Estimation device

Abstract

An estimation device (100) according to the present disclosure is provided with an estimation unit (104) that: acquires point cloud data on the surface of a reinforced concrete structure and a vibration spectrum which results from irradiation of the surface of the reinforced concrete structure with a vibration excitation laser for exciting vibration thereon and a vibration measurement laser and further from measurement of the intensity of a reflective wave resulting from reflection of the vibration measurement laser at the surface of the reinforced concrete structure; and estimates the internal state of the reinforced concrete structure on the basis of the presence or absence of a peak in the vibration spectrum and the presence or absence of irregularities on the surface of the reinforced concrete structure indicated in the point cloud data.

Description

Estimation device

[0001] This disclosure relates to an estimation device.

[0002] Since the bearing capacity of a reinforced concrete structure decreases due to deterioration such as exposed reinforcement, it is necessary to evaluate its safety. Structural analysis using the finite element method (FEM (Finite Element Method) analysis) is an effective method for evaluating the safety of the target structure.

[0003] In order to perform FEM analysis, it is necessary to create a model that mimics the target structure. Generally, the shape of the target structure is represented by a model consisting of elements (meshes), and deterioration information such as exposed reinforcement is reproduced by boundary conditions of the target site or model modification. The shape information of the target structure can be obtained from drawings or the like. Also, deterioration information is often obtained from photos or sketches at the time of inspection of the target structure. In this case, it is inefficient because the shape information and deterioration information of the target object are obtained separately.

[0004] As a method for mechanically obtaining the shape information of a structure, there is a method of obtaining point cloud data such as LiDAR (Light Detection And Ranging). Non-Patent Document 1 proposes a method for mechanically creating a CAD model from point cloud data. According to the method described in Non-Patent Document 1, a model for structural analysis can be created without specialized skills.

[0005] “Point2CAD: Reverse Engineering CAD Models from 3D Point Clouds”, [online], [searched on October 31, 2024], Internet <URL: https: / / arxiv.org / pdf / 2312.04962>

[0006] It is desirable to create a more accurate model that reflects the internal state of reinforced concrete structures. However, since point cloud data is coordinate information of the surface of the reinforced concrete structure, it is difficult to estimate the internal state of the reinforced concrete structure. For example, if there is a bulge on the surface of a reinforced concrete structure, it is not possible to determine from point cloud data alone whether the bulge is due to expansion caused by corrosion of the reinforcing steel inside the reinforced concrete structure or whether it is the original shape.

[0007] In light of the problems described above, the purpose of this disclosure is to provide an estimation device that can estimate the internal state of a reinforced concrete structure in more detail.

[0008] An estimation device according to one embodiment is an estimation device for estimating the internal state of a reinforced concrete structure, comprising an estimation unit that acquires point cloud data of the surface of the reinforced concrete structure, a vibration excitation laser that excites vibrations on the surface of the reinforced concrete structure, and a vibration measurement laser, and measures the intensity of the reflected waves reflected by the vibration measurement laser from the surface of the reinforced concrete structure, and estimates the internal state of the reinforced concrete structure based on the presence or absence of irregularities on the surface of the reinforced concrete structure shown in the point cloud data and the presence or absence of peaks in the vibration spectrum.

[0009] According to this disclosure, the internal state of reinforced concrete structures can be estimated in more detail.

[0010] This figure shows an example of the configuration of an estimation device according to one embodiment of the present disclosure. This is a flowchart showing an example of the operation of the estimation device shown in Figure 1. This figure shows an example of a vibration spectrum in a sound reinforced concrete structure. This figure shows an example of a vibration spectrum in a defective reinforced concrete structure. This figure illustrates vibration caused by impact to a reinforced concrete structure. This figure shows an example of model creation by the model creation unit shown in Figure 1. This figure shows another example of model creation by the model creation unit shown in Figure 1. This figure shows yet another example of model creation by the model creation unit shown in Figure 1. This figure shows yet another example of model creation by the model creation unit shown in Figure 1. This figure illustrates the calculation of corrosion expansion length by the calculation unit shown in Figure 1. This figure illustrates the calculation of the rebar diameter in a corroded area by the calculation unit shown in Figure 1. This figure shows an example of the configuration of a computer that functions as an estimation device according to the present disclosure.

