Road guardrail upright post burial depth detection device based on ground penetrating radar

Abstract

The invention provides a road guardrail stand column burial depth detection device based on a ground penetrating radar, and relates to the technical field of traffic safety facility detection.The road guardrail stand column burial depth detection device comprises the ground penetrating radar and a data processing device.The ground penetrating radar is placed on the road surface and moves in the direction parallel to the driving direction and away from a target stand column by a preset distance, and meanwhile the ground penetrating radar detects the burial depth of the target stand column; diffracted waves at the bottom of a target stand column are subjected to side detection by using the beam width of a radar antenna, and the buried depth of the bottom of the target stand column is calculated according to reflected waves of a layer interface where the buried depth of the target stand column is located and diffracted waves of diffraction points in combination with the number of strata, so that mobile detection can be performed on a road surface, and the detection efficiency is greatly improved; and high-accuracy and high-resolution target detection is realized, and engineering detection requirements are met.

Description

Technical Field

[0001] The invention relates to the technical field of traffic safety facility detection, and in particular to a device for detecting the buried depth of highway guardrail posts based on ground penetrating radar. Background Art

[0002] As the main body that bears the impact of vehicles rushing out of the road, whether the highway guardrail column has sufficient burial depth according to the design requirements will directly affect its protection ability against vehicles and is an extremely important indicator. Therefore, it is necessary to detect the burial depth at the bottom of the column. The traditional method is to pull out the column on site, that is, to pull out the column and then test it. Although this method has the highest accuracy, it is labor-intensive and easy to damage the integrity of the slope and roadbed. After pulling out the column, the roadbed needs to be re-compacted before it can be driven in again. Therefore, the on-site column pulling method cannot be used as a daily detection method. Therefore, the engineering community is eagerly looking forward to effective and reliable non-destructive testing technology and equipment.

[0003] The current non-destructive testing methods can be roughly divided into three categories: (1) electromagnetic induction method; (2) ultrasonic method; (3) impact elastic wave. However, these methods are very inefficient and the detection accuracy cannot be guaranteed. Therefore, the present invention provides a highway guardrail post buried depth detection device based on ground penetrating radar, which can perform mobile detection on the road surface, greatly improving the detection efficiency. Summary of the invention

[0004] The purpose of the present invention is to provide a device for detecting the buried depth of highway guardrail posts based on ground penetrating radar. The ground penetrating radar is placed on the road surface. While the ground penetrating radar moves in a direction parallel to the driving direction and at a preset distance from the target post, the beam width of the radar antenna is used to perform lateral detection of the diffraction wave at the bottom of the target post. The buried depth of the bottom of the target post is calculated based on the reflection wave at the interface of the layer where the buried depth of the target post is located and the diffraction wave at the diffraction point, combined with the number of strata. Not only can mobile detection be performed on the road surface, greatly improving the detection efficiency, but also high-accuracy and high-resolution target detection is achieved, meeting the requirements of engineering detection.

[0005] In order to solve the above technical problems, the present invention adopts the following solutions: A device for detecting the buried depth of highway guardrail posts based on ground penetrating radar comprises a ground penetrating radar and a data processing device. The ground penetrating radar is placed on the road surface. When the ground penetrating radar moves in a direction parallel to the driving direction and at a preset distance from a target post, the ground penetrating radar uses the beam width of the radar antenna to perform lateral detection on the target post. The data processing device is used to analyze and process radar wave data collected by the ground penetrating radar.

[0006] Furthermore, when the ground penetrating radar uses the beam width of the radar antenna to detect the side of the target column, when the diameter of the target column is smaller than the wavelength, a diffraction wave is generated. Furthermore, the side detection refers to detecting a target column that deviates from directly below the radar antenna through the beam width of the radar antenna, thereby realizing side detection of the target column.

[0007] Furthermore, the radar antenna adopts ground-close detection or inclined detection. When detecting close to the ground, the radar antenna is in close contact with the road surface; when detecting at an angle, the radar antenna is equipped with a wedge-shaped structure device, which creates an angle between the wedge-shaped structure device and the road surface to change the beam incident angle.

