Measurement device, measurement system, measurement method, and program

Abstract

The present invention provides a measuring device (1020) that includes a height difference acquisition unit (131) that acquires the height difference between two points on the bottom face of a structure, and a material flexural strength calculation unit (141) that calculates the material flexural strength of the structure on the basis of the height difference.

Description

[Technical field]

[0001] The present disclosure relates to a measurement device, a measurement system, a measurement method, and a program for estimating the strength of a structure from its deformation. [Background technology]

[0002] Structures need to be designed to be able to fully withstand the loads that will be placed on them in the environment in which they will be used, based on the strength of the materials used. Therefore, it is assumed that the characteristics of the materials used are fully understood during the design process. However, the strength of materials used over long periods of time may change due to deterioration, etc. A decrease in the strength of structural materials directly leads to a decrease in the bearing capacity of the structure, so the owner or responsible person of the structure needs to be properly aware of any decrease in material strength.

[0003] For example, resin concrete (hereinafter referred to as "REC") is a material that is widely used in structures, etc. There are more than 100,000 NTT communication manholes (hereinafter referred to as "RECMH") made of REC throughout Japan. REC is also the material used for sewer manholes (see Non-Patent Document 1).

[0004] Much research has been conducted on the material properties of REC, and its strength (flexural strength, compressive strength, tensile strength, shear strength, etc.) is said to be 3 to 5 times that of cement concrete (see Non-Patent Document 2). On the other hand, changes in the material properties of REC over time remained unclear for many years, but it has recently been reported that its strength decreases over time (see Non-Patent Document 3).

[0005] Methods for investigating the material strength of a structure vary depending on the material, but the most direct method involves taking a part of the structure as a sample and conducting compression and tensile tests, etc.

[0006] In addition, there is a non-destructive testing technique that uses ultrasonic measurement to measure the strength of RECMH (see Non-Patent Document 4). [Prior art documents] [Non-patent literature]

[0007] [Non-Patent Document 1] Japan Resin Products Association, "Sewerage manhole", [online], [searched on April 19, 2021], Internet<URL:http: / / www.jrpa.gr.jp / seihin / manhool.html> [Non-Patent Document 2] Sanrec Co., Ltd., “What is resin concrete?”, [online], [searched on April 19, 2021], Internet<URL:http: / / www.sunrec.co.jp / about#concrete / > [Non-Patent Document 3] Takashi Miwa, Kazue Takahashi, Hiroyuki Takahashi, and Takashi Sawada, "Strength reduction mechanism and strength estimation of underground buried unsaturated polyester resin concrete," Materials and Environment, 2020, Vol. 69, No. 6, pp. 161-167 [Non-Patent Document 4] NTT Access Service Systems Laboratories, "Non-destructive testing technology for resin concrete manholes," [online], [searched March 24, 2021], Internet<URL:https: / / www.ansl.ntt.co.jp / history / infra / in0221.html> Summary of the Invention [Problem to be solved by the invention]

[0008] The above-mentioned destructive testing is generally not preferred because it takes time and money, and also because there are cases where damaging structures is not acceptable from the perspective of safety, etc. Regarding RECMH, it is not realistic to carry out destructive testing on all 100,000 RECMHs nationwide.

[0009] Non-destructive testing is more cost-effective than destructive testing, but it has some drawbacks, such as the need for specialized equipment, the need for pre-processing of the surface to be measured by ultrasonic waves, and the time required for measurement.

[0010] The present disclosure aims to provide a measurement device, a measurement system, a measurement method, and a program that estimate the material bending strength of a structure by simply measuring its length. [Means for solving the problem]

[0011] A measuring device in one embodiment includes an elevation difference acquisition unit that acquires an elevation difference, which is the difference in vertical displacement between two points on the bottom surface of a structure, and a material bending strength calculation unit that calculates the material bending strength of the structure based on the elevation difference.

[0012] A measurement system according to one embodiment comprises the measurement device and measurement equipment, the measurement equipment comprising a horizontal member, a first vertical member fixed to the horizontal member so as to be movable vertically relative to the horizontal member and having a displacement indicating unit indicating a first displacement in the vertical direction, and a second vertical member fixed to a position on the horizontal member different from the first vertical member so as to be movable vertically relative to the horizontal member and having a displacement indicating unit indicating a second displacement in the vertical direction, and the measurement device obtains an elevation difference based on the first displacement and the second displacement.

[0013] A measurement method according to one embodiment includes an elevation difference acquisition step of acquiring an elevation difference, which is the difference in vertical displacement between two points on the bottom surface of a structure, and a material bending strength acquisition step of calculating the material bending strength of the structure based on the elevation difference information.