[0011] Embodiments of this disclosure will be described below with reference to the drawings.

[0012] Figure 1 shows an example of the configuration of an estimation device 100 according to one embodiment of the present disclosure. The estimation device 100 according to the present disclosure estimates the internal state of a reinforced concrete structure. Based on the estimated internal state of the reinforced concrete structure, the estimation device 100 according to this embodiment creates a model of the reinforced concrete structure for FEM analysis and the like.

[0013] As shown in Figure 1, the estimation device 100 according to this embodiment includes a point cloud data storage unit 101, a vibration spectrum storage unit 102, a structure information storage unit 103, an estimation unit 104, a calculation unit 105, a model creation unit 106, and a model storage unit 107.

[0014] The point cloud data storage unit 101 receives point cloud data of the surface of the reinforced concrete structure and stores the input point cloud data. The point cloud data is, for example, data acquired using LiDAR and shows the surface irregularities of the reinforced concrete structure.

[0015] The vibration spectrum storage unit 102 receives and stores the input vibration spectrum. The vibration spectrum is data obtained by laser impact sounding, which measures the intensity of the reflected waves reflected from the surface of a reinforced concrete structure. Specifically, the vibration spectrum is data obtained by irradiating the surface of a reinforced concrete structure with a vibration excitation laser to excite vibrations and a vibration measurement laser, and measuring the intensity of the reflected waves reflected from the surface of the reinforced concrete structure by the vibration measurement laser.

[0016] The structural information storage unit 103 receives structural information, which is information about the structure and material of the reinforced concrete structure that is the target of internal state estimation, and stores the input structural information. The structural information includes, for example, the Young's modulus E and density ρ of the concrete that makes up the reinforced concrete structure. The structural information also includes, for example, the thickness from the reinforcing bars that make up the reinforced concrete structure to the surface of the reinforced concrete structure (cover thickness d).

[0017] The estimation unit 104 acquires point cloud data stored in the point cloud data storage unit 101 and vibration spectra stored in the vibration spectrum storage unit 102. Based on the acquired point cloud data and vibration spectra, the estimation unit 104 estimates the internal state of the reinforced concrete structure. Specifically, the estimation unit 104 estimates the internal state of the reinforced concrete structure based on the presence or absence of surface irregularities shown in the point cloud data and the presence or absence of peaks in the vibration spectrum.

[0018] The estimation unit 104 estimates, for example, the presence or absence of corrosion of the reinforcing bars constituting the reinforced concrete structure as an internal state of the reinforced concrete structure. The estimation unit 104 also estimates, for example, the presence or absence of voids inside the reinforced concrete structure as an internal state of the reinforced concrete structure. Details of the estimation of the internal state of the reinforced concrete structure by the estimation unit 104 will be described later.

[0019] The calculation unit 105 acquires structural information from the structural information storage unit 103. Using the acquired structural information, the calculation unit 105 calculates the corrosion expansion length, which is the thickness of the reinforcement due to corrosion, for the reinforcement estimated to be corroded by the estimation unit 104. Then, based on the calculated corrosion expansion length of the reinforcement, the calculation unit 105 calculates the diameter of the reinforcement in the corroded part of the reinforcement (the diameter of the reinforcement that has thinned due to corrosion). Details of the calculation of corrosion expansion length and reinforcement diameter by the calculation unit 105 will be described later.

[0020] The model creation unit 106 creates a model of a reinforced concrete structure. Specifically, the model creation unit 106 creates a model that mimics the shape of the reinforced concrete structure based on point cloud data of the reinforced concrete structure. The model creation unit 106 then creates the model by reflecting the internal state of the reinforced concrete structure estimated by the estimation unit 104 and the diameter of the corroded reinforcing bars calculated by the calculation unit 105 at corresponding positions on the model.

[0021] The model storage unit 107 stores the models produced by the model production unit 106.

[0022] Next, the operation of the estimation device 10 according to this embodiment will be described. Figure 2 is a flowchart showing an example of the operation of the estimation device 10 according to this embodiment, and is a diagram for explaining the estimation method performed by the estimation device 10 according to this embodiment.