[0008] Furthermore, the analysis and processing process of the data processing device is as follows: S1, obtaining radar wave data of the ground penetrating radar in real time, detecting the radar wave data, if the reflected wave of the interface of the layer where the target column is buried and the diffraction waves of each diffraction point are detected, the horizontal distance between the current ground penetrating radar and the target column is obtained, and then go to step S2; S2, performing layered medium judgment on the reflected wave at the interface of the layer where the target column is buried, and obtaining the stratum number of the interface of the layer where the target column is buried according to the layered medium judgment result; S3. According to the horizontal distance between the current ground penetrating radar and the target column, the number of strata at the interface of the layer where the target column is buried, and the diffraction waves of each diffraction point, the buried depth of the bottom of the target column is calculated according to the ray path of the radar wave.

[0009] Furthermore, the step S3 includes the following steps: S31, obtaining the number of the stratum layer of the layer interface where the buried depth of at least one target column is located; S32, calculating the layer velocity of each layer and the arrival time of the radar wave to the layer according to the layer number of the layer interface where the target column is buried; S33. According to the layer velocity of the stratum layer, the arrival time of the radar wave at the stratum layer, the horizontal distance between the current ground penetrating radar and the target column, and the diffraction waves of each diffraction point, the buried depth of the bottom of the target column is calculated according to the radar wave ray path.

[0010] Furthermore, in S3, the process of calculating the layer velocity of each layer and the arrival time of the radar wave to the layer according to the layer number of the layer interface where the target column is buried is as follows: According to the order of the stratigraphic layers at the interface of the layer where the target column is buried, the speed at which the radar wave reaches the stratigraphic layers is fitted in turn to obtain the layer velocity of the stratigraphic layers. At the same time, the time when the radar wave reaches the stratigraphic layers is calculated according to the layer velocity of the stratigraphic layers to obtain the arrival time of the radar wave to the stratigraphic layers.

[0011] Further, in S31, the stratigraphic layer number of the layer interface where the burial depth of at least one target column is located is obtained. When the stratigraphic layer number of the layer interface where the burial depth of one target column is located is obtained, the diffraction waves of each diffraction point detected are the diffraction waves at the bottom of the target column; when the stratigraphic layer numbers of the layer interfaces where the burial depths of multiple target columns are located are obtained, the diffraction waves of each diffraction point detected include the diffraction waves at the intersection of multiple target columns and the layer interface where the burial depth of the target column is located, and the diffraction waves at the bottom of the target column.

[0012] Furthermore, the process of calculating the buried depth of the bottom of the target column in step S33 is as follows: When the stratum number of the layer interface where the buried depth of a target column is located is obtained, the shortest time of the diffraction wave at the bottom of the target column is obtained according to the diffraction wave at the bottom of the target column, and then the buried depth of the bottom of the target column is calculated according to the layer velocity of the stratum number, the shortest time of the diffraction wave at the bottom of the column and the horizontal distance between the ground penetrating radar and the target column and the radar wave ray path; When the stratum numbers of the layer interfaces where the buried depths of multiple target columns are located are obtained, the shortest time of the diffraction waves at the bottom of the column is obtained according to the diffraction waves at the bottom of the target column, and the incident angle of the radar wave reaching each layer interface is calculated according to the diffraction waves at the intersection of the multiple target columns and the layer interface where the buried depths of the target columns are located, so as to obtain the incident angles of the radar waves at different stratum numbers, and according to the layer velocities of the multiple stratum numbers, the arrival time of the radar waves at the stratum numbers, the shortest time of the diffraction waves at the bottom of the column, the horizontal distance between the ground penetrating radar and the target column and the incident angles of the radar waves at different stratum numbers, the buried depth of the bottom of the target column is calculated according to the radar wave ray path.

