Test body

Abstract

To provide a test body capable of examining the influence of cracks in a hydraulic test, a water permeability test, or a hydraulic fracture test with high accuracy.SOLUTION: The test body 1 is used to perform at least one of a hydraulic test for examining hydraulic characteristics, a water permeability test for examining a water permeability coefficient, and a hydraulic fracturing test for examining fracture characteristics due to water pressure. The test object 1 includes a plurality of structures 10 - 1a to 10 - 8b constituting a cube and having a shape obtained by dividing the cube along a predetermined division plane DP, and is configured such that distances between the structures are adjustable.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a test specimen. [Background technology]

[0002] Test specimens are known that are used for hydraulic tests to examine hydraulic properties, permeability tests to examine hydraulic conductivity, or hydraulic fracturing tests to examine fracture properties due to water pressure. For example, the test specimen described in Patent Document 1 is a cube cut out from bedrock. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-349813 Summary of the Invention [Problem to be solved by the invention]

[0004] In hydraulic tests, permeability tests, or hydraulic fracturing tests, multiple identical test specimens may be required. For this purpose, it is conceivable to manufacture test specimens, for example, cubes made of resin. However, in this case, cracks in rock mass are not simulated, and therefore, the influence of cracks in hydraulic tests, permeability tests, or hydraulic fracturing tests cannot be investigated.

[0005] One of the objects of the present invention is to investigate with high accuracy the influence of cracks in hydraulic tests, permeability tests, or hydraulic fracturing tests. [Means for solving the problem]

[0006] In one aspect, the test specimen is used for performing at least one of a hydraulic test for examining hydraulic properties, a permeability test for examining hydraulic conductivity, and a hydraulic fracturing test for examining fracture properties due to hydraulic pressure. The test specimen includes a plurality of constituent elements each having a shape obtained by dividing a cube along a predetermined dividing plane, and is configured such that the distance between the constituent elements is adjustable. [Effects of the Invention]

[0007] The effects of cracks in hydraulic tests, permeability tests, or hydraulic fracturing tests can be investigated with high accuracy. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a perspective view of a test specimen according to the first embodiment. [Figure 2] FIG. 2 is a perspective view of a test specimen according to the first embodiment. [Figure 3] FIG. 2 is a plan view of a test specimen according to the first embodiment. [Figure 4] FIG. 2 is a bottom view of the test specimen of the first embodiment. [Figure 5] FIG. 2 is a cross-sectional view of a test specimen according to the first embodiment. [Figure 6] FIG. 2 is a side view of the test specimen of the first embodiment. [Figure 7] FIG. 2 is a cross-sectional view of a test specimen according to the first embodiment. [Figure 8] FIG. 2 is a front view of the test specimen of the first embodiment. [Figure 9] FIG. 2 is a cross-sectional view of a test specimen according to the first embodiment. [Figure 10] FIG. 2 is an exploded perspective view of the test specimen of the first embodiment. [Figure 11] FIG. 2 is an exploded perspective view of the test specimen of the first embodiment. [Figure 12] FIG. 10 is a cross-sectional view of a test specimen of a first modified example of the first embodiment. [Figure 13] FIG. 10 is a perspective view of a test specimen of a second modified example of the first embodiment. [Figure 14] FIG. 10 is a perspective view of a test specimen of a second modified example of the first embodiment. [Figure 15] FIG. 10 is a cross-sectional view of a test specimen of a third modified example of the first embodiment. [Figure 16] FIG. 10 is a cross-sectional view of a test specimen of a third modified example of the first embodiment. [Figure 17] FIG. 10 is a cross-sectional view of a test specimen of a third modified example of the first embodiment. [Figure 18] FIG. 10 is a perspective view of a test specimen according to a second embodiment. [Figure 19] FIG. 10 is a perspective view of a test specimen according to a second embodiment. [Figure 20] FIG. 10 is a plan view of a test specimen according to a second embodiment. [Figure 21] FIG. 10 is a bottom view of the test specimen of the second embodiment. [Figure 22] FIG. 10 is a cross-sectional view of a test specimen according to a second embodiment. [Figure 23] FIG. 10 is a side view of a test specimen according to a second embodiment. [Figure 24] FIG. 10 is a cross-sectional view of a test specimen according to a second embodiment. [Figure 25] FIG. 10 is a front view of a test specimen according to a second embodiment. [Figure 26] FIG. 10 is a cross-sectional view of a test specimen according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the test specimen of the present invention will be described with reference to FIGS.