[0014] A program according to one embodiment causes a computer to function as the measurement device. Effect of the Invention

[0015] According to the present disclosure, it is possible to provide a measurement device, a measurement system, and a measurement method that estimate the bending strength of a material by simply measuring the length when a structure is loaded. [Brief description of the drawings]

[0016] [Figure 1A] FIG. 1 shows a perspective view of a RECMH where a measuring device estimates material strength according to one embodiment. [Figure 1B] 1B shows a top view, a front view, a right side view and a bottom view of the RECMH shown in FIG. 1A. [Diagram 2] The load applied to RECMH during the loading test is shown. [Diagram 3] The figure shows the lower deck of the test RECMH and the strain gauge attached to the lower deck. [Figure 4A] FIG. 1 is a perspective view of a test RECMH. [Figure 4B] FIG. 4B is a cross-sectional view taken along the cutting plane C in FIG. 4A, showing a sketch of the deformation behavior. [Diagram 5] This shows the relationship between the pressure exerted on the upper deck of the test RECMH and the strain measured by the strain gauge. [Figure 6] Shows deformation of the top surface of the lower deck. [Figure 7] This is a diagram assuming that the deformation of the top surface of the lower deck is a circular arc. [Figure 8] The relationship between the vertical displacement at the surface of the sub-deck slab and the bending strength of the test RECMH is shown. [Figure 9] This shows the RECMH and the stagnant water present within it. [Figure 10] 1 illustrates a bird's-eye view of a measurement system according to an embodiment. [Figure 11] FIG. 11 is a side view of the measurement system of FIG. [Figure 12] This shows how the measuring equipment captures the elevation difference at the bottom of the structure. [Figure 13] FIG. 1 shows a block diagram of a measurement device according to an embodiment. [Figure 14] FIG. 13 shows a block diagram of a measurement device according to another embodiment. [Figure 15] 10 is a flowchart showing an example of pre-processing executed by the measurement device. [Figure 16] 1 is a flowchart illustrating an example of a process for estimating the bending strength of a material on-site using a measurement device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] As described above, we propose a measuring device, a measuring system, and a measuring method that estimate material strength by simply measuring length, taking advantage of the characteristic that the degree of deformation varies depending on the bending strength of the material when a load is applied to a structure. The deformation behavior of a structure when a load is applied varies depending on the loading position, size, material strength, shape of the structure, etc. These are stored in a database and can be grasped during inspection. An example of a target structure is a resin concrete manhole made of resin concrete, whose strength changes over time. In this embodiment, the technology is explained using an example where the structure is a RECMH.

[0018] 1A and 1B show the structure of a structure, RECMH 10. RECMH 10 has a hollow rectangular parallelepiped shape and includes an upper deck 11, two short side walls 12, two long side walls 13, and a lower deck 14. Typically, the upper deck 11 and the lower deck 14 of RECMH 10 are installed parallel to a horizontal plane, but the present invention is also applicable even if at least one of them is inclined relative to the horizontal plane. In the following example, it is assumed that the upper deck 11 and the lower deck 14 are installed parallel to a horizontal plane.

[0019] A circular opening 11o is provided in the upper deck 11, and a rectangular opening 12o is provided in each of the short side walls 12. The number or shape of the openings provided in the RECMH 10 may be changed.

[0020] RECMH10 is an underground structure, and the loads on RECMH10 after installation include earth pressure, which is constantly applied, and vehicle loads, which are applied when vehicles pass over it. During inspection of RECMH10, no vehicles will be running over it, so deformation due to earth pressure only needs to be considered.

[0021] The vertical earth pressure on RECMH10 is generated by the soil on the upper deck 11. Strictly speaking, the horizontal earth pressure should also be taken into consideration, but here we consider that the effect of the horizontal earth pressure on the deformation of RECMH10 can be ignored, and therefore we will omit the explanation of the horizontal earth pressure.

[0022] According to the Tunnel Standard Specifications (Japan Society of Civil Engineers, "Tunnel Standard Specifications (Cut and Cover) and Commentary," 1986, p. 22, top), the unit weight of backfill soil (below the groundwater level) is 2.0 t / m 3 =19.6kN / m 3 The depth from the ground surface to the upper deck 11 of RECMH10, i.e., the soil thickness, is generally 0.5 m. In this case, the vertical earth pressure on RECMH10 is 19.6 x 0.5 = 9.8 kN / m 2 It becomes.

[0023] In order to investigate the deformation behavior when a load equivalent to the above-mentioned vertical earth pressure is applied to RECMH10, a test specimen RECMH10' equivalent to RECMH10 was prepared and a loading test was carried out. Since the test specimen RECMH10' has the same components as RECMH10, the components of the test specimen RECMH10' are given the same symbols as those of RECMH10.

[0024] The test RECMH10' used here has a known REC material bending strength (hereinafter simply referred to as "bending strength" in this document) according to JIS A 1181:2005, which is 6.5 MPa.

[0025] There are several different RECMH dimensions, but for the test RECMH10' we used the most common one, measuring 3000mm length x 1400mm width x 1700mm height.

[0026] In the loading test, loading was performed as shown in Fig. 2. That is, a monotonic uniaxial compression loading test was performed using a 10MN structural testing machine 20.

