Underground pipeline peripheral disease detection method based on radar in pipe and transient impact

Abstract

The invention relates to an underground pipeline periphery disease detection method based on an in-pipe radar and transient impact, and the method comprises the steps: scanning a pipeline through the in-pipe radar disposed in the underground pipeline in the axis direction, obtaining radar reflection data of the pipeline and a medium around the pipeline, processing the data, and recognizing a suspected pipeline periphery disease region; an electromagnetic transient impact device and a structure response sensor are arranged at the position, corresponding to the suspected pipe periphery disease area, of the inner wall of the underground pipeline, the electromagnetic transient impact device applies an electromagnetic transient impact load to the inner wall of the pipeline, and the structure response sensor collects coupling dynamic response data of a pipe periphery structure; analyzing the response data, extracting structural dynamic response abnormal features and determining corresponding spatial positions; when the corresponding space position is located in the suspected pipe periphery disease area, the suspected pipe periphery disease area is a real pipe periphery disease area, and the disease type is judged; according to the invention, accurate identification and quantitative evaluation of the underground pipeline peripheral diseases are realized, and the detection accuracy is improved.

Description

(I) Technical Field: This invention relates to a method for detecting pipe periphery defects, and more particularly to a method for detecting underground pipe periphery defects based on in-pipe radar and transient impact. (II) Background Technology: During long-term service, urban underground pipelines are affected by various factors such as poor backfill quality, groundwater and soil erosion, ground disturbance, and external loads, resulting in defects such as loose backfill, voids, and localized cavities around the pipelines. These defects are characterized by their high degree of concealment and difficulty in direct observation of their development. Once they develop further, they can easily lead to ground subsidence and damage to the underground pipeline structure.

[0001] Existing underground pipeline defect detection technologies utilize in-pipe radar, a type of ground-penetrating radar applied inside pipelines. In-pipe radar can identify abnormal areas based on differences in the electromagnetic properties of the underground medium, and has a good application foundation in pipeline location identification and the detection of voids and cavities around the pipe. However, the detection results of in-pipe radar mainly reflect electromagnetic anomalies in the medium and cannot directly reflect the load-bearing capacity and mechanical performance of the surrounding pipe structure.

[0002] On the other hand, existing methods for detecting the mechanical properties of underground pipeline perimeter structures mostly rely on surface or external loading, inferring the state of the perimeter structure through external pipeline responses. In practical applications, these methods are easily affected by soil cover conditions and geological heterogeneity, and are difficult to effectively elicit the true dynamic response of the perimeter structure system, resulting in limited stability and insufficient specificity of the detection results.

[0003] Existing technologies generally have the problem of being strong at "identifying suspiciousness" of pipe perivascular diseases, but lacking the ability to "quantitatively assess their structural authenticity and load-bearing status". (III) Summary of the Invention: The technical problem to be solved by the present invention is to provide a method for detecting periphery defects of underground pipelines based on in-pipe radar and transient impact. This method enables accurate identification and quantitative assessment of periphery defects in underground pipelines, thereby improving the accuracy and reliability of periphery defect detection.