[0010] First Embodiment (overview) The test specimen of the first embodiment is used to conduct at least one of a hydraulic test to examine hydraulic properties, a permeability test to examine the permeability coefficient, and a hydraulic fracturing test to examine fracture properties due to water pressure. The test specimen comprises a plurality of constituent elements that form a cube and have a shape obtained by dividing the cube along a predetermined dividing plane, and is configured so that the distance between the constituent elements is adjustable.

[0011] This allows the distance between the constituents to be adjusted. For example, by sandwiching a thin plate having a thickness corresponding to the target value of the distance between the constituents between two constituents and shortening the distance between the constituents, the distance between the constituents can be easily adjusted to the target value. This makes it possible to simulate cracks in rock mass with high accuracy. As a result, the effect of cracks in hydraulic tests, permeability tests, or hydraulic fracturing tests can be investigated with high accuracy. Next, the test specimen of the first embodiment will be described in more detail.

[0012] (composition) The specimen 1 of the first embodiment will be described below using a right-handed Cartesian coordinate system having an x-axis, a y-axis, and a z-axis, as shown in Figures 1 to 11. Note that in this specification, a similar coordinate system will also be used in Figures 12 to 26, which will be described later.

[0013] In this example, the x-axis direction, the y-axis direction, and the z-axis direction may be respectively expressed as the left-right direction of the test specimen 1, the front-rear direction of the test specimen 1, and the up-down direction of the test specimen 1. Also, in this example, the positive direction of the x-axis, the negative direction of the x-axis, the positive direction of the y-axis, the negative direction of the y-axis, the positive direction of the z-axis, and the negative direction of the z-axis may be respectively expressed as the left direction of the test specimen 1, the right direction of the test specimen 1, the rear direction of the test specimen 1, the front direction of the test specimen 1, the up direction of the test specimen 1, and the down direction of the test specimen 1.

[0014] Fig. 1 is a view of the test specimen 1 as seen from a position to the left of the test specimen 1, in front of the test specimen 1, and above the test specimen 1 (in other words, a left-front upper perspective view). Fig. 2 is a view of the test specimen 1 as seen from a position to the left of the test specimen 1, in front of the test specimen 1, and below the test specimen 1 (in other words, a left-front lower perspective view).

[0015] Fig. 3 is a view of the test specimen 1 as seen from above (in other words, a plan view). Fig. 4 is a view of the test specimen 1 as seen from below (in other words, a bottom view). Fig. 5 is a view of the cross section of the test specimen 1 cut by the plane represented by line VV in Fig. 4 as seen in the positive direction of the x-axis.

[0016] Fig. 6 is a view of the test specimen 1 as viewed to the right of the test specimen 1 (in other words, a right side view). Fig. 7 is a view of a cross section of the test specimen 1 cut along a plane represented by line VII-VII in Fig. 6 as viewed in the positive direction of the z-axis.

[0017] Fig. 8 is a view of the test specimen 1 as seen from the front of the test specimen 1 (in other words, a front view). Fig. 9 is a view of a cross section of the test specimen 1 cut by a plane represented by line IX-IX in Fig. 8 as seen in the positive direction of the x-axis.

[0018] Fig. 10 is a left-front upper perspective view of the multiple components that make up the test specimen 1 when the test specimen 1 is disassembled. Fig. 11 is a right-front lower perspective view of the multiple components that make up the test specimen 1 when the test specimen 1 is disassembled. 10 and 11, bolts and nuts, which will be described later, are omitted from the illustration.

[0019] In this example, the test specimen 1 is used to conduct a hydraulic test to examine hydraulic properties, a permeability test to examine the permeability coefficient, or a hydraulic fracturing test to examine fracture properties due to hydraulic pressure. For example, the test specimen 1 may be used to conduct a hydraulic test, a permeability test, or a hydraulic fracturing test in a state where compressive stress is applied in at least one direction selected from the x-axis direction, the y-axis direction, and the z-axis direction.