[0013] Beneficial effects of the present invention: The present invention provides a buried depth detection device for highway guardrail posts based on ground penetrating radar. The existing ground penetrating radar is used for detection. The ground penetrating radar is placed on the road surface. While moving in a direction parallel to the driving direction and at a preset distance from the target post, the beam width of the radar antenna is used to perform lateral detection of the diffraction wave at the bottom of the target post. Through the lateral detection, not only the reflected wave of the layer interface directly below can be detected, but also the diffraction wave at the bottom of the side target post can be detected. The reflected wave and the diffraction wave can be analyzed and processed to calculate the buried depth of the bottom of the target post. The buried depth detection device for highway guardrail posts in the present invention performs mobile detection on the road surface, which overcomes the disadvantage of low efficiency of traditional methods. In addition, while meeting the non-contact detection of the buried depth of highway posts, radar antennas of different frequencies can also be used to achieve detection of different depths and resolutions, thereby achieving fast and high-resolution radar detection and meeting engineering detection requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1It is a schematic plan view of the road surface when the ground penetrating radar performs lateral detection on a pillar in Example 1 of the present invention; Figure 2 It is a schematic diagram of changing the beam width of the ground penetrating radar when performing side detection on a column in Example 1 of the present invention; Figure 3 It is a schematic diagram of the beam width when the ground penetrating radar that forms an angle with the road surface performs lateral detection on a pillar in Example 1 of the present invention; Figure 4 Schematic diagram of the process of analysis and processing in Example 1 of the present invention; Figure 5 It is a schematic cross-sectional diagram of the principle of side detection of a target column by a ground penetrating radar when the target column is buried at a single layer in Example 1 of the present invention; Figure 6 It is a schematic cross-sectional view of the principle of side detection of a target column by a ground penetrating radar when the target column is buried at a depth of two layers in Example 1 of the present invention; Figure 7 It is a schematic cross-sectional diagram of the principle of side detection of a target column by a ground penetrating radar when the target column is buried at three layers in Example 1 of the present invention; Figure 8 It is a schematic diagram of a vertical slice of a three-dimensional model for simulating the bottom detection of a target column in Example 1 of the present invention; Fig. 9 This is a schematic diagram of a radar profile obtained by ground-penetrating radar detection of a simulated target column buried at two layers in Example 1 of the present invention. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] The relative arrangement of components and steps, the numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

[0017] At the same time, it should be understood that for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0018] Additionally, descriptions of well-known structures, functions, and configurations may be omitted for clarity and conciseness.One of ordinary skill in the art will recognize that various changes and modifications may be made to the examples described herein without departing from the spirit and scope of the present disclosure.

[0019] Technologies, methods, and apparatus known to ordinary technicians in the relevant field may not be discussed in detail, but where appropriate, such technologies, methods, and apparatus should be considered part of the authorization specification.

[0020] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0021] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments: Example 1 In this embodiment, a device for detecting the buried depth of a highway guardrail post based on a ground penetrating radar is provided, including a ground penetrating radar and a data processing device. Figure 1 As shown, a plurality of pillars are arranged on the road surface of the highway, a ground penetrating radar is placed on the road surface of the highway, and the ground penetrating radar is moved along its ground penetrating radar moving line for detection, and the ground penetrating radar moving line moves along a preset distance from the target pillar and parallel to the driving direction, and radar wave data can be collected while moving; the data processing device is used to analyze and process the radar wave data collected by the ground penetrating radar, and obtain the buried depth of the bottom of the target pillar through analysis and processing.

[0022] The data processing device includes a Windows system computer with a graphics card and data processing software. The data processing software is developed based on MATLAB and has the functions of importing, processing, displaying and exporting radar data.

[0023] When the ground penetrating radar detects radar waves, the beam radiated by the radar antenna has a width. Therefore, the ground penetrating radar can not only detect the target directly below the radar antenna, but also detect the target that deviates from the directly below within a certain range. The present invention uses the beam width of the radar antenna to detect the side of the target column, such as Figure 2 As shown, the side detection mainly refers to detecting the target column that deviates from directly below the radar antenna through the beam width of the radar antenna, thereby realizing side detection of the target column.

