A riprap foundation settlement monitoring device and system
By constructing a reference plate and riser structure on the riprap foundation, and combining a GNSS receiver and data fusion algorithm, the problem of measuring the settlement of underwater riprap foundations was solved, achieving high-precision and stable settlement monitoring and data transmission.
Patent Information
- Application Number
- CN202511601773.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-04
- Publication Date
- 2026-01-09
AI Technical Summary
Existing technologies make it difficult to establish a stable absolute benchmark based on underwater rock dumping. Traditional monitoring methods cannot accurately measure sedimentation in underwater environments and are easily affected by marine environmental interference, leading to data distortion.
A settlement monitoring device for riprap foundations was designed, including a reference plate, a riser, and a GNSS receiver. A stable absolute spatial reference is constructed, and noise is filtered out through a multi-source data fusion algorithm to achieve high-precision settlement measurement.
It achieves high-precision measurement of the absolute settlement of riprap foundations, ensuring the continuity and accuracy of monitoring data, avoiding system failure caused by benchmark instability, and supporting unattended automated monitoring and remote data transmission.
Smart Images
Figure CN121297778A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of settlement monitoring technology, specifically to a settlement monitoring device and system for riprap foundations. Background Technology
[0002] In coastal engineering projects such as artificial islands, port engineering, coastal protection, and cross-sea bridges, riprap foundations are widely used as an economical and efficient foundation treatment method. However, because the riprap itself is composed of loose and uneven boulders, under its own weight and the continuous load of the superstructure, its post-construction settlement is large, the settlement duration is long, and it is often uneven. The settlement amount and settlement rate of the riprap foundation directly affect the safety, stability, and long-term service life of the entire superstructure. Therefore, accurate and reliable settlement monitoring of the riprap foundation is a key link in ensuring project safety, optimizing design schemes, and controlling project costs.
[0003] Currently, monitoring the settlement of riprap foundations, especially in underwater environments, faces numerous technical challenges, and traditional methods have the following significant drawbacks: Underwater monitoring benchmarks are difficult to establish and maintain. Currently, traditional sensors such as hydrostatic levels and settlement gauges require stable and reliable benchmarks for measurement; however, underwater, especially on newly completed rock-fill foundations, such a stable reference point is lacking. Directly burying sensors in the rock-fill body will result in the inability to measure the absolute settlement due to the sensors settling along with the foundation. Furthermore, the buried cables and sensor bodies are extremely vulnerable to damage from subsequent rock-fill construction and rock displacement, resulting in a very low survival rate.
[0004] Directly employing traditional optical and conventional GNSS methods can lead to measurement failures. For underwater subsidence, traditional optical measurement methods (such as total stations) are completely unusable due to water obstruction and lack of line-of-sight. Although the Global Navigation Satellite System (GNSS) can provide absolute coordinates, its application is severely limited. First, the sea surface, as a strong reflective surface, will cause severe multipath effects on GNSS signals, introducing a large number of errors and significantly reducing positioning accuracy. Second, the wave action in the marine environment will cause continuous and periodic swaying of any monitoring structure above the water surface, resulting in frequent signal loss for the GNSS receiver, making it impossible to obtain stable and continuous observation data, and even more difficult to extract slow subsidence trend signals from centimeter-level or millimeter-level swaying noise.
[0005] Finally, the existing monitoring structure itself lacks stability: even if an attempt is made to construct a monitoring riser extending from the seabed to the surface, the stability of its underwater foundation is crucial. If the foundation is poorly designed, it is prone to slippage under horizontal loads such as waves and currents, or tilting on soft seabeds due to insufficient bearing capacity. Both of these situations will cause displacement of the spatial reference of the monitoring system itself, resulting in distorted measurement data and completely negating the monitoring significance for the true settlement of the riprap foundation.
[0006] Therefore, there is an urgent need in this field for a settlement monitoring device and solution for riprap foundations that can overcome the aforementioned shortcomings. This involves establishing a long-term, stable, and absolutely reliable physical benchmark on the underwater riprap body and transmitting this benchmark to the surface without interference and with high precision, so that continuous and accurate absolute displacement measurements can be performed using GNSS technology. Summary of the Invention
[0007] To address the aforementioned technical problems, this invention provides a riprap foundation settlement monitoring device and system, which has a physical reference and transmits this reference to the water surface without interference and with high precision, enabling continuous and accurate absolute displacement measurement using GNSS technology.
