Water-blocking curtain wall stability monitoring system based on FBG sensing technology

Abstract

The invention relates to a waterproof curtain wall stability monitoring system based on an FBG sensing technology, and the system comprises a project management module which is used for selecting a position in a to-be-monitored curtain wall and arranging an FBG sensor; the data acquisition module is used for acquiring real-time internal parameters of a to-be-monitored curtain wall through an FBG sensor; the risk early warning module is used for carrying out risk early warning based on the real-time internal parameters and generating an early warning record; and the data storage module is used for storing the real-time internal parameters and the early warning records to form a data report. According to the invention, a plurality of FBG sensors are arranged in the waterproof curtain wall, so that real-time monitoring of parameters such as displacement, strain and osmotic pressure in the waterproof curtain wall is realized.

Description

Technical Field

[0001] The invention relates to the technical field of water-blocking curtain wall stability monitoring, and in particular to a water-blocking curtain wall stability monitoring system based on FBG sensing technology. Background Art

[0002] With the continuous exploration of water blocking and drainage in large water mines by relevant scholars at home and abroad, it is found that the use of grouting water-stopping technology for curtain grouting water-stopping can achieve good results. Curtain grouting has become one of the main means of groundwater prevention and control in mines at home and abroad. It mainly uses grouting technology to block the water-conducting channels around the mining area to form a water-blocking curtain wall to achieve the purpose of reducing the amount of water inflow underground. It has been applied in many large water mines and has achieved good water blocking effects. However, with the influence of factors such as underground mining and old empty water erosion, the continuous stability monitoring of the water blocking effect of curtain grouting engineering is particularly important. The general monitoring method mainly revolves around the mechanical stability of the water-blocking curtain wall, including field measurement of deformation and stress state, numerical simulation technology and microseismic monitoring technology. At the same time, due to the particularity of the water-blocking curtain in the mining area, hydrological observation holes can also be arranged around the water-blocking curtain wall. By analyzing the changing laws of water level and water temperature, the purpose of monitoring the stability of the water-blocking curtain wall can be indirectly achieved. However, the current research on the stability monitoring technology of the water-blocking curtain wall rarely considers the seepage stability of the curtain wall. Therefore, a water-blocking curtain wall stability monitoring system based on FBG sensing technology is provided. Summary of the invention

[0003] The purpose of the present invention is to provide a water-blocking curtain wall stability monitoring system based on FBG sensing technology, which realizes real-time monitoring of parameters such as displacement, strain and osmotic pressure inside the water-blocking curtain wall by arranging multiple FBG sensors inside the water-blocking curtain wall.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] The water-blocking curtain wall stability monitoring system based on FBG sensing technology includes:

[0006] Project management module, data collection module, risk warning module, data storage module;

[0007] The project management module is used to select locations in the curtain wall to be monitored and to deploy FBG sensors;

[0008] The data acquisition module is used to collect the real-time internal parameters of the curtain wall to be monitored through the FBG sensor;

[0009] The risk warning module is used to issue risk warnings based on the real-time internal parameters and generate warning records;

[0010] The data storage module is used to store the real-time internal parameters and the warning records to form data reports.

[0011] Optionally, the project management module includes: an information acquisition unit and a location layout unit;

[0012] The information acquisition unit is used to acquire the structural information of the curtain wall to be monitored, and analyze the danger zone according to the structural information;

[0013] The position layout unit is used to select a layout position in the danger zone and drill holes to install the FBG sensor.

[0014] Optionally, the FBG sensor includes: a single-point fiber Bragg grating piezometer, a fiber Bragg grating embedded strain gauge, a fiber Bragg grating cable strain gauge, and a fiber Bragg grating thermometer.

[0015] Optionally, the data acquisition module includes: a data acquisition unit and a data processing unit;

[0016] The data acquisition unit is used to obtain real-time data of the FBG sensor;

[0017] The data processing unit is used to convert the real-time data of the FBG sensor to obtain the seepage pressure, deformation and temperature information in the drilled hole of the curtain wall to be monitored.

[0018] Optionally, a fiber grating demodulator is used to convert the real-time data of the FBG sensor, and the fiber grating demodulator is used to measure the output wavelength of the FBG sensor and convert the output wavelength into the seepage pressure, deformation and temperature information in the curtain wall borehole to be monitored.