[0027] To investigate the deformation behavior of the test RECMH 10', a strain gauge 30 was attached along the longitudinal direction of the lower deck 14 at the position shown in FIG. 3, i.e., at the center of the upper surface of the lower deck 14 of the test RECMH 10'.

[0028] In the 10MN structural testing machine 20 shown in Fig. 2, a test specimen (RECMH10' for testing) is placed on a steel floor 21, and a load is applied vertically downward by a loading plate 22 that covers the entire upper surface of the test specimen. This applies a uniformly distributed load, indicated by the downward arrow from the loading plate 22, and a reaction force, indicated by the upward arrow from the steel floor 21, to the test specimen. The loading speed was 0.01 mm / sec.

[0029] Fig. 4A is a perspective view of the test RECMH 10'. Fig. 4B is a cross-sectional view taken along cut plane C that passes through the centre of the test RECMH 10' in the longitudinal direction, showing a sketch of the deformation behaviour. Note that the two-dot chain line in Fig. 4B shows the shape of the test RECMH 10' before deformation, and the solid line shows the shape of the test RECMH 10' after deformation. In Fig. 4B, an opening 12o exists in the short side wall 12, but the opening 12o is shown incompletely. The lower deck slab 14, to which the strain gauge 30 was attached, was deformed so as to bulge inwards.

[0030] The deformation shown in Fig. 4B is believed to be due to a reaction force against the load applied vertically downward from the loading plate 22 shown in Fig. 2. Although this loading test did not take into account horizontal earth pressure, the effect of horizontal earth pressure on such deformation of the lower deck 14 is believed to be small.

[0031] When considering on-site measurements, it is preferable to use the displacement difference d between at least one end and the center in the longitudinal direction of the lower deck 14 as an index of the degree of deformation of the structure, as shown in the sketch in Figure 4B, in order to achieve both ease of measurement and accuracy. Therefore, when conducting such an experiment, it is basically sufficient to measure the vertical displacement difference d between one end and the center.

[0032] In this embodiment, deformation of the end of the cut surface C passing through the center of the test RECMH 10' along the longitudinal direction is considered, but the extension direction between the end and the center can also be changed. For example, referring to Fig. 3, deformation on a surface passing through the center of the test RECMH 10' along the lateral direction can be considered. The extension direction between the end and the center can also be determined so that measurement is not hindered by wiring or the like present in the test RECMH 10'.

[0033] As a method other than directly measuring the displacement difference d between the end and center as described above, there is a method of calculating the displacement difference between the end and center from the horizontal displacement (strain). An example of this method is described below. First, for example, at the center of the lower deck 14, the elongation along the center line extending in the longitudinal direction is calculated from the longitudinal strain of the lower deck 14. Then, the vertical displacement at the center of the center line of the lower deck 14 is calculated from the elongation along the center line of the lower deck 14, thereby calculating the displacement difference d between the end and center. A specific example is shown below.

[0034] When examining the end of the lower deck 14 in a direction other than the longitudinal direction, the strain of the lower deck 14 corresponding to that direction is measured.

[0035] Figure 5 shows the relationship between the pressure applied to the upper deck 11 of the test RECMH 10' by the loading plate 22 of the 10MN structural testing machine 20 shown in Figure 2 and the strain measured by the strain gauge attached to the upper surface of the lower deck 14 as shown in Figure 4B. The strain gauge is placed on the longitudinal center axis of the lower deck 14. The vertical earth pressure of 9.8 N / m 2 When a pressure of 12×10 is applied to the upper deck 11 of the test specimen RECMH10', the strain is 12×10 -6 It became.

[0036] In this way, the horizontal strain of the lower deck 14 is 12 x 10 -6 Consider the vertical displacement of the center when the strain is equal to or greater than the center of the lower deck 14. The strain measured here is greatest at the center of the lower deck 14 on the longitudinal centerline (indicated by a two-dot chain line) of the lower deck 14, as shown in Figure 6. Conversely, the strain decreases toward the ends, and is zero at the ends. Taking into account the strain values ​​that change continuously along the centerline of the lower deck 14 in this way, we consider the elongation due to deformation at the centerline.

[0037] A small section on the center line of the lower deck 14 in the longitudinal direction is defined as Δx. The elongation in this section is defined as ΔLx. The maximum value of ΔLx / Δx is 12×10 -6and the minimum value is 0. Since the deformation of the center line (length L = 3000 mm) before deformation is symmetrical, the half section L 1 / 2 Consider the deformation of (here 1500 mm). In this case, this half section is L 1 / 2 / Δx. 1 / 2 Of the sections divided into / Δx, the section with the largest distortion (12×10 -6 ) is the section closest to the center, and the section with the smallest distortion (0) is the section at the extreme end.