[0024] When the ground-penetrating radar is detecting radar waves, the radar waves will emit electromagnetic scattering when encountering a target. When the target is much larger than the wavelength, reflection occurs. Reflection is a special case of scattering. When the target is smaller than the wavelength, diffraction occurs. Therefore, when the ground-penetrating radar uses the beam width of the radar antenna to detect the side of the target column, when the diameter of the target column is smaller than the wavelength, a diffraction wave is generated. In addition, when the ground-penetrating radar uses the beam width of the radar antenna to detect the side of the target column, the radar wave encounters the interface of the target layer and is reflected. When it encounters the intersection of the target column and the interface of the layer where the target column is buried, diffraction occurs. This intersection is the diffraction point.

[0025] Therefore, when using the beam width of the radar antenna to perform lateral detection on the target column, not only the diffraction wave at the bottom of the target column can be detected, but also the reflected wave at the layer interface directly below can be detected. By analyzing and processing the reflected wave at the layer interface, the structural characteristics of the stratum can be obtained, and the stratum layer number of the layer interface where the target column is buried can be obtained through analysis and processing.

[0026] In the process of analyzing and processing the radar wave data collected by the ground penetrating radar, the data processing device considers the layered media in the stratum layers at the interface of the layer where the burial depths of different target columns are located, and obtains the layer velocity of multiple stratum layers by means of velocity fitting. Then, with the help of ray relationship, the burial depth of the bottom of the target column can be calculated, and the burial depth of the bottom of the target column can be accurately obtained.

[0027] In addition, considering the complexity of underground conditions, when detection is sometimes difficult, an auxiliary device can be used to appropriately change the beam direction and increase the radiation energy of the radar antenna toward the bottom of the target column. In one embodiment, Figure 3 As shown, the radar antenna adopts tilted detection, and a wedge-shaped structure is mounted on the radar antenna. The wedge-shaped structure creates a certain angle between the radar antenna and the road surface, which is used to change the beam incident angle.

[0028] When the beam width of the radar antenna is used to detect the side of the target column, the ground penetrating radar can collect radar wave data in real time and upload the radar wave data to the data processing device, so that the data processing device analyzes and processes the radar wave data, such as Figure 4 As shown, the specific process is as follows: S1, obtaining radar wave data of the ground penetrating radar in real time, detecting the radar wave data, if the reflected wave of the interface of the layer where the target column is buried and the diffraction waves of each diffraction point are detected, the horizontal distance between the current ground penetrating radar and the target column is obtained, and then go to step S2; Among them, the horizontal distance between the GPR and the target column was directly measured by a tape measure; S2, performing layered medium judgment on the reflected wave at the interface of the layer where the target column is buried, and obtaining the stratum number of the interface of the layer where the target column is buried according to the layered medium judgment result; S3. According to the horizontal distance between the current ground penetrating radar and the target column, the number of strata at the interface of the layer where the target column is buried, and the diffraction waves of each diffraction point, the buried depth of the bottom of the target column is calculated according to the ray path of the radar wave.

[0029] Preferably, step S3 includes the following steps: S31, obtaining the number of the stratum layer of the layer interface where the buried depth of at least one target column is located; S32, calculating the layer velocity of each layer and the arrival time of the radar wave to the layer according to the layer number of the layer interface where the target column is buried; S33. According to the layer velocity of the stratum layer, the arrival time of the radar wave at the stratum layer, the horizontal distance between the current ground penetrating radar and the target column, and the diffraction waves of each diffraction point, the buried depth of the bottom of the target column is calculated according to the radar wave ray path.

[0030] Since the structural characteristics of the strata are composed of strata arranged in sequence from top to bottom, when the ground penetrating radar uses the beam width of the radar antenna to perform lateral detection on the target column, the radar waves can reach multiple strata in sequence from top to bottom and generate corresponding reflected waves or diffracted waves at the layer interfaces corresponding to the multiple strata.

