Anchor rod nondestructive testing method

Abstract

The invention relates to the technical field of anchor rod detection, and provides an anchor rod nondestructive testing method, an anchor rod comprises an insertion section inserted into an anchor hole and an exposed section exposed out of the anchor hole, and the method comprises the following steps: determining the position, away from the anchor hole by a preset distance, of the exposed section as a detection point position; sound waves are excited and generated at the detection point, and first reflection waves caused by the sound waves are received at the detection point; and an oscillogram is drawn according to the first reflected wave, and the grouting compactness of the anchor rod and the position where the grouting defect exists are determined according to the oscillogram. According to the nondestructive testing method for the anchor rod, the preset distance between the detection point position and the anchor hole is reasonably set, so that the detection point position can be close to the anchor hole as much as possible, energy loss of sound waves and first reflection waves in the transmission process is reduced, the accuracy of a detection result is improved, an exposed section does not need to be cut off, and auxiliary ribs do not need to be arranged; the defect that in the prior art, detection is difficult when long exposed special-shaped anchor rods with elbows and the like are detected is effectively overcome.

Description

Technical Field

[0001] The invention relates to the technical field of anchor rod detection, and in particular to a non-destructive detection method for anchor rods. Background Art

[0002] Nondestructive testing of special-shaped anchors such as long exposed anchors with elbows is a major difficulty in the industry. In order to obtain accurate test results, it is usually necessary to cut off the exposed part of the anchor. However, in some testing scenarios, such as testing long exposed anchors in key areas such as rock anchor beams, nondestructive testing is usually required and cutting off the anchor is not allowed. To solve this problem, some hydropower projects have adopted the method of pre-setting auxiliary reinforcement. Although this method can evaluate the anchoring quality of long exposed anchors, it has resulted in an increase in investment and increased difficulty in controlling the anchor construction process. In addition, when the construction effect of the pre-set auxiliary reinforcement is not good, not only will it not have a good detection effect, but it will also have a certain impact on the fullness of the grouting in the hole. Summary of the invention

[0003] The invention provides a non-destructive testing method for anchor rods, which is used to solve the defect in the prior art that it is difficult to test special-shaped anchor rods such as long exposed anchor rods with elbows.

[0004] The present invention provides a method for nondestructive testing of an anchor rod, wherein the anchor rod comprises an insertion section inserted into an anchor hole and an exposed section exposed outside the anchor hole, comprising: Determine the position of the exposed section at a preset distance from the anchor hole as a detection point; Exciting and generating a sound wave at the detection point, and receiving a first reflected wave caused by the sound wave at the detection point; A waveform diagram is drawn according to the first reflected wave, and the grouting density of the anchor rod and the location of the grouting defects are determined according to the waveform diagram.

[0005] According to the anchor bolt nondestructive testing method of the present invention, before the step of determining the position of the exposed section at a preset distance from the anchor hole as the testing point, the method further comprises: Making an anchor rod model, and in the case where the anchor rod model has exposed sections of different lengths, exciting and generating sound waves at the detection point, and obtaining a free end reflected wave formed by reflection of the exposed section at the detection point; Extracting the waveform characteristics of the free end reflected wave and constructing a filtering model; Accordingly, the step of drawing a waveform diagram according to the first reflected wave includes: Filtering the first reflected wave based on the filtering model to remove interference waves and obtain filtered data; The waveform diagram is drawn according to the filtered data.

[0006] According to the anchor rod nondestructive testing method of the present invention, the preset distance is not greater than 12 cm and not less than 8 cm.

[0007] According to the anchor bolt nondestructive testing method of the present invention, before the step of exciting and generating sound waves at the testing point, the method further comprises: Install an excitation device and a receiving device at the detection point; Wherein, the exciting device is used to excite and generate the sound wave; and the receiving device is used to receive the first reflected wave.

[0008] According to the anchor rod nondestructive testing method of the present invention, the excitation end face of the excitation device and the receiving end face of the receiving device are both perpendicular to the length direction of the insertion section.

[0009] According to the anchor bolt nondestructive testing method of the present invention, the step of installing the excitation device and the receiving device at the testing point comprises: Install a fixture at the detection point, and install the excitation device and the receiving device on the fixture; The clamp is provided with a mounting hole, the exposed section is passed through the mounting hole, and the hole wall of the mounting hole is in contact with the exposed section.