[0038] In such a case, it is difficult to calculate all ΔLx corresponding to the minute section Δx. Therefore, in the most general case, the maximum value ΔLx max From L 1 / 2 / Δx times and finally reaches the minimum value 0, the half interval length L 1 / 2 Elongation ΔL at 1 / 2 can be expressed as follows: With the above assumptions, the elongation on the center line of the lower deck 14 can be calculated as a fairly accurate approximation.

[0039]

number

[0040] However, L 1 / 2 It is necessary to set Δx appropriately so that / Δx takes an integer value. The above formula is the sum of an arithmetic progression, and is expressed as follows, where n is an integer.

[0041]

number

[0042] ΔL 1 / 2 is the elongation of half the section, so multiplying it by two gives the elongation of the entire section, ΔL.

[0043]

number

[0044] By solving the above equation, the elongation during RECMH deformation can be roughly calculated.

[0045] In this study, L 1 / 2 = 1500mm, ΔLx max =12×10 -6 If Δx = 1 mm, we get the first equation below, which is further expanded.

[0046]

number

[0047] Therefore, the length of the upper surface along the center line after deformation is approximately 3000.018 mm.

[0048] In the field of material mechanics, deformation due to bending of a beam is often calculated by regarding it as a circular arc (for example, see Reference 1 below). This is particularly well approximated when the angle θ of the circular arc is small. Therefore, as shown in Figure 7, we assume that the top surface (length L') of the axial centerline of the lower deck slab 14 deformed in the vertical direction is a circular arc with radius r and angle θ. [References 1] Nagasaki University, Faculty of Engineering, Department of Structural Engineering, "Introduction to Structural Engineering", [online], [Retrieved April 27, 2021], Internet<URL:http: / / www.st.nagasaki-u.ac.jp / ken / matsuda / lecture / kozo-nyumon / 2003 / ohp.pdf>

[0049] Then, the arc length of the circular arc is expressed as follows:

[0050]

number

[0051] Furthermore, from the definition of trigonometric ratios for a right-angled triangle, the following equation holds:

[0052]

number

[0053] Under these conditions, L' = 3000.018 and L = 3000. Substituting these values ​​and solving the above two equations (Equation 5 and Equation 6) as simultaneous equations, we get θ ≒ 0.012 (rad) and r ≒ 2.50 × 10 5 (mm). θ is infinitesimal, so the above approximation of the circular arc is valid. In this case, the maximum displacement y in the vertical direction is expressed by the following formula. Here, a is the length of the perpendicular line drawn from the center of the circular arc to the center line in the axial direction before deformation.

[0054]

number

[0055] Therefore, y ≈ 4.5. Therefore, on the surface of the lower deck 14 in the test RECMH 10', the maximum vertical displacement at the center line is 4.5 mm, and the difference with the end (displacement 0 mm) is 4.5 mm.

[0056] As described above, the bending strength of the test RECMH 10' used this time is known and is 6.5 MPa. Therefore, for a RECMH in an environment where only earth pressure acts in the vertical direction, when the vertical difference between the center and end on the longitudinal center line of the sub-slab 14 is 4.5 mm, the material bending strength of the RECMH can be estimated to be 6.5 MPa.

[0057] In this way, it is possible to obtain the relationship between material strength and vertical displacement from the results of load tests or simulations using the finite element method, etc., and estimate the material strength by measuring the vertical displacement on site.

[0058] If the relationship between material strength and vertical displacement is obtained under multiple conditions, an approximation line showing the correlation between the two can be obtained, making it possible to estimate a wider range of material strength. For example, when a load test was conducted on RECMH with a bending strength of 15.9 MPa using the same method as described above, a 9.8 N / m 2 When a pressure of 5×10 is applied to the upper deck 11 of the test RECMH10', the strain is 5×10 -6 At this time, the vertical displacement at the center line on the surface of the lower deck 14 in the test RECMH10' was 2.9 mm, so as shown in Figure 8, two points are plotted: (flexural strength MPa, vertical displacement mm) = (6.5, 4.5) and (15.9, 2.9).

[0059] Next, we can derive the approximation line connecting these two points, (flexural strength) = -5.875 x (vertical displacement) + 32.938. The reason for using a linear approximation is that the stress-strain relationship when stress is applied to the test specimen RECMH10' is a linear relationship in the small strain region as in this case (for example, see Reference 2 below). [Reference 2] Takeshi Mukai, "Resin Concrete and Resin Mortar and Their Properties", Concrete Journal, Japan Concrete Institute, 1973, Vol. 11, No. 4, p. 15 (Figure 10)

[0060] It is possible to obtain a better approximation by increasing the number of conditions and obtaining more plots. To obtain the approximation, for example, the least squares method can be used. Also, for example, when estimating the strength of other materials, the approximation may show a curve.

[0061] When measuring the vertical displacement of an actual RECMH, it is easy to use the stagnant water 90 that exists in many RECMHs 10 as shown in Figure 9. The water surface of the stagnant water 90 is horizontal, and the center height H' and end height H of the stagnant water 90 can be easily measured using a ruler or the like. By calculating the difference between the center height H' and the end height H, the displacement difference between the center and end of the structure (RECMH10) can be calculated. The strength of the RECMH10 can be estimated from this displacement difference.

