Bridge culvert flood liquid level and flow velocity monitoring device

Abstract

The utility model discloses a bridge and culvert flood liquid level and flow velocity monitoring devices belongs to intelligent flood control and disaster prevention equipment field. A bridge and culvert flood liquid level and flow velocity monitoring device, including flow velocity monitoring subassembly, sensing optical cable and signal processing equipment, the flow velocity monitoring subassembly is including impeller, the impact generating part of impeller drive and vibration transmission rod, one end of vibration transmission rod is connected with impact generating part, and the other end of vibration transmission rod is fixedly connected with the cable body of sensing optical cable, sensing optical cable is laid on the surface of structure with continuous path, and this continuous path extends according to non straight line path in vertical direction, signal processing equipment is connected with sensing optical cable. In the utility model, utilize the same set of optical cable and demodulation system to obtain flow velocity and liquid level information, reduce the equipment quantity and wiring complexity.

Description

Technical Field

[0001] This utility model belongs to the field of intelligent flood control and disaster prevention equipment, and in particular relates to a device for monitoring the level and velocity of flood discharge in bridges and culverts. Background Technology

[0002] Bridges and culverts along railway lines are crucial components of rail transit infrastructure, and their structural integrity directly impacts the safety and capacity of railway transport. Heavy rainfall-induced flooding events can easily cause erosion, siltation, and runoff scouring in the downstream areas of bridges and culverts, leading to safety hazards such as erosion of bridge pier foundations, culvert blockage, or underpass scouring of rail foundations, directly threatening the structural stability of rail transit. These hazards are particularly pronounced during periods of heavy rain and flooding, and can lead to uneven track support, accelerated sleeper damage, and even railway line deformation or interruption, resulting in serious traffic accidents and economic losses. Unlike obvious structural cracks or deformations, flood accumulation, sudden changes in flow velocity, and underpass scouring under bridges and culverts are often difficult to detect visually or through routine inspections in their early stages. Especially in low visibility, inclement weather, or at night, traditional manual inspections and isolated water gauge monitoring methods have limitations in terms of timeliness and spatial coverage. This is not only labor-intensive and inefficient but also fails to provide timely early warnings, thus increasing maintenance costs and operational risks. Utility Model Content

[0003] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a monitoring device for the level and velocity of flood discharge in bridges and culverts, which can be used to accurately monitor the level and velocity of flood discharge in bridges and culverts.

[0004] This utility model is achieved through the following technical solution: a bridge and culvert flood discharge level and flow velocity monitoring device, including a flow velocity monitoring component, a sensing optical cable and a signal processing device;

[0005] The flow rate monitoring component includes an impeller, an impact generator driven by the impeller, and a vibration transmission rod. One end of the vibration transmission rod is connected to the impact generator, and the other end of the vibration transmission rod is fixedly connected to the cable body of the sensing optical cable.

[0006] The sensing optical cable is laid on the surface of the structure in a continuous path, and the continuous path extends in a non-linear path in the vertical direction.

[0007] The signal processing device is connected to the sensing optical cable.

[0008] Furthermore, the impeller is a propeller, and the shaft of the propeller is connected to the impact generator via a transmission mechanism.

[0009] Furthermore, the flow rate monitoring component also includes a streamlined shroud, and the propeller is disposed inside the shroud.

[0010] Furthermore, the impact generating element is a mechanical striking pin mechanism or a cam mechanism.

[0011] Furthermore, the vibration transmission rod is fixedly connected to the cable body of the sensing optical cable by a clamp.

[0012] Furthermore, the vibration transmission rod and the clamp are either an integral structure or a separate connection.

[0013] Furthermore, the sensing optical cable is an integrated sensing optical cable.

[0014] Furthermore, the non-linear path is S-shaped, spiral-shaped, or stepped.

[0015] Furthermore, the signal processing device includes an optical fiber host and a parsing host, the optical fiber host being connected to the sensing optical cable and the parsing host respectively.

[0016] Furthermore, the bridge and culvert flood discharge level and flow velocity monitoring device also includes a support frame, on which the flow velocity monitoring component is mounted.

