical problems in the prior art, the present application provides a slope deep deformation monitoring device based on optical fiber strain measurement and a use method thereof.

[0005] To solve the above technical problems, the present application provides the following technical scheme: a slope deep deformation monitoring device based on optical fiber strain measurement, comprising a PVC pipe, a plurality of groups of microgrooves are formed on the outer surface of the PVC pipe, a tight-fitting optical fiber is arranged in each group of microgrooves, a hot melt adhesive base covering layer is wrapped outside the PVC pipe to fix the tight-fitting optical fiber, and a temperature measurement node is arranged at the end of the tight-fitting optical fiber.

[0006] Preferably, the outer diameter and inner diameter of the PVC pipe are 70mm and 60mm respectively, at least four groups of microgrooves are formed on the outer surface of the PVC pipe, the four groups of microgrooves are arranged at equal intervals, and the microgrooves are formed on the surface of the PVC pipe by laser etching.

[0007] Preferably, the tight-fitting optical fiber comprises a fiber body, a strain isolation layer, a temperature conduction layer and a mechanical protection layer, the strain isolation layer is wrapped outside the fiber body, the temperature conduction layer is wrapped outside the strain isolation layer, and the mechanical protection layer is wrapped outside the temperature conduction layer.

[0008] Preferably, the tight-fitting optical fiber is pre-stretched when buried, and the pre-stretching length of the tight-fitting optical fiber is 30%-50% of the calibrated limit deformation length.

[0009] Preferably, the hot melt adhesive base covering layer is formed by winding the hot melt adhesive base preformed tape and then heating and hot melting, and the thickness of the hot melt adhesive base covering layer is 1.5 times the sum of the micro groove depth, the tight-fitting optical fiber diameter and 0.5 mm.

[0010] Preferably, the end of the tight-fitting optical fiber is reserved as a lead wire for 0.5 m, and the temperature measuring node is connected in the end lead wire part of the tight-fitting optical fiber 2.

[0011] A use method of a slope deep deformation monitoring device based on optical fiber strain measurement, comprising the following steps:

[0012] Step S1, manufacturing a slope deep deformation monitoring device;

[0013] Step S2, arranging the slope deep deformation monitoring device based on optical fiber strain measurement on the slope to be detected, and connecting the slope deep deformation monitoring devices based on optical fiber strain measurement to form a monitoring system;

[0014] Step S3, acquiring monitoring data through the monitoring system and processing the data.

[0015] Preferably, the step S1 comprises,

[0016] Step S11, preparing a PVC pipe with an outer diameter of 70 mm and an inner diameter of 60 mm, and opening four groups of micro grooves with the same spacing on the surface of the PVC pipe by laser etching;

[0017] Step S12, burying a tight-fitting optical fiber in each group of micro grooves, leaving 0.5 m as a lead wire at both ends of the tight-fitting optical fiber, and pre-tensioning the tight-fitting optical fiber;

[0018] Step S13, winding a hot melt adhesive base preformed tape on the outer surface of the PVC pipe, and heating the hot melt adhesive base preformed tape through a heating mold to make the hot melt adhesive base preformed tape melt and fill into the gap between the micro groove and the tight-fitting optical fiber;

[0019] Step S14, after the hot melt adhesive base preformed tape completely melts to form a hot melt adhesive base covering layer, keeping warm for five minutes, and after the keeping warm is completed, removing the mold to make the hot melt adhesive base covering layer naturally cool to room temperature;

[0020] Step S15, the apparent detection is carried out to the hot melt adhesive base covering layer, the continuous non-breakpoint, no bubble and the edge and the base pipe transition smooth of the hot melt adhesive base covering layer are ensured, and the performance detection is carried out to the tight sleeve optical fiber, and the OTDR test loss increment is ensured ≤0.1 dB / km.