[0019] Optionally, the risk warning module includes: a threshold setting unit and a risk warning unit;

[0020] The threshold setting unit is used to set a change threshold for each monitored internal parameter;

[0021] The risk warning unit is used to issue a warning when the change amount of the real-time internal parameter exceeds the change threshold and generate a warning record.

[0022] Optionally, the data storage module includes: a data storage unit and a data query unit;

[0023] The data storage unit is used to store the real-time internal parameters of the curtain wall to be monitored as a change curve according to the time sequence, and mark the warning record on the change curve;

[0024] The data query unit is used to query and derive the change curve.

[0025] Optionally, the system also includes a data API interface for data transmission between the project management module, data acquisition module, risk warning module, and data storage module.

[0026] The beneficial effects of the present invention are:

[0027] The present invention arranges multiple FBG sensors inside the water-blocking curtain wall to achieve real-time monitoring of parameters such as displacement, strain and osmotic pressure inside the water-blocking curtain wall, providing monitoring data support for subsequent early warning analysis of the instability risk of the water-blocking curtain wall, and being able to perform all-round and accurate monitoring of the stability of the water-blocking curtain wall to ensure safe production in mines. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 It is a schematic structural diagram of a water-blocking curtain wall stability monitoring system based on FBG sensing technology according to an embodiment of the present invention;

[0030] Figure 2 This is a graph of monitoring the internal permeability of a wall according to an embodiment of the present invention;

[0031] Figure 3 This is a curve diagram of the internal strain monitoring of a wall according to an embodiment of the present invention;

[0032] Figure 4 This is a curve diagram of cumulative displacement monitoring inside a wall according to an embodiment of the present invention;

[0033] Figure 5 This is a wall internal temperature monitoring curve diagram according to an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] This embodiment provides a water-blocking curtain wall stability monitoring system based on FBG sensing technology, such as Figure 1 As shown, it includes: project management module, data acquisition module, risk warning module, and data storage module;

[0037] Project management module, used to select locations in the curtain wall to be monitored and to deploy FBG sensors;

[0038] A data acquisition module, used to collect real-time internal parameters of the curtain wall to be monitored through FBG sensors;

[0039] The risk warning module is used to issue risk warnings based on real-time internal parameters and generate warning records;

[0040] The data storage module is used to store real-time internal parameters and warning records to form data reports.

[0041] Furthermore, the project management module includes: an information acquisition unit, a location layout unit;

[0042] An information acquisition unit, used to acquire structural information of the curtain wall and analyze the danger zone based on the structural information;

[0043] The location layout unit is used to select the layout location in the danger zone and drill holes to install the FBG sensor.

[0044] Specifically, the principle of FBG sensor: changes in temperature or strain will cause axial deformation of the optical fiber, thereby increasing the period of the grating, reducing the radius of the core and cladding, and indirectly causing changes in the refractive index of the optical fiber and the wavelength of the grating. Both strain and temperature are related to the central wavelength λ B There is a good linear relationship and they are independent of each other. B The drift amount can be obtained as the deformation or temperature change of the optical fiber. Assuming that the core refractive index is n ef , period Λ, then:

[0045] λ B =2n eff Λ

[0046] Δλ B =α ε ε+α T ΔT

[0047] In the formula, α ε is the fiber Bragg grating strain sensitivity coefficient, α T is the temperature sensitivity coefficient of the fiber Bragg grating, ΔT is the temperature change value, and ε is the strain.

[0048] FBG sensors can measure micro-deformations of materials and can be connected to elastic components to make various sensors such as pressure, displacement and strain for monitoring various types of variables.

[0049] In this embodiment, several boreholes are drilled at appropriate locations in the danger zone, and FBG sensors are installed in each borehole. The FBG sensors include: single-point fiber Bragg grating piezometer, fiber Bragg grating embedded strain gauge, fiber Bragg grating cable strain gauge, and fiber Bragg grating thermometer.

[0050] The sensor is installed by lowering the sensor to the specified position with a counterweight guide head, and a 7mm plastic-sealed armored communication optical cable is used as the loop. The layer where the single-point fiber grating piezometer is located is backfilled with medium-coarse sand, and the remaining hole layers are grouting backfilled and sealed by returning the slurry to the bottom of the hole with plain cement.

