Evaluation method for tension force of ground anchor

Abstract

To easily measure the tension force of an anchor.SOLUTION: An evaluation method includes the steps for: acquiring detection data, from a sensor detecting elastic waves, which indicates the detection result of an elastic wave at the time of being input to an anchor and the detection result of an elastic wave reflected within the anchor and input to the sensor; calculating the velocity of the elastic wave propagating through the anchor on the basis of the detection data; and calculating a tension force pe occurring in the anchor on the basis of the following equation (1), where Vp0 is a reference velocity of the elastic wave propagating through the anchor measured in advance, Vpa is a calculated elastic wave velocity, and θ is a correlation coefficient.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to an evaluation method, a program, and an evaluation device. [Background technology]

[0002] There are known techniques for evaluating the soundness of ground anchors installed to prevent slope collapse. For example, Patent Document 1 discloses a technique for evaluating the soundness of a ground anchor based on the propagation velocity of elastic waves traveling through the anchor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-322401 Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, the tension acting on a ground anchor is measured by a lift-off test. Because the lift-off test is performed using testing equipment such as a hydraulic jack, it requires the steps of assembling the testing equipment, taking measurements, and then dismantling the testing equipment, which can be time-consuming.

[0005] An object of the present disclosure is to provide an evaluation method, program, and evaluation device that can easily measure the tension of a ground anchor. [Means for solving the problem]

[0006] The evaluation method of the present disclosure includes the steps of: acquiring, from a sensor that detects elastic waves, detection data indicating the detection result of the elastic waves at the time when the elastic waves are input to the anchor and the detection result of the elastic waves reflected inside the anchor and input to the sensor; calculating the speed of the elastic waves propagating through the anchor based on the detection data; and calculating a reference speed of the elastic waves propagating through the anchor that has been measured in advance as V p0 , the calculated velocity of the elastic wave is V pa , and the correlation coefficient is θ, the tension p occurring in the anchor is e and calculating based on the following formula (1):

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[0007] The program of the present disclosure includes a step of acquiring, from a sensor that detects elastic waves, detection data indicating the detection result of the elastic waves at the time when the elastic waves are input to the anchor and the detection result of the elastic waves reflected inside the anchor and input to the sensor; a step of calculating the speed of the elastic waves propagating through the anchor based on the detection data; and a step of calculating a reference speed of the elastic waves propagating through the anchor that has been measured in advance as V. p0 , the calculated velocity of the elastic wave is V pa , and the correlation coefficient is θ, the tension p occurring in the anchor is e and calculating based on the following formula (1):

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[0008] The evaluation device of the present disclosure includes a detection data acquisition unit that acquires, from a sensor that detects elastic waves, detection results of the elastic waves at the time of input to the anchor and detection data indicating the detection results of the elastic waves reflected inside the anchor and input to the sensor, a velocity calculation unit that calculates the velocity of the elastic waves traveling through the anchor based on the detection data, and a reference velocity of the elastic waves traveling through the anchor that is measured in advance and is referred to as V. p0, the velocity of the elastic wave calculated by the velocity calculation unit is V pa , and the correlation coefficient is θ, the tension p occurring in the anchor is e and a tension calculation unit that calculates the tension based on the following formula (1).

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[0009] According to the present disclosure, the tension of an anchor can be easily measured. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram of a ground anchor according to a first embodiment. [Figure 2] FIG. 2 is a diagram for explaining the method for detecting an elastic wave according to the first embodiment. [Figure 3] FIG. 3 is a block diagram showing an example of the configuration of the evaluation device according to the first embodiment. [Figure 4] FIG. 4 is a diagram for explaining a method for calculating the velocity of an elastic wave according to the first embodiment. [Figure 5] FIG. 5 is a diagram for explaining a method for deriving a correlation equation between tension and elastic wave velocity according to the first embodiment. [Figure 6] FIG. 6 is a flowchart showing the flow of the tension calculation method according to the first embodiment. [Figure 7] FIG. 7 is a block diagram showing an example of the configuration of an evaluation device according to the second embodiment. [Figure 8] FIG. 8 is a flowchart showing the flow of the soundness evaluation method according to the second embodiment. [Figure 9] FIG. 9 is a diagram for explaining a method for evaluating an anchor according to the third embodiment. [Figure 10] FIG. 10 is a flowchart showing the flow of the soundness evaluation method according to the third embodiment. [Figure 11]FIG. 11 is a diagram for explaining a method for inputting an elastic wave to an anchor according to the fourth embodiment. [Figure 12] FIG. 12 is a block diagram showing an example of the configuration of an impact device according to the fourth embodiment. [Figure 13] FIG. 13 is a flowchart showing the flow of the tension calculation method according to the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Note that the present disclosure is not limited to these embodiments, and in the following embodiments, the same components are designated by the same reference numerals, and redundant description will be omitted.