[0021] Preferably, the step S2 comprises:

[0022] Step S21, the deformation observation hole opening position is planned in the slope to be monitored, and the deformation observation hole comprises a horizontal observation hole for monitoring horizontal deformation and a vertical observation hole for observing vertical deformation;

[0023] Step S22, the slope deep deformation monitoring device based on optical fiber strain measurement is placed into the horizontal observation hole and the vertical observation hole, the adjacent PVC pipes in the slope deep deformation monitoring device based on optical fiber strain measurement are connected through threads or rivets, the tight sleeve optical fiber is fused by a fusion machine, and the temperature measuring node and part of the tight sleeve optical fiber are exposed outside the PVC pipe when the adjacent PVC pipes are connected;

[0024] Step S23, after the combination of the slope deep deformation monitoring device based on optical fiber strain measurement is installed, the concrete is poured into the observation hole, the concrete reinforces and fixes the bottom of the combined slope deep deformation monitoring device based on optical fiber strain measurement, and the concrete reinforced area is used as a calculation boundary condition;

[0025] Step S24, the lead wires of all the set combination of the slope deep deformation monitoring device based on optical fiber strain measurement are connected in series through the series lead wires, and the series lead wires are electrically connected with the external monitoring terminal to form a monitoring system.

[0026] Preferably, the step S3 comprises:

[0027] Step S31, the external monitoring terminal injects pulse light into each slope deep deformation monitoring device based on optical fiber strain measurement in series through the series lead wires according to a preset monitoring frequency, and strain information and temperature information are acquired respectively;

[0028] Step S32, the strain monitoring spatial resolution is set as R1m, the temperature spatial resolution is set as R2, and the spatial resolutions of temperature and strain are unified;

[0029] The temperature data is subjected to cubic spline interpolation, the temperature spatial resolution is increased to R1, the temperature change information corresponding to each strain node is acquired, and the strain change is corrected by using the temperature change;

[0030] Brillouin frequency shift Simultaneously subjected to temperature change And strain change The temperature change between the two monitoring values is obtained, the temperature influence on the Brillouin frequency shift is removed, and the strain change of the optical fiber is obtained as follows:

[0031] ;

[0032] In the formula, is the Brillouin frequency shift amount, is the temperature change between the two monitoring values, is the strain change between the two monitoring values, is a strain frequency shift influence coefficient, representing that a frequency shift change is caused by 1με of strain change, is a temperature frequency shift influence coefficient, representing that a frequency shift change is caused by 1℃ of change;

[0033] In step S33, the displacement of the soil body in any direction inside the inclinometer tube is calculated according to the strain of the optical fiber inside the inclinometer tube.

[0034] According to the axial strain of the inclinometer tube, the deflection calculation formula of the ac direction and the bd direction of the inclinometer tube is established as follows:

[0035] ;

[0036] In the formula, is the deflection of the ac direction or the bd direction at a distance Z from the bottom of the hole, is the strain of the a optical fiber or the b optical fiber in the inclinometer tube at a distance Z from the bottom of the hole, is the strain of the c optical fiber or the d optical fiber in the inclinometer tube at a distance Z from the bottom of the hole, r is the radius of the inclinometer tube, and C and D are coefficients determined by boundary conditions, and C and D can be taken as 0 according to the boundary conditions because the bottom is not deformed;

[0037] At this time, according to the calculation method of discrete values, assuming that the length of the inclinometer tube is L and the spatial resolution of the optical fiber is R1, there are N=L / R1 measurement nodes on the inclinometer tube, and the deflection deformation value of the kth measurement node is:

[0038] ;

[0039] ;

[0040] wherein k∈(0, N) and i∈(0, k), is the first derivative of the deflection of the ac or bd direction at the kth node, is the deflection of the ac or bd direction at the kth node, is the strain of the a optical fiber or the b optical fiber in the inclinometer tube from the i th node at the bottom of the hole, is the strain of the c optical fiber or the d optical fiber in the inclinometer tube from the i th node at the bottom of the hole;

[0041] By calculating the vertical deflection of vertically and horizontally deployed inclinometer tubes, three-dimensional displacement monitoring in any direction within the soil mass is achieved.

[0042] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0043] 1. This invention overcomes the limitations of traditional fiber optic monitoring methods, such as susceptibility to environmental influences, low installation efficiency, and low monitoring accuracy. It also extends the traditional single horizontal displacement monitoring to three-dimensional displacement within the rock and soil body, making it widely applicable in geological disaster monitoring. Attached Figure Description

[0044] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0045] Figure 2 This is a schematic diagram of the tight-buffered optical fiber layout of the present invention;

[0046] Figure 3 This is a partial three-dimensional structural diagram of the present invention;

[0047] Figure 4 This is a schematic diagram of the three-dimensional structure of the tight-buffered optical fiber of the present invention;

[0048] Figure 5 This is a schematic diagram of the present invention.

