Detection method and detection system for hydraulic structure defects

Abstract

The invention discloses a hydraulic structure defect detection method and system, and belongs to the technical field of hydraulic engineering. Generation and collapse of bubbles are controlled through a bubble excitation device arranged underwater, shock waves generated by collapse of the bubbles are transmitted to a sensor preset in a hydraulic structure in water, and the sensor generates induction signals after receiving the shock waves and transmits the generated induction signals to a signal processing terminal. And the signal processing terminal forms a real-time signal waveform according to the received signal, and judges defect information of the hydraulic structure according to the real-time signal waveform and the initial reference signal waveform. According to the scheme, the problems that in the existing underwater / deep and long hydraulic tunnel concrete structure defect detection process, a gate needs to be closed for water drainage, workers or robots enter the tunnel for detection, the detection period is long, the cost is high, and operation safety risks exist can be solved; especially in areas with narrow space and complex environment, such as a vertical shaft, nondestructive detection of concrete deep layer defects is difficult to effectively realize.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydraulic engineering, in particular to a detection method and system for defects of hydraulic structures. BACKGROUND

[0002] With the development of China's economy and society, water conservancy projects, as important infrastructure of the national economy, directly relate to the national economy and people's livelihood. However, in actual engineering construction, cracks, honeycombs, and peeling of concrete structures often occur due to factors such as temperature stress and construction technology, which not only threaten the safety of engineering structures, but also may have a serious impact on the safety of life and property of surrounding people, especially concrete structures in underwater environments, which have high concealment and difficulty in repair, making quality control more critical. Therefore, a scientific and effective underwater concrete quality detection technology is of great significance to ensure the long-term safe and stable operation of water conservancy projects.

[0003] Currently, taking underwater / long water tunnel concrete structure inspection as an example, it mainly uses underwater robots to shoot or manually enters the tunnel to shoot, and obtains the distribution of surface defects of concrete based on image recognition. However, for the detection of deep defects of underwater concrete structures, underwater crawling robots are used to impact the concrete surface to generate vibrations, and vibration curves are obtained through fixed position seismic receivers of concrete, and combined with frequency spectrum analysis and other technologies to determine whether the concrete has defects.

[0004] However, the existing above-mentioned technologies still have the following shortcomings when applied to actual underwater concrete structure defect detection: ① The robot needs to be attached to the concrete surface to move, and the flow environment factors are numerous and the flow state is complex, making it difficult to ensure the stability of the crawling robot; ② The current above-mentioned technology is still in its infancy and is only suitable for underwater concrete structure defect detection within a water depth of 5m; ③ For deep and long tunnels, the inspection requires emptying and stopping water, which is costly and time-consuming, and even under emptying conditions, there are problems such as difficult detection and long time consumption; ④ Manual detection is high-risk, with an accident rate of up to 23% in vertical shaft detection (from "Water Conservancy Engineering Safety White Paper 2023"). SUMMARY

[0005] The present application discloses a detection method and system for defects of hydraulic structures to solve the problems of long detection period, high cost, and safety risks in the existing underwater / long water tunnel concrete structure defect detection process, which requires closing the gate and putting water into the tunnel for detection by manual or robot. Especially in narrow and complex environments such as vertical shafts, it is difficult to effectively realize non-destructive testing of deep defects of concrete.

[0006] To solve the above problems, the present application adopts the following technical solutions: In a first aspect, the present application provides a method for detecting defects of a hydraulic structure, which comprises the following steps: controlling the generation and collapse of bubbles by a bubble generating device arranged underwater, and transmitting the shock wave generated by the collapse of the bubbles to a sensor arranged in the hydraulic structure, the sensor generating an induction signal after receiving the shock wave and transmitting the generated induction signal to a signal processing terminal, the signal processing terminal forming a real-time signal waveform according to the received signal, and judging the defect information of the hydraulic structure according to the real-time signal waveform and an initial reference signal waveform.

[0007] Optionally, the number of sensors is multiple groups, and the multiple groups of sensors are uniformly distributed along the thickness direction of the hydraulic structure.

[0008] Optionally, the initial reference signal waveform is an induction signal generated by the sensor receiving the shock wave generated by the collapse of the bubbles in the working environment after the initial construction of the hydraulic structure is completed, and the induction signal is transmitted to the signal processing terminal, the signal processing terminal forms a real-time signal waveform according to the received induction signal, and the initial real-time signal waveform is taken as the initial signal waveform.

[0009] Optionally, the sensor is a piezoelectric sensor suitable for underwater use.