[0012] [First embodiment] (Schematic diagram of ground anchor) An overview of the ground anchor according to the first embodiment will be described using Fig. 1. Fig. 1 is a schematic diagram of the ground anchor according to the first embodiment. Hereinafter, the ground anchor will be simply referred to as the anchor.

[0013] The anchor 10 is composed of PC steel strands, multi-layer PC steel strands, PC steel rods, continuous fiber reinforcement, etc. The anchor 10 is installed on a slope such as a cut slope or an embankment slope. One end of the anchor 10 is connected to the slope and the other end is connected to stable ground, thereby utilizing tension to stabilize the slope and prevent the slope from collapsing. The total length of the anchor 10 is assumed to be L1 [m].

[0014] The anchor 10 has a free length portion 12 and a restrained length portion 14. The restrained length portion 14 is formed, for example, by injecting grout into stable ground underground. One end of the free length portion 12 is fixed to the stable ground underground by the restrained length portion 14. The other end of the free length portion 12 is exposed above ground. The other end of the free length portion 12 is fixed to a structure 18 provided on the ground surface by an anchor head 16. The structure 18 is, for example, a concrete structure. The anchor head 16 and the structure 18 are fixed together with a fastener such as a nut. Because one end of the free length portion 12 is fixed to the restrained length portion 14, tension can be applied to the free length portion 12 by pulling the other end of the free length portion 12. The anchor head 16 maintains the tension applied to the free length portion 12 by fixing the other end of the free length portion 12 to the structure 18 while tension is applied to the free length portion 12. The extra length portion 12a is a portion of the free length portion 12 that is exposed to the ground. The length of the free length portion 12 is assumed to be L2 [m].

[0015] The sensor 20 is provided at the tip of the excess length portion 12a. The sensor 20 detects elastic waves incident on one end of the anchor 10 and elastic waves reflected at the other end of the anchor 10. Specifically, elastic waves are incident on one end of the free length portion 12 of the anchor 10 and reflected at the other end of the free length portion 12. The sensor 20 is, for example, a piezoelectric sensor, but is not limited to this.

[0016] The evaluation device 100 is communicably connected to the sensor 20 via a wired or wireless network. The evaluation device 100 calculates the speed of the elastic wave traveling through the free length portion 12 of the anchor 10 based on the detection result of the elastic wave detected by the sensor 20. The evaluation device 100 calculates the tension occurring in the free length portion 12 of the anchor 10 based on the calculated speed of the elastic wave.

[0017] (Method for detecting elastic waves) The elastic wave detection method according to the first embodiment will be described with reference to Fig. 2. Fig. 2 is a diagram for explaining the elastic wave detection method according to the first embodiment.

[0018] As shown in FIG. 2 , in the present disclosure, when calculating the tension generated in the free length portion 12 of the anchor 10, a sensor 20 is attached to the tip of the excess length portion 12a. The sensor 20 is connected to the evaluation device 100 by a cable 22. To calculate the tension of the anchor 10, an elastic wave is input to the anchor 10. In the present disclosure, an elastic wave is input to the anchor 10 by applying an impact to the sensor 20. For example, an operator can input an elastic wave to the anchor 10 by applying an impact to the head of the sensor 20 with a hammer 30 or the like. In this case, the impact applied to the sensor 20 may be a light impact that just touches the sensor 20. For example, the impact applied to the sensor 20 may be an impact that does not damage the sensor 20. The sensor 20 detects the elastic wave input to the anchor 10 at the timing when the impact is applied by the hammer 30. The input elastic wave propagates through the free length portion 12 and is reflected at the other end of the free length portion 12. The elastic wave reflected at the other end of the free length portion 12 travels through the free length portion 12 of the anchor 10 and is input to the sensor 20. As a result, the sensor 20 detects the elastic wave reflected at the other end of the free length portion 12. In the present disclosure, by applying an impact to the sensor 20 to input an elastic wave to the anchor 10, the input point of the elastic wave and the detection point of the reflected elastic wave coincide with each other, thereby improving the detection accuracy of the sensor 20 for elastic waves.