[0020] The test specimen 1 may also be used to evaluate a test device for performing a hydraulic test, a permeability test, or a hydraulic fracturing test. The test specimen 1 may also be used to evaluate or analyze test results in a hydraulic test, a permeability test, or a hydraulic fracturing test.

[0021] As shown in FIGS. 1 to 9, the test specimen 1 is a cube. In this example, the length of a side of the test specimen 1 is 300 mm. The length of a side of the test specimen 1 may be 100 mm to 600 mm. In this example, the surface of the test specimen 1 is smooth. The surface of the test specimen 1 may be rough to simulate the surface of a bedrock or rock.

[0022] In this example, the test specimen 1 includes 14 components 10-1a, 10-1b, 10-2a, 10-3a, 10-4a, 10-4b, 10-5a, 10-5b, 10-6a, 10-6b, 10-7a, 10-7b, 10-8a, and 10-8b (hereinafter also referred to as components 10-1a to 10-8b). The number of components included in the test specimen 1 may be 2 to 13, or may be 15 or more.

[0023] In this example, each of the components 10-1a to 10-8b is made of ABS (Acrylonitrile Butadiene Styrene) resin. However, each of the components 10-1a to 10-8b may be made of a resin other than ABS resin (e.g., urethane resin, ASA (Acrylate Styrene Acrylonitrile) resin, polypropylene resin, epoxy resin, acrylic resin, polycarbonate resin, polyamide resin, etc.).

[0024] As shown in Figures 1, 2, 10, and 11, the 14 components 10-1a to 10-8b have shapes obtained by dividing a cube constituting the specimen 1 into n equal parts in each of three directions (in this example, the x-axis direction, the y-axis direction, and the z-axis direction) perpendicular to each of the three pairs of outer wall surfaces of the cube, and then dividing the cube along a predetermined dividing plane DP. In this example, n represents 2. Note that n may also represent an integer of 3 or greater. In this example, the dividing plane DP is a plane.

[0025] Therefore, the 14 components 10-1a to 10-8b are n 3 The specimen 1 is made up of eight small cubes 10-1, 10-2, 10-3, 10-4, 10-5, 10-6, 10-7, and 10-8 (hereinafter referred to as small cubes 10-1 to 10-8). Each of the small cubes 10-1 to 10-8 has a side length that is 1 / n of the side length of the cube constituting the specimen 1.

[0026] The constituents 10-1a and 10-1b constitute the small cube 10-1. The constituents 10-2a constitute the small cube 10-2. The constituents 10-3a constitute the small cube 10-3. The constituents 10-4a and 10-4b constitute the small cube 10-4. The constituents 10-5a and 10-5b constitute the small cube 10-5. The constituents 10-6a and 10-6b constitute the small cube 10-6. The constituents 10-7a and 10-7b constitute the small cube 10-7. The constituents 10-8a and 10-8b constitute the small cube 10-8.

[0027] The specimen 1 has a plurality of through-hole forming portions 11 (40 in this example) that form through-holes that penetrate the cube in three directions (x-axis direction, y-axis direction, and z-axis direction in this example) that are perpendicular to each of the three pairs of outer wall surfaces of the cube that constitutes the specimen 1. The number of through-hole forming portions 11 that the specimen 1 has may be 1 to 39, or may be 41 or more.

[0028] Each through-hole forming portion 11 provided in the specimen 1 has a position where it does not intersect with other through-hole forming portions 11. 6 and 7, in this example, the specimen 1 has eight through-hole forming portions 11 in the x-axis direction. Note that the number of through-hole forming portions 11 in the x-axis direction that the specimen 1 has may be one to seven, or may be nine or more.