[0010] According to the anchor rod nondestructive testing method of the present invention, a mounting plane is provided on the outer wall of the clamp, and the excitation device and the receiving device are mounted on the mounting plane.

[0011] According to the anchor rod nondestructive testing method of the present invention, the clamp comprises a first part and a second part, the first part and the second part are detachably connected, and the first part and the second part are abutted to form the mounting hole.

[0012] The anchor rod nondestructive testing method of the present invention determines the position of the exposed section at a preset distance from the anchor hole as the testing point, generates sound waves at the testing point, and collects the waveform signal of the first reflected wave generated by the sound wave in the anchor rod. The waveform diagram drawn according to the waveform signal can analyze the grouting density of each position of the anchor rod and the position where the grouting defects exist. At the same time, by reasonably setting the preset distance between the testing point and the anchor hole, the testing point can be as close to the anchor hole as possible, reducing the energy loss of the sound wave and the first reflected wave during the transmission process, which is conducive to improving the accuracy of the test results. There is no need to cut off the exposed section or set auxiliary ribs, which effectively solves the defect of the prior art that it is difficult to detect special-shaped anchor rods such as long exposed elbows. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0014] Figure 1 It is one of the flow diagrams of the anchor rod nondestructive testing method provided by the embodiment of the present invention.

[0015] Figure 2 This is the second flow chart of the anchor rod nondestructive testing method provided in the embodiment of the present invention.

[0016] Figure 3 It is a schematic diagram of an anchor rod, an anchor hole, an excitation device, a receiving device and a clamp provided in an embodiment of the present invention.

[0017] Figure 4 Schematic diagram of a clamp provided in an embodiment of the present invention.

[0018] Figure 5 This is one of the test result diagrams of the first test of the embodiment of the present invention.

[0019] Figure 6 This is the second test result diagram of the first test of the embodiment of the present invention.

[0020] Figure 7 This is one of the test result diagrams of the second test of the embodiment of the present invention.

[0021] Figure 8 This is the second test result diagram of the second test of the embodiment of the present invention.

[0022] Fig. 9 This is one of the test result diagrams of the third test of the embodiment of the present invention.

[0023] Fig.10 This is the second test result diagram of the third test of the embodiment of the present invention.

[0024] Fig.11 This is the third test result diagram of the third test of the embodiment of the present invention.

[0025] Fig.12 This is the fourth test result diagram of the third test of the embodiment of the present invention.

[0026] Fig.13 This is the fifth test result diagram of the third test of the embodiment of the present invention.

[0027] Fig.14 This is one of the test result diagrams of the fourth test of the embodiment of the present invention.

[0028] Fig.15 This is the second test result diagram of the fourth test of the embodiment of the present invention.

[0029] Fig.16 This is the third test result diagram of the fourth test of the embodiment of the present invention.

[0030] Fig.17 This is the fourth test result diagram of the fourth test of the embodiment of the present invention.

[0031] Fig.18 This is the fifth test result diagram of the fourth test of the embodiment of the present invention.

[0032] Fig.19 This is the sixth test result diagram of the fourth test of the embodiment of the present invention.

[0033] Reference numerals: 1. Anchor rod; 11. Insertion section; 12. Exposed section; 2. Anchor hole; 3. Excitation device; 4. Receiving device; 5. Clamp; 51. Mounting hole; 52. First part; 53. Second part. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. 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.

[0035] Combine the following Figure 1-Figure 19 The present invention describes the anchor bolt nondestructive testing method.

[0036] In some embodiments, Figure 1 and Figure 3 As shown, the present invention provides a method for nondestructive testing of anchor rods, wherein the anchor rod 1 comprises an insertion section 11 inserted into the anchor hole 2 and an exposed section 12 exposed outside the anchor hole 2, and the method for nondestructive testing of anchor rods comprises the following steps: Step S101: determining the position of the exposed section at a preset distance from the anchor hole as a detection point.

[0037] Step S102: Excite and generate sound waves at the detection point, and receive the first reflected waves caused by the sound waves at the detection point.