[0019] (Evaluation device) An example of the configuration of the evaluation device according to the first embodiment will be described with reference to Fig. 3. Fig. 3 is a block diagram showing an example of the configuration of the evaluation device according to the first embodiment.

[0020] The evaluation device 100 includes a communication unit 102 , a storage unit 104 , an input unit 106 , an output unit 108 , and a control unit 110 .

[0021] The communication unit 102 is communicably connected to the sensor 20 via a wired or wireless network. The communication unit 102 receives detection data from the sensor 20 that indicates the detection result of the elastic wave.

[0022] The memory unit 104 stores various types of information. The memory unit 104 stores, for example, speed information related to the reference speed of elastic waves propagating through the free length portion 12 of the anchor 10. The reference speed of elastic waves is, for example, a speed calculated in advance using a model that imitates the anchor 10. The reference speed of elastic waves is, for example, a speed calculated when the anchor 10 is installed on a slope or the like. The memory unit 104 stores, for example, a model formula for calculating the tension generated in the anchor. The memory unit 104 stores information such as the contents of calculations by the control unit 110 and programs. The memory unit 104 includes, for example, at least one of a random access memory (RAM), a main memory such as a read only memory (ROM), and an external memory such as an HDD (hard disk drive).

[0023] The input unit 106 accepts various input operations for the evaluation device 100. The input unit 106 outputs an operation signal corresponding to the accepted input operation to the control unit 110. The input unit 106 includes, for example, a switch, a button, a keyboard, a mouse, a touch panel, etc. When a touch panel is used as the input unit 106, the input unit 106 is disposed on the output unit 108.

[0024] The output unit 108 displays various types of video. The output unit 108 is, for example, a display including a liquid crystal display, an organic EL (Electro-Luminescence) display, etc. The output unit 108 may also include a speaker that outputs audio.

[0025] The control unit 110 controls each unit of the evaluation device 100. The control unit 110 has, for example, an information processing device such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit), and a storage device such as a RAM or a ROM. The control unit 110 executes a program that controls the operation of the evaluation device 100 according to the present invention. The control unit 110 may be realized by an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). The control unit 110 may be realized by a combination of hardware and software.

[0026] The control unit 110 includes a data acquisition unit 120 , a speed calculation unit 122 , a tension calculation unit 124 , and an output control unit 126 .

[0027] The data acquiring unit 120 acquires detection data of the elastic waves detected by the sensor 20 from the sensor 20 via the communication unit 102. Specifically, the data acquiring unit 120 acquires detection data related to the detection results of the elastic waves input from one end of the free length portion 12 of the anchor 10 and the elastic waves reflected at the other end of the free length portion 12 of the anchor 10, which are detected by the sensor 20.

[0028] The velocity calculation unit 122 calculates the velocity of the elastic wave traveling through the free length portion 12. The velocity calculation unit 122 calculates the velocity of the elastic wave based on the detected data of the elastic wave acquired by the data acquisition unit 120. FIG. 4 is a diagram for explaining a method for calculating the velocity of the elastic wave according to the first embodiment. In FIG. 4, the horizontal axis represents time [ms (milliseconds)] and the vertical axis represents signal strength [mV]. A waveform 41 shows the detection result of an elastic wave input from one end of the free length portion 12. A waveform 42 shows the detection result of an elastic wave reflected from the other end of the free length portion 12. In the example shown in FIG. 4, the elastic wave input to one end of the free length portion 12 is detected by the sensor 20 at timing t1. The elastic wave is reflected from the other end of the free length portion 12 at timing t2. The elastic wave reflected from the other end of the free length portion 12 is detected by the sensor 20 at timing t3. The velocity calculation unit 122 calculates the time from timing t1 to timing t2, which is the time it takes for an elastic wave incident on one end of the free length portion 12 to reach the other end of the free length portion 12, based on timing t1 and timing t3. The time from timing t1 to timing t2 is half the time from timing t1 to timing t3. The time from timing t1 to timing t2 is assumed to be Δt [ms]. Since the total length of the free length portion 12 is L2 [m], the velocity calculation unit 122 calculates the velocity V of the elastic wave. pa ,V pa =L2 / Δt[km / s].