[0017] Compared with the prior art, this utility model has the following advantages and beneficial effects:

[0018] (1) This utility model uses the same optical cable and a set of signal processing equipment to synchronously acquire flow rate and liquid level information, which reduces the number of equipment and wiring complexity;

[0019] (2) The current velocity monitoring component in this utility model is a pure mechanical structure without underwater electronic devices. The sensing optical cable is laid along the surface of the structure, which is resistant to flood erosion and silt abrasion, has strong impact resistance, high reliability, and is suitable for long-term monitoring.

[0020] (3) In this utility model, the sensing optical cable is laid out along a non-linear path in the vertical direction. Combined with the high spatial resolution of distributed optical fiber sensing, continuous and accurate measurement of the liquid level of the entire monitoring section can be realized. Attached Figure Description

[0021] The accompanying drawings, which are included to provide a further understanding of the embodiments of the present invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0022] Figure 1 This is a schematic diagram of a flow velocity monitoring component in this utility model;

[0023] Figure 2 This is a schematic diagram showing the layout of the sensing optical cable at the flood warning height in this utility model.

[0024] Figure 3 This is a schematic diagram showing the location of the sensing optical cable at the Xinghong Bridge in this utility model.

[0025] Figure 4 This is a schematic diagram of the composition of the flood discharge level and flow velocity monitoring device for bridges and culverts in this utility model;

[0026] In the diagram, 1—bridge / culvert, 2—sensing optical cable, 3—flow velocity monitoring component, 31—propeller, 32—vibration transmission rod, 33—clamp, 4—fiber optic host, 5—analysis host, 6—data server, 7—monitoring terminal. Detailed Implementation

[0027] The technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0028] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the present invention. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0029] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "inner," and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this utility model. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0030] In the description of this utility model, unless otherwise explicitly specified and limited, the term "connection" or similar designation indicating the connection relationship between components should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0031] like Figures 1 to 4 As shown, this utility model discloses a device for monitoring the flood discharge level and flow velocity of bridges and culverts.

[0032] A device for monitoring the level and velocity of flood discharge in bridges and culverts includes a velocity monitoring component 3, a sensing optical cable 2, and a signal processing device.

[0033] like Figure 1 As shown, the flow rate monitoring component 3 includes an impeller, an impact generator driven by the impeller, and a vibration transmission rod 32. One end of the vibration transmission rod 32 is connected to the impact generator, and the other end of the vibration transmission rod 32 is fixedly connected to the cable body of the sensing optical cable 2.

[0034] like Figure 2 As shown, the sensing optical cable 2 is laid on the surface of the structure in a continuous path, and the continuous path extends in a non-linear path in the vertical direction.

[0035] The signal processing device is connected to the sensing optical cable 2.

[0036] The principle of the monitoring device in this invention for monitoring flow rate and liquid level is as follows:

[0037] The flow velocity monitoring component 3 is fixed at a predetermined position on the flood discharge section of the bridge culvert 1. When floodwater flows through, the dynamic pressure of the water flow drives the impeller to rotate. According to the preset mechanical transmission ratio, every time the impeller rotates a specific angle (e.g., 1 / 4 turn), the impact generator produces a high signal-to-noise ratio mechanical impact pulse. This mechanical impact pulse is directly transmitted to the sensing optical cable 2 laid close to the surface through the vibration transmission rod 32. This design ingeniously transforms the continuous fluid velocity information, which is difficult to measure directly through optical fiber, into a discrete mechanical vibration pulse sequence that is easily sensed by the optical cable and whose frequency is strictly linearly proportional to the flow velocity, thus realizing passive digital encoding of the flow velocity.

[0038] In this embodiment, the sensing optical cable 2 is laid on the surface of the structure in a continuous path, and this continuous path extends in a non-linear manner in the vertical direction. Utilizing the meter-level high spatial resolution characteristics of distributed optical fibers, it is possible to sensitively capture the differences in the medium environment of optical cable segments at different heights: the optical cable segment submerged in water exhibits specific low-frequency fluctuation characteristics in its vibration signal due to water damping and water flow impact, while high-frequency noise is suppressed; the optical cable segment exposed to air is mainly affected by wind noise or environmental freaks, resulting in relatively low vibration energy and an active spectral response. By comparing the vibration energy spectrum and frequency characteristics along the longitudinal direction of the optical cable, the location of the "gas-liquid" interface where the vibration mode changes abruptly can be clearly identified. Combined with the elevation parameters of the optical cable layout, the real-time flood level height can be calculated, effectively solving the blind zone problem of traditional water level gauges.