[0031] Therefore, when the ground penetrating radar uses the beam width of the radar antenna to perform lateral detection on the target column, at least one stratigraphic layer number of the layer interface where the target column is buried will be obtained. In addition, since different stratigraphic layer numbers will affect the radar wave ray path, the radar wave data collected by the ground penetrating radar are different. Specifically, when the stratigraphic layer number of the layer interface where the depth of a target column is buried is obtained, the diffraction wave at the bottom of the target column can be detected in the radar wave data; when the stratigraphic layer numbers of the layer interfaces where the depths of multiple target columns are buried are obtained, the diffraction waves at the intersection of multiple target columns and the layer interface where the depth of the target column is buried, and the diffraction waves at the bottom of the target column can be detected in the radar wave data.

[0032] Based on the radar wave data collected from the above-mentioned different numbers of strata, the analysis and processing methods of the data processing device are also different. According to the different numbers of strata, the data analysis and processing methods are divided into the following two methods: The first data analysis and processing method: when the stratum number of the interface where the target column is buried is obtained, the shortest time of the diffraction wave at the bottom of the target column is obtained according to the diffraction wave at the bottom of the target column, and then the burial depth of the bottom of the target column is calculated according to the layer velocity of the stratum number, the shortest time of the diffraction wave at the bottom of the column and the horizontal distance between the ground penetrating radar and the target column, and the radar wave ray path; The second data analysis and processing method: when the stratigraphic layers of the layer interfaces where the buried depths of multiple target columns are located are obtained, the shortest time of the diffraction waves at the bottom of the column is obtained according to the diffraction waves at the bottom of the target column, and the incident angle of the radar wave reaching each layer interface is calculated according to the diffraction waves at the intersection of the multiple target columns and the layer interface where the buried depths of the target columns are located, and the incident angle of the radar wave at different stratigraphic layers is obtained. According to the layer velocity of multiple stratigraphic layers, the arrival time of the radar wave at the stratigraphic layers, the shortest time of the diffraction waves at the bottom of the column, the horizontal distance between the ground penetrating radar and the target column and the incident angle of the radar wave at different stratigraphic layers, the buried depth of the bottom of the target column is calculated according to the radar wave ray path.

[0033] Based on the above two data analysis and processing methods, the specific process of analyzing and processing the radar wave data is explained when obtaining the stratigraphic layer number of the layer interface where one target column is buried, the stratigraphic layer number of the layer interface where two target columns are buried, and the stratigraphic layer number of the layer interface where three target columns are buried.

[0034] like Figure 5 As shown in FIG. 1 , when the stratum number of the layer interface where the target column is buried is obtained, the layered medium is a single-layer medium, and the layer interface where the target column is buried is a single layer, that is, the target column is buried in the stratum layer number 1. The ground penetrating radar can only receive the direct wave and the diffraction wave at the bottom of the target column. The single-channel waveform closest to the target column is Figure 5 On the right side, as the ground penetrating radar moves along the ground penetrating radar mobile survey line, the phase axis composed of the direct wave is distributed in a straight line, and the diffraction wave of the target column is distributed in a hyperbolic curve. At this time, the burial depth h of the bottom of the target column is: ; Where t is the shortest time of diffraction wave at the bottom of the target column; v 1 is the layer velocity of layer 1; D is the horizontal distance between the ground penetrating radar and the target column; where v 1 It can be obtained through velocity fitting method, or based on prior knowledge when the diffraction wave is unclear.