[0010] Optionally, the hydraulic structure is a hydraulic tunnel with a concrete structure, and the hydraulic tunnel structure is in a full water state in the working environment.

[0011] Optionally, the number of sensors is multiple groups, and the multiple groups of sensors are uniformly distributed along the circumferential direction and the extension direction of the hydraulic tunnel, and each group of sensors comprises multiple sensors uniformly distributed along the thickness direction of the hydraulic tunnel wall.

[0012] Optionally, the interval distance between two adjacent groups of sensors is 50-200m, the interval distance between two adjacent sensors in each group is less than or equal to 1m, and the embedding depths of the two sensors adjacent to the inner wall and the outer wall of the hydraulic tunnel are greater than or equal to 1 / 8 of the wall thickness of the hydraulic tunnel, respectively.

[0013] Optionally, the bubble generating device generates a bubble collapse expansion critical size greater than or equal to 1 / 10 of the diameter of the hydraulic tunnel and less than or equal to 1 / 5 of the diameter of the hydraulic tunnel.

[0014] In a second aspect, the present application further provides a detection system for defects of hydraulic structures, comprising a signal processing terminal, a bubble excitation device and sensors preset in the underwater structures; the bubble excitation device is used for controlling the generation and collapse of bubbles in the underwater environment; the sensors are uniformly distributed in multiple groups and are arranged at intervals in the hydraulic structures, and each group of sensors comprises at least two sensors arranged at intervals along the thickness direction of the hydraulic structures, the sensors are used for generating sensing signals under the action of the collapse shock wave of the bubbles and transmitting the generated sensing signals to the signal processing terminal; and the signal processing terminal is used for receiving the signals of the sensors and generating real-time signal waveforms according to the received signals.

[0015] The technical scheme adopted by the present application can achieve the following beneficial effects: The detection method and system for defects of hydraulic structures disclosed by the present application can realize nondestructive and efficient detection of deep defects of underwater / long hydraulic tunnel concrete under the condition of normal operation of the hydraulic tunnel without damaging the structural integrity, are suitable for long-term safety monitoring and health assessment of concrete structures of deep hydraulic tunnels such as water diversion tunnels, flood discharge tunnels, flood regulation and water diversion tunnels, and have the advantages of high detection efficiency, wide application range, high sensitivity, safe operation and good economy. BRIEF DESCRIPTION OF DRAWINGS

[0016] The accompanying drawings, which are included to provide a further understanding of the present application, constitute a part of the present application and illustrate the illustrative embodiments of the present application and their description serve to explain the present application, and do not constitute improper limitations on the present application. In the drawings: Fig. 1 A flowchart of the detection method for defects of hydraulic structures disclosed in the embodiments of the present application; Fig. 2 A cross-sectional structure schematic diagram of the setting mode of the sensors in the artificial tunnel disclosed in the embodiments of the present application; Fig. 3 A longitudinal cross-sectional structure schematic diagram of the setting mode of the sensors in the artificial tunnel disclosed in the embodiments of the present application; Legend of reference signs: 100-artificial tunnel, 200-bubble excitation device, 210-bubble, 300-sensor. DETAILED DESCRIPTION

[0017] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described clearly and completely below in combination with specific embodiments of the present application and corresponding drawings. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0018] The technical solutions disclosed in the various embodiments of the present application will be described in detail below in combination with the drawings.

[0019] Please refer to Figs. 1 to 3 As shown in the drawings, the embodiments of the present application disclose a detection method for defects of hydraulic structures, which comprises the following steps: the generation and collapse of bubbles 210 are controlled by a bubble exciting device 200 arranged underwater, and the shock wave generated by the collapse of the bubbles 210 is transmitted in the water to a sensor 300 preset in the hydraulic structure, the sensor 300 generates an induction signal after receiving the shock wave, and transmits the generated induction signal to a signal processing terminal, the signal processing terminal forms a real-time signal waveform according to the received signal, and judges the defect information of the hydraulic structure according to the real-time signal waveform and an initial reference signal waveform.