[0029] The tension calculation unit 124 calculates the tension acting on the anchor 10. The tension calculation unit 124 calculates the tension acting on the anchor 10 based on the velocity of the elastic wave calculated by the velocity calculation unit 122.

[0030] In the present disclosure, an anchor model experiment using a model simulating the anchor 10 revealed that the elastic wave velocity differs between the free length portion 12 and the restrained length portion 14. The anchor model experiment also revealed that when the anchor 10 is a PC steel strand, an increase in tensioning force results in a slight decrease in velocity. Based on these findings, a correlation equation (model equation) between the velocity of elastic waves traveling through the free length portion 12 and tensioning force was derived. FIG. 5 is a diagram for explaining a method for deriving the correlation equation between tensioning force and elastic wave velocity according to the first embodiment. In FIG. 5, the horizontal axis represents tensioning force [kN] and the vertical axis represents elastic wave velocity [km / s]. In FIG. 5, open triangles represent the correlation between tensioning force and elastic wave velocity in the anchor model experiment. Open circles represent the correlation between tensioning force and elastic wave velocity in an actual anchor in the field. As the open triangles and circles indicate, the elastic wave velocity decreases as tensioning force increases. The regression line 43 is a regression line derived based on the correlation between tension and elastic wave velocity in the anchor model experiment. The regression line 44 is a regression line derived based on the correlation between tension and elastic wave velocity in the anchor 10 at the actual site. The regression lines 43 and 44 almost coincide. Therefore, based on the elastic wave velocity calculated at the actual site, the tension occurring in the anchor 10 can be calculated using the correlation equation derived based on the correlation between tension and elastic wave velocity in the anchor model experiment. Tension p e is the reference velocity of the elastic wave propagating through the anchor 10, which was previously measured by an anchor model experiment. p0 , the velocity of the elastic wave calculated by the velocity calculation unit 122 is V pa When the correlation coefficient is θ, it can be calculated using the correlation formula shown in the following formula (1).

[0031]

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[0032] The tension calculation unit 124 calculates the tension acting on the anchor 10 by substituting the velocity of the elastic wave calculated by the velocity calculation unit 122 into the above equation (1).

[0033] The output control unit 126 controls the output unit 108. The output control unit 126 controls the output unit 108 to cause the output unit 108 to output the calculation result of the tension force by the tension force calculation unit 124.

[0034] (Tension force calculation method) The flow of the tension calculation method according to the first embodiment will be described with reference to Fig. 6. Fig. 6 is a flowchart showing the flow of the tension calculation method according to the first embodiment.

[0035] The data acquiring unit 120 acquires detection data of the elastic waves input to the anchor 10 via the communication unit 102 (step S10). Specifically, the data acquiring unit 120 acquires detection data of the elastic waves incident on one end of the free length portion 12 and the elastic waves reflected at the other end of the free length portion 12. Then, the process proceeds to step S12.

[0036] The velocity calculation unit 122 calculates the velocity of the elastic wave traveling through the free length portion 12 based on the detection data acquired by the data acquisition unit 120 (step S12). Then, the process proceeds to step S14.

[0037] The tension calculation unit 124 calculates the tension occurring in the free length portion 12 based on the velocity of the elastic wave calculated by the velocity calculation unit 122 (step S14). Then, the process proceeds to step S16.

[0038] The output control unit 126 controls the output unit 108 to output the calculation result of the tension force (step S16), and then ends the processing of FIG.

[0039] As described above, in the first embodiment, the velocity of the elastic waves is calculated from the detection results of the elastic waves input to one end of the free length part of the anchor and the detection results of the elastic waves reflected at the other end of the free length part of the anchor, and the tension generated in the anchor can be calculated based on the calculated velocity. This makes it possible to easily evaluate the tension generated in the anchor installed on the slope.