[0035] like Figure 6 As shown in FIG. 1 , when the stratum number of the interface of the layer where the two target columns are buried is obtained, the layered medium is a two-layer medium, and the interface of the layer where the target column is buried is two layers, that is, the target column burial depths are stratum number 1 and stratum number 2 from top to bottom. In addition to receiving the direct wave, the ground penetrating radar can also receive the diffraction wave at the intersection of the target column and the interface of the layer where the target column is buried, the diffraction wave at the bottom of the target column, and the reflection wave at the interface of the layer where the target column is buried. The single-channel waveform closest to the target column is Figure 6On the right side, as the ground penetrating radar moves along the ground penetrating radar mobile survey line, the direct wave and the reflected waves of stratum layer 1 and stratum layer 2 form a linear distribution of the event axis, and each diffraction wave presents a hyperbolic distribution. At this time, the burial depth h of the bottom of the target column is: ; ; in, ,h 1 is the thickness of layer number 1, h 2 is the burial depth of the target column in the stratum layer 2, t is the shortest diffraction wave time at the bottom of the target column, t 1 is the reflection time of the reflected wave of layer 1, v 1 is the velocity of layer 1, v 2 is the layer velocity of layer 1, D is the horizontal distance between the ground penetrating radar and the target column, is the incident angle of the radar wave at layer 1, is the incident angle of the radar wave at layer number 2.

[0036] like Figure 7 As shown in FIG. 1 , when the stratigraphic layer numbers of the layer interfaces where the three target columns are buried are obtained, the layered medium is a three-layer medium, and the layer interfaces where the target columns are buried are three layers, that is, the target columns are buried from top to bottom in the order of stratigraphic layer number 1, stratigraphic layer number 2, and stratigraphic layer number 3. At this time, the ground penetrating radar is similar to the ground penetrating radar received when the stratigraphic layer numbers of the layer interfaces where the two target columns are buried are obtained as mentioned above. In addition to receiving the direct wave, it can also receive the diffraction wave at the intersection of the target column and the layer interface where the target column is buried, the diffraction wave at the bottom of the target column, and the reflection wave at the layer interface where the target column is buried. The single-channel waveform closest to the target column is Figure 7 On the right side of the figure, as the ground penetrating radar moves along the ground penetrating radar mobile survey line, the direct wave and the reflected waves of the stratum layers 1, 2, and 3 are distributed in a straight line, and each diffraction wave is distributed in a hyperbolic curve. At this time, the data processing device analyzes and processes the radar wave data in a similar way to the above-mentioned way of analyzing and processing the radar wave data when obtaining the stratum layer number of the interface where the burial depths of the two target columns are located. The burial depth h of the bottom of the target column can be given as: ; ; ; in, ; h 1 is the thickness of layer number 1, h 2 is the thickness of layer number 2, h 3is the burial depth of the target column in the stratum layer 2, t is the shortest diffraction wave time at the bottom of the target column, t 1 is the reflection time of the reflected wave of layer 1, t 2 is the reflection time of the reflected wave of layer 2, v 1 is the layer velocity of layer number 1, v 2 is the layer velocity of layer number 1, v 3 is the layer velocity of layer 1, D is the horizontal distance between the ground penetrating radar and the target column, is the incident angle of the radar wave at layer 1, is the refraction angle / incident angle of the radar wave in the stratum layer 2, is the refraction angle of radar wave in layer 3.

[0037] To summarize, the present invention mainly proposes two data analysis and processing methods based on ground penetrating radar and a data processing device, one is a data analysis and processing method for a target column buried at a single layer, and the other is a data analysis and processing method for a target column buried at a multi-layer layer. Although the specific process of the above data analysis and processing gives a maximum of three layers, the specific process of analyzing and processing radar wave data in other multi-layer cases can be deduced based on the above data analysis and processing.