[0023] The estimation unit 104 acquires the point cloud data stored in the point cloud data storage unit 101 (step S11). The estimation unit 104 also acquires the vibration spectrum stored in the vibration spectrum storage unit 102 (step S12).

[0024] The estimation unit 104 determines whether or not a peak exists in the acquired vibration spectrum (step S13).

[0025] Figure 3A shows an example of a vibration spectrum obtained by laser tapping on a sound reinforced concrete structure with no internal defects. Figure 3B shows an example of a vibration spectrum obtained by laser tapping on a defective area of ​​a reinforced concrete structure with internal defects.

[0026] As shown in Figure 3A, in sound areas, there are no large peaks in the vibration spectrum. On the other hand, as shown in Figure 3B, peaks are present in the vibration spectrum at defective areas. Now, let's assume that there is a defect De inside the concrete, such as a void or corrosion of the reinforcing steel, as shown in Figure 4. In this case, if the width of defect De is 2a and the thickness from defect De to the concrete surface is l, then the thin, plate-like concrete portion between defect De and the concrete surface undergoes deflection resonance due to vibration caused by irradiation with a vibration excitation laser, and as a result, a peak is generated in the vibration spectrum, as shown in Figure 3B. The frequency f of the peak in the vibration spectrum is the resonance frequency of the deflection resonance, and is l / a ２ The frequency is proportional to this. In other words, by determining whether or not a peak exists in the vibration spectrum, it is possible to estimate whether or not a defect De exists inside the reinforced concrete structure.

[0027] Referring again to Figure 2, if it is determined that there are no peaks in the vibration spectrum (step S13: No), the estimation unit 104 determines that the internal state of the reinforced concrete structure is sound and free of internal defects (step S14).

[0028] If it is determined that a peak exists in the vibration spectrum (step S13: Yes), the estimation unit 104 determines whether or not there are irregularities on the surface of the reinforced concrete structure based on the point cloud data (step S15).

[0029] If it is determined that there are no irregularities on the surface of the reinforced concrete structure (Step S15: No), the estimation unit 104 estimates that there are cavities inside the reinforced concrete structure (Step S16). That is, if the estimation unit 14 determines that there are peaks in the vibration spectrum and determines that there are no irregularities on the surface of the reinforced concrete structure based on the point cloud data, it estimates that there are cavities inside the reinforced concrete structure.

[0030] If it is determined that there are irregularities on the surface of the reinforced concrete structure (Step S15: Yes), the estimation unit 104 estimates that the reinforcing steel inside the reinforced concrete structure is corroded (Step S17). That is, if the estimation unit 14 determines that there are peaks in the vibration spectrum and determines that there are irregularities on the surface of the reinforced concrete structure based on the point cloud data, it estimates that the reinforcing steel inside the reinforced concrete structure is corroded.

[0031] If the estimation unit 104 estimates that the reinforcing bars inside the reinforced concrete structure are corroded, the calculation unit 105 calculates the corrosion expansion length, which is the thickness of the reinforcing bars due to corrosion in the corroded area where corrosion is estimated to be occurring. Then, the calculation unit 105 calculates the diameter of the reinforcing bars in the corroded area based on the calculated corrosion expansion length of the reinforcing bars (step S18).

[0032] After the processing in step S14, step S16, or step S18, the model creation unit 106 creates a model of the reinforced concrete structure (step S19).

[0033] As described above, if there are no peaks in the vibration spectrum, the estimation unit 104 estimates that the internal state of the reinforced concrete structure is sound, regardless of whether or not there are irregularities on the surface of the reinforced concrete structure (step S14). In this case, if the point cloud data indicates that there are no irregularities on the surface of the reinforced concrete structure, it is estimated that the surface of the reinforced concrete structure is flat and that there are no defects inside the reinforced concrete structure, as shown in Figure 5A. In this case, the model creation unit 106 models the shape of the surface of the reinforced concrete structure as shown in the point cloud data, as shown in Figure 5A. The model creation unit 106 also creates a model assuming that there are no defects inside the reinforced concrete structure.