[0008] To achieve the above objectives, the present invention provides the following technical solution: a riprap foundation settlement monitoring device, comprising a reference plate set on the plane of the riverbed or seabed to be monitored, the reference plate being used to provide a stable absolute spatial reference, a vertical pipe being fixedly connected to the reference plate, a protective pipe being sleeved on the outside of the vertical pipe, the bottom end of the protective pipe being fixed to the reference plate, the top end of the vertical pipe extending above the water surface, an adjustable height adjustment component being provided above the vertical pipe, an extension frame being connected to the height adjustment component, and a GNSS receiver being connected to the top end of the extension frame, the GNSS receiver being used to receive satellite signals to determine its own three-dimensional spatial coordinates; The base plate and riser are surrounded by riprap. The base plate, riser, and GNSS receiver together form a rigid or quasi-rigid integral structure, so that the coordinate changes of the GNSS receiver can directly reflect the settlement of the riprap foundation.
[0009] As a preferred technical solution of the riprap foundation settlement monitoring device of the present invention, a number of extension arms are arranged horizontally outward along the center at the outer edge of the reference plate. The top of the extension arm is connected to a vertically upward protective frame, and the bottom of two adjacent sets of protective frames are connected to a stress relief frame. The protective frame is used to protect the entire monitoring device.
[0010] As a preferred technical solution of the riprap foundation settlement monitoring device of the present invention, the unloading frame is provided in three parts, and the three unloading frames and the protective frame form a triangular prism component. Connecting arms of the same triangular component are arranged in parallel above the unloading frame. A locking frame is fixedly connected at the connection of the connecting arm. A locking knob is connected to the top of the protective frame. The bottom end of the locking frame is inserted into the interior of the protective frame and locked by rotating the locking knob.
[0011] As a preferred technical solution of the riprap foundation settlement monitoring device of the present invention, the height adjustment component includes an extension tube set above the riser. The two ends of the extension tube are respectively inserted into the interior of the riser and the extension frame. A riser extension locking knob is screwed and connected to the ends of the riser and the extension frame. The riser extension locking knob locks the extension tube during rotation. By rotating the riser extension locking knob, the end of the extension tube can be loosened from the riser or the extension frame, thereby adjusting the extension amount of the extension tube. A solar panel is also mounted on the extension frame via a bracket, and the solar panel is used to power the GNSS receiver.
[0012] As a preferred technical solution of the riprap foundation settlement monitoring device of the present invention, a constraint cage can be fixedly welded to the outer wall of the triangular prism structure formed by the three protective frames, the unloading frame and the connecting arm. The riprap can be directly poured into the inner side of the constraint cage, and the riprap is constrained by the constraint cage to further prevent the riprap from shifting.
[0013] The bottom of the protective frame is provided with a structure to increase its anti-slip and anti-tilting capabilities, including micropiles set at the bottom of the protective frame.
[0014] As a preferred technical solution of the rock-fill foundation settlement monitoring device of the present invention, a first unloading arm is also provided at the outer edge of the unloading frame. The first unloading arm is an obtuse-angled triangular component. The three sets of first unloading arms on the outer side of the unloading frame form a hexagonal component, which further improves the accuracy of the rock-fill cage in applying pressure to the spatial reference.
[0015] As a preferred technical solution of the rock-fill foundation settlement monitoring device of the present invention, a second auxiliary unloading arm is also provided on the outside of the first unloading arm. The end of the second auxiliary unloading arm is bent toward the protective frame and extended and connected. The middle part of the second auxiliary unloading arm is fixedly connected to the first unloading arm for further monitoring of the settlement of the rock-fill cage.
[0016] As a preferred technical solution of the riprap foundation settlement monitoring device of the present invention, a riprap cage can be placed above the first unloading arm and the second auxiliary unloading arm. The riprap cage can be a cage-type component. The inside of the riprap cage can be equipped with a riprap net bag. Multiple riprap stones of equal mass are respectively placed around the riser and apply pressure to the extension arm, unloading frame, first unloading arm and second auxiliary unloading arm.
