Ground subsidence monitoring device

Abstract

The utility model relates to the technical field of geological monitoring, in particular to a land subsidence monitoring device which comprises more than two reference columns, the reference columns are deeply buried in the edge position of a monitored area, the tops of the reference columns are close to the ground, and a fiber bragg grating strain sensor is connected between the tops of any two reference columns. The fiber bragg grating strain sensor is buried in soil. The non-intrusive monitoring device effectively overcomes the defects of the existing non-intrusive monitoring device in the aspects of measurement accuracy and underground soil layer deformation information acquisition, and provides powerful technical support for accurate and timely monitoring of land subsidence.

Description

Technical Field

[0001] The utility model relates to the technical field of geological monitoring, and specifically relates to a ground settlement monitoring device. Background Art

[0002] Ground settlement is a common geological disaster. Ground settlement not only affects the safe operation of urban infrastructure, but also poses a huge threat to transportation, resource dispatching, economic development and residents' lives. Therefore, it is particularly important to accurately and timely monitor ground settlement.

[0003] Non-invasive monitoring devices have been widely used in practical applications due to their advantages such as simple installation and little interference to the ground environment. However, during the measurement process, such monitoring devices are often interfered by natural changes on the ground, such as changes in external conditions such as atmospheric refraction, temperature, humidity, wind force, and fluctuations in geological factors such as soil moisture and groundwater level. These factors will increase the error of the measurement results. Although non-invasive monitoring devices such as the Global Positioning System (GPS) and Synthetic Aperture Radar Interferometry (InSAR) can continuously monitor over a large area, their measurement accuracy is restricted by various factors. Although GPS monitoring technology can obtain high-precision ground elevation data, in an urban environment, due to problems such as high-rise buildings and signal blockage, its measurement accuracy will be affected to a certain extent. InSAR technology simulates the three-dimensional model characteristics of measurement points through interference images and waveform signals, but factors such as atmospheric interference and changes in surface cover will affect the accuracy of its measurement results.

[0004] In addition, non-invasive monitoring devices also face a common problem, that is, they cannot directly obtain the deformation information of underground soil layers. Ground settlement is a complex engineering geological phenomenon, and its occurrence is often accompanied by the consolidation and compression of underground soil layers and the change of pore water pressure. Non-invasive monitoring devices can only indirectly infer the deformation of underground soil layers through surface deformation, and this kind of inference often has great uncertainty.

[0005] Therefore, in order to solve the defects of the prior art, a new type of ground settlement monitoring device is urgently needed. Summary of the Utility Model

[0006] The purpose of the utility model is to provide a ground settlement monitoring device to solve the problems put forward in the above background art.

[0007] To achieve the above purpose, the utility model provides the following technical solutions:

[0008] A ground settlement monitoring device includes more than two reference columns. The reference columns are buried deep into the edge position of the monitored area, and the tops of the reference columns are close to the ground. An optical fiber grating strain sensor is connected between the tops of any two reference columns, and the optical fiber grating strain sensor is buried in the soil.

[0009] Further, a pointed head is provided at the bottom of the reference column, and a sensor end fixing device is detachably connected to the head of the reference column. The sensor end fixing device includes a screw rod. Above the screw rod, one or more end sleeves are rotatably connected. A hexagonal prism-shaped wrench head is provided at the top of the screw rod. A threaded hole is provided in the head of the reference column, and the screw rod is threadedly connected to the threaded hole. An end jack is provided on the end sleeve, and the joint of the optical fiber grating strain sensor is inserted and matched with the end jack. A locking nut is threadedly connected to the side wall of the end jack.

[0010] Further, an anvil seat that extends horizontally outwards is further provided at the head of the reference column, and the anvil seat is higher than the upper port of the threaded hole.

[0011] Further, the reference column is made of galvanized steel pipe, aluminum alloy or stainless steel.

[0012] Further, the optical fiber grating strain sensor includes an optical fiber grating, and a protective sleeve is coated outside the optical fiber grating.

[0013] Further, the protective sleeve is made of stainless steel.

[0014] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0015] 1. In the present utility model, the deformation of the underground soil layer is directly measured by the optical fiber grating strain sensor, avoiding the interference of external factors such as atmospheric refraction, temperature, humidity, etc., and the influence of changes in surface coverings on the measurement results, thus significantly improving the measurement accuracy; the reference columns are installed in a deep-buried manner, which is not only stable and reliable, but also not easily affected by ground activities, and the design of the sensor end fixing device makes the installation and disassembly of the optical fiber grating strain sensor simple and fast, facilitating maintenance and replacement. The present utility model effectively solves the deficiencies of existing non-invasive monitoring devices in terms of measurement accuracy and obtaining underground soil layer deformation information, providing strong technical support for the accurate and timely monitoring of ground settlement.