[0034] Furthermore, if there are no peaks in the vibration spectrum and the point cloud data indicates that there are irregularities on the surface of the reinforced concrete structure, the estimation unit 104 estimates, as shown in Figure 5B, that there are irregularities in the original shape of the reinforced concrete structure and that there are no defects inside the reinforced concrete structure. In this case, the model creation unit 106 models the shape of the surface of the reinforced concrete structure as shown in the point cloud data, as shown in Figure 5B. The model creation unit 106 also creates a model assuming that there are no defects inside the reinforced concrete structure.

[0035] Furthermore, if a peak exists in the vibration spectrum and the point cloud data indicates that there are no irregularities on the surface of the reinforced concrete structure, the estimation unit 104 estimates, as shown in Figure 5C, that the surface of the reinforced concrete is flat and that a cavity Ca exists inside the reinforced concrete structure. In this case, the model creation unit 106 models the shape of the surface of the reinforced concrete structure as shown in the point cloud data, as shown in Figure 5C. The model creation unit 106 also creates a model assuming that a cavity Ca exists inside the reinforced concrete structure. The model creation unit 106 can calculate the size of the cavity Ca, for example, by the method described in Reference 1. [Reference 1] "Non-contact acoustic exploration method using sound wave irradiation excitation for non-destructive testing of buildings", [online], [Retrieved October 31, 2024], Internet<URL: https: / / www.jstage.jst.go.jp / article / sicejl / 58 / 11 / 58_848 / _pdf / -char / ja>

[0036] Furthermore, if a peak exists in the vibration spectrum and the point cloud data indicates that there are irregularities on the surface of the reinforced concrete structure, the estimation unit 104 estimates, as shown in Figure 5D, that corrosion products Co exist around the reinforcing bars, and that the surface of the reinforced concrete structure is raised due to these corrosion products Co. In this case, the model creation unit 106 models the shape of the surface of the reinforced concrete structure as shown in the point cloud data, as shown in Figure 5D. The model creation unit 106 also reduces the thickness of the reinforcing bars Re to match the diameter of the reinforcing bars calculated by the calculation unit 105, and then creates the model.

[0037] As mentioned above, point cloud data alone cannot estimate the internal state of a reinforced concrete structure. Furthermore, while vibration spectra can be used to estimate the presence of defects (voids or corrosion of reinforcing bars) inside a reinforced concrete structure, it is not possible to determine whether the defect is due to corrosion of the reinforcing bars or a void inside the reinforced concrete structure. In this embodiment, by combining point cloud data and vibration spectral grams, the internal state of the reinforced concrete structure can be estimated in more detail, as described above.

[0038] Referring again to Figure 2, the model storage unit 107 stores the model manufactured by the model manufacturing unit 106 (step S20).

[0039] Next, the calculation of the reinforcing bar diameter in the corroded area by the calculation unit 105 will be explained. As described above, the calculation unit 105 calculates the corrosion expansion length of the reinforcing bar and calculates the reinforcing bar diameter in the corroded area based on the calculated corrosion expansion length. First, the calculation of the corrosion expansion length will be explained with reference to Figure 6.

[0040] As shown in Fig. 6, hereinafter, the thickness (cover thickness) from the reinforcing bar Re to the surface of the reinforced concrete structure is denoted as d, the length of the unevenness on the surface of the reinforced concrete (surface unevenness length) is denoted as z, the length from the surface of the reinforced concrete structure to the corrosion product Co around the reinforcing bar Re (length to the internal corrosion part) is denoted as h, and the thickness of the corrosion product Co from the surface of the reinforcing bar Re (corrosion expansion length) is denoted as b. The cover thickness d can be obtained from the structure information. Also, the surface unevenness length z can be obtained from the point cloud data.

[0041] In a reinforced concrete structure, usually, the cover thickness d = the length h to the internal corrosion part. However, due to the corrosion product Co generated by the corrosion of the reinforcing bar Re, as shown in Fig. 6, when a part of the concrete bulges, the mortar finish on the surface of the reinforced concrete structure peels off at the bulging part, and often the cover thickness d ≠ the length h to the internal corrosion part. In Fig. 6, an example where the concrete at the corroded part of the reinforcing bar protrudes more than other parts is shown, but it is not limited to this, and the concrete at the corroded part of the reinforcing bar may be recessed more than other parts. In this case, a negative value may be used as the surface unevenness length z.