[0020] It is easy to understand that the above-mentioned initial reference signal waveform is that the sensor 300 receives the induction signal generated by the collapse of the bubbles 210, and transmits the induction signal to the signal processing terminal, the signal processing terminal forms a real-time signal waveform according to the received induction signal, and takes the initial real-time signal waveform as the initial signal waveform Compared with the prior art, the detection method disclosed in the embodiments uses the shock explosion shock wave generated by the collapse of the bubbles 210 as a non-destructive detection excitation source, which can realize deep defect detection under the normal operation state of the hydraulic tunnel, without the need for closing the gate to discharge water and personnel submersion detection, and has the advantages of large detection depth, wide coverage, high detection efficiency, and is suitable for long-term health monitoring and defect early warning of deep and long hydraulic tunnels and complex underwater concrete structures. In particular, the existing acoustic detection technology usually needs to be in contact with the detected structure when applied, and the vibration source needs to be closely attached to the concrete wall surface during application. The water depth and tunnel length that can be adapted when it is applied to the detection of defects of the concrete structure of the hydraulic tunnel are limited, and there are great limitations in the application of safe maintenance of the concrete of the hydraulic tunnel and the underwater concrete under deep and long water conditions, and the detection sensitivity is also easily affected by the operating environment of the hydraulic tunnel.

[0021] Specifically, the detection process can comprise the following steps: Step S1: During tunnel construction, the sensor 300 is pre-embedded in the concrete structure layer of the tunnel. After the tunnel construction is completed, the detection is triggered when the tunnel is full of water. First, the bubble excitation device 200 is used to control the bubble 210 to be excited and collapse to generate a shock wave. Then, the sensor 300 pre-embedded in the concrete structure layer of the tunnel is used to collect the complete initial reference signal waveform and store it in the signal processing terminal for subsequent long-term detection and comparison.

[0022] Step S2: During tunnel operation, the bubble excitation device 200 is periodically or as needed to generate shock waves, and real-time signals are collected by the sensor 300 embedded in the tunnel concrete structure layer and transmitted to the signal processing terminal to form real-time signal waveforms.

[0023] Step S3: The signal processing terminal compares and analyzes the real-time signal waveform with the initial reference waveform; if there are obvious changes in signal characteristics such as sudden peaks, waveform distortion, or amplitude attenuation, it is determined that the concrete structure at the corresponding location may have deep defects such as cracks, holes, or spalling.

[0024] Step S4: Based on the time delay and waveform characteristics of the abnormal signals received by different sensors 300, the location and scale of the defects can be calculated by using the location of the sensor 300 and the propagation speed of the shock wave, and an inspection report can be generated to provide a basis for tunnel operation, maintenance and health status assessment.

[0025] In this embodiment, in order to ensure the integrity of the signal sensing coverage and the detection sensitivity, multiple sets of sensors 300 are set. The multiple sets of sensors 300 are evenly distributed at intervals in the hydraulic structure, and each set of sensors 300 includes at least two sensors 300 distributed at intervals along the thickness direction of the hydraulic structure, thereby forming a grid-like deep array structure to achieve all-round monitoring of different propagation paths of shock waves and better ensure the detection effect.

[0026] Preferably, such as Fig. 2 and Fig. 3 In the setup shown, the interval between two adjacent groups of sensors 300 can be 50-200m, and the interval between two adjacent sensors 300 in each group is less than or equal to 1m. The burial depth of the two sensors 300 adjacent to the inner and outer walls of the artificial tunnel 100 is greater than or equal to 1 / 8 of the wall thickness of the artificial tunnel 100. Based on this setup standard, it can be ensured that the adjacent sensors 300 are within the shock wave range generated by the collapse of the bubble 210, so that the sensors 300 within the shock wave range can generate continuous sensing signals, avoiding the problem that the sensors 300 do not generate sensing signals due to the interval distance, which would affect the subsequent defect judgment.

[0027] Meanwhile, the bubble excitation device 200 generates a bubble 210 whose collapse expansion critical size is greater than or equal to 1 / 10 of the diameter of the artificial tunnel 100, so as to ensure that the shock wave from the collapse of the bubble 210 can reach the intensity of the sensing signal generated by the sensor 300; and the bubble excitation device 200 generates a bubble 210 whose collapse expansion critical size is less than or equal to 1 / 5 of the diameter of the artificial tunnel 100, so as to avoid the cavitation effect generated by the collapse of the bubble 210 from damaging the artificial tunnel 100.

[0028] This embodiment also discloses a detection system for defects in hydraulic structures, applicable to the above-described detection method; the disclosed detection system includes a signal processing terminal, a bubble excitation device 200, and a sensor 300 pre-installed in the underwater structure.

[0029] The bubble generating device 200 is used in the underwater environment to control the generation and collapse of bubbles 210. The number of sensors 300 is multiple sets, which are evenly distributed at intervals in the hydraulic structure. Each set of sensors 300 includes at least two sensors 300 distributed at intervals along the thickness direction of the hydraulic structure. The sensors 300 are used to generate induction signals under the action of the collapse shock wave of the bubbles 210 and transmit the generated induction signals to the signal processing terminal. The signal processing terminal is used to receive the signals from the sensors 300 and generate real-time signal waveforms based on the received signals.