[0038] Step S103: Draw a waveform diagram according to the first reflected wave, and determine the grouting density of the anchor rod and the location of the grouting defect according to the waveform diagram.

[0039] First, before testing, it is necessary to determine the testing point on the exposed section 12 of the anchor rod 1. The distance between the testing point and the anchor hole 2 is a preset distance. It can be understood that the preset distance can be determined based on factors such as the overall length of the anchor rod 1, the length of the exposed section 12, the structural shape of the exposed section 12, etc., or it can also be an empirical value obtained after multiple tests.

[0040] It can be understood that the detection point needs to be as close to the anchor hole 2 as possible so that sound waves can be stimulated at the detection point later. When the sound waves are transmitted to the insertion section 11 of the anchor rod 1, the length of the exposed section 12 through which the sound waves pass can be reduced, thereby reducing the energy loss of the sound waves when they are transmitted to the insertion section 11, thereby making the intensity of the sound waves and the corresponding reflected waves higher.

[0041] After determining the detection point, a device for exciting sound waves and receiving reflected waves can be set at the detection point, and the sound waves are excited at the detection point. The sound waves are transmitted along the anchor rod 1 and form a first reflected wave in the anchor rod 1. The waveform, period, wave number and other characteristics of the first reflected wave will be affected by the grouting density around the anchor rod 1. By collecting the waveform signal of the first reflected wave and drawing the corresponding waveform diagram, the grouting density of each position of the anchor rod 1 can be determined by analyzing the waveform, period, wave number and other characteristics of the first reflected wave, and the position of the grouting defect can be determined, thereby realizing non-destructive detection of the anchoring quality of the anchor rod.

[0042] The anchor rod nondestructive testing method of the present invention determines the position of the exposed section 12 at a preset distance from the anchor hole 2 as the testing point, excites and generates sound waves at the testing point, and collects the waveform signal of the first reflected wave generated by the sound wave in the anchor rod 1. The waveform diagram drawn according to the waveform signal can analyze the grouting density and the position of the grouting defects at various positions of the anchor rod 1. At the same time, by reasonably setting the preset distance between the testing point and the anchor hole 2, the testing point can be as close to the anchor hole 2 as possible, reducing the energy loss of the sound wave and the first reflected wave during the transmission process, which is conducive to improving the accuracy of the test results. There is no need to cut off the exposed section 12, and there is no need to set auxiliary ribs, which effectively solves the defect of the prior art that it is difficult to detect special-shaped anchor rods such as long exposed elbows.

[0043] It is understandable that when the exposed section 12 of the anchor rod 1 has a special-shaped structure such as a curved section, the detection point is set on the portion of the exposed section 12 that is directly connected to the inserted section 11 and coaxial with the inserted section 11 .

[0044] In some embodiments, Figure 2 and Figure 3 As shown, before step S101: determining the position of the exposed section at a preset distance from the anchor hole as the detection point, the method further includes: Step S080: making an anchor model, and in the case where the anchor model has exposed sections of different lengths, exciting and generating sound waves at the detection point, and obtaining free end reflected waves formed by reflection of the exposed section at the detection point.

[0045] Step S090: extracting the waveform characteristics of the free end reflected wave and constructing a filtering model.

[0046] Before testing the anchor rod 1 in the actual application scenario, multiple anchor rod models with the same specifications as the anchor rod 1 can be made first, and the anchor rod model can be truncated into exposed section models of different lengths. The corresponding detection points are determined on each exposed section model according to the preset distance in the aforementioned embodiment, and excitation is set at the detection points to generate sound waves. The sound waves will form free end reflection waves in the exposed section model. The free end reflection wave signals generated by the exposed section models of different lengths are collected to extract the waveform characteristics of the free end reflection wave signals generated by the exposed section models at each length, and a filtering model is established based on the length of the exposed section 12 and the corresponding waveform characteristics.

[0047] Accordingly, in this embodiment, the step of drawing a waveform diagram according to the first reflected wave includes: The first reflected wave is filtered based on the filtering model to remove the interference wave and obtain filtered data.

[0048] Draw a waveform graph based on the filtered data.