[0029] Of the eight through-hole forming portions 11 in the x-axis direction, two are located in each of the four groups of x-axis small cubes. An x-axis small cube group consists of two small cubes lined up in the x-axis direction. For example, an x-axis small cube group consists of small cube 10-1 and small cube 10-4. The two through-hole forming portions 11 in each x-axis small cube group are located at the center in the z-axis direction and at both ends in the y-axis direction in a cross section of the x-axis small cube group taken along a plane perpendicular to the x-axis.

[0030] 8 and 9, in this example, the test specimen 1 has 16 through-hole forming portions 11 in the y-axis direction. Note that the number of through-hole forming portions 11 in the y-axis direction that the test specimen 1 has may be 1 to 15, or may be 17 or more.

[0031] Of the 16 through-hole forming portions 11 in the y-axis direction, four are located in each of the four groups of y-axis small cubes. A y-axis small cube group consists of two small cubes aligned in the y-axis direction. For example, a y-axis small cube group consists of small cube 10-1 and small cube 10-2. The four through-hole forming portions 11 in each y-axis small cube group are located at the four corners of the cross section of the y-axis small cube group taken along a plane perpendicular to the y-axis.

[0032] 4 and 5, in this example, the specimen 1 has 16 through-hole forming portions 11 in the z-axis direction. The number of through-hole forming portions 11 in the z-axis direction that the specimen 1 has may be 1 to 15, or may be 17 or more.

[0033] Of the 16 through-hole forming portions 11 in the z-axis direction, four are located in each of the four groups of z-axis small cubes. A z-axis small cube group consists of two small cubes lined up in the z-axis direction. For example, a z-axis small cube group consists of small cube 10-1 and small cube 10-5. The four through-hole forming portions 11 in each z-axis small cube group are located at both ends in the y-axis direction, between both ends and the center in the x-axis direction, in a cross section of the z-axis small cube group taken along a plane perpendicular to the z-axis.

[0034] As shown in FIGS. 5, 7, and 9, each through-hole forming portion 11 includes two pairs of countersunk hole forming portions 11a and two communicating hole forming portions 11b. The two pairs of countersunk hole forming portions 11a form two pairs of countersunk holes that open in two pairs of outer wall surfaces of two small cubes that make up the x-axis small cube group, the y-axis small cube group, or the z-axis small cube group. In this example, the countersunk holes are cylindrical.

[0035] The two communication hole forming portions 11b each form two communication holes that connect the two pairs of countersunk hole forming portions 11a. The communication holes formed by each communication hole forming portion 11b have a smaller cross-sectional area than the countersunk holes formed by the countersunk hole forming portions 11a. In this example, the communication holes are cylindrical. Therefore, in this example, the diameter of the communication holes is smaller than the diameter of the countersunk holes.

[0036] With this configuration, two countersunk holes formed by two countersunk hole forming sections 11a located on two pairs of outer wall surfaces of two small cubes that make up the x-axis small cube group, the y-axis small cube group, or the z-axis small cube group, where the small cubes do not contact each other, correspond to a pair of openings, among the through holes formed by the through hole forming section 11, that open on a pair of outer wall surfaces of the cubes that make up the test piece 1.

[0037] In addition, the two communicating holes formed by the two communicating hole forming portions 11b located on each of the two small cubes constituting the x-axis direction small cube group, the y-axis direction small cube group, or the z-axis direction small cube group, and the two countersunk holes formed by the two countersunk hole forming portions 11a located on each of the two pairs of outer wall surfaces of the two small cubes where the small cubes contact each other, correspond to communicating portions of the through holes formed by the through hole forming portion 11 that communicate a pair of openings and have a cross-sectional area of ​​at least the portion connected to the openings that is smaller than that of the openings.

[0038] In addition, the two countersunk holes formed by the two countersunk hole forming portions 11a located on the two pairs of outer wall surfaces of the two small cubes that make up the x-axis small cube group, the y-axis small cube group, or the z-axis small cube group, where the small cubes are in contact with each other, may have the same cross section as the communicating hole formed by the communicating hole forming portion 11b.

[0039] The test specimen 1 is provided with a bolt 21 and a nut 22 for each through-hole forming portion 11 . The bolt 21 includes a head 21a and a shaft 21b.