[0040] [Second embodiment] (Evaluation device) An example of the configuration of the evaluation device according to the second embodiment will be described with reference to Fig. 7. Fig. 7 is a block diagram showing an example of the configuration of the evaluation device according to the second embodiment.

[0041] As shown in FIG. 7, the evaluation device 100A differs from the evaluation device 100 shown in FIG.

[0042] The soundness evaluation unit 128 evaluates the soundness of the anchor 10. The soundness evaluation unit 128 evaluates the soundness of the anchor 10 based on the tension calculated by the tension calculation unit 124, the yield tensile force of the anchor 10, and the ultimate tensile force of the anchor 10. Information on the yield tensile force of the anchor 10 and the ultimate tensile force of the anchor 10 may be stored in the storage unit 104.

[0043] (Soundness evaluation method) The flow of the soundness evaluation method according to the second embodiment will be described with reference to Fig. 8. Fig. 8 is a flowchart showing the flow of the soundness evaluation method according to the second embodiment.

[0044] The processes from step S20 to step S24 are the same as the processes from step S10 to step S14 shown in FIG. 6, respectively, and therefore will not be described.

[0045] The soundness evaluation unit 128 evaluates the soundness of the anchor 10 (step S26). Specifically, the ultimate tensile force of the anchor 10 is T us , the yield tensile force of the anchor 10 is T ysThe soundness evaluation unit 128 determines whether the tension occurring in the free length portion 12 is 0.1 T. us If the tension generated in the free length portion 12 is less than 0.1 T, the anchor 10 is determined to be non-functional. us More than 0.3T us If the tension generated in the free length portion 12 is less than 0.3T, the soundness of the anchor 10 is judged to be in a declining trend. us More than 0.6T us If the tension generated in the free length portion 12 is less than 0.6T, the anchor 10 is determined to be sound. us Over 0.65T us If the tension generated in the free length portion 12 is less than 0.65T, the soundness of the anchor 10 is judged to be in a declining trend. us Over 0.9T ys If the tension generated in the free length portion 12 is less than 0.9 T, the anchor 10 is determined to be in a dangerous state. ys As a result of the above, it is determined that there is a risk of breakage of the anchor 10. Then, the process proceeds to step S28.

[0046] The output control unit 126 controls the output unit 108 to output the calculation result of the tension force and the evaluation result of the health (step S28), and then ends the processing of FIG.

[0047] As described above, in the second embodiment, it is possible to calculate based on the tension generated in the anchor. This makes it possible to easily evaluate the soundness of the anchor installed on the slope in the first embodiment.

[0048] [Third embodiment] The anchor evaluation method according to the third embodiment will be described with reference to Fig. 9. Fig. 9 is a diagram for explaining the anchor evaluation method according to the third embodiment. The evaluation device according to the third embodiment is the same as the evaluation device 100A shown in Fig. 7, and therefore the description will be omitted.

[0049] As shown in Figure 9, multiple anchors 10 are installed along a slope 50. Conventionally, anchors 10 have been evaluated using a lift-off test. Because the lift-off test is expensive and time-consuming, only anchors 10 selected by the worker are subject to evaluation of tension and soundness. As a result, the anchors 10 that are subject to evaluation are only a few percent of the multiple anchors 10 installed on the slope 50. For this reason, if the soundness of a certain anchor 10 is poor and it needs to be replaced, the anchors 10 around it also need to be replaced, which can result in additional cost and effort.

[0050] In contrast, as described in the first and second embodiments, the present disclosure can easily evaluate the tension generated in the anchors 10 and the soundness of the anchors 10, so that all anchors 10 installed on the slope surface 50 can be evaluated. That is, in the third embodiment, a plurality of anchors 10 installed on the slope surface 50 can be evaluated area-wide. By evaluating a plurality of anchors 10 area-wide, it is possible to generate map information showing the evaluation results of the tension or soundness of each of all anchors 10 installed on the slope surface 50. The map information is, for example, information in which the locations where the anchors 10 are installed are associated with the evaluation results of the tension or soundness. By checking the map information, the worker can easily grasp the locations where anchors 10 with good evaluation results for tension or soundness are installed and anchors 10 with poor evaluation results for tension or soundness are installed. Note that when evaluating the soundness of the anchors 10 area-wide, it is not necessarily necessary to evaluate all anchors 10. For example, the soundness of all anchors 10 installed on the slope surface 50 may be evaluated every other anchor.