[0049] During actual detection, the first reflected wave collected at the detection point is actually a synthetic wave formed at the detection point by the reflected wave generated by the exposed section 12 and the reflected wave generated by the inserted section 11. By performing direction filtering on the first reflected wave based on the filtering model, the interference caused by the reflected wave generated by the exposed section 12 in the first reflected wave can be filtered out, thereby obtaining the corresponding filtered data. The waveform signal-to-noise ratio of the waveform returned according to the filtered data is higher, which can better reflect the grouting density of each position of the inserted section 11, thereby making the detection result more accurate and reliable.

[0050] Specifically, in some embodiments, the preset distance is not greater than 12 cm and not less than 8 cm. In this embodiment, by limiting the preset distance to between 8 cm and 12 cm, the detection point can be as close to the anchor hole 2 as possible, reducing the energy loss of the sound wave and the reflected wave in the process of passing through the exposed section 12, which is conducive to improving the accuracy of the detection. At the same time, there is also a certain distance between the detection point and the anchor hole 2 to facilitate the installation of corresponding instruments and equipment.

[0051] For example, the preset distance is 12 cm or 8 cm. Preferably, the preset distance may be 10 cm, and the detected waveform has the best effect.

[0052] In some embodiments, Figure 3 and Figure 4 As shown, before the step of exciting the detection point to generate sound waves, it also includes: Install the excitation device and the receiving device at the detection point.

[0053] The exciting device 3 is used to generate sound waves; the receiving device 4 is used to receive the first reflected wave.

[0054] In this embodiment, by installing an excitation device 3 and a receiving device 4 at the detection point, the excitation device 3 can generate sound waves at the detection point, and the receiving device 4 is used to receive the first reflected wave induced by the sound wave in the anchor rod 1.

[0055] Furthermore, in some embodiments, Figure 3 As shown, the excitation end face of the excitation device 3 and the receiving end face of the receiving device 4 are both perpendicular to the length direction of the insertion section 11. In this embodiment, by making the excitation end face of the excitation device 3 perpendicular to the length direction of the insertion section 11, so that the excitation direction of the excitation device 3 is set along the length direction of the insertion section 11, similarly, the receiving direction of the receiving device 4 is also set along the length direction of the insertion section 11, which is conducive to improving the waveform signal quality of the first reflected wave received by the receiving device 4, thereby improving the quality of the waveform diagram drawn based on the waveform signal, so as to better analyze the grouting density of each position of the insertion section 11.

[0056] In some embodiments, Figure 3 and Figure 4 As shown, the steps of installing the excitation device and the receiving device at the detection point include the following steps: A fixture is installed at the detection point, and the excitation device and the receiving device are installed on the fixture.

[0057] The fixture 5 is provided with a mounting hole 51 , and the exposed section 12 is passed through the mounting hole 51 , and the hole wall of the mounting hole 51 is in contact with the exposed section 12 .

[0058] In this embodiment, before setting the excitation device 3 and the receiving device 4, it is necessary to first set the clamp 5 at the detection point of the exposed section 12, and then install the excitation device 3 and the receiving device 4 on the clamp 5. The wall of the mounting hole 51 of the clamp 5 can fit tightly with the exposed section 12, so that the clamp 5 and the anchor rod 1 have high coupling and integrity, so that the sound wave is distorted when propagating between the clamp 5 and the anchor rod 1, so that the clamp 5 can transmit the sound wave between the anchor rod 1 and the excitation device 3 and the receiving device 4, and avoid the anchor rod 1 and the excitation device 3 directly contacting the anchor rod 1. It is understandable that the surface of the anchor rod 1 is usually rough and may have uneven structures or threads. If the excitation device 3 and the receiving device 4 are directly connected to the anchor rod 1, it is difficult to make the excitation device 3 and the receiving device 4 in close contact with the anchor rod 1. At the same time, during the detection process, the anchor rod 1 may also be affected by the sound waves and produce slight vibrations, which further leads to poor contact between the excitation device 3 and the receiving device 4 and the anchor rod 1, affecting the detection effect. The clamp 5 of this embodiment can ensure the effect of sound wave transmission between the excitation device 3 and the receiving device 4 and the anchor rod 1 during the detection process, so as to improve the accuracy of the detection results.