[0016] 2. In the present utility model, the screw rod is threadedly connected to the threaded hole at the head of the reference column to achieve detachable connection, and the end sleeve is rotatably connected around the screw rod, facilitating the adjustment of the angle to adapt to the joint of the optical fiber grating strain sensor.

[0017] 3. In the present utility model, the anvil seat facilitates hammering the reference column to bury it into the deep soil layer, and the anvil seat is higher than the upper port of the threaded hole, forming protection for the threaded hole.

[0018] 4. In the present utility model, the protective sleeve can protect the fiber Bragg grating, and the protective sleeve made of stainless steel has both strength, stiffness and anti-corrosion performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic structural diagram of a ground settlement monitoring device;

[0020] Figure 2 is a schematic structural diagram of the end part of the reference column and the fiber Bragg grating strain sensor;

[0021] Figure 3 is a schematic structural diagram of the fixing device for the top of the reference column and the sensor end;

[0022] Figure 4 is a schematic structural diagram of the reference column;

[0023] Figure 5 is a schematic structural diagram of the sensor end fixing device;

[0024] Figure 6 is a schematic structural diagram of the fiber Bragg grating strain sensor.

[0025] In the figure: 1. Reference column; 2. Fiber Bragg grating strain sensor; 3. Pointed head; 4. Sensor end fixing device; 5. End sleeve; 6. End socket; 7. Locking nut; 8. Screw rod; 9. Wrench head; 10. Connector; 11. Threaded hole; 12. Anvil; 13. Fiber Bragg grating; 14. Protective sleeve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0027] Embodiment 1: Please refer to Figures 1 to 6 , a ground settlement monitoring device, including more than two reference columns 1, the reference columns 1 are buried deep into the edge position of the monitored area, the tops of the reference columns 1 are close to the ground, and a fiber Bragg grating strain sensor 2 is connected between the tops of any two reference columns 1, and the fiber Bragg grating strain sensor 2 is buried in the soil.

[0028] The working principle of this embodiment:

[0029] In this embodiment, more than two reference columns 1 are used as stable reference points. These reference columns 1 are deeply buried at the edge of the monitored area to ensure their relative fixation during ground settlement. The deep burial of the reference columns 1 can reduce the interference of shallow soil settlement on the position deviation of the reference columns 1. The top of the reference column 1 is close to the ground, facilitating the connection with the fiber Bragg grating strain sensor 2. The fiber Bragg grating strain sensor 2 is buried in the soil and connected between the tops of any two reference columns 1. When the ground subsides, the deformation of the soil and the underground soil layer acts on the fiber Bragg grating strain sensor 2, causing the fiber Bragg grating 13 inside it to generate strain. This strain will change the reflection wavelength of the fiber Bragg grating. By measuring the change in the reflection wavelength, the strain received by the fiber Bragg grating can be accurately calculated, and then the degree of ground settlement can be inferred.

[0030] Compared with traditional non-invasive monitoring devices such as GPS and InSAR, this device in this embodiment directly measures the deformation of the underground soil layer through the fiber Bragg grating strain sensor 2, avoiding the interference of external factors such as atmospheric refraction, temperature, and humidity, as well as the influence of changes in surface coverings on the measurement results, thus significantly improving the measurement accuracy; this embodiment can directly measure the deformation of the underground soil layer, solving the problem that non-invasive monitoring devices cannot directly obtain the deformation information of the underground soil layer; in this embodiment, the reference column 1 is installed in a deeply buried manner, which is not only stable and reliable but also not easily affected by ground activities, and the design of the sensor end fixing device 4 makes the installation and disassembly of the fiber Bragg grating strain sensor 2 simple and fast, facilitating maintenance and replacement; due to the advantages of high sensitivity and strong anti-interference ability of the fiber Bragg grating strain sensor 2, this device can adapt to various complex geological environments and climate conditions to ensure long-term and stable monitoring effects.

[0031] This embodiment effectively solves the deficiencies of existing non-invasive monitoring devices in terms of measurement accuracy and obtaining deformation information of the underground soil layer, providing strong technical support for the accurate and timely monitoring of ground settlement.