[0051] (Soundness evaluation method) The flow of the soundness evaluation method according to the third embodiment will be described with reference to Fig. 10. Fig. 10 is a flowchart showing the flow of the soundness evaluation method according to the third embodiment.

[0052] The processes from step S30 to step S36 are the same as the processes from step S26 to step S28 shown in FIG. 8, respectively, and therefore will not be described here.

[0053] The control unit 110A determines whether or not the evaluation of the soundness of all anchors 10 installed on the slope 50 has been completed (step S38). Specifically, if there is an input to the input unit 106 indicating that the evaluation of all anchors 10 has been completed, the control unit 110A determines that the evaluation of the soundness of all anchors 10 has been completed. If it is determined that the evaluation of the soundness of all anchors 10 has been completed (step S38; Yes), the process proceeds to step S40. If it is not determined that the evaluation of the soundness of all anchors 10 has been completed (step S38; No), the process of step S38 is repeated.

[0054] If the determination in step S38 is Yes, the soundness evaluation unit 128 generates map information of the soundness of all anchors 10 installed on the slope 50 based on the evaluation results of the soundness of all anchors 10 (step S40). Then, the process proceeds to step S42.

[0055] The soundness evaluation unit 128 controls the output unit 108 to output the generated map information of soundness (step S42). By referring to the map information, the worker can properly and easily grasp the status of all anchors 10 installed on the slope face. Then, the processing of FIG. 10 ends.

[0056] In step S40, the tension calculation unit 124 may generate map information of tensions for all anchors 10 installed on the slope face 50. In this case, in step S42, the tension calculation unit 124 may control the output unit 108 to output the generated map information of tensions.

[0057] As described above, in the third embodiment, by evaluating the anchors installed on the slope surface area-wise, it is possible to appropriately and easily grasp the status of all anchors installed on the slope surface. As a result, the third embodiment makes it possible to appropriately grasp, among multiple anchors, anchors that need to be replaced and anchors that need maintenance, thereby reducing the occurrence of unnecessary costs and effort.

[0058] [Fourth embodiment] A method for inputting an elastic wave to an anchor according to the fourth embodiment will be described with reference to Fig. 11. Fig. 11 is a diagram for explaining a method for inputting an elastic wave to an anchor according to the fourth embodiment.

[0059] As shown in FIG. 11, the fourth embodiment differs from the first embodiment shown in FIG. 1 in that a striking device 200 is provided at the tip of the extra length portion 12a.

[0060] (percussion device) An example of the configuration of the impact device according to the fourth embodiment will be described with reference to Fig. 12. Fig. 12 is a block diagram showing an example of the configuration of the impact device according to the fourth embodiment.

[0061] 12, the impact device 200 includes a sensor 20, an impact unit 202, and a drive unit 204. The impact device 200 is a device that can input elastic waves to the anchor 10 by having the impact unit 202 impact the sensor 20.

[0062] The striking unit 202 is driven by the driving unit 204 to directly strike the sensor 20. The striking unit 202 is, for example, a hammer, but is not limited to this.

[0063] The driving unit 204 is a driving mechanism including a motor, gears, etc. For example, when the driving unit 204 is driven and a driving force is transmitted to the hitting unit 202, the hitting unit 202 directly hits the sensor 20. As a result, an elastic wave is input to the anchor 10.

[0064] The impact device 200 may have a configuration in which the impact unit 202 impacts the sensor 20 in accordance with the operation of an operator. The impact device 200 may have a configuration in which the impact unit 202 impacts the sensor 20 in accordance with the control of the evaluation device 100.

[0065] (Tension force calculation method) The flow of the tension calculation method according to the fourth embodiment will be described with reference to Fig. 13. Fig. 13 is a flowchart showing the flow of the tension calculation method according to the fourth embodiment.

[0066] The control unit 110 controls the driving unit 204 of the impact device 200 to make the impact unit 202 directly impact the sensor 20 (step S50). Then, the process proceeds to step S52.

[0067] The processes from step S52 to step S58 are the same as the processes from step S10 to step S16 shown in FIG. 6, respectively, and therefore will not be described here.