[0059] Based on the above embodiment, the present application conducted a comparative test on the anchor rod 1 with and without the fixture 5 installed, wherein the first test parameters are as follows: The length of anchor rod 1 is 2.0 m, the length of inserted section 11 is 2.0 m, and the length of exposed section 12 is 0.0 m.

[0060] Figure 5 The results of the detection of excitation and reception directly at the end of the anchor rod 1 are shown, the upper figure is a waveform diagram of the received waveform signal, and the lower figure is a phase diagram. The overall density of the inserted section 11 is 50%.

[0061] Figure 6 The results of the test are shown in which a fixture 5 is directly installed on the end of the anchor rod 1 and excitation and reception are performed on the fixture 5. The upper figure is a waveform diagram of the received waveform signal, and the lower figure is a phase diagram. The overall density of the inserted section 11 is 50%.

[0062] The parameters for the second test are as follows: The length of the calf anchor rod 1 of the factory building is 5.4m, and the length of the exposed section 12 is 0.1m.

[0063] Figure 7 The results of the detection of excitation and reception directly at the end of the anchor rod 1 are shown, the upper figure is a waveform diagram of the received waveform signal, and the lower figure is a phase diagram. The overall density of the inserted section 11 is 93%.

[0064] Figure 8The results of the test are shown in which a fixture 5 is directly installed on the end of the anchor rod 1 and excitation and reception are performed on the fixture 5. The upper figure is a waveform diagram of the received waveform signal, and the lower figure is a phase diagram. The overall density of the inserted section 11 is 92%.

[0065] The third test conditions and parameters are as follows: The length of the anchor rod 1 is 9.0 m, the length of the inserted section 11 is 7.5 m, and the length of the exposed section 12 is 1.5 m. The inserted section 11 is inserted into a long tube and grouting is performed in the long tube.

[0066] Fig. 9 The results of the detection of excitation and reception directly at the end of the anchor rod 1 are shown. The exposed section 12 can be seen to have multiple strong reflections. The upper figure is the waveform of the received waveform signal, and the lower figure is the phase diagram. The overall density of the inserted section 11 detected is 91%.

[0067] Fig.10 It shows that auxiliary reinforcement is set on one side of the anchor rod 1. The length of the auxiliary reinforcement is 7.6m, of which the length of the exposed part is 0.1m. The detection results of excitation and reception are carried out at the end of the auxiliary reinforcement. The upper figure is the waveform diagram of the received waveform signal, and the lower figure is the phase diagram. The measured overall density of the inserted section 11 is 96%.

[0068] Fig.11 The figure shows the test results of installing the fixture 5 at a distance of 0.1m between the exposed section 12 and the anchor hole 2, and performing excitation and reception on the fixture 5. The upper figure is a waveform diagram of the received waveform signal, and the lower figure is a phase diagram. The measured overall density of the inserted section 11 is 97%.

[0069] Fig.12 The figure shows the test results of cutting open a long pipe, installing a fixture 5 at a distance of 0.1 m between the exposed section 12 and the anchor hole 2, and performing excitation and reception on the fixture 5. The upper figure is a waveform diagram of the received waveform signal, and the lower figure is a phase diagram. The overall density of the inserted section 11 is measured to be 96%.

[0070] Fig.13 The figure shows the detection result of cutting open a long tube and then cutting off the exposed section 12, the length of the exposed section after cutting off is 0.1m, and directly exciting and receiving at the end of the section. The upper figure is the waveform diagram of the received waveform signal, and the lower figure is the phase diagram. The overall density of the inserted section 11 is measured to be 96%.

[0071] It can be seen that when the exposed section 12 is long, the detection result of directly exciting and receiving at the end of the anchor rod 1 has a large deviation. However, the consistency between the truncation detection and the detection method of the present application is better.

[0072] The experimental conditions and parameters of the fourth test are as follows: Six long exposed anchor rods 1 are set on the secondary slope of the ring reservoir road. The design rod length of the test anchor rods 1 is 9.0m, the rod diameter is 25mm, and the length of the exposed section 12 is 2.0m. A clamp 5 is set on the exposed section 12 at a distance of 0.1m from the anchor hole 2 to perform excitation and reception. The specific parameters of the anchor rod 1 are shown in Table 1.