[0062] (Measurement System) Next, a measurement system for measuring the strength of a structure using the results of the above-mentioned load test or simulation will be described below. A bird's-eye view of the measurement system is shown in Fig. 10, and a side view seen in the horizontal direction is shown in Fig. 11. As shown in the figure, the measurement system includes a measurement instrument 1010 and a measurement device 1020.

[0063] The measurement equipment 1010 comprises a horizontal member 1011 , a first vertical member 1012 and a second vertical member 1013 .

[0064] It is preferable that the horizontal member 1011 can expand and contract in the axial direction, and it is preferable that the horizontal member 1011 cannot be displaced in the radial direction. The horizontal member 1011 may be fixed by a screw or the like in a state in which it expands and contracts in the axial direction.

[0065] The first vertical member 1012 and the second vertical member 1013 preferably have the same shape and are rigid. In this embodiment, the first vertical member 1012 and the second vertical member 1013 are cylindrical. The first vertical member 1012 and the second vertical member 1013 are not completely bonded to the horizontal member 1011, but are fixed to the horizontal member 1011 so as to be movable only in a direction perpendicular to the axis of the horizontal member 1011. This configuration can be realized, for example, by providing a small gap between the horizontal member 1011 and the first vertical member 1012 and the second vertical member 1013. An unevenness may be provided on any of the members to limit the range of movement of the first vertical member 1012 and the second vertical member 1013 relative to the horizontal member 1011.

[0066] 12, for example, by measuring the first and second protrusion amounts while keeping the horizontal member 1011 horizontal, the height difference h of the ground contact point can be grasped. The measuring device 1010 may be equipped with a spirit level so that the horizontal member 1011 can be oriented horizontally. Note that the first and second protrusion amounts referred to here may refer not only to the amount by which the first vertical member 1012 and the second vertical member 1013 protrude from the surface of the horizontal member 1011, but also to the amount by which they are retracted.

[0067] The surface of RECMH 10 has small irregularities, and the grounding points are not necessarily horizontal, so it is preferable that the cross-sectional radius of first vertical member 1012 and second vertical member 1013 is 1 cm or more, and the grounding parts of first vertical member 1012 and second vertical member 1013 are preferably hemispherical.

[0068] When measuring the height difference of the lower deck 14 of RECMH10, the first vertical member 1012 is grounded to the longitudinal end of the lower deck 14, while the second vertical member 1013 is grounded to the center (or vice versa), thereby making it possible to measure the displacement difference (height difference) between the end and the center easily and with high accuracy.

[0069] In addition, a displacement sensor as a displacement presentation unit may be provided on the first vertical member 1012 and the second vertical member 1013, and a signal corresponding to the vertical protrusion amount of the first vertical member 1012 and the second vertical member 1013 may be output to the elevation difference acquisition unit 131 of the measuring device 1020.

[0070] In another embodiment, instead of the measuring equipment 1010 automatically measuring the protrusion amount, the peripheral surfaces of the first vertical member 1012 and the second vertical member 1013 can be used as a ruler to provide a scale for indicating the protrusion amount in the vertical direction. The scale can also be printed on the peripheral surfaces. The scale may be made of unevenness on the peripheral surfaces. In these cases, the user can input the confirmed protrusion amount to the height difference acquisition unit 131 of the measuring device 1020. Hereinafter, the vertical protrusion amount of the first vertical member 1012 is referred to as the first protrusion amount, and the vertical protrusion amount of the second vertical member 1013 is referred to as the second protrusion amount.

[0071] (Measuring Equipment) Fig. 13 is a schematic block diagram of the measuring device 1020 shown in Fig. 10. The measuring device 1020 includes an elevation difference acquisition unit 131 and a material bending strength calculation unit 132. The measuring device 1020 may further include a material strength display unit 133. The material bending strength calculation unit 132 is a control unit (controller) and may be configured with dedicated hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array), may be configured with a processor, or may be configured including both.

[0072] 10, and is an input interface that acquires the elevation difference measured by the measuring equipment 1010. In another embodiment, the elevation difference acquisition unit 131 may be configured so that an operator can input the acquired elevation difference.

[0073] The material bending strength calculation unit 132 obtains the material bending strength of the structure from the vertical height difference acquired by the height difference acquisition unit 131. Specifically, for example, a relational expression between vertical displacement and bending strength, as shown in Fig. 8, is obtained in advance and stored in the material bending strength calculation unit 132. Then, based on this relational expression, the material bending strength of the structure is obtained from the vertical displacement.

[0074] The material strength display unit 133 displays the material bending strength of the structure calculated by the material bending strength calculation unit 132 on a display or the like. The measuring device 1020 may further include a display that displays the material bending strength of the structure calculated by the material bending strength calculation unit 132.