[0068] As described above, in the fourth embodiment, elastic waves can be input to the anchor using a percussion device. This allows elastic waves of a certain intensity to be input to the anchor, thereby improving the accuracy of anchor evaluation.

[0069] [Other embodiments] In the above embodiments, the anchor 10 is described as being installed on a slope, but the present disclosure is not limited to this. The anchor 10 may also connect a building on the ground to stable ground underground.

[0070] (effect) The evaluation method according to the first aspect of the present disclosure includes the steps of: acquiring, from a sensor 20 that detects elastic waves, detection data indicating the detection result of the elastic waves at the time of input to the anchor 10 and the detection result of the elastic waves reflected inside the anchor 10 and input to the sensor 20; calculating the speed of the elastic waves propagating through the anchor 10 based on the detection data; and setting a previously measured reference speed of the elastic waves propagating through the anchor 10 as V p0, the calculated elastic wave velocity V pa , and the correlation coefficient is θ, the tension p occurring in the anchor 10 is e and calculating based on the following formula (1): This makes it possible to easily evaluate the tension occurring in the anchor 10 based on the velocity of the elastic wave input to the anchor 10.

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[0071] An evaluation method according to a second aspect of the present disclosure is the evaluation method according to the first aspect, in which the sensor 20 is provided at the tip of the anchor 10, and elastic waves are input to the anchor 10 by directly striking the sensor 20. This ensures that the point where the elastic waves are input coincides with the point where the waves are reflected inside the anchor 10 and input to the sensor 20, thereby improving the accuracy of evaluation of the tension of the anchor 10.

[0072] The evaluation method according to a third aspect of the present disclosure is the evaluation method according to the first or second aspect, further comprising: e This allows the tension occurring in the anchor to be evaluated.

[0073] An evaluation method according to a fourth aspect of the present disclosure is the evaluation method according to any one of the first to third aspects, in which the anchor 10 is installed along the slope 50. This makes it possible to evaluate the anchor 10 installed on the slope.

[0074] An evaluation method according to a fifth aspect of the present disclosure is the evaluation method according to the fourth aspect, in which a plurality of anchors 10 are installed along the slope face 50, and includes the steps of: evaluating the tension forces of the plurality of anchors 10 area-wise; and generating map information that indicates the evaluation results of the tension forces of the plurality of anchors 10. This makes it possible to evaluate the plurality of anchors 10 installed on the slope face 50 area-wise.

[0075] An evaluation method according to a sixth aspect of the present disclosure is the evaluation method according to any one of the first to fifth aspects, wherein the sensor 20 is integrally configured with a striking unit 202 that strikes the sensor and a driving unit 204 that drives the striking unit 202, the sensor 20 is provided at the tip of the anchor 10, and includes a step of controlling the driving unit 204 to cause the striking unit 202 to directly strike the sensor 20, thereby inputting elastic waves into the anchor 10. This allows elastic waves of a constant intensity to be input into the anchor 10, thereby improving the evaluation accuracy.

[0076] The program according to the seventh aspect of the present disclosure includes the steps of: acquiring, from a sensor 20 that detects elastic waves, detection data indicating the detection result of the elastic waves at the time of input to the anchor and the detection result of the elastic waves reflected inside the anchor 10 and input to the sensor 20; calculating the speed of the elastic waves propagating through the anchor based on the detection data; and calculating a reference speed of the elastic waves propagating through the anchor 10 measured in advance as V p0 , the calculated elastic wave velocity V pa , and the correlation coefficient is θ, the tension p occurring in the anchor 10 is e and calculating, based on the following formula (1), the tension generated in the anchor 10. This makes it possible to easily evaluate the tension generated in the anchor 10 based on the velocity of the elastic wave input to the anchor 10.

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[0077] The program according to the eighth aspect of the present disclosure includes a data acquisition unit 120 that acquires, from a sensor 20 that detects elastic waves, detection data indicating the detection result of the elastic waves at the time of input to the anchor 10 and the detection result of the elastic waves reflected inside the anchor 10 and input to the sensor 20; a velocity calculation unit 122 that calculates the velocity of the elastic waves propagating through the anchor 10 based on the detection data; and a reference velocity of the elastic waves propagating through the anchor 10 that has been measured in advance, V p0 , the velocity of the elastic wave calculated by the velocity calculation unit 122 is V pa , and the correlation coefficient is θ, the tension p occurring in the anchor 10 ise and a tension calculation unit 124 that calculates the tension based on the velocity of the elastic wave input to the anchor 10. This makes it possible to easily evaluate the tension generated in the anchor 10 based on the velocity of the elastic wave input to the anchor 10.