[0038] Specifically, taking the case of two layers, stratum layer number 1 and stratum layer number 2 from top to bottom, as an example, a vertical slice of the three-dimensional model of the target column bottom detection is obtained by simulation, such as Figure 8 As shown, the target column is buried at a depth of 1.5 meters, the thickness of layer 1 is 0.5 meters, the relative dielectric constant of layer 1 is 6.4, the resistivity of layer 1 is 1000 ohm-meters, the relative dielectric constant of layer 2 is 5, and the resistivity of layer 2 is 200 ohm-meters. At this time, the horizontal distance D between the current ground penetrating radar and the target column is 0.3 meters. The radar wave data, i.e., the radar profile, is simulated and obtained, as shown in FIG. Fig. 9 As shown, from Fig. 9 In the figure, we can clearly see the direct wave, the reflected wave, the diffraction wave at the intersection of the target column and the target column burial depth layer interface, and the diffraction wave at the bottom of the target column. According to the two diffraction waves, the layer velocities of the stratum layer 1 and the stratum layer 1 can be fitted in turn as 0.119m / ns and 0.134m / ns respectively; then according to the reflection time of the reflected wave of the stratum layer 1 of 8.1ns, the layer thickness of the stratum layer 1 can be calculated as 0.476m; then the shortest time of the diffraction wave at the bottom of the target column is read as 25ns, and according to the above formula, the burial depth of the target column in the stratum layer 2 is calculated as 1.0m, and combined with the layer thickness of the stratum layer 1 and the length of the burial depth of the stratum layer 2 of 1.0m, the burial depth of the bottom of the target column can be calculated as 1.59m.

[0039] In summary, the present invention provides a buried depth detection device for highway guardrail posts based on ground penetrating radar, which uses an existing ground penetrating radar for detection. The ground penetrating radar is placed on the road surface, and while moving in a direction parallel to the driving direction and at a preset distance from the target post, the beam width of the radar antenna is used to perform lateral detection of the diffraction wave at the bottom of the target post. Through the lateral detection, not only the reflected wave of the layer interface directly below can be detected, but also the diffraction wave at the bottom of the side target post can be detected. The reflected wave and the diffraction wave can be analyzed and processed to calculate the buried depth of the bottom of the target post, so that the buried depth detection device for highway guardrail posts in the present invention can perform mobile detection on the road surface, thereby overcoming the disadvantage of low efficiency of traditional methods. In addition, while meeting the non-contact detection of the buried depth of highway posts, radar antennas of different frequencies can also be used to achieve detection of different depths and resolutions, thereby achieving fast and high-resolution radar detection to meet engineering detection requirements.

[0040] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. According to the technical essence of the present invention, within the spirit and principles of the present invention, any simple modification, equivalent replacement and improvement made to the above embodiment still falls within the protection scope of the technical solution of the present invention.

Claims

1. A device for detecting buried depth of highway guardrail posts based on ground penetrating radar, characterized in that: The invention comprises a ground penetrating radar and a data processing device. The ground penetrating radar is placed on the road surface. When the ground penetrating radar moves in a direction parallel to the driving direction and at a preset distance from a target column, the ground penetrating radar uses the beam width of the radar antenna to perform lateral detection on the target column. The data processing device is used to analyze and process the radar wave data collected by the ground penetrating radar.

2. The device for detecting buried depth of highway guardrail posts based on ground penetrating radar according to claim 1 is characterized in that: When the ground penetrating radar uses the beam width of the radar antenna to perform side detection on the target column, when the diameter of the target column is smaller than the wavelength, diffraction waves are generated.

3. The device for detecting buried depth of highway guardrail posts based on ground penetrating radar according to claim 1 is characterized in that: The side detection refers to detecting a target column that deviates from directly below the radar antenna through the beam width of the radar antenna, thereby realizing side detection of the target column.

4. The device for detecting buried depth of highway guardrail posts based on ground penetrating radar according to claim 1, characterized in that: The radar antenna adopts ground-close detection or inclined detection. When detecting close to the ground, the radar antenna is in close contact with the road surface; when detecting at an angle, the radar antenna is equipped with a wedge-shaped structure device, which creates an angle between the wedge-shaped structure device and the road surface to change the beam incident angle.