[0049] The numbers in the diagram represent:

[0050] 1. PVC pipe; 11. Microgroove; 2. Tight-buffered optical fiber; 21. Optical fiber body; 22. Strain isolation layer; 23. Temperature conduction layer; 24. Mechanical protection layer; 3. Hot melt adhesive base covering layer; 4. Temperature measurement node. Detailed Implementation

[0051] The present invention will be further described below with reference to the accompanying drawings and embodiments, which illustrate the above and other technical features and advantages of the present invention. However, the following embodiments are merely preferred embodiments of the present invention and are not exhaustive.

[0052] Example:

[0053] like Figures 1-5 As shown, the present invention provides a slope deep deformation monitoring device based on fiber optic strain measurement, including a PVC pipe 1 with an outer diameter of 70 mm and an inner diameter of 60 mm. At least four sets of microgrooves 11 are formed on the outer surface of the PVC pipe 1. The four sets of microgrooves 11 are arranged at equal intervals. The microgrooves 11 are formed on the surface of the PVC pipe 1 by laser etching. The laser etching method can avoid the microgrooves 11 from bending and causing fiber microbending loss.

[0054] The tight-fitting optical fiber 2 is embedded in each group of micro grooves 11, and the tight-fitting optical fiber 2 includes a fiber body 21, a strain isolation layer 22, a temperature conduction layer 23 and a mechanical protection layer 24, the strain isolation layer 22 is wrapped outside the fiber body 21, the temperature conduction layer 23 is wrapped outside the strain isolation layer 22, and the mechanical protection layer 24 is wrapped outside the temperature conduction layer 23;

[0055] The tight-fitting optical fiber 2 is pre-stretched when embedded, and the pre-stretching length of the tight-fitting optical fiber 2 is 30-50% of the calibrated limit deformation length.

[0056] The PVC pipe 1 is externally hot-melt wrapped with a hot-melt adhesive base covering layer 3, the hot-melt adhesive base covering layer 3 is formed by winding a hot-melt adhesive base preformed tape and then heated to be hot-melted, the thickness of the hot-melt adhesive base covering layer 3 is 1.5 times the sum of the groove depth of the micro groove 11 and the diameter of the tight-fitting optical fiber 2 plus 0.5 mm, and the hot-melt adhesive base covering layer 3 fixes the tight-fitting optical fiber 2.

[0057] The end of the tight-fitting optical fiber 2 is provided with a temperature measuring node 4, and 0.5 m of the end of the tight-fitting optical fiber 2 is reserved as a lead wire, and the temperature measuring node 4 is connected to the lead wire part of the end of the tight-fitting optical fiber 2.

[0058] The use method of the slope deep deformation monitoring device based on fiber strain measurement comprises the following steps:

[0059] Step S1, manufacturing the slope deep deformation monitoring device;

[0060] Step S11, preparing a PVC pipe 1 with an outer diameter of 70 mm and an inner diameter of 60 mm, and opening four groups of micro grooves 11 with the same spacing on the surface of the PVC pipe 1 by laser etching;

[0061] Step S12, embedding the tight-fitting optical fiber 2 in each group of micro grooves 11, leaving 0.5 m at both ends of the tight-fitting optical fiber 2 as lead wires, and pre-tensioning the tight-fitting optical fiber 2;

[0062] Step S13, winding a hot-melt adhesive base preformed tape on the outer surface of the PVC pipe 1, and heating the hot-melt adhesive base preformed tape by a heating mold to make the hot-melt adhesive base preformed tape melt and fill into the gap between the micro groove 11 and the tight-fitting optical fiber 2;

[0063] Step S14, after the hot-melt adhesive base preformed tape is completely melted to form the hot-melt adhesive base covering layer 3, keeping warm for five minutes, and after the keeping warm is completed, removing the mold to make the hot-melt adhesive base covering layer 3 naturally cool to room temperature;

[0064] Step S15, performing apparent detection on the hot-melt adhesive base covering layer 3 to ensure that the hot-melt adhesive base covering layer 3 is continuous without breakpoints, without bubbles and with smooth edges and base pipe transitions, and performing performance detection on the tight-fitting optical fiber 2 to ensure that the OTDR test loss increment is less than or equal to 0.1 dB / km.