[0051] Furthermore, the data acquisition module includes: a data acquisition unit and a data processing unit;

[0052] A data acquisition unit, used to obtain real-time data from the FBG sensor;

[0053] The data processing unit is used to convert the real-time data of the FBG sensor and obtain the seepage pressure, deformation and temperature information in the curtain wall drilling hole.

[0054] Specifically, the FBG sensor is connected to the fiber Bragg grating demodulator. In this embodiment, the fiber Bragg grating demodulator measurement sensor adopts the NZS-FBG-A02 wireless fiber Bragg grating demodulator, which is used to measure the output wavelength of the single-point fiber Bragg grating piezometer, the fiber Bragg grating embedded strain gauge, the fiber Bragg grating cable strain gauge and the fiber Bragg grating thermometer, and convert it into the seepage pressure, deformation and temperature information in the curtain wall borehole.

[0055] Using fiber Bragg grating as a micro-force measuring element, the fiber Bragg grating embedded strain gauge is installed in the structure to be measured, so that the sensor structure and the structure to be measured produce strain coupling. Based on the FBG sensor principle, the output wavelength of the sensor is measured using a fiber Bragg grating demodulator, and the strain change and stress change of the structure to be measured can be obtained by conversion.

[0056] The single-point fiber Bragg grating piezometer is mainly suitable for measuring liquid pressure such as underground pore water pressure, oil and gas pressure, and tunnel seepage pressure. The product has the characteristics of small size, serial measurement, multiple burials in one hole, corrosion resistance, and good long-term stability. The sensor has its own temperature sensing element and has the function of temperature self-compensation.

[0057] The fiber grating thermometer uses the fiber grating as a micro temperature measuring element, and synchronously senses the temperature of the environment in which the sensor is located through the fiber grating. The output wavelength of the sensor is measured by the fiber grating demodulator, and the temperature change of the environment can be obtained by conversion.

[0058] Further, the risk warning module includes: a threshold setting unit and a risk warning unit;

[0059] A threshold setting unit, used to set a change threshold for each monitored internal parameter;

[0060] The risk warning unit is used to issue a warning when the change in real-time internal parameters exceeds the change threshold and generate a warning record.

[0061] Further, the data storage module includes: a data storage unit and a data query unit;

[0062] A data storage unit, used to store the real-time internal parameters of the monitored curtain wall as a change curve according to the time sequence, and mark the warning record on the change curve;

[0063] The data query unit is used to query and export the change curve.

[0064] To further optimize the technical solution, the water-blocking curtain wall stability monitoring system based on FBG sensing technology proposed in this embodiment also includes a data API interface for data transmission between the project management module, data acquisition module, risk warning module, and data storage module.

[0065] The following is a functional verification of the system proposed in this embodiment in conjunction with a specific example:

[0066] Xinjiang Liuhuanggou Coal Mine is located in the mining area in northwest my country. The old and abandoned goaf areas in the shallow part of the coal seam are widely distributed. They are of different sizes and shapes and are located at shallow depths. The eastern part of the mine field is Toutun River, which belongs to the regional surface water system and flows from southwest to northeast. Some of the old goaf areas have a certain recharge relationship with the Toutun River on the surface. If the ground collapses in the old goaf areas, a recharge channel will be formed with the Toutun River, and the water inflow in the old goaf areas will increase, which will increase the risk of water inrush in the mining area.

[0067] In response to the above-mentioned water inrush risks, Liuhuanggou Coal Mine implemented the Touhun River riverbed ground curtain grouting old goaf water hazard control project in 2019, and carried out grouting and blocking treatment on the key water conducting channels discovered, forming an underground water-blocking curtain wall with an average thickness of 6m on the east side of the mining area, which cut off the hydraulic connection between the underground mining area and the goaf on the east side, and sharply reduced the water inrush from the old goaf of the mine to about 10m3 / h. After three hydrological years (2019-2021), the water inrush was not affected during the rainy season.

[0068] However, three years after the completion of the water-blocking curtain wall, in July 2021, the underground water inflow in the Liuhuanggou Coal Mine increased abnormally, and stabilized to 23m3 / h after a certain period of time. It is speculated that this is related to the fluctuation of the stability of the water-blocking curtain wall. Through the analysis of the structural characteristics of the old empty areas, water conduits and water-blocking curtain walls in the Liuhuanggou Coal Mine and its surrounding areas, holes (JC-2, JC-3, and JC-4 holes) were set in the wall to install single-point fiber Bragg piezometers, fiber Bragg embedded strain gauges, fiber Bragg cable strain gauges, and fiber Bragg thermometers in dangerous areas where the curtain wall may be deformed or leaked.