[0075] In the above-mentioned configuration, the relational equation between the vertical displacement and the bending strength is pre-stored in the material bending strength calculation unit 132. In contrast to this, the configuration shown in Fig. 14 allows the relational equation to be updated by additional loading tests, etc. In this configuration, the elevation difference acquisition unit 131 and the material strength display unit 133 are the same as those shown in Fig. 13, so the description will be omitted.

[0076] 14 includes an elevation difference acquisition unit 131, a material bending strength calculation unit 141, a material strength display unit 133, a strength-displacement relationship derivation unit 142, and a storage unit 145. The measurement device 1020 may further include a strain bending strength acquisition unit 143 and a vertical displacement calculation unit 144. The material bending strength calculation unit 141 and the strength-displacement relationship derivation unit 142 constitute a control unit (controller), which may be configured by dedicated hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array), may be configured by a processor, or may include both.

[0077] The storage unit 145 stores in advance two pairs of vertical displacement and bending strength (bending strength MPa, vertical displacement mm)=(6.5, 4.5), (15.9, 2.9), as plotted in FIG. 8, for example. These pairs can be obtained based on the results of a load test or the results of a simulation using the finite element method or the like, as described above. The storage unit 145 includes one or more memories, and may include, for example, a semiconductor memory, a magnetic memory, an optical memory, or the like. Each memory included in the storage unit 12 may function as, for example, a main memory device, an auxiliary memory device, or a cache memory.

[0078] The strength-displacement relationship derivation unit 142 derives a function indicating the relationship between bending strength and vertical displacement, based on two or more pairs of vertical displacement and bending strength stored in the storage unit 145. For example, as described above, the strength-displacement relationship derivation unit 142 can derive the function (bending strength) = -5.875 × (vertical displacement) + 32.938, based on the two pairs of vertical displacement and bending strength, (bending strength MPa, vertical displacement mm) = (6.5, 4.5), (15.9, 2.9). A repeated explanation of the derivation method will be omitted.

[0079] The material bending strength calculation unit 141 uses the function derived by the strength-displacement relationship derivation unit 142 to calculate the bending strength with respect to the height difference, which is the difference in vertical displacement.

[0080] A bending strength and a set of pressures due to applied loads on strains can be input to the strain bending strength acquisition unit 143. For example, a user can input to the strain bending strength acquisition unit 143 that the bending strength of the test structure on which the load test was performed is 6.5 MPa, and can also input a set of pressures due to applied loads on strains shown in FIG.

[0081] The vertical displacement calculation unit 144 can obtain the vertical displacement from the horizontal strain and the direction in which the strain is measured. The calculation method has been described above, so a description thereof will be omitted.

[0082] The strength-displacement relationship derivation unit 142, the strain-bending strength acquisition unit 143, the vertical displacement calculation unit 144, or the storage unit 145 may be provided outside the measurement device 1020. According to the measurement device 1020 shown in Fig. 14, the results of the load test or the results of the simulation using the finite element method or the like can be updated more easily.

[0083] (Measurement method) Next, a measurement method according to an embodiment will be described. Figures 15 and 16 are flowcharts showing an example of processing executed by the measurement device 1020 shown in Figure 14. The processing shown in Figure 15 is so-called pre-processing, which is performed in a laboratory or the like before estimating the bending strength of a material on-site. The processing shown in Figure 16 shows processing for estimating the bending strength of a material on-site based on this pre-processing.

[0084] The pretreatment is generally carried out during the load test, which is carried out in a laboratory or the like, rather than on-site, as described above.

[0085] In step S151 in Fig. 15, the vertical displacement calculation unit 144 of the measuring device 1020 shown in Fig. 14 calculates the vertical displacement of a test structure (test RECMH10', see Fig. 2) simulating a structure (RECMH10, see Fig. 1) for which material strength is to be estimated on-site. This calculation is based on the strain and bending strength acquired by the strain and bending strength acquisition unit 143. In the above example, a test RECMH10' with a bending strength of 6.5 MPa was prepared. A vertical earth pressure of 9.8 N / m 2 When a pressure of 12×10 was applied to the upper deck 11 of the test RECMH10', the longitudinal strain at the center of the upper surface of the upper deck 11 was measured, and it was 12×10 as shown in Figure 5. -6 From these results, the strain bending strength acquisition unit 143 acquires that the bending strength of the test structure subjected to the load test is 6.5 MPa, and a set of pressures due to the applied load against the strain shown in Fig. 5. Then, as described above, the vertical displacement calculation unit 144 calculates the vertical displacement of the test RECMH 10' from this set, and calculates that the difference in vertical displacement between the center and the ends on the center line in the longitudinal direction of the lower deck slab 14 is 4.5 mm.

[0086] In step S152, the memory unit 145 of the measuring device 1020 stores a pair of the vertical displacement calculated in step S151 and the material bending strength of RECMH10'. In the above example, the memory unit 145 stores (bending strength MPa, vertical displacement mm) = (6.5, 4.5), (15.9, 2.9).