[0065] Step S2, a slope deep deformation monitoring device based on fiber strain measurement is arranged in the slope to be monitored, and the slope deep deformation monitoring devices based on fiber strain measurement are connected in series to form a monitoring system;

[0066] Step S21, a deformation observation hole opening position is planned in the slope to be monitored, and the hole is opened according to the position. The deformation observation hole includes a horizontal observation hole for monitoring horizontal deformation and a vertical observation hole for observing vertical deformation;

[0067] Step S22, the combined slope deep deformation monitoring device based on fiber strain measurement is placed into the horizontal observation hole and the vertical observation hole. The PVC pipe 1 in the adjacent slope deep deformation monitoring device based on fiber strain measurement is connected through threads or rivets. The tight sleeve fiber 2 is fused by a fusion machine. When the adjacent PVC pipe 1 is connected, the temperature measuring node 4 and part of the tight sleeve fiber 2 are exposed outside the PVC pipe 1;

[0068] Step S23, after the combined slope deep deformation monitoring device based on fiber strain measurement is installed, the observation hole is poured with concrete. The concrete reinforces and fixes the bottom of the combined slope deep deformation monitoring device based on fiber strain measurement. The concrete reinforced area is used as a calculation boundary condition;

[0069] Step S24, the leads of all the set combined slope deep deformation monitoring devices based on fiber strain measurement are connected in series through a series lead. The series lead is electrically connected with an external monitoring terminal to form a monitoring system;

[0070] Step S3, the monitoring data is acquired through the monitoring system, and the data is processed;

[0071] Step S31, the external monitoring terminal injects pulse light into each slope deep deformation monitoring device based on fiber strain measurement in turn through the series lead according to a preset monitoring frequency, and acquires strain information and temperature information respectively;

[0072] Step S32, the strain monitoring spatial resolution is set as R1m, and the temperature spatial resolution is set as R2. The spatial resolutions of temperature and strain are unified;

[0073] The temperature data is subjected to cubic spline interpolation, the temperature spatial resolution is increased to R1, the temperature change information corresponding to each strain node is acquired, and the strain change is corrected by using the temperature change;

[0074] Brillouin frequency shift affected by the temperature change and the strain change The temperature change between the two monitoring values is acquired, the Brillouin frequency shift affected by the temperature is removed, and the strain change of the fiber is acquired is:

[0075]

[0076] In the formula, is the Brillouin frequency shift amount, is the temperature change amount between two monitoring, is the strain change amount between two monitoring, is the strain frequency shift influence coefficient, indicating that each 1με strain change causes the frequency shift change, is the temperature frequency shift influence coefficient, indicating that each 1℃ change causes the frequency shift change;

[0077] Step S33, according to the strain of the inclinometer inside the optical fiber, the displacement of the soil body in any direction is calculated;

[0078] According to the axial strain of the inclinometer, the deflection calculation formula of the ac direction and bd direction of the inclinometer is established:

[0079]

[0080] In the formula is the deflection of the ac direction or bd direction at the distance Z from the bottom of the hole, is the strain of the a optical fiber or b optical fiber in the inclinometer at the distance Z from the bottom of the hole, is the strain of the c optical fiber or d optical fiber in the inclinometer at the distance Z from the bottom of the hole, r is the radius of the inclinometer, C and D are coefficients determined by the boundary conditions Since the bottom has no deformation, according to the boundary conditions, C and D can be taken as 0;

[0081] At this time, according to the calculation method of discrete values, assuming that the length of the inclinometer is L and the spatial resolution of the optical fiber is R1, there are N=L / R1 measurement nodes on the inclinometer, and the deflection deformation value of the kth measurement node is:

[0082]

[0083]

[0084] Wherein, k∈(0, N), i∈(0, k), is the first derivative of the deflection of the ac or bd direction at the kth node, is the deflection of the ac or bd direction at the kth node, is the strain of the a optical fiber or b optical fiber in the inclinometer from the bottom of the hole at the ith node, is the strain of the c optical fiber or d optical fiber in the inclinometer from the bottom of the hole at the ith node;

[0085] ​​​​The vertical direction deflection of the vertical and horizontal inclinometer pipes is solved, and the three-dimensional displacement monitoring in any direction in the soil body is solved.