[0042] When striking the concrete surface of the corroded part, the theoretical value of the resonance frequency f (Hz) of the wave multiply reflected between the striking surface and the corroded part, assuming the primary frequency when the corrosion length in the extending direction of the reinforcing bar is sufficiently long compared to the wavelength of the vibration, is expressed by the following formula (1) (see References 2 and 3). Here, E and ρ are the longitudinal elastic modulus and density of the concrete that constitutes the reinforced concrete structure, respectively, and can be obtained from the structure information. [Reference 2] "Theory and Practice of Non-Destructive Testing of Concrete", [online], [searched on October 31, 2024], Internet <URL: https: / / www.jstage.jst.go.jp / article / coj / 51 / 4 / 51_340 / _pdf> [Reference 3] "Relationship between Elastic Constants and Elastic Wave Velocity of Concrete", [online], [searched on October 31, 2024], Internet <URL: https: / / data.jci-net.or.jp / data_pdf / 29 / 029-01-2106.pdf>

[0043] From FIG. 6, the following equation (2) holds. h = d + z - b Equation (2)

[0044] Substituting Equation (1) into Equation (2) and transforming it, the following equation (3) can be obtained.

[0045] The calculation unit 105 can calculate the corrosion expansion length b by inputting the cover thickness d, the surface unevenness length z, and the resonance frequency f into Equation (3). As described above, the cover thickness d can be obtained from the structure information, and the surface unevenness length z can be obtained from the point cloud data. Also, the resonance frequency f is the frequency of the peak of the vibration spectrum.

[0046] Next, the calculation of the diameter of the reinforcing bar in the corroded part will be described.

[0047] Generally, it is known that the volume expansion rate when the reinforcing bar corrodes is 2.5 times (see Reference 4). Therefore, as shown in FIG. 7, when the diameter (radius) of the sound reinforcing bar Re is r, the reduction amount of the reinforcing bar diameter due to corrosion is a, and the increase amount of the reinforcing bar diameter due to the corrosion product (that is, the corrosion expansion length) is b, then the corrosion-reduced area × 2.5 = the area of the corrosion product holds. That is, the following equation (4) holds. {r ２ π - (r - a) ２ π} × 2.5 = (r + b) ２ π - (r - b) ２Equation π (4) [Reference 4] "Study on Modeling Crack Width Due to Corrosion Products," [online], [Retrieved October 31, 2024], Internet <URL: https: / / www.jstage.jst.go.jp / article / jscej1984 / 1998 / 585 / 1998_585_69 / _pdf / -char / ja>

[0048] In equation (4), the diameter r of the reinforcing bar when it is sound is known, and the corrosion expansion length b can be calculated by equation (3). Therefore, the calculation unit 105 can calculate the decrease in the diameter of the reinforcing bar due to corrosion a by inputting the diameter r of the reinforcing bar when it is sound and the corrosion expansion length b into equation (4). Once the decrease in the diameter of the reinforcing bar due to corrosion a is calculated, the diameter of the reinforcing bar that has thinned due to corrosion, i.e., the diameter of the reinforcing bar in the corroded part, can be calculated from r - a.

[0049] As described above, the estimation device 100 according to this embodiment includes an estimation unit 104. The estimation unit 104 acquires point cloud data of the surface of the reinforced concrete structure, a vibration excitation laser that excites vibrations on the surface of the reinforced concrete structure, and a vibration measurement laser that irradiates the surface of the reinforced concrete structure and measures the reflected wave reflected by the vibration measurement laser from the surface of the reinforced concrete structure. The estimation unit 104 then estimates the internal state of the reinforced concrete structure based on the presence or absence of surface irregularities shown in the point cloud data and the presence or absence of peaks in the vibration spectrum.