[0073] Table 1 Supplementary test anchor parameters

[0074] Fig.14 The test results of anchor bolt 1 are shown. The upper figure is the waveform diagram of the received waveform signal, and the lower figure is the phase diagram. Anchor bolt 1 is designed as a complete anchor bolt without any defects. From the test waveform, the waveform is relatively regular, the decay is relatively rapid, the reflected wave energy is relatively small, and the grouting density is 92%.

[0075] Fig.15 The test results of anchor bolt 2 1 are shown. The upper figure is the waveform of the received waveform signal, and the lower figure is the phase diagram. The section between anchor bolt 2 1.0 and 7.0m away from the hole mouth of anchor hole 2 is the grouting defect section. The distance between the grouting section and the hole mouth of anchor hole 2 is 0-1.0m, and the designed grouting density is 14.3% (assuming that the non-defective hole section is dense). From the waveform diagram, there is an obvious strong reflection at a distance of 1.0m from the hole mouth of anchor hole 2. There is an obvious mutation point in the phase spectrum at this point, and the strong reflection energy appears periodically in the phase spectrum. It shows that the starting point of the empty slurry section at 1.0m is obviously reflected in the waveform, and the starting position of the waveform response is consistent with the actual defect position.

[0076] Fig.16 The test results of anchor bolt 1 No. 3 are shown. The section 3.5-4.5m away from anchor bolt 1 No. 3 and the hole mouth of anchor hole 2 is a grouting defect section, and the designed grouting density is 85.7% (assuming that the non-defective hole section is dense). From the waveform diagram, the phase spectrum at 3.55m and 4.58m shows a sudden change, and the reflection at 4.58m is enhanced, and 3.55-4.58m is divided into an abnormal section. The actual defect position is consistent with the starting position of the waveform response, and the tested grouting density is 85.3%.

[0077] Fig.17 The test results of anchor bolt 1 No. 4 are shown. The section 3.0-5.0m between anchor bolt 1 No. 4 and the hole opening of anchor hole 2 is a grouting defect section, and the designed grouting density is 71.4% (assuming that the non-defective hole section is dense). From the waveform diagram, the waveform at 3.07m and 5.19m shows abnormal changes, and the reflected wave at 5.19m is enhanced, dividing 3.07-5.19m into an abnormal section. The actual defect position is well consistent with the starting position of the waveform response, and the tested grouting density is 69.7%.

[0078] Fig.18The test results of anchor bolt 1 No. 5 are shown. The section of 6.0-7.0m between anchor bolt 1 No. 5 and the hole opening of anchor hole 2 is a grouting defect section, and the designed grouting density is 85.7% (assuming that the non-defective hole section is dense). From the waveform diagram, a waveform mutation is seen at 6.09m, and 6.09m is divided as the starting point of the abnormal section. The actual defect position is well consistent with the starting position of the waveform response, and the tested grouting density is 85%.

[0079] Fig.19 The test results of anchor bolt 1 No. 6 are shown. The section 5.0-7.0m away from anchor bolt 1 No. 6 and the hole opening of anchor hole 2 is a grouting defect section, and the designed grouting density is 71.4% (assuming that the non-defective hole section is dense). From the waveform diagram, a sudden change in the waveform is seen at 5.08m, and 6.08m is divided as the starting point of the abnormal section. The actual defect position is well consistent with the starting position of the waveform response, and the tested grouting density is 73.1%.

[0080] In some embodiments, Figure 3 and 4 As shown, a mounting plane is provided on the outer wall of the fixture 5, and the exciting device 3 and the receiving device 4 are mounted on the mounting plane.

[0081] In this embodiment, by setting a mounting plane for mounting the excitation device 3 and the receiving device 4 on the outer wall of the fixture 5, the mounting plane can ensure close contact with the excitation device 3 and the receiving device 4 during the contact process, thereby ensuring the excitation and reception effects of the sound waves, and further improving the accuracy and reliability of the detection results.

[0082] Optionally, the hole wall of the mounting hole 51 of the clamp 5 may be a smooth hole wall.

[0083] Optionally, in some embodiments, the exposed section 12 of the anchor rod 1 has a first thread, and correspondingly, the hole wall of the mounting hole 51 of the clamp 5 has a second thread that matches the first thread, and the clamp 5 and the anchor rod 1 are threadedly connected.