[0086] The above description is only the preferred embodiment of the present application, which is only illustrative but not restrictive. Those skilled in the art understand that many changes, modifications and even equivalents can be made to the present application within the spirit and scope defined by the claims of the present application, but all will fall within the protection scope of the present application.

Claims

1. A slope deep deformation monitoring device based on fiber optic strain measurement, characterized in that, The PVC pipe (1) has several sets of microgrooves (11) on its outer surface. Each set of microgrooves (11) contains a tight-buffered optical fiber (2). The PVC pipe (1) is wrapped with a hot melt adhesive base covering layer (3) which fixes the tight-buffered optical fiber (2). A temperature measuring node (4) is provided at the end of the tight-buffered optical fiber (2).

2. The slope deep deformation monitoring device based on fiber optic strain measurement as described in claim 1, characterized in that, The outer diameter and inner diameter of the PVC pipe (1) are 70mm and 60mm respectively. At least four sets of microgrooves (11) are opened on the outer surface of the PVC pipe. The four sets of microgrooves (11) are arranged at equal intervals. The microgrooves (11) are opened on the surface of the PVC pipe (1) by laser etching.

3. The slope deep deformation monitoring device based on fiber optic strain measurement as described in claim 2, characterized in that, The tight-buffered optical fiber (2) includes an optical fiber body (21), a strain isolation layer (22), a temperature conduction layer (23), and a mechanical protection layer (24). The strain isolation layer (22) is wrapped around the outside of the optical fiber body (21), the temperature conduction layer (23) is wrapped around the outside of the strain isolation layer (22), and the mechanical protection layer (24) is wrapped around the outside of the temperature conduction layer (23).

4. The slope deep deformation monitoring device based on fiber optic strain measurement as described in claim 2, characterized in that, The tight-buffered optical fiber (2) is pre-stretched during installation, and the pre-stretch length of the tight-buffered optical fiber (2) is 30%-50% of the calibrated limit deformation length.

5. The slope deep deformation monitoring device based on fiber optic strain measurement as described in claim 4, characterized in that, The hot melt adhesive base cover layer (3) is formed by heating and melting the hot melt adhesive base preformed tape after winding. The thickness of the hot melt adhesive base cover layer (3) is 1.5 times the sum of the groove depth of the microgroove (11) and the diameter of the tight-buffered optical fiber (2) plus 0.5 mm.

6. The slope deep deformation monitoring device based on fiber optic strain measurement as described in claim 5, characterized in that, The end of the tight-buffered optical fiber (2) is reserved with a 0.5m lead wire, and the temperature measuring node (4) is connected to the end lead wire portion of the tight-buffered optical fiber (2).

7. A method of using the fiber optic strain measurement-based deep slope deformation monitoring device according to any one of claims 1-6, characterized in that, Includes the following steps: Step S1: Fabricate a deep slope deformation monitoring device; Step S2: Deploy a deep deformation monitoring device based on fiber optic strain measurement on the slope to be inspected, and connect the deep deformation monitoring devices based on fiber optic strain measurement in series to form a monitoring system. Step S3: Acquire monitoring data and process the data through the monitoring system.

8. The slope deep deformation monitoring device based on fiber optic strain measurement as described in claim 7, characterized in that, Step S1 includes, Step S11: Prepare a PVC pipe (1) with an outer diameter of 70 mm and an inner diameter of 60 mm. Create four sets of microgrooves (11) with the same spacing on the surface of the PVC pipe (1) by laser etching. Step S12: Bury tight-fitting optical fiber (2) inside each microgroove (11), leaving 0.5m at both ends of the tight-fitting optical fiber (2) as lead wires, and pre-tighten the tight-fitting optical fiber (2); Step S13: Wrap a hot melt adhesive-based preformed tape around the outer surface of the PVC pipe (1), and heat the hot melt adhesive-based preformed tape with a heating mold to melt the hot melt adhesive-based preformed tape and fill it into the gap between the microgroove (11) and the tight-fitting optical fiber (2). Step S14: After the hot melt adhesive base preformed strip is completely melted to form the hot melt adhesive base covering layer (3), keep it warm for five minutes. After the warming is completed, remove the mold and let the hot melt adhesive base covering layer (3) cool naturally to room temperature. Step S15: Perform appearance inspection on the hot melt adhesive base coating layer (3) to ensure that the hot melt adhesive base coating layer (3) is continuous without breaks, without bubbles, and that the edges transition smoothly with the base tube. Perform performance inspection on the tight-buffered optical fiber (2) to ensure that the OTDR test loss increment is ≤0.1dB / km.