[0017] As a preferred technical solution of the riprap foundation settlement monitoring device of the present invention, the system further includes an attitude sensing module that can be integrated into the riser, the attitude sensing module including at least one of an angle sensor and an inertial measurement unit (IMU); The GNSS receiver is a professional-grade receiver that supports carrier phase observations; the system also includes a data acquisition and transmission module electrically connected to the GNSS receiver, and the data acquisition and transmission module includes a wireless communication unit; The wireless communication unit is a 4G / 5G communication module, a LoRa module, or a satellite communication module; The system comprises multiple underwater stabilization foundations and connected risers and GNSS receivers, forming a monitoring network; the various GNSS receivers in the monitoring network communicate with each other via a wireless ad hoc network.
[0018] A preferred technical solution for a riprap foundation settlement monitoring method according to the present invention includes the following steps: The monitoring system was deployed on the riprap foundation; Raw observation data of the time series were acquired using a GNSS receiver; Based on the original observation data, the three-dimensional coordinate sequence of the GNSS receiver is calculated; The three-dimensional coordinate sequence is processed to separate the high-frequency swaying component and the low-frequency settling trend component. The steps of outputting the settlement amount and settlement rate of the riprap foundation; and the data processing of the three-dimensional coordinate sequence include using a Kalman filter or a high-pass filter to filter out the high-frequency swaying component caused by waves, and obtaining low-frequency displacement data representing the settlement trend. The method also includes acquiring auxiliary data from the attitude sensing module and using the auxiliary data to dynamically compensate the three-dimensional coordinates calculated by the GNSS receiver in order to correct coordinate errors caused by the tilt or sway of the riser. The method further includes comparing the calculated settlement amount or settlement rate with a preset threshold, and generating and sending an early warning message when the settlement amount or settlement rate exceeds the preset threshold.
[0019] Compared with the prior art, the beneficial effects of the present invention are: 1. Through an innovative integrated design of a caisson-type underwater stabilizing foundation and a central riser, a stable absolute spatial benchmark extending from the loose riprap body to the water surface was successfully constructed. This benchmark deforms in tandem with the riprap foundation, directly and non-destructively transmitting the underwater settlement, which is difficult to measure directly, into elevation changes above the water surface that can be accurately captured by GNSS technology. This enables direct measurement of the absolute settlement of the riprap foundation and solves the inherent defect of traditional sensors being unable to obtain an absolute benchmark.
[0020] 2. The structure of this design effectively resists the impact and damage that may be caused by subsequent rock-laying construction and marine organism attachment, ensuring the long-term survivability of the monitoring facilities. It absorbs wave energy, significantly suppressing harmful swaying at the top of the riser, greatly improving the GNSS signal lock-off problem, and ensuring the continuity of data acquisition.
[0021] 3. By introducing a multi-source data fusion algorithm, GNSS data is combined with attitude sensor data, which can intelligently filter out periodic swaying noise caused by waves and accurately extract millimeter-level settlement trends from centimeter-level dynamic noise, thus solving the serious interference of sea surface multipath effect and structural sway on positioning accuracy.
[0022] 4. The various optimized designs of the caisson-type underwater stable foundation give it excellent resistance to tilting and slippage, ensuring that it remains stable under complex marine hydrogeological conditions such as soft seabed and strong tidal currents. This characteristic guarantees the long-term and absolute reliability of the monitoring benchmark, fundamentally avoiding the major risk of the entire monitoring system failing due to the instability of the benchmark itself.
[0023] 5. The system integrates a wireless communication module, enabling 24 / 7 unattended automated monitoring and real-time remote data transmission, completely changing the high-cost, high-risk, and low-efficiency model of traditional manual on-site measurement. By constructing a monitoring network, comprehensive perception of uneven settlement across the entire riprap foundation area can be achieved. Furthermore, the intelligent early warning mechanism based on settlement data can proactively alarm when the settlement amount or rate exceeds a safety threshold, gaining valuable time for emergency rescue and decision support, effectively avoiding major safety accidents, and yielding significant safety and economic benefits. Attached Figure Description
[0024] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.