[0040] The head 21a has a rectangular columnar shape. In this example, the head 21a has a hexagonal columnar shape. In a cross section taken along a plane perpendicular to the central axis of the communicating hole formed by the communicating hole forming portion 11b, the head 21a has a larger cross-sectional area than the communicating hole and a smaller cross-sectional area than the countersunk hole formed by the countersunk hole forming portion 11a.

[0041] The shaft portion 21b is rod-shaped and extends from the head portion 21a. In this example, the shaft portion 21b is cylindrical. The cross-sectional area of ​​the shaft portion 21b, taken along a plane perpendicular to the central axis of the communicating hole formed by the communicating hole forming portion 11b, is smaller than that of the communicating hole.

[0042] The head 21a of the bolt 21 is accommodated in one of a pair of openings of the through hole formed by the through hole forming portion 11, and the shaft portion 21b is inserted into the communicating portion of the through hole.

[0043] The test piece 1 may be provided with a washer between the head 21a and the bottom surface of the countersunk hole forming portion 11a. For example, the washer may be a plain washer or a spring washer.

[0044] The nut 22 is in the shape of a square pillar having a through hole. In this example, the nut 22 is in the shape of a hexagonal pillar having a through hole. The nut 22 is fastened to the tip end of the shank 21b by screwing. When the nut 22 is fastened to the tip end of the shank 21b, the nut 22 is housed in the other of the pair of openings of the through holes formed by the through-hole forming part 11.

[0045] When the nut 22 is fastened to the tip of the shaft portion 21b, the nut 22 and the tip of the shaft portion 21b have a cross-sectional area larger than that of the communicating hole formed by the communicating hole forming portion 11b in a cross section taken along a plane perpendicular to the central axis of the communicating hole, and a cross-sectional area smaller than that of the countersunk hole formed by the countersunk hole forming portion 11a.

[0046] The test piece 1 may include a washer between the nut 22 and the bottom surface of the countersunk hole forming portion 11a. For example, the washer may be a plain washer or a spring washer.

[0047] In this example, when nut 22 is fastened to the tip end of shank 21b, nut 22, the tip end of shank 21b, and head 21a correspond to a pair of heads respectively accommodated in a pair of openings of the through hole formed by through-hole forming portion 11. Furthermore, when nut 22 is fastened to the tip end of shank 21b, shank 21b corresponds to a connecting portion that is inserted into a communicating portion of the through hole formed by through-hole forming portion 11 and connects the pair of heads.

[0048] With this configuration, by relatively rotating the bolt 21 and the nut 22 to tighten the screws, the distance between the head 21 a and the nut 22 becomes shorter. Also, by relatively rotating the bolt 21 and the nut 22 to loosen the screws, the distance between the head 21 a and the nut 22 becomes longer. In this way, in this example, the distance between the head 21a and the nut 22 for each through-hole forming portion 11 can be changed.

[0049] In this way, the test piece 1 is configured so that the distance between the components can be adjusted in each of three directions (in this example, the x-axis direction, y-axis direction, and z-axis direction) perpendicular to each of the three pairs of outer wall surfaces of the cube that constitutes the test piece 1.

[0050] Furthermore, the test piece 1 may be configured so that the distance between the components is adjustable in only one or two of the three directions (in this example, the x-axis direction, y-axis direction, and z-axis direction) that are perpendicular to each of the three pairs of outer wall surfaces of the cube that constitutes the test piece 1.

[0051] For example, if the distance between the components is adjustable only in the x-axis direction, the test piece 1 may only have a through-hole forming portion 11 in the x-axis direction, and may not have a through-hole forming portion 11 in the y-axis direction or a through-hole forming portion 11 in the z-axis direction. Furthermore, for example, if the distance between the constituent bodies is adjustable in both the x-axis direction and the y-axis direction, the test body 1 may have a through-hole forming portion 11 in the x-axis direction and a through-hole forming portion 11 in the y-axis direction, but may not have a through-hole forming portion 11 in the z-axis direction.