[0004] The technical solution of the present invention: A method for detecting periphery defects in underground pipelines based on in-pipe radar and transient impact includes the following steps: Step 1: Install an in-pipe radar inside the underground pipeline. The in-pipe radar scans the underground pipeline along its axis to obtain radar reflection data of the underground pipeline and the surrounding medium. Step 2: Analyze and process the obtained radar reflection data to identify suspected pipe periphery disease areas; Step 3: Inspect each suspected peripipe disease area sequentially to determine the authenticity of the suspected peripipe disease area; the inspection method for each suspected peripipe disease area is as follows: Step 3.1: Install electromagnetic transient impact devices and structural response sensors on the inner wall of the underground pipeline corresponding to the suspected pipe periphery defect area. Apply electromagnetic transient impact loads from the inside to the outside to the inner wall of the pipeline through the electromagnetic transient impact devices, so that the underground pipeline structure acts as an excitation source to actively act on the pipe periphery medium, thereby stimulating the coupled dynamic response of the underground pipeline periphery structure. Use structural response sensors to collect coupled dynamic response data of the underground pipeline periphery structure under the electromagnetic transient impact load. Step 3.2: Perform time-domain and / or frequency-domain analysis on the collected coupled dynamic response data of the underground pipeline perimeter structure to obtain the structural dynamic response characteristics. The structural dynamic response characteristics include response peak value, response attenuation characteristics and frequency characteristics. The structural dynamic response characteristics are used to characterize the load-bearing state of the pipeline perimeter structure. Step 3.3: Extract structural dynamic response anomaly features from the structural dynamic response features and determine the spatial location corresponding to the structural dynamic response anomaly features; Step 3.4: Verify the consistency between the spatial location corresponding to the abnormal structural dynamic response characteristics and the suspected pipe periphery defect areas identified by the in-pipe radar. When the spatial location corresponding to the abnormal characteristics of the structural dynamic response is located within the suspected pipe periphery disease area identified by the in-pipe radar, the suspected pipe periphery disease area is determined to be the actual pipe periphery disease area. When the spatial location corresponding to the abnormal characteristics of the structural dynamic response is not within the suspected pipe periphery defect area identified by the in-pipe radar, it is determined that the abnormality may be caused by local material inhomogeneity or measurement error, and the suspected pipe periphery defect area is marked as an area to be reviewed.

[0005] Based on the consistency judgment results in step 3.4, the disease types in the actual pipe periphery disease areas are identified, and the quality of the pipe periphery structure is evaluated according to the structural dynamic response characteristics.

[0006] By inverting the spatial locations corresponding to suspected pipe perimeter defects and abnormal structural dynamic response characteristics, material parameters such as modulus, Poisson's ratio, and damping ratio of the pipe perimeter structure, as well as the interlayer contact state, are obtained, thereby enabling the assessment of the quality of the pipe perimeter structure.

[0007] In step 2, the obtained radar reflection data is analyzed and processed. Based on the abnormal amplitude, abnormal travel time and / or abnormal reflection pattern of the radar reflection signal, suspected pipe periphery disease areas are identified.

[0008] In step 2, suspected pipe periphery disease areas include suspected pipe periphery void areas, suspected backfilling incomplete areas, suspected local void areas, and suspected pipe periphery structural stiffness degradation areas, etc.

[0009] In step 3.1, the electromagnetic transient impact load is a transient dynamic load with controllable amplitude and duration. According to the preset loading strategy, electromagnetic transient impact loads with different amplitudes and / or durations are applied to the inner wall of the pipe N times through the electromagnetic transient impact device, where N is a natural number greater than or equal to 1. By analyzing the variation law of the structural dynamic response characteristics under multiple loading conditions, the stability and reliability of the defect identification and quality assessment results are improved.

[0010] The in-tube radar is a radar detection robot, model X5-LS, manufactured by Wuhan Zhongyi IoT Technology Co., Ltd.

[0011] The beneficial effects of this invention are: 1. This invention applies an electromagnetic transient impact load from the inside out to the inner wall of an underground pipeline, causing the pipeline structure to act as an excitation source and actively interact with the surrounding medium. The coupled dynamic response of the pipeline's surrounding structure is closer to the actual service state of the pipeline, making the detection results more accurate.