[0025] Figure 1 This is a schematic diagram of the monitoring device structure of the present invention; Figure 2 This is a schematic diagram of the stone-throwing structure constraint structure of the monitoring device in this invention; Figure 3This is a schematic diagram showing the further stabilization structure of the monitoring device in this invention; Figure 4 This is a schematic diagram of the monitoring system process in this invention; In the diagram: 1. Base plate; 2. Riser; 3. Extension pipe; 4. Extension frame; 5. GNSS receiver; 6. Solar panel; 7. Riser extension locking knob; 8. Extension arm; 9. Unloading frame; 10. Protective frame; 11. Micropile; 12. Locking knob; 13. Locking frame; 14. Connecting arm; 15. First unloading arm; 16. Second auxiliary unloading arm; 17. Rock cage; 18. Rock net; 19. Rock; 20. Protective pipe; 21. Restraint cage. Detailed Implementation
[0026] The technical solutions of the embodiments of the present invention 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. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0027] Example like Figure 1-4 As shown, the present invention discloses a riprap foundation settlement monitoring device, including a reference plate 1 set on the plane of the riverbed or seabed to be monitored. The reference plate 1 is used to provide a stable absolute spatial reference. A riser 2 is vertically fixedly connected to the reference plate 1. A protective pipe 20 is also sleeved on the outside of the riser 2. The bottom end of the protective pipe 20 is fixed to the reference plate 1. The protective pipe 20 is used to protect the riser 2. A fixed space is formed between the riser 2 and the protective pipe 20 to prevent the riser 2 from directly contacting the riprap 19 and to prevent the pressure from being directly applied to the riser 2 when the riprap is displaced, which would cause the riser 2 to deflect. The top of the riser 2 extends above the water surface. An adjustable height adjustment component is set above the riser 2. An extension frame 4 is connected to the height adjustment component. A GNSS receiver 5 is connected to the top of the extension frame 4. The GNSS receiver 5 is used to receive satellite signals to determine its own three-dimensional spatial coordinates. The area around the reference plate 1 and riser 2 is filled with riprap 19. The reference plate 1, riser 2 and GNSS receiver 5 together form a rigid or quasi-rigid overall structure, so that the coordinate change of GNSS receiver 5 can directly reflect the settlement of the riprap foundation. As a preliminary solution, riprap can be directly scattered around the reference plate 1 and riser 2, and the settlement of the riprap on the entire seabed can be detected by detecting the settlement of the riprap.
[0028] Specifically, several extension arms 8 are arranged horizontally outward from the center at the outer edge of the reference plate 1. The top of the extension arm 8 is connected to a vertically upward protective frame 10. The bottom of two adjacent sets of protective frames 10 are connected to a stress relief frame 9. The protective frame 10 is used to protect the entire monitoring device. In this embodiment, the extension arm 8 and the stress relief frame 9 are used to further increase the arm span of the reference plate 1, so that part of the weight of the thrown stone can be applied to the reference plate 1, thereby improving the measurement accuracy of the settlement of the reference plate 1.
[0029] Specifically, three unloading frames 9 are provided. The three unloading frames 9 and the protective frame 10 form a triangular prism component. Connecting arms 14 of the same triangular components are arranged in parallel above the unloading frames 9. A locking frame 13 is fixedly connected at the connection of the connecting arms 14. A locking knob 12 is connected to the top of the protective frame 10. The bottom end of the locking frame 13 is inserted into the interior of the protective frame 10 and locked by rotating the locking knob 12. The triangular prism component formed in this embodiment can further protect the monitoring device and prevent the monitoring device from being damaged by external impact.
[0030] Specifically, the height adjustment component includes an extension tube 3 located above the riser 2. Both ends of the extension tube 3 are inserted into the interior of the riser 2 and the extension frame 4, respectively. A riser extension locking knob 7 is screwed onto the ends of both the riser 2 and the extension frame 4. The riser extension locking knob 7 locks the extension tube 3 during rotation. By rotating the riser extension locking knob 7, the end of the extension tube 3 can be loosened from the riser 2 or the extension frame 4, thereby adjusting the extension amount of the extension tube 3. A solar panel 6 is also installed on the extension frame 4 via a bracket. The solar panel 6 is used to power the GNSS receiver 5. In this embodiment, the locking knob 7 can be a conventional design used in daily life.