[0030] Meanwhile, the sensor 300 is preferably a piezoelectric sensor suitable for underwater use. Piezoelectric sensors have the advantages of high sensitivity, strong water pressure resistance, and long-term stable operation, so they can be better suited to the operating environment of hydraulic structures. The bubble arousal device 200 can be an existing bubble nozzle or bubble gun, etc., and there can be multiple of them arranged in an array. They are placed at the corresponding positions of the hydraulic structure during detection operations. Typically, the bubble nozzle or bubble gun is connected to an air supply system and a control valve. The control valve can control the air pressure inside the bubble 210, thereby controlling the oscillation frequency and collapse of the bubble 210. Since it is an existing mechanical structure, the specific structure of the bubble arousal device 200 will not be described in detail in this embodiment.

[0031] It should be noted that the detection method and system for detecting defects in artificial structures disclosed in this embodiment include, but are not limited to, defect detection in concrete structures of artificial tunnels. It can also be applied to defect detection in other structures operating in water-rich environments. However, due to the limitations of the operating environment of artificial tunnels on existing detection technologies, the detection method and system disclosed in this embodiment have significant advantages and effects compared to existing technologies.

[0032] The above embodiments of the present invention focus on describing the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. For the sake of brevity, they will not be described in detail here.

[0033] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A method for detecting defects in hydraulic structures, characterized in that, Includes the following steps: The generation and collapse of bubbles are controlled by a bubble excitation device installed underwater. The shock wave generated by the collapse of the bubbles is transmitted in the water to a sensor pre-installed in the hydraulic structure. After receiving the shock wave, the sensor generates a sensing signal and transmits the generated sensing signal to a signal processing terminal. The signal processing terminal generates a real-time signal waveform based on the received signal and determines the defect information of the hydraulic structure based on the real-time signal waveform and the initial reference signal waveform.

2. The method for detecting defects in hydraulic structures according to claim 1, characterized in that, The sensors are arranged in multiple groups, and the multiple groups of sensors are evenly distributed at intervals on the hydraulic structure. Each group of sensors includes at least two sensors that are spaced apart along the thickness direction of the hydraulic structure.

3. The method for detecting defects in hydraulic structures according to claim 2, characterized in that, The initial reference signal waveform is generated by the sensor receiving the shock wave of bubble collapse under the working environment after the initial construction of the hydraulic structure is completed. The sensor then transmits the sensing signal to the signal processing terminal, which generates a real-time signal waveform based on the received sensing signal and uses this initial real-time signal waveform as the initial reference signal waveform.

4. The method for detecting defects in hydraulic structures according to claim 3, characterized in that, The sensor is a piezoelectric sensor suitable for underwater use.

5. The method for detecting defects in hydraulic structures according to any one of claims 1 to 4, characterized in that, The hydraulic structure is a concrete-structured hydraulic tunnel, and the hydraulic tunnel structure is in a full-water state under working conditions.

6. The method for detecting defects in hydraulic structures according to claim 5, characterized in that, The sensors are arranged in multiple groups, and the multiple groups of sensors are evenly distributed at intervals along the circumference and extension direction of the hydraulic tunnel. Each group of sensors includes multiple sensors distributed at intervals along the wall thickness direction of the hydraulic tunnel.

7. The method for detecting defects in hydraulic structures according to claim 6, characterized in that, The spacing between two adjacent groups of sensors is 50-200m; the spacing between two adjacent sensors in each group is less than or equal to 1m, and the burial depth of the two sensors adjacent to the inner and outer walls of the hydraulic tunnel is greater than or equal to 1 / 8 of the wall thickness of the hydraulic tunnel.

8. The method for detecting defects in hydraulic structures according to claim 5, characterized in that, The critical size of the collapse expansion of the bubbles generated by the bubble initiation device is greater than or equal to 1 / 10 of the diameter of the hydraulic tunnel and less than or equal to 1 / 5 of the diameter of the hydraulic tunnel.

9. A detection system for defects in hydraulic structures, characterized in that, The system includes a signal processing terminal, a bubble induction device, and sensors pre-installed in the underwater structure. The bubble induction device is used to control the generation and collapse of bubbles in the underwater environment. Multiple sets of sensors are evenly distributed throughout the hydraulic structure, and each set includes at least two sensors spaced apart along the thickness of the structure. These sensors generate induction signals under the impact of bubble collapse shock waves and transmit these signals to the signal processing terminal. The signal processing terminal receives the signals from the sensors and generates real-time signal waveforms based on the received signals.

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