[0012] 2. This invention combines in-pipe radar detection with structural dynamic response analysis to make a consistency judgment between the spatial location corresponding to the abnormal characteristics of structural dynamic response and the suspected pipe periphery disease area identified by in-pipe radar. This enables accurate identification and quantitative assessment of pipe periphery diseases in underground pipelines, improving the accuracy and reliability of pipe periphery disease detection. (iv) Description of the attached drawings: Figure 1 This is a schematic diagram of radar detection around an underground pipeline under normal operating conditions. Figure 2 A schematic diagram of radar detection under the condition of void around an underground pipeline. Figure 3 This is a schematic diagram of the time history curve of the detection location obtained by applying electromagnetic transient impact load to the inner wall of an underground pipeline. (V) Specific Implementation Methods: The method for detecting periphery defects in underground pipelines based on in-pipe radar and transient impact includes the following steps: Step 1: The underground pipeline is buried in the soil. The pipeline material parameters and soil parameters are set according to commonly used engineering values. An in-pipe radar is installed inside the underground pipeline. The in-pipe radar scans the underground pipeline along its axis to obtain radar reflection data of the underground pipeline and the surrounding medium, resulting in radar detection maps of two measuring points, as shown below. Figure 1 and 2 As shown; Step 2: Analyze and process the obtained radar reflection data to identify suspected pipe periphery disease areas; analysis of the figure shows that... Figure 1It is a normal, defect-free operating condition, and the radar detection map shows normal operation. Figure 2 This is a case of pipe periphery defects. The radar detection map shows that there is a void around the pipe at a distance of 0.25m from the top of the pipe. Step 3: Inspect each suspected peripipe disease area sequentially to determine the authenticity of the suspected peripipe disease area; the inspection method for each suspected peripipe disease area is as follows: Step 3.1: Install electromagnetic transient impact devices and structural response sensors on the inner wall of the underground pipeline corresponding to the suspected pipe periphery defect area. The working end of the electromagnetic transient impact device is against the inner wall of the pipeline. According to the preset loading strategy, the electromagnetic transient impact device applies multiple electromagnetic transient impact loads from the inside to the outside to the inner wall of the pipeline, so that the underground pipeline structure acts as an excitation source to actively act on the pipe periphery medium, and excite the coupled dynamic response of the underground pipeline periphery structure. The structural response sensor is used to collect the coupled dynamic response data of the underground pipeline periphery structure under the electromagnetic transient impact load. It can also detect the structural performance of the pipeline itself, and obtain the time history curve of the detection location through data processing, such as... Figure 3 As shown; Step 3.2: Perform time-domain and / or frequency-domain analysis on the collected coupled dynamic response data of the underground pipeline perimeter structure to obtain the structural dynamic response characteristics. The structural dynamic response characteristics include response peak value, response attenuation characteristics and frequency characteristics. The structural dynamic response characteristics are used to characterize the load-bearing state of the pipeline perimeter structure. Step 3.3: Extract structural dynamic response anomaly features from the structural dynamic response features and determine the spatial location corresponding to the structural dynamic response anomaly features; Step 3.4: Verify the consistency between the spatial location corresponding to the abnormal structural dynamic response characteristics and the suspected pipe periphery defect areas identified by the in-pipe radar. When the spatial location corresponding to the abnormal characteristics of the structural dynamic response is located within the suspected pipe periphery disease area identified by the in-pipe radar, the suspected pipe periphery disease area is determined to be the actual pipe periphery disease area. When the spatial location corresponding to the abnormal characteristics of the structural dynamic response is not within the suspected pipe periphery defect area identified by the in-pipe radar, it is determined that the abnormality may be caused by local material inhomogeneity or measurement error, and the suspected pipe periphery defect area is marked as an area to be reviewed.

[0013] Based on the consistency judgment results in step 3.4, the disease types in the actual pipe periphery disease areas are identified, and the quality of the pipe periphery structure is evaluated according to the structural dynamic response characteristics.

[0014] Numerical simulation results show that under the condition of pipe circumference voiding, the peak value of the dynamic response of the inner wall of the pipe increases significantly and the response decay time is significantly prolonged, which is significantly different from the condition without voiding. Combining the radar detection results inside the pipe and the structural dynamic response characteristics, it is determined that there is a pipe circumference voiding defect in this area, and the quality of the pipe circumference structure is assessed as being below normal service condition.

[0015] By inverting the spatial locations corresponding to suspected pipe perimeter defects and abnormal structural dynamic response characteristics, material parameters such as modulus, Poisson's ratio, and damping ratio of the pipe perimeter structure, as well as the interlayer contact state, are obtained, thereby enabling the assessment of the quality of the pipe perimeter structure.

[0016] In step 2, the obtained radar reflection data is analyzed and processed. Based on the abnormal amplitude, abnormal travel time and / or abnormal reflection pattern of the radar reflection signal, suspected pipe periphery disease areas are identified.

[0017] In step 2, suspected pipe periphery disease areas include suspected pipe periphery void areas, suspected backfilling incomplete areas, suspected local void areas, and suspected pipe periphery structural stiffness degradation areas, etc.

[0018] In step 3.1, the electromagnetic transient impact load is a transient dynamic load with controllable amplitude and duration. According to the preset loading strategy, electromagnetic transient impact loads with different amplitudes and / or durations are applied to the inner wall of the pipe N times through the electromagnetic transient impact device, where N is a natural number greater than or equal to 1. By analyzing the variation law of the structural dynamic response characteristics under multiple loading conditions, the stability and reliability of the defect identification and quality assessment results are improved.