[0039] In some embodiments of this example, the impeller is a propeller 31, and the shaft of the propeller 31 is connected to the impact generator via a transmission mechanism.

[0040] In some embodiments of this example, the flow rate monitoring component 3 further includes a streamlined shroud, and the propeller 31 is disposed inside the shroud.

[0041] In these embodiments, the flow guide can effectively converge and guide water flow, improve the impeller's driving efficiency and response sensitivity, and at the same time provide physical protection for the internal mechanical mechanism, extending the service life of the flow rate monitoring component 3 in complex water flow environments.

[0042] In some embodiments of this example, the impact generator is a mechanical striking pin mechanism or a cam mechanism.

[0043] In these embodiments, both the mechanical striker mechanism and the cam mechanism can reliably convert rotational motion into instantaneous, high signal-to-noise ratio mechanical impact or periodic pushing motion, generating vibration signals (such as mechanical impact pulses) that are easily recognized by fiber optic sensing systems.

[0044] When the floodwaters flow, the dynamic pressure of the water drives the propeller 31 to rotate. The shaft of the propeller 31 is connected to the internally sealed mechanical striker structure (or cam mechanism). According to the preset mechanical transmission ratio, every time the propeller 31 rotates a certain angle (e.g., 1 / 4 turn), the striker is released and strikes the vibration transmission metal wall or directly acts on the coupling component, generating a mechanical impact pulse with a high signal-to-noise ratio.

[0045] In some embodiments of this example, the vibration transmission rod 32 is fixedly connected to the cable body of the sensing optical cable 2 by a clamp 33.

[0046] The vibration transmission rod 32 is used to transmit the mechanical impact pulse generated by the impact generator to the sensing optical cable 2.

[0047] For example, the vibration transmission rod 32 is a metal rod, and the clamp 33 is a metal clamp 33.

[0048] In these embodiments, the connection between the vibration transmission rod 32 and the sensing optical cable 2 is achieved by the clamp 33, which improves the stability of the connection and makes it easy to adjust, ensuring that the vibration signal can be efficiently transmitted to the optical cable.

[0049] In some embodiments of this example, the vibration transmission rod 32 and the clamp 33 are either an integral structure or a separate connection.

[0050] In some embodiments of this example, the sensing optical cable 2 is an integrated sensing optical cable.

[0051] In these implementations, the integrated sensing and transmission optical cable combines sensing and transmission functions, simplifying system wiring.

[0052] In some embodiments of this example, the non-linear path is S-shaped, spiral, or stepped.

[0053] like Figure 3 As shown, the structure is a bridge pier, culvert sidewall, or measuring scale stake.

[0054] For example, the sensing optical cable 2 is laid tightly in an S-shape, spiral shape, or stepped shape at predetermined vertical intervals on the side walls of bridge piers, culverts, or measuring scale stakes.

[0055] In some embodiments of this example, the bridge and culvert flood discharge level and flow velocity monitoring device further includes a support frame, and the flow velocity monitoring component 3 is mounted on the support frame.

[0056] The bracket is used to fix the flow velocity monitoring component 3 at a predetermined position on the flood discharge section of the bridge culvert 1.

[0057] In some implementations of this embodiment, such as Figure 4 As shown, the signal processing device includes an optical fiber host 4 and a parsing host 5, with the optical fiber host 4 connected to the sensing optical cable 2 and the parsing host 5 respectively.

[0058] The fiber optic host 4 is connected to one end of the sensing optical cable 2. Using phase-sensitive optical time-domain reflectometry (Φ-OTDR) technology, it continuously transmits probe pulses to the sensing optical cable 2 and collects backscattered Rayleigh light signals to reconstruct the vibration waveform, frequency, and intensity at any position along the sensing optical cable 2. The analysis host 5 receives the above data, performs spectrum analysis to extract the impact frequency and invert the flow velocity, and identifies the gas-liquid interface and calculates the liquid level by analyzing the spatial distribution gradient of the signal.