[0050] Point cloud data alone cannot estimate the internal state of a reinforced concrete structure. Furthermore, while vibration spectra can be used to estimate the presence of defects (voids or corrosion of reinforcing bars) inside a reinforced concrete structure, it is not possible to determine whether the defect is due to corrosion of the reinforcing bars or a void inside the reinforced concrete structure. In this embodiment, by combining point cloud data and vibration spectral data, it is possible to estimate the internal state of a reinforced concrete structure, such as voids or corrosion of the reinforcing bars, in more detail.

[0051] The estimation device 100 described above can be implemented by the computer 20 shown in Figure 8. A program for causing the computer 20 to function as the estimation device 100 may be provided. This program may be stored on a storage medium or provided via a network. Figure 8 is a block diagram illustrating the schematic configuration of the computer 20 functioning as the estimation device 100. The computer 20 may be a general-purpose computer, a dedicated computer, a workstation, a PC (Personal Computer), an electronic notepad, etc. Program instructions may be program code, code segments, etc., for executing the necessary tasks.

[0052] As shown in Figure 8, the computer 20 includes a processor 21, ROM (Read Only Memory) 22, RAM (Random Access Memory) 23, storage 24, input unit 25, display unit 26, and communication interface (I / F) 27. Each component is connected to each other via a bus 29 so as to be able to communicate with each other. The processor 21 is specifically a CPU (Central Processing Unit), MPU (Micro Processing Unit), GPU (Graphics Processing Unit), DSP (Digital Signal Processor), SoC (System on a Chip), etc., and may be composed of multiple processors of the same or different types.

[0053] The processor 21 is a control unit that controls each configuration and performs various calculations. Specifically, the processor 21 reads a program from the ROM 22 or storage 24 and executes the program using the RAM 23 as a working area. The processor 21 controls each configuration and performs various calculations according to the program stored in the ROM 22 or storage 24. In this embodiment, the ROM 22 or storage 24 stores a program for operating the computer 20 as the estimation device 100 according to this disclosure. When this program is read and executed by the processor 21, each configuration of the estimation device 100, such as the estimation unit 104, the calculation unit 105, and the model creation unit 106, is realized.

[0054] The program may be provided in a form stored on a non-transitory storage medium such as a CD-ROM (Compact Disk Read Only Memory), DVD-ROM (Digital Versatile Disk Read Only Memory), or USB (Universal Serial Bus) memory. Alternatively, the program may be provided in a form that can be downloaded from an external device via a network.

[0055] ROM 22 stores various programs and data. RAM 23 temporarily stores programs or data as a working area. Storage 24 is composed of an HDD (Hard Disk Drive) or SSD (Solid State Drive) and stores various programs and data, including the operating system. ROM 22, RAM 23, and storage 24 operate as, for example, a point cloud data storage unit 101, a vibration spectrum storage unit 102, a structural information storage unit 103, and a model storage unit 107.

[0056] The input unit 25 includes a pointing device such as a mouse and a keyboard, and is used for various types of input.

[0057] The display unit 26 is, for example, a liquid crystal display and displays various information. The display unit 26 may also function as an input unit 25 by employing a touch panel system.

[0058] The communication interface 27 is an interface for communicating with other devices, for example, a LAN interface.

[0059] The following additional information is disclosed regarding the embodiments described above.

[0060] [Note 1] Estimation device for estimating the internal state of a reinforced concrete structure, comprising a control unit, wherein the control unit acquires point cloud data of the surface of the reinforced concrete structure, a vibration excitation laser for exciting vibrations on the surface of the reinforced concrete structure, and a vibration measurement laser for irradiating the surface of the reinforced concrete structure with vibrations and measuring the intensity of the reflected waves reflected by the vibration measurement laser from the surface of the reinforced concrete structure, and is configured to estimate the internal state of the reinforced concrete structure based on the presence or absence of irregularities on the surface of the reinforced concrete structure shown in the point cloud data and the presence or absence of peaks in the vibration spectrum.

[0061] [Addendum 2] Estimation device as described in Addendum 1, wherein the control unit determines that a peak exists in the vibration spectrum and determines that there are irregularities on the surface of the reinforced concrete structure based on the point cloud data, estimates that the reinforcing bars inside the reinforced concrete structure are corroded; determines that a peak exists in the vibration spectrum and determines that there are no irregularities on the surface of the reinforced concrete structure based on the point cloud data, estimates that there are cavities inside the reinforced concrete structure; and determines that there are no peaks in the vibration spectrum, estimates that the internal state of the reinforced concrete structure is sound.