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[0078] The components of each device shown in the figure are conceptual functional components and do not necessarily have to be physically configured as shown. In other words, the specific form of distribution and integration of each device is not limited to that shown in the figure, and all or part of them can be functionally or physically distributed and integrated in any unit depending on various loads and usage conditions. This distribution and integration configuration may also be performed dynamically.

[0079] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the contents of these embodiments. Furthermore, the above-described components include those that can be easily imagined by a person skilled in the art, those that are substantially the same, and those that are within the so-called equivalent range. Furthermore, the above-described components can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the spirit of the above-described embodiments. [Explanation of symbols]

[0080] 10. Anchor 12 Free length section 12a Extra length 14 Confinement Head 16 Anchorhead 18 Structures 20 sensors 100,100A evaluation device 102 Communications Department 104 Storage section 106 Input section 108 Output section 110,110A control unit 120 Data Acquisition Unit 122 Speed ​​calculation section 124 Tension force calculation section 126 Output control section 128 Soundness Assessment Department 200 Percussion Device 202 Striking section 204 Drive unit

Claims

1. A step of acquiring detection data from a sensor that detects elastic waves, which indicates a detection result of the elastic waves at the time when the elastic waves are input to the anchor and a detection result of the elastic waves that are reflected inside the anchor and input to the sensor; Calculating the velocity of the elastic wave traveling through the anchor based on the detection data; The reference velocity of the elastic wave traveling through the anchor, which was measured in advance, is V ｐ０ , the calculated velocity of the elastic wave is V ｐａ , and the correlation coefficient is θ, the tension p occurring in the anchor is ｅ based on the following formula (1); Evaluation methods, including: [Equation 1]

2. the sensor is provided at a tip portion of the anchor, The elastic wave is input to the anchor by directly striking the sensor. The evaluation method according to claim 1 .

3. The calculated tension p ｅ evaluating the health of the anchor based on The evaluation method according to claim 1 or 2.

4. The anchor is installed along the slope. The evaluation method according to claim 1 or 2.

5. A plurality of the anchors are installed along the slope, A step of area-wise evaluating tension forces of the plurality of anchors; and generating map information indicating the evaluation results of the tension forces of the plurality of anchors. The evaluation method according to claim 3.

6. the sensor is integrally configured with a striking section that strikes the sensor and a driving section that drives the striking section, and the sensor is provided at the tip end of the anchor, controlling the driving unit to cause the impact unit to directly impact the sensor, thereby inputting elastic waves into the anchor; The evaluation method according to claim 1 .

7. A step of acquiring detection data from a sensor that detects elastic waves, which indicates a detection result of the elastic waves at the time when the elastic waves are input to the anchor and a detection result of the elastic waves that are reflected inside the anchor and input to the sensor; Calculating the velocity of the elastic wave traveling through the anchor based on the detection data; The reference velocity of the elastic wave traveling through the anchor, which was measured in advance, is V ｐ０ , the calculated velocity of the elastic wave is V ｐａ , and the correlation coefficient is θ, the tension p occurring in the anchor is ｅ based on the following formula (1); A program that causes a computer to execute the following. [Equation 2]

8. a detection data acquisition unit that acquires, from a sensor that detects elastic waves, detection results of the elastic waves at the time of input to the anchor and detection data indicating the detection results of the elastic waves reflected inside the anchor and input to the sensor; a velocity calculation unit that calculates the velocity of the elastic wave traveling through the anchor based on the detection data; The reference velocity of the elastic wave traveling through the anchor, which was measured in advance, is V ｐ０ , the velocity of the elastic wave calculated by the velocity calculation unit is V ｐａ , and the correlation coefficient is θ, the tension p occurring in the anchor is ｅ a tension calculation unit that calculates the tension based on the following formula (1); An evaluation device comprising: [Equation 3]

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