[0052] In this example, the portions of the surfaces of the constituents 10-1a, 10-1b, 10-4a, 10-4b, 10-5a, 10-5b, 10-6a, 10-6b, 10-7a, 10-7b, 10-8a, and 10-8b that form the dividing plane DP are smooth. However, the portions of the surfaces of the constituents 10-1a, 10-1b, 10-4a, 10-4b, 10-5a, 10-5b, 10-6a, 10-6b, 10-7a, 10-7b, 10-8a, and 10-8b that form the dividing plane DP may be roughened to simulate a crack surface in a rock mass or rock.

[0053] Moreover, instead of the bolt 21 and the nut 22, the test specimen 1 may include a rod-shaped body that is inserted into a communicating portion of the through hole formed by the through-hole forming portion 11, and a pair of nuts that are fastened by screwing to both ends of the rod-shaped body. Moreover, instead of the bolt 21, the test specimen 1 may include a screw. Moreover, instead of the bolt 21 and the nut 22, the test specimen 1 may include a rod-shaped body that is inserted into a communicating portion of the through hole formed by the through-hole forming portion 11 and has threaded holes at both ends, and a pair of screws that are fastened by screwing to the threaded holes at both ends of the rod-shaped body.

[0054] (Adjustment method) Next, a method for adjusting the distance between the constituent elements in the test piece 1 of the first embodiment will be described. First, multiple components 10-1a to 10-8b are arranged to form a cube. Next, for each through-hole forming portion 11, shank 21b of bolt 21 is inserted into the through-hole formed by through-hole forming portion 11, and nut 22 is fastened to the tip of shank 21b.

[0055] Next, a thin plate having a thickness corresponding to the target value of the distance between the components is sandwiched between the components that make up the dividing surface DP. In this example, the thin plate extends over a partial area of ​​the dividing surface DP. Note that the thin plate may also extend over substantially the entire dividing surface DP. Also, multiple thin plates may be sandwiched between the components that make up the dividing surface DP. Also, the thin plate may be made of a material that melts with a solvent. Also, the thin plate may be made of metal, resin, or paper.

[0056] Next, the bolt 21 and nut 22 are rotated relative to each through-hole forming portion 11 so as to tighten the screws. This shortens the distance between the head 21a and the nut 22. As a result, the distance between the components that make up the dividing plane DP is adjusted to the target value.

[0057] As described above, the test specimen 1 of the first embodiment is used to conduct at least one of a hydraulic test to examine hydraulic characteristics, a permeability test to examine hydraulic conductivity, and a hydraulic fracturing test to examine fracture characteristics due to hydraulic pressure. The test specimen 1 comprises a plurality of constituents 10-1a to 10-8b that form a cube and have shapes obtained by dividing the cube along a predetermined dividing plane DP, and is configured so that the distance between the constituents is adjustable.

[0058] This allows the distance between the constituents to be adjusted. For example, by sandwiching a thin plate having a thickness corresponding to the target value of the distance between the constituents between two constituents and shortening the distance between the constituents, the distance between the constituents can be easily adjusted to the target value. This makes it possible to simulate cracks in rock mass with high accuracy. As a result, the effect of cracks in hydraulic tests, permeability tests, or hydraulic fracturing tests can be investigated with high accuracy.

[0059] Furthermore, the test piece 1 of the first embodiment includes a through-hole forming portion 11 that forms a through-hole that penetrates the cube in a direction perpendicular to a pair of outer wall surfaces of the cube that constitutes the test piece 1. The through-hole has a pair of openings that open on the pair of outer wall surfaces, respectively, and a communicating portion that communicates with the pair of openings and has a cross-sectional area of ​​at least the portion that connects to the openings that is smaller than that of the openings.

[0060] The test specimen 1 comprises a pair of heads (in this example, head 21a, the tip of shaft 21b, and nut 22) that have a larger cross-sectional area than the portion of the communicating portion that connects to the opening and are respectively accommodated in a pair of openings, and a connecting portion (in this example, shaft 21b) that is inserted into the communicating portion and connects the pair of heads, and is configured so that the distance between the heads is changeable.

[0061] This allows the distance between the heads to be changed, making it possible to easily adjust the distance between the components.

[0062] Furthermore, the test specimen 1 of the first embodiment is configured so that the distance between the constituent elements is adjustable in each of