[0031] The outer wall of the triangular prism structure formed by the three protective frames 10, the unloading frame 9, and the connecting arm 14 can also be fixed by welding with a constraint cage 21. The boulders 19 can be directly poured into the inner side of the constraint cage 21. The constraint cage 21 constrains the boulders 19 and further prevents the boulders 19 from shifting.
[0032] Specifically, the bottom of the protective frame 10 is provided with a structure to increase the anti-slip and anti-tilt capabilities, including a micropile 11 set at the bottom of the protective frame 10. In this embodiment, the micropile 11 further enhances the wave resistance of the protective frame 10.
[0033] Specifically, a first unloading arm 15 is also provided at the outer edge of the unloading frame 9. The first unloading arm 15 is an obtuse triangular component. The three sets of first unloading arms 15 on the outer side of the unloading frame 9 form a hexagonal component, which further improves the accuracy of the rock cage 17 in applying pressure to the spatial reference. The first unloading arm 15 can further extend the lifting range of the reference plate 1, so that one-third of the mass of the rock cage 17 is applied to the reference plate 1, further improving the monitoring accuracy of the reference plate 1.
[0034] Specifically, a second auxiliary unloading arm 16 is also provided on the outer side of the first unloading arm 15. The end of the second auxiliary unloading arm 16 is bent toward the protective frame 10 and extended and connected. The middle part of the second auxiliary unloading arm 16 is fixedly connected to the first unloading arm 15 for further monitoring of the settlement of the rock cage 17. In this embodiment, the second auxiliary unloading arm 16 further increases the lifting range of the reference plate 1, so that half of the mass of the rock cage 17 is transferred to the reference plate 1, thereby further improving the monitoring accuracy of the reference plate 1.
[0035] Specifically, a rock-throwing cage 17 can be placed above the first unloading arm 15 and the second auxiliary unloading arm 16. The rock-throwing cage 17 can be a cage-type component. A rock-throwing net 18 can be set inside the rock-throwing cage 17. Multiple rock blocks 19 of equal mass are respectively set around the riser 2 and apply pressure to the extension arm 8, the unloading frame 9, the first unloading arm 15 and the second auxiliary unloading arm 16. In this embodiment, the rock-throwing cage 17 is used to further constrain the rock blocks 19 and prevent the rock blocks 19 from deflecting and displacing under the action of waves.
[0036] Specifically, the system also includes an attitude sensing module that can be integrated into riser 2. This module includes at least one of a tilt sensor and an inertial measurement unit (IMU). The attitude sensing module is a multi-sensor system, its core being the collaborative operation of at least one IMU and at least one high-precision dual-axis tilt sensor. The IMU is the core dynamic sensing unit of the module, used to measure the object's three-dimensional angular velocity and three-dimensional linear acceleration. It typically includes a three-axis gyroscope and a three-axis accelerometer. The gyroscope's zero-bias instability should be better than 1° / h, and the accelerometer's zero-bias instability should be better than 0.5mg, to meet the requirements for long-term accurate calculation of low-frequency settlement signals. It can output raw or pre-processed angular velocity and acceleration data in real time. The high-precision tilt sensor, as a supplement to the IMU data and a static calibration reference, is used to directly measure the static tilt angle of the riser relative to the direction of gravity in two orthogonal directions (i.e., roll and pitch). Its advantages are high long-term absolute accuracy and no cumulative error. The IMU and tilt sensor are integrated into a pressure-resistant, waterproof, and corrosion-resistant sealed housing.
[0037] The housing is fixed to the bottom inner wall of the submerged riser 2 by mechanical connectors (clamps) to ensure a rigid connection between the module and the monitoring structure and synchronous movement. The module integrates a data preprocessing circuit and is connected to the data acquisition unit on the top through a watertight cable or an underwater wireless transmission module to achieve power supply and data communication.
[0038] GNSS receiver 5 is a professional-grade receiver that supports carrier phase observations; the system also includes a data acquisition and transmission module electrically connected to GNSS receiver 5, which includes a wireless communication unit; The wireless communication unit is a 4G / 5G communication module, a LoRa module, or a satellite communication module; The system includes multiple underwater stabilizing foundations and risers 2 connected to them, as well as GNSS receivers 5, forming a monitoring network. In this embodiment, each GNSS receiver 5 in the monitoring network communicates through a wireless ad hoc network.