[0059] In some embodiments of this example, the signal processing device further includes a data server 6 and a monitoring terminal 7. The data server 6 is communicatively connected to the analysis host 5 and the monitoring terminal 7, respectively. The data server 6 receives and stores information such as flow rate and liquid level from the analysis host 5. The monitoring terminal 7 consists of a desktop computer, a monitor, a sound system, and an audible and visual alarm, providing interactive services directly to on-duty personnel. The desktop computer accesses the data server 6 through a browser, displaying the bridge / culvert 1 location information, real-time liquid level / flow rate dashboard, alarm status list, emergency response flowchart, and monitoring data statistical reports intuitively on the monitor interface. The sound system has a "listening" function for on-site vibration signals. In extreme cases where there is no video surveillance or inspection personnel cannot arrive in time, it can accurately reproduce the on-site acoustics by playing the impact rhythm or water flow impact sound collected by the optical cable, assisting personnel in making judgments based on experience. The audible and visual alarm can simultaneously trigger a high-decibel dual alarm with sound and light when the flood level or flow rate exceeds the preset warning line, actively reminding on-duty personnel to deal with the emergency in a timely manner.

[0060] The following example will further illustrate the solution of this embodiment.

[0061] For certain railway flood control bridge and culvert monitoring scenarios, the affected areas are arid, and the ditches under the railway bridges are dry year-round, often serving as passageways for people and livestock, only suddenly forming rapid floods during heavy rains. This special operating condition of "normal passage, flood discharge in emergencies" requires the system to have extremely strong resistance to physical damage and the ability to effectively distinguish between biological disturbances and actual water conditions. The monitoring device provided in this embodiment can cope with this complex environmental challenge.

[0062] In this embodiment, the flow rate monitoring component 3 uses a 30cm diameter four-bladed stainless steel propeller, with a heavy-duty metal mesh cover to effectively prevent impact from gravel and accidental contact by animals. The component integrates an IP68-rated sealed "four-peak cam" transmission mechanism with a transmission ratio of "speed:impact frequency = 1:4", meaning that the propeller 31 drives the striker to strike 4 times per revolution, thereby generating a mechanical vibration signal.

[0063] The component is welded and fixed to the bridge pier at a depth of 0.5 meters below the low water level on the upstream side via an I-beam bracket, and connected to a solid steel pole with a diameter of 20mm. The steel pole is flexibly connected to the bridge to ensure that vibrations are not physically attenuated. The steel pole extends vertically to the optical cable, serving as a vibration transmission rod 32, further ensuring the efficiency and accuracy of signal transmission.

[0064] To reduce construction difficulty and protect the optical cable, the cable is connected to the connecting rod via a metal coupling clamp 33. Contact pressure is used to transmit mechanical vibrations from the connecting rod to the optical fiber without stripping the armor layer. This design ensures the integrity of the optical fiber while achieving efficient vibration transmission. The optical cable used is a GYTA53 type outdoor reinforced armored optical cable, which has strong anti-interference capabilities. Furthermore, flow rate and liquid level monitoring functions are implemented using the same cable, simplifying deployment and maintenance.

[0065] In the liquid level monitoring section, the optical cable is laid vertically along the sidewall of the bridge pier using an "S-shaped" serpentine layout. Every 20cm ascent, the cable is folded back laterally to ensure a total height covering a 15-meter range from the riverbed to the bottom of the beam, thus improving vertical resolution. This layout effectively enhances the accuracy of liquid level monitoring and provides more reliable support for subsequent data acquisition.

[0066] Fiber optic host 4 is deployed in a station equipment room 5km away. Based on phase-sensitive optical time-domain reflectometry (Φ-OTDR) technology, its core parameters are set as follows: laser linewidth <3kHz, probe pulse 100ns, sampling rate 10kHz, and spatial resolution 2m. Fiber optic host 4 is directly connected to the field via a spare fiber core of the existing communication optical cable, forming a closed-loop monitoring system.