[0069] Real-time monitoring data such as Figure 2-Figure 5 As shown in the figure, the changes of various monitoring indicators are summarized as follows:

[0070] ① The internal osmotic pressure of the water-blocking curtain wall gradually tends to equilibrium with the increase of time, and the overall change is not large, varying between 0.10MPa and 0.30MPa, and no obvious abnormality is observed.

[0071] ② The strain in the monitored borehole gradually increases in the range of 50 to 450 με, which is consistent with the general characteristics of stratum settlement after grouting. The strain growth amplitude is very weak, and the maximum increase does not exceed 200 με.

[0072] ③The internal displacement of the grouting curtain wall changes periodically, and the overall change is not large, ranging from -0.08mm to 0.06mm.

[0073] ④ There is no obvious fluctuation in the internal osmotic pressure of the water-blocking curtain wall as a whole, and the temperature of each monitoring point gradually decreases with the burial depth.

[0074] In summary, combined with the underground water inflow data (stable at 23m 3 / h), it can be seen that the overall structure of the existing water-blocking curtain wall was in a temporary equilibrium state from the occurrence of leakage to June 11, 2024, and all monitoring indicators fluctuated within a stable range.

[0075] The embodiments described above are only descriptions of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. The water-blocking curtain wall stability monitoring system based on FBG sensing technology is characterized by: include: Project management module, data collection module, risk warning module, data storage module; The project management module is used to select locations in the curtain wall to be monitored and to deploy FBG sensors; The data acquisition module is used to collect the real-time internal parameters of the curtain wall to be monitored through the FBG sensor; The risk warning module is used to perform risk warning based on the real-time internal parameters and generate warning records; The data storage module is used to store the real-time internal parameters and the warning records to form data reports.

2. The water-blocking curtain wall stability monitoring system based on FBG sensing technology according to claim 1 is characterized in that: The project management module includes: an information acquisition unit and a location layout unit; The information acquisition unit is used to acquire the structural information of the curtain wall to be monitored, and analyze the danger zone according to the structural information; The position layout unit is used to select a layout position in the danger zone and drill holes to install the FBG sensor.

3. The water-blocking curtain wall stability monitoring system based on FBG sensing technology according to claim 2 is characterized in that: The FBG sensor includes: a single-point fiber Bragg grating osmometer, a fiber Bragg grating embedded strain gauge, a fiber Bragg grating cable strain gauge, and a fiber Bragg grating thermometer.

4. The water-blocking curtain wall stability monitoring system based on FBG sensing technology according to claim 1 is characterized in that: The data acquisition module includes: a data acquisition unit and a data processing unit; The data acquisition unit is used to obtain real-time data of the FBG sensor; The data processing unit is used to convert the real-time data of the FBG sensor to obtain the seepage pressure, deformation and temperature information in the drilled hole of the curtain wall to be monitored.

5. The water-blocking curtain wall stability monitoring system based on FBG sensing technology according to claim 4 is characterized in that: The real-time data of the FBG sensor is converted by using a fiber Bragg grating demodulator, which is used to measure the output wavelength of the FBG sensor and convert the output wavelength into the seepage pressure, deformation and temperature information in the borehole of the curtain wall to be monitored.

6. The water-blocking curtain wall stability monitoring system based on FBG sensing technology according to claim 1 is characterized in that: The risk warning module includes: a threshold setting unit and a risk warning unit; The threshold setting unit is used to set a change threshold for each monitored internal parameter; The risk warning unit is used to issue a warning when the change amount of the real-time internal parameter exceeds the change threshold and generate a warning record.

7. The water-blocking curtain wall stability monitoring system based on FBG sensing technology according to claim 1 is characterized in that: The data storage module includes: a data storage unit and a data query unit; The data storage unit is used to store the real-time internal parameters of the curtain wall to be monitored as a change curve according to the time sequence, and mark the warning record on the change curve; The data query unit is used to query and derive the change curve.

8. The water-blocking curtain wall stability monitoring system based on FBG sensing technology according to any one of claims 1 to 7, characterized in that: The system also includes a data API interface for data transmission among the project management module, data acquisition module, risk warning module, and data storage module.

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