[0084] In this embodiment, a second thread matching the first thread is provided on the wall of the mounting hole 51 of the clamp 5, so that the clamp 5 and the anchor rod 1 can be tightly connected through threaded matching, and the clamp 5 can be prevented from being offset during the detection process. The structure is simple, convenient and practical.

[0085] In some embodiments, Figure 4 As shown, the clamp 5 includes a first part 52 and a second part 53 , the first part 52 and the second part 53 are detachably connected, and the first part 52 and the second part 53 are aligned to form a mounting hole 51 .

[0086] In this embodiment, the clamp 5 is divided into a detachable first part 52 and a second part 53, and the first part 52 and the second part 53 respectively have a partial hole wall structure of the mounting hole 51, so that the first part 52 and the second part 53 can be aligned to form the mounting hole 51, and the operation is more convenient when the clamp 5 is disassembled and assembled on the anchor rod 1.

[0087] Specifically, in some embodiments, the clamp 5 is a carbon steel clamp or an alloy clamp with magnetic adsorption characteristics (such as iron alloy). The carbon steel clamp and the alloy clamp in this embodiment have good structural strength and can be fixed on the anchor rod 1 more firmly. At the same time, the wave impedance difference between the carbon steel clamp and the alloy clamp and the anchor rod 1 is small, and the sound waves can be well transmitted between the anchor rod 1 and the excitation device 3 and the receiving device 4, which is conducive to improving the accuracy and reliability of the detection effect.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for nondestructive testing of an anchor rod, wherein the anchor rod comprises an insertion section inserted into an anchor hole and an exposed section exposed outside the anchor hole, characterized in that: include: Determine the position of the exposed section at a preset distance from the anchor hole as a detection point; Exciting and generating a sound wave at the detection point, and receiving a first reflected wave caused by the sound wave at the detection point; A waveform diagram is drawn according to the first reflected wave, and the grouting density of the anchor rod and the location of the grouting defects are determined according to the waveform diagram.

2. The anchor bolt nondestructive testing method according to claim 1, characterized in that: Before the step of determining the position of the exposed section at a preset distance from the anchor hole as the detection point, the method further includes: Making an anchor rod model, and in the case where the anchor rod model has exposed sections of different lengths, exciting and generating sound waves at the detection point, and obtaining a free end reflected wave formed by reflection of the exposed section at the detection point; Extracting the waveform characteristics of the free end reflected wave and constructing a filtering model; Accordingly, the step of drawing a waveform diagram according to the first reflected wave includes: Filtering the first reflected wave based on the filtering model to remove interference waves and obtain filtered data; The waveform diagram is drawn according to the filtered data.

3. The anchor bolt nondestructive testing method according to claim 1, characterized in that: The preset distance is no greater than 12 cm and no less than 8 cm.

4. The anchor bolt nondestructive testing method according to claim 1, characterized in that: Before the step of exciting and generating sound waves at the detection point, the method further comprises: Install an excitation device and a receiving device at the detection point; Wherein, the exciting device is used to excite and generate the sound wave; and the receiving device is used to receive the first reflected wave.

5. The anchor bolt nondestructive testing method according to claim 4, characterized in that: The excitation end face of the excitation device and the receiving end face of the receiving device are both perpendicular to the length direction of the insertion section.

6. The anchor bolt nondestructive testing method according to claim 4, characterized in that: The step of installing the excitation device and the receiving device at the detection point includes: Install a fixture at the detection point, and install the excitation device and the receiving device on the fixture; The clamp is provided with a mounting hole, the exposed section is passed through the mounting hole, and the hole wall of the mounting hole is in contact with the exposed section.

7. The anchor bolt nondestructive testing method according to claim 6, characterized in that: An installation plane is provided on the outer wall of the clamp, and the excitation device and the receiving device are installed on the installation plane.

8. The anchor bolt nondestructive testing method according to claim 6, characterized in that: The clamp comprises a first part and a second part, wherein the first part and the second part are detachably connected, and the first part and the second part are abutted against each other to form the mounting hole.

9. The anchor bolt nondestructive testing method according to claim 6, characterized in that: The clamp is a carbon steel clamp or an alloy clamp with magnetic adsorption characteristics.

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