[0087] In step S153, the strength-displacement relationship deriving unit 142 of the measuring device 1020 derives a function indicating the relationship between the material bending strength of RECMH10' and the vertical displacement. In the above example, the function (bending strength) = -5.875 × (vertical displacement) + 32.938 is derived. Here, the pre-processing ends.

[0088] Hereinafter, referring to FIG. 16, the process in which the measuring device 1020 estimates the bending strength of a structure on-site based on the pre-processing will be described. In step S161, the user acquires the elevation difference, which is the difference in vertical displacement between two points on the bottom surface of the structure. In the above-mentioned example, the user grounds the first vertical member 1012 of the measuring equipment 1010 at the center of the lower floor slab 14 of the RECMH 10 and the second vertical member 1013 at the end of the lower floor slab 14, as shown in FIG. 12, for example. At that time, the displacement sensor of the measuring device 1020 measures that the elevation difference is, for example, 3.5 mm, and outputs a signal based on the measurement result to the elevation difference acquisition unit 131 of the measuring device 1020. In the other example described above, the user measures the center height H' and end height H of the retained water 90 using a ruler or the like, as shown in FIG. 9. After that, the user inputs the center height H' and end height H to the elevation difference acquisition unit 131 of the measuring device 1020. The elevation difference acquisition unit 131 calculates the difference between the center height H' and the end height H, thereby calculating the elevation difference between the center and the end of the RECMH10.

[0089] In step S162, the material bending strength calculation unit 132 or 141 of the measuring device 1020 calculates the material bending strength of the structure based on the elevation difference information. For example, if the elevation difference is 3.5 mm, the material bending strength calculation unit 141 estimates (bending strength) = -5.875 x 3.5 + 32.938 = 12.376 MPa.

[0090] In step S162, the material strength display unit 133 of the measuring device 1020 displays on a display or the like the material bending strength of the structure calculated by the material bending strength calculation unit 132 or 141. The process then ends.

[0091] Through the above process, the user can obtain an estimate of the material strength of the structure by simply measuring the length. The user can then perform maintenance of the structure as necessary based on the estimated material bending strength.

[0092] A computer capable of executing program instructions may be used to function as the above-described measuring device 1020. Here, the computer may be a general-purpose computer, a special-purpose computer, a workstation, a personal computer (PC), an electronic notepad, etc. The program instructions may be program code, code segments, etc., for performing the necessary tasks.

[0093] The computer includes a processor, a storage unit, an input unit, an output unit, and a communication interface. The processor may be a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a GPU (Graphics Processing Unit), a DSP (Digital Signal Processor), a SoC (System on a Chip), or the like, and may be composed of multiple processors of the same type or different types. The processor reads a program from the storage unit and executes it to control each of the above components and perform various arithmetic processing. Note that at least a part of the processing contents may be realized by hardware. The input unit is an input interface that receives a user's input operation and acquires information based on the user's operation, and is a pointing device, a keyboard, a mouse, or the like. The output unit is an output interface that outputs information, and is a display, a speaker, or the like. The communication interface is an interface for communicating with an external device.

[0094] The program may be recorded on a computer-readable recording medium. By using such a recording medium, the program can be installed on the computer. Here, the recording medium on which the program is recorded may be a non-transitory recording medium. The non-transitory recording medium is not particularly limited, and may be, for example, a CD-ROM, a DVD-ROM, or a USB (Universal Serial Bus) memory. In addition, the program may be in a form that is downloaded from an external device via a network.

[0095] The following supplementary notes are further disclosed regarding the above embodiment.

[0096] (Additional note 1) Obtain the elevation difference between two points on the bottom of the structure, a control unit for calculating a material bending strength of the structure based on the elevation difference A measuring device comprising: (Additional note 2) A storage unit that stores in advance a set of a vertical displacement of the test structure that is calculated in advance based on a horizontal strain of the test structure simulating the structure against a load, and a material bending strength of the test structure; The control unit is Deriving a function indicating a relationship between the material bending strength and the vertical displacement of the test structure based on two or more pairs of the material bending strength and the vertical displacement stored in the memory unit; The measuring device according to claim 1, further comprising: a measuring section for measuring the bending strength of the material with respect to the height difference using the function. (Additional note 3) The measurement device according to claim 1 or 2, wherein the control unit calculates the material bending strength based on an extension direction of a straight line connecting the two points. (Additional note 4) A measurement system including the measurement device according to any one of claims 1 to 3 and a measurement instrument, The measuring equipment includes: A horizontal member; a first vertical member fixed to the horizontal member so as to be movable in a vertical direction relative to the horizontal member, the first vertical member having a protrusion amount indicating portion indicating a first protrusion amount in the vertical direction; a second vertical member that is fixed to the horizontal member at a position different from the first vertical member so as to be movable in a vertical direction relative to the horizontal member, and that has a protrusion amount indicating portion that indicates a second protrusion amount in the vertical direction; The measurement system, wherein the measurement device obtains a height difference based on the first protrusion amount and the second protrusion amount. (Additional note 5) an elevation difference acquisition step for acquiring an elevation difference between two points on the bottom surface of the structure; A material bending strength acquisition step of determining a material bending strength of the structure based on the elevation difference; Measurement methods including: (Additional note 6) A vertical direction calculation step of calculating a vertical displacement of the structure based on a horizontal strain against a load during a load test of a test structure simulating the structure; a storing step of storing a pair of the vertical displacement calculated by the vertical orientation calculating step and the material bending strength of the test structure; and a strength-displacement relationship deriving step of deriving a function indicating a relationship between the material bending strength and the vertical displacement of the test structure based on two or more sets of the material bending strength and the vertical displacement stored by the storing step, The measurement method according to claim 5, wherein the material bending strength calculation step calculates the material bending strength for the elevation difference using the function. (Additional note 7) The structure contains standing water; 7. The measurement method according to claim 5, wherein the elevation difference acquisition step determines the elevation difference as a difference in water depth between two points of the stagnant water. (Additional note 8) A non-transitory storage medium storing a program executable by a computer, A non-transitory storage medium storing a program that causes the computer to function as the measurement device according to any one of claims 1 to 3.