[0019] The in-tube radar is a radar detection robot, model X5-LS, manufactured by Wuhan Zhongyi IoT Technology Co., Ltd.

Claims

1. A method for detecting periphery defects in underground pipelines based on in-pipe radar and transient impact, comprising the following steps: Step 1: Install an in-pipe radar inside the underground pipeline. The in-pipe radar scans the underground pipeline along its axis to obtain radar reflection data of the underground pipeline and the surrounding medium. Step 2: Process the obtained radar reflection data to identify suspected pipe periphery disease areas; Step 3: Inspect each suspected peripipe disease area sequentially to determine the authenticity of the suspected peripipe disease area; the inspection method for each suspected peripipe disease area is as follows: Step 3.1: Install electromagnetic transient impact devices and structural response sensors on the inner wall of the underground pipeline corresponding to the suspected pipe periphery defect area. Apply electromagnetic transient impact loads from the inside to the outside to the inner wall of the pipeline through the electromagnetic transient impact devices to excite the coupled dynamic response of the underground pipeline periphery structure. Use structural response sensors to collect coupled dynamic response data of the underground pipeline periphery structure under the electromagnetic transient impact load. Step 3.2: Perform time-domain and / or frequency-domain analysis on the collected coupled dynamic response data of the underground pipeline perimeter structure to obtain the structural dynamic response characteristics, including response peak value, response attenuation characteristics and frequency characteristics. Step 3.3: Extract structural dynamic response anomaly features from the structural dynamic response features and determine the spatial location corresponding to the structural dynamic response anomaly features; Step 3.4: Verify the consistency between the spatial location corresponding to the abnormal structural dynamic response characteristics and the suspected pipe periphery defect areas identified by the in-pipe radar. When the spatial location corresponding to the abnormal characteristics of structural dynamic response is located within the suspected pipe peritoneal disease area, the suspected pipe peritoneal disease area is determined to be the actual pipe peritoneal disease area. When the spatial location corresponding to the abnormal characteristics of structural dynamic response is not within the suspected pipe perivascular disease area, the suspected pipe perivascular disease area is marked as an area to be reviewed.

2. The method for detecting periphery defects of underground pipelines based on in-pipe radar and transient impact as described in claim 1, characterized in that: Based on the consistency judgment results of step 3.4, the disease type of the actual pipe periphery disease area is identified, and the quality of the pipe periphery structure is evaluated according to the structural dynamic response characteristics.

3. The method for detecting periphery defects of underground pipelines based on in-pipe radar and transient impact as described in claim 2, characterized in that: The modulus, Poisson's ratio, and damping ratio of the pipe periphery structure are obtained by inverting the spatial locations corresponding to the suspected periphery disease areas and abnormal structural dynamic response characteristics. wait These material parameters and interlayer contact conditions enable the assessment of the quality of the pipe perimeter structure.

4. The method for detecting periphery defects of underground pipelines based on in-pipe radar and transient impact as described in claim 1, characterized in that: In step 2, the obtained radar reflection data is processed, and the abnormalities in the amplitude, travel time and / or reflection morphology of the radar reflection signal are identified to identify suspected pipe periphery disease areas.

5. The method for detecting periphery defects of underground pipelines based on in-pipe radar and transient impact as described in claim 1, characterized in that: In step 2, the suspected pipe periphery disease areas include suspected pipe periphery void areas, suspected backfilling incomplete areas, suspected local void areas, and suspected pipe periphery structural stiffness degradation areas.

6. The method for detecting periphery defects of underground pipelines based on in-pipe radar and transient impact as described in claim 1, characterized in that: In step 3.1, the electromagnetic transient impact load is a transient dynamic load with controllable amplitude and duration. The electromagnetic transient impact load with different amplitudes and / or durations is applied to the inner wall of the pipe N times by the electromagnetic transient impact device, where N is a natural number greater than or equal to 1.

7. The method for detecting periphery defects of underground pipelines based on in-pipe radar and transient impact as described in claim 1, characterized in that: The in-tube radar is a radar detection robot located within a tube.

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