5. The device for detecting buried depth of highway guardrail posts based on ground penetrating radar according to claim 1, characterized in that: The analysis and processing process of the data processing device is as follows: S1, obtaining radar wave data of the ground penetrating radar in real time, detecting the radar wave data, if the reflected wave of the interface of the layer where the target column is buried and the diffraction waves of each diffraction point are detected, the horizontal distance between the current ground penetrating radar and the target column is obtained, and then go to step S2; S2, performing layered medium judgment on the reflected wave at the interface of the layer where the target column is buried, and obtaining the stratum number of the interface of the layer where the target column is buried according to the layered medium judgment result; S3. According to the horizontal distance between the current ground penetrating radar and the target column, the number of strata at the interface of the layer where the target column is buried, and the diffraction waves of each diffraction point, the buried depth of the bottom of the target column is calculated according to the ray path of the radar wave.

6. The device for detecting buried depth of highway guardrail posts based on ground penetrating radar according to claim 5, characterized in that: The step S3 includes the following steps: S31, obtaining the number of the stratum layer of the layer interface where the buried depth of at least one target column is located; S32, calculating the layer velocity of each layer and the arrival time of the radar wave to the layer according to the layer number of the layer interface where the target column is buried; S33. According to the layer velocity of the stratum layer, the arrival time of the radar wave at the stratum layer, the horizontal distance between the current ground penetrating radar and the target column, and the diffraction waves of each diffraction point, the buried depth of the bottom of the target column is calculated according to the radar wave ray path.

7. The device for detecting buried depth of highway guardrail posts based on ground penetrating radar according to claim 5, characterized in that: In S3, the process of calculating the layer velocity of each layer and the arrival time of the radar wave to the layer according to the layer number of the layer interface where the target column is buried is as follows: According to the order of the stratigraphic layers at the interface of the layer where the target column is buried, the speed at which the radar wave reaches the stratigraphic layers is fitted in turn to obtain the layer velocity of the stratigraphic layers. At the same time, the time when the radar wave reaches the stratigraphic layers is calculated according to the layer velocity of the stratigraphic layers to obtain the arrival time of the radar wave to the stratigraphic layers.

8. The device for detecting buried depth of highway guardrail posts based on ground penetrating radar according to claim 6, characterized in that: In S31, the stratigraphic layer number of the layer interface where the burial depth of at least one target column is located is obtained. When the stratigraphic layer number of the layer interface where the burial depth of one target column is located is obtained, the diffraction waves of each diffraction point detected are the diffraction waves at the bottom of the target column; when the stratigraphic layer numbers of the layer interfaces where the burial depths of multiple target columns are located are obtained, the diffraction waves of each diffraction point detected include the diffraction waves at the intersection of multiple target columns and the layer interface where the burial depth of the target column is located, and the diffraction waves at the bottom of the target column.

9. The device for detecting buried depth of highway guardrail posts based on ground penetrating radar according to claim 6, characterized in that: The process of calculating the buried depth of the bottom of the target column in step S33 is as follows: When the stratum number of the layer interface where the buried depth of a target column is located is obtained, the shortest time of the diffraction wave at the bottom of the target column is obtained according to the diffraction wave at the bottom of the target column, and then the buried depth of the bottom of the target column is calculated according to the layer velocity of the stratum number, the shortest time of the diffraction wave at the bottom of the column and the horizontal distance between the ground penetrating radar and the target column and the radar wave ray path; When the stratum numbers of the layer interfaces where the buried depths of multiple target columns are located are obtained, the shortest time of the diffraction waves at the bottom of the column is obtained according to the diffraction waves at the bottom of the target column, and the incident angle of the radar wave reaching each layer interface is calculated according to the diffraction waves at the intersection of the multiple target columns and the layer interface where the buried depths of the target columns are located, so as to obtain the incident angles of the radar waves at different stratum numbers, and according to the layer velocities of the multiple stratum numbers, the arrival time of the radar waves at the stratum numbers, the shortest time of the diffraction waves at the bottom of the column, the horizontal distance between the ground penetrating radar and the target column and the incident angles of the radar waves at different stratum numbers, the buried depth of the bottom of the target column is calculated according to the radar wave ray path.

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