[0039] Specifically, it includes the following steps: First, deploy the monitoring system on the riprap foundation; Then, the raw observation data of the time series is acquired through GNSS receiver 5; Then, based on the original observation data, the three-dimensional coordinate sequence of GNSS receiver 5 was calculated; The three-dimensional coordinate sequence was then processed to separate the high-frequency swaying component and the low-frequency settling trend component. Finally, the settlement amount and settlement rate of the riprap foundation are output; the data processing steps for the three-dimensional coordinate sequence include using Kalman filtering or high-pass filtering to filter out the high-frequency swaying components caused by waves and obtain low-frequency displacement data representing the settlement trend. The method used in this scheme also includes acquiring auxiliary data from the attitude sensing module and using the auxiliary data to dynamically compensate the three-dimensional coordinates calculated by the GNSS receiver 5 in order to correct the coordinate error caused by the tilt or sway of the riser 2. The method also includes comparing the calculated settlement amount or settlement rate with a preset threshold, and generating and sending an early warning message when the settlement amount or settlement rate exceeds the preset threshold.
[0040] The working principle and usage process of this invention: In the process of using this invention, the workers first assemble the extension arm 8, the unloading frame 9 and the protective frame 10 on the outside of the reference plate 1, and connect the connecting arm 14. The extension pipe 3 and the GNSS receiver 5 are installed on the riser pipe 2. Then, the entire device is hoisted to the seabed or riverbed using hoisting equipment. After that, boulders 19 are filled around the riser pipe 2. The boulders 19 can be placed into the boulders net bag 18 and dropped into the boulders cage 17. Then, the GNSS receiver 5 monitors the settlement during operation.
[0041] The above description is merely a preferred embodiment of the present invention and is not intended to further limit the present invention. All equivalent changes made based on the description and drawings of the present invention are within the protection scope of the present invention.
Claims
1. A settlement monitoring device for riprap foundations, characterized in that, The system includes a reference plate (1) set on the seabed plane to be monitored. The reference plate (1) is used to provide a stable absolute spatial reference. A riser (2) is vertically fixed on the reference plate (1). A protective tube (20) is also sleeved on the outside of the riser (2). The bottom end of the protective tube (20) is fixed on the reference plate (1). The top end of the riser (2) extends above the water surface. An adjustable height adjustment component is set above the riser (2). An extension frame (4) is connected to the height adjustment component. A GNSS receiver (5) is connected to the top end of the extension frame (4). The GNSS receiver (5) is used to receive satellite signals to determine its own three-dimensional spatial coordinates. The base plate (1) and the riser (2) are surrounded by rubble blocks (19). The base plate (1), the riser (2) and the GNSS receiver (5) together form a rigid integral structure, so that the coordinate change of the GNSS receiver (5) can directly reflect the settlement of the rubble foundation.
2. The riprap foundation settlement monitoring device according to claim 1, characterized in that: Several extension arms (8) are provided horizontally outward from the center at the outer edge of the reference plate (1). A vertically upward protective frame (10) is connected to the top of the extension arm (8). A stress relief frame (9) is connected to the bottom of two adjacent sets of protective frames (10). The protective frame (10) is used to protect the entire monitoring device.
3. The riprap foundation settlement monitoring device according to claim 2, characterized in that: The unloading frame (9) is provided in three parts. The three unloading frames (9) and the protective frame (10) form a triangular prism component. The unloading frame (9) is provided with connecting arms (14) of the same triangular component arranged in parallel above it. The connecting arm (14) is fixedly connected with a locking frame (13). The top of the protective frame (10) is connected with a locking knob (12). The bottom end of the locking frame (13) is inserted into the interior of the protective frame (10) and locked by rotating the locking knob (12). The bottom of the protective frame (10) is provided with a structure to increase the anti-slip and anti-tilting capabilities, including a micropile (11) set at the bottom end of the protective frame (10).