[0097] Although the above-mentioned embodiment has been described as a representative example, it is obvious to those skilled in the art that many modifications and substitutions can be made within the spirit and scope of the present disclosure. Therefore, the present invention should not be interpreted as being limited by the above-mentioned embodiment, and various modifications or changes can be made without departing from the scope of the claims. For example, it is possible to integrate multiple building blocks shown in the configuration diagram of the embodiment, or to divide one building block. [Explanation of symbols]

[0098] 10 RECMH 10' Test RECMH 11 Upper floor plate 11o opening 12 Short side wall 12o opening 13 Long side wall 14 Lower floor version 20 10MN structural testing machine 21 Steel floor 22 loading version 30 Strain Gauge 90 Stagnant water 131 Strength calculation section 132 Height difference acquisition part 133 Material strength display section 141 Strength calculation section 142 Strength-displacement relationship derivation part 143 Strength acquisition section 144 Vertical Displacement Calculation Section 145 Storage section 1010 Measuring Equipment 1011 Horizontal member 1012 First vertical member 1013 Second vertical member 1020 Measuring equipment

Claims

1. an elevation difference acquisition unit that acquires an elevation difference between two points on a bottom surface of a structure whose bottom surface shape in an initial state is known; a material bending strength calculation unit that calculates a material bending strength of the structure based on the elevation difference; A storage unit that stores in advance a set of a vertical displacement of the test structure that is calculated in advance based on a horizontal strain of the test structure simulating the structure against a load, and a material bending strength of the test structure; a strength-displacement relationship deriving unit that derives a function indicating a relationship between the material bending strength and the vertical displacement of the test structure based on two or more pairs of the material bending strength and the vertical displacement stored in the memory unit; Equipped with The material bending strength calculation unit is a measuring device that calculates the material bending strength with respect to the elevation difference using the function.

2. The measurement device according to claim 1 , wherein the material bending strength calculation unit calculates the material bending strength based on an extension direction of a straight line connecting the two points.

3. A measurement system comprising the measurement device according to claim 1 or 2 and a measurement tool, The measuring equipment includes: A horizontal member; a first vertical member fixed to the horizontal member so as to be movable in a vertical direction relative to the horizontal member, the first vertical member having a protrusion amount indicating portion indicating a first protrusion amount in the vertical direction; a second vertical member that is fixed to the horizontal member at a position different from the first vertical member so as to be movable in a vertical direction relative to the horizontal member, and that has a protrusion amount indicating portion that indicates a second protrusion amount in the vertical direction; A measurement system in which the measurement device obtains a height difference based on the first protrusion amount and the second protrusion amount.

4. an elevation difference acquisition step of acquiring an elevation difference between two points on a bottom surface of a structure whose bottom surface shape in an initial state is known; A material bending strength acquisition step of determining a material bending strength of the structure based on the elevation difference; A vertical direction calculation step of calculating a vertical displacement of the structure based on a horizontal strain against a load during a load test of a test structure simulating the structure; a storing step of storing a pair of the vertical displacement calculated by the vertical orientation calculating step and the material bending strength of the test structure; a strength-displacement relationship deriving step of deriving a function indicating a relationship between the material bending strength and the vertical displacement of the test structure based on two or more sets of the material bending strength and the vertical displacement stored by the storing step; Including, The material bending strength calculation step calculates the material bending strength with respect to the elevation difference using the function, in this measurement method.

5. The structure contains standing water; The measurement method according to claim 4 , wherein the elevation difference acquisition step determines the elevation difference as a difference in water depth between two points of the standing water.

6. A program for causing a computer to function as the measurement device according to claim 1 or 2.

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