[0062] [Appendix 3] The estimation device described in Appendix 2 further comprises a calculation unit that calculates the corrosion expansion length b, which is the thickness of the expansion of the reinforcing bar due to corrosion in the corroded part of the reinforcing bar, using the following formula, and calculates the diameter of the reinforcing bar in the corroded part based on the calculated corrosion expansion length b. An estimation device in which, d is the concrete cover thickness from the surface of the reinforced concrete structure to the reinforcing bars, z is the length of the surface irregularities of the reinforced concrete structure, E is the Young's modulus of the concrete constituting the reinforced concrete structure, ρ is the density of the concrete, and f is the frequency of the peak of the vibration spectrum.

[0063] [Appendix 4] An estimation method performed by an estimation device for estimating the internal state of a reinforced concrete structure, comprising: obtaining point cloud data of the surface of the reinforced concrete structure, irradiating the surface of the reinforced concrete structure with a vibration excitation laser to excite vibrations and a vibration measurement laser, and obtaining a vibration spectrum by measuring the intensity of the reflected waves reflected by the vibration measurement laser from the surface of the reinforced concrete structure, and estimating the internal state of the reinforced concrete structure based on the presence or absence of surface irregularities shown in the point cloud data and the presence or absence of peaks in the vibration spectrum.

[0064] [Appendix 5] A non-temporary storage medium storing a program executable by a computer, the non-temporary storage medium storing a program that causes the computer to operate as an estimation device described in any one of the appendix items 1 to 3.

[0065] Although the embodiments described above are representative examples, it will be apparent to those skilled in the art that many modifications and substitutions are possible within the spirit and scope of this disclosure. Therefore, the present invention should not be construed as being limited by the embodiments described above, and various modifications or changes are possible without departing from the claims. For example, it is possible to combine multiple component blocks shown in the configuration diagram of the embodiments into one, or to divide one component block.

[0066] 100 Estimation device 101 Point cloud data storage unit 102 Vibration spectrum storage unit 103 Structural information storage unit 104 Estimation unit 105 Calculation unit 106 Model creation unit 107 Model storage unit 20 Computer 21 Processor 22 ROM 23 RAM 24 Storage 25 Input unit 26 Display unit 27 Communication I / F 29 Path

Claims

1. An estimation device for estimating the internal state of a reinforced concrete structure, comprising: an estimation unit that acquires point cloud data of the surface of the reinforced concrete structure, a vibration excitation laser that excites vibrations on the surface of the reinforced concrete structure, and a vibration measurement laser, and measures the intensity of the reflected waves reflected by the vibration measurement laser from the surface of the reinforced concrete structure, and estimates the internal state of the reinforced concrete structure based on the presence or absence of surface irregularities shown in the point cloud data and the presence or absence of peaks in the vibration spectrum.

2. The estimation device according to claim 1, wherein the estimation unit determines that a peak exists in the vibration spectrum and determines that there are irregularities on the surface of the reinforced concrete structure based on the point cloud data, it estimates that the reinforcing bars inside the reinforced concrete structure are corroded; determines that a peak exists in the vibration spectrum and determines that there are no irregularities on the surface of the reinforced concrete structure based on the point cloud data, it estimates that there are cavities inside the reinforced concrete structure; and determines that there are no peaks in the vibration spectrum, it estimates that the internal state of the reinforced concrete structure is sound.

3. The estimation device according to claim 2, further comprising a calculation unit that calculates the corrosion expansion length b, which is the thickness of the expansion of the reinforcing bar due to corrosion in the corroded portion of the reinforcing bar, using the following formula, and calculates the diameter of the reinforcing bar in the corroded portion based on the calculated corrosion expansion length b, An estimation device in which, d is the concrete cover thickness from the surface of the reinforced concrete structure to the reinforcing bars, z is the length of the surface irregularities of the reinforced concrete structure, E is the Young's modulus of the concrete constituting the reinforced concrete structure, ρ is the density of the concrete, and f is the frequency of the peak of the vibration spectrum.

Images