4. The riprap foundation settlement monitoring device according to claim 3, characterized in that: The height adjustment assembly includes an extension tube (3) set above the riser (2). The two ends of the extension tube (3) are respectively inserted into the interior of the riser (2) and the extension frame (4). The ends of the riser (2) and the extension frame (4) are screwed and connected with riser extension locking knobs (7). The riser extension locking knobs (7) lock the extension tube (3) during rotation. By rotating the riser extension locking knobs (7), the end of the extension tube (3) can be loosened from the riser (2) or the extension frame (4), thereby adjusting the extension amount of the extension tube (3). A solar panel (6) is also installed on the extension frame (4) via a bracket, and the solar panel (6) is used to power the GNSS receiver (5).
5. The riprap foundation settlement monitoring device according to claim 4, characterized in that: The outer wall of the triangular prism structure formed by the three protective frames (10), the unloading frame (9) and the connecting arm (14) can also be fixed by welding with a constraint cage (21). The boulders (19) can be directly poured into the inner side of the constraint cage (21). The constraint cage (21) constrains the boulders (19) and further prevents the boulders (19) from shifting.
6. The riprap foundation settlement monitoring device according to claim 4, characterized in that: The outer edge of the unloading frame (9) is also provided with a first unloading arm (15). The first unloading arm (15) is an obtuse triangular component. The three sets of first unloading arms (15) on the outer side of the unloading frame (9) form a hexagonal component, which further improves the accuracy of the rock cage (17) in applying pressure to the spatial reference.
7. A settlement monitoring device for riprap foundations according to claim 6, characterized in that: A second auxiliary unloading arm (16) is also provided on the outside of the first unloading arm (15). The end of the second auxiliary unloading arm (16) is bent toward the protective frame (10) and extended and connected. The middle part of the second auxiliary unloading arm (16) is fixedly connected to the first unloading arm (15) for further monitoring of the settlement of the riprap cage (17).
8. A settlement monitoring device for riprap foundations according to claim 7, characterized in that: A rock-throwing cage (17) can be placed above the first unloading arm (15) and the second auxiliary unloading arm (16). The rock-throwing cage (17) can be a cage-type component. A rock-throwing net (18) can be set inside the rock-throwing cage (17). Multiple rock blocks (19) of equal mass are respectively set around the riser (2) and apply pressure to the extension arm (8), the unloading frame (9), the first unloading arm (15) and the second auxiliary unloading arm (16).
9. The system according to any one of claims 1-8 applied to the aforementioned riprap foundation settlement monitoring device, characterized in that: The system also includes an attitude sensing module that can be integrated into the riser (2), the attitude sensing module including at least one of a tilt sensor and an inertial measurement unit (IMU); The GNSS receiver (5) is a professional-grade receiver that supports carrier phase observations; the system also includes a data acquisition and transmission module electrically connected to the GNSS receiver (5), and the data acquisition and transmission module includes a wireless communication unit; The wireless communication unit is a 4G / 5G communication module, a LoRa module, or a satellite communication module; The system comprises multiple underwater stabilizing foundations and risers (2) connected to them, and GNSS receivers (5) forming a monitoring network; each GNSS receiver (5) in the monitoring network communicates through a wireless ad hoc network.
10. The system for monitoring settlement of a riprap foundation according to claim 9, characterized in that: Includes the following steps: Step 1: Deploy the monitoring system on the riprap foundation; Step 2: Acquire the raw observation data of the time series using a GNSS receiver (5); Step 3: Based on the original observation data, calculate the three-dimensional coordinate sequence of the GNSS receiver (5); Step 4: Perform data processing on the three-dimensional coordinate sequence to separate the high-frequency swaying component and the low-frequency settling trend component; Step 5: Output the settlement amount and settlement rate of the riprap foundation; the step of data processing of the three-dimensional coordinate sequence includes using Kalman filtering or high-pass filtering to filter out the high-frequency swaying components caused by waves and obtain low-frequency displacement data representing the settlement trend. The method also includes acquiring auxiliary data from the attitude sensing module and using the auxiliary data to dynamically compensate the three-dimensional coordinates calculated by the GNSS receiver (5) to correct the coordinate error caused by the tilt or sway of the riser (2). The method further includes comparing the calculated settlement amount or settlement rate with a preset threshold, and generating and sending an early warning message when the settlement amount or settlement rate exceeds the preset threshold.