9. A slope deep deformation monitoring device based on fiber optic strain measurement as described in claim 7, characterized in that, Step S2 includes: Step S21: Plan the location of deformation observation holes within the slope to be monitored. The deformation observation holes include horizontal observation holes for monitoring horizontal deformation and vertical observation holes for monitoring vertical deformation. Step S22: The slope deep deformation monitoring device based on fiber optic strain measurement is placed into the horizontal observation hole and the vertical observation hole. The PVC pipes (1) in the adjacent slope deep deformation monitoring devices based on fiber optic strain measurement are connected by threads or rivets. The tight-fitting optical fibers (2) are fused together by a fusion splicer. When connecting adjacent PVC pipes (1), the temperature measuring node (4) and part of the tight-fitting optical fiber (2) are exposed outside the PVC pipe (1). Step S23: After the combined fiber optic strain measurement-based deep slope deformation monitoring device is installed, concrete is poured into the observation hole. The concrete reinforces and fixes the bottom of the combined fiber optic strain measurement-based deep slope deformation monitoring device, and the reinforced area is used as the calculation boundary condition. Step S24: Connect all the pre-set combined slope deep deformation monitoring devices based on fiber optic strain measurement in series using fiber optic leads, and electrically connect the series leads to external monitoring equipment to form a monitoring system.

10. A slope deep deformation monitoring device based on fiber optic strain measurement as described in claim 7, characterized in that, Step S3 includes: Step S31: The external monitoring terminal injects pulse light into each of the deep slope deformation monitoring devices based on fiber optic strain measurement through a series lead wire according to the preset monitoring frequency, and obtains strain information and temperature information respectively. Step S32: Set the spatial resolution of strain monitoring to R1m and the spatial resolution of temperature to R2 to unify the spatial resolution of temperature and strain. Cubic spline interpolation is performed on the temperature data to improve the temperature spatial resolution to R1, obtain the temperature change information corresponding to each strain node, and use the temperature change to correct the strain change. Brillouin Shift Simultaneously affected by temperature changes and strain change The influence of temperature was assessed by obtaining the temperature change between two monitoring values, removing the Brillouin frequency shift, and then obtaining the strain change of the optical fiber. ； In the formula, For Brillouin frequency shift, This represents the temperature change between two monitoring sessions. This represents the change in strain between the two monitoring sessions. The strain frequency shift influence coefficient represents the frequency shift caused by each 1 με strain change. The temperature frequency shift influence coefficient represents the frequency shift caused by a change of 1°C. Step S33: Calculate the displacement in any direction inside the soil based on the strain of the optical fiber inside the inclinometer tube; Based on the axial strain of the inclinometer tube, the following formulas are established for calculating the deflection of the inclinometer tube in the ac and bd directions: ； In the formula Let Z be the deflection in the ac or bd direction at a distance Z from the bottom of the hole. Let Z be the strain of fiber a or fiber b in the inclinometer tube at a distance Z from the bottom of the borehole. The strain of fiber c or fiber d in the inclinometer tube at a distance Z from the bottom of the hole, r is the radius of the inclinometer tube, and C and D are coefficients determined by the boundary conditions. Since there is no deformation at the bottom, C and D can both be taken as 0 according to the boundary conditions. Following the discrete value calculation method, assuming the inclinometer tube length is L and the fiber spatial resolution is R1, then there are N = L / R1 measurement nodes on the inclinometer tube. The deflection deformation value of the k-th measurement node is then: ； ； Where, k∈(0,N), i∈(0,k). Let be the first derivative of the deflection in the ac or bd direction at the k-th node. Let be the deflection in the ac or bd direction at the k-th node. To measure the strain of either fiber a or fiber b in the inclined tube from the i-th node at the bottom of the borehole, To measure the strain of either fiber c or fiber d in the inclined tube from the i-th node at the bottom of the borehole; By calculating the vertical deflection of vertically and horizontally deployed inclinometer tubes, three-dimensional displacement monitoring in any direction within the soil mass is achieved.

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