[0032] Embodiment 2: Please refer to Figures 1 to 5 , a ground settlement monitoring device, which is different from that of Embodiment 1 in that a pointed head 3 is provided at the bottom of the reference column 1, and a sensor end fixing device 4 is detachably connected to the head of the reference column 1. The sensor end fixing device 4 includes a screw rod 8, above which is rotatably connected one or more end sleeves 5. A hexagonal prism-shaped wrench head 9 is provided at the top of the screw rod 8. A threaded hole 11 is provided at the head of the reference column 1, and the screw rod 8 is threadedly connected to the threaded hole 11. An end socket 6 is provided on the end sleeve 5, and the joint 10 of the fiber Bragg grating strain sensor 2 is inserted and matched with the end socket 6. A locking nut 7 is threadedly connected to the side wall of the end socket 6.

[0033] The head of the reference column 1 is also provided with an anvil 12 that extends horizontally outward, and the anvil 12 is higher than the upper port of the threaded hole 11.

[0034] The reference column 1 is made of galvanized steel pipe, aluminum alloy or stainless steel.

[0035] In this embodiment,

[0036] The pointed tip 3 at the bottom of the reference column 1 is designed to easily penetrate the soil during the embedding process to ensure that the reference column can be firmly buried deep at the edge of the monitored area. The screw 8 is threadedly connected to the threaded hole 11 at the head of the reference column 1 to achieve a detachable connection. During installation, the screw 8 is screwed into the threaded hole 11 until the sensor end fixing device 4 is firmly fixed on the reference column 1. The end sleeve 5 is rotatably connected around the screw 8 to facilitate adjusting the angle to adapt to the joint 10 of the fiber Bragg grating strain sensor 2. The end socket 6 is designed to receive the joint 10 of the fiber Bragg grating strain sensor 2 to achieve a plug-in fit and ensure a stable connection between the sensor and the reference column. By rotating the locking nut 7 and threadedly connecting it to the side wall of the end socket 6, the joint 10 of the fiber Bragg grating strain sensor 2 is tightened to prevent it from loosening or falling off during the monitoring process. The anvil 12 facilitates hammering the reference column 1 to bury it in the deep soil layer. The anvil 12 is higher than the upper port of the threaded hole 11 to protect the threaded hole 11. The reference column 1 can be made of galvanized steel pipe, aluminum alloy or stainless steel and has good anti-corrosion performance.

[0037] Embodiment 3: Please refer to Figure 6 , a ground settlement monitoring device, which is different from that in Embodiment 1 in that the fiber Bragg grating strain sensor 2 includes a fiber Bragg grating 13, and the outside of the fiber Bragg grating 13 is coated with a protective sleeve 14.

[0038] The protective sleeve 14 is made of stainless steel.

[0039] In this embodiment, the protective sleeve 14 can protect the fiber Bragg grating 13, and the stainless steel protective sleeve 14 has both strength, stiffness and anti-corrosion performance.

Claims

1. A ground subsidence monitoring device, comprising two or more reference columns (1), characterized in that: The reference columns (1) are buried deep at the edge of the monitored area, the tops of the reference columns (1) are close to the ground, a fiber grating strain sensor (2) is connected between the tops of any two reference columns (1), and the fiber grating strain sensor (2) is buried in the soil.

2. A land subsidence monitoring device according to claim 1, characterized in that: The base column (1) is provided with a pointed head (3), the head of the base column (1) is detachably connected to a sensor terminal fixing device (4), the sensor terminal fixing device (4) comprises a screw (8), the upper part of the screw (8) is rotatably connected to one or more terminal sleeves (5), the top of the screw (8) is provided with a hexagonal wrench head (9), the head of the base column (1) is provided with a threaded hole (11), the screw (8) is threadedly connected to the threaded hole (11), the terminal sleeve (5) is provided with a terminal socket (6), the connector (10) of the fiber optic grating strain sensor (2) is plugged into and matched with the terminal socket (6), and a locking nut (7) is threadedly connected to the side wall of the terminal socket (6).

3. A land subsidence monitoring device according to claim 2, characterized in that: The head of the reference column (1) is also provided with an anvil (12) extending outward horizontally, and the anvil (12) is higher than the upper end of the threaded hole (11).

4. A land subsidence monitoring device according to claim 1, characterized in that: The reference column (1) is made of galvanized steel pipe, aluminum alloy or stainless steel.

5. A land subsidence monitoring device according to claim 1, characterized in that: The fiber grating strain sensor (2) comprises a fiber grating (13), and the outer side of the fiber grating (13) is covered with a protective sleeve (14).

6. A land subsidence monitoring device according to claim 5, characterized in that: The protective sleeve (14) is made of stainless steel.

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