[0067] When a sudden flood submerges the propeller, taking the current flow velocity of 2.0 m / s as an example, the water flow drives the propeller 31 to rotate at a speed of 2 revolutions per second. Through a 1:4 transmission structure, this generates an 8Hz mechanical impact pulse, which is coupled to the optical cable. Simultaneously, the remote fiber optic host 4 and the analysis host 5 continuously collect Rayleigh scattering signals along the optical cable and perform dual edge computing calculations: on the one hand, a short-time Fourier transform (STFT) is performed on the flow velocity segment signal to clearly identify the 8Hz fundamental frequency and its harmonics, with a calibration coefficient k = 0.25 m / s / Hz. The formula V = k × f is used to calculate the flow velocity as 2.0 m / s in real time. On the other hand, energy spectrum analysis is performed on the optical cable at the liquid level segment. Utilizing the significant difference between underwater "low-frequency surging noise" and airborne "weak high-frequency wind noise," the energy gradient mutation algorithm accurately locates the gas-liquid interface, determining the real-time liquid level to be 4.5 meters. Finally, the calculated data is sent to the data server 6 via the railway dedicated network. If the liquid level exceeds the 5.0-meter warning line, the system immediately triggers a multi-level response: a red alarm is pushed to monitoring terminal 7, triggering the audible and visual alarms on-site and at the terminal, and automatically playing real-time audio collected by the fiber optic cable. By hearing a clear and rapid "tap-tap-tap" impact sound and the sound of flowing water, the on-duty personnel achieve dual verification through "data + audio." After confirming a genuine flood hazard, they can immediately activate the emergency plan to implement measures such as closing off or limiting the speed of the affected section.

[0068] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above description is only a specific embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A device for monitoring the flood discharge level and flow velocity of bridges and culverts, characterized in that, This includes flow rate monitoring components, sensing optical cables, and signal processing equipment; The flow rate monitoring component includes an impeller, an impact generator driven by the impeller, and a vibration transmission rod. One end of the vibration transmission rod is connected to the impact generator, and the other end of the vibration transmission rod is fixedly connected to the cable body of the sensing optical cable. The sensing optical cable is laid on the surface of the structure in a continuous path, and the continuous path extends in a non-linear path in the vertical direction. The signal processing device is connected to the sensing optical cable.

2. The bridge and culvert flood discharge level and flow velocity monitoring device according to claim 1, characterized in that, The impeller is a propeller, and the shaft of the propeller is connected to the impact generator through a transmission mechanism.

3. The bridge and culvert flood discharge level and flow velocity monitoring device according to claim 2, characterized in that, The flow rate monitoring component also includes a streamlined shroud, and the propeller is disposed inside the shroud.

4. The bridge and culvert flood discharge level and flow velocity monitoring device according to claim 1, characterized in that, The impact generator is a mechanical striking pin mechanism or a cam mechanism.

5. The bridge and culvert flood discharge level and flow velocity monitoring device according to claim 1, characterized in that, The vibration transmission rod is fixedly connected to the cable body of the sensing optical cable by a clamp.

6. The bridge and culvert flood discharge level and flow velocity monitoring device according to claim 5, characterized in that, The vibration transmission rod and the clamp are either an integral structure or connected separately.

7. The bridge and culvert flood discharge level and flow velocity monitoring device according to claim 1, characterized in that, The sensing optical cable is an integrated sensing optical cable.

8. The bridge and culvert flood discharge level and flow velocity monitoring device according to claim 1, characterized in that, The non-linear path is S-shaped, spiral, or stepped.

9. A bridge and culvert flood discharge level and flow velocity monitoring device according to claim 1, characterized in that, The signal processing device includes an optical fiber host and an analysis host, with the optical fiber host connected to the sensing optical cable and the analysis host respectively.

10. A bridge and culvert flood discharge level and flow velocity monitoring device according to claim 1, characterized in that, The bridge and culvert flood discharge level and flow velocity monitoring device also includes a support frame, on which the flow velocity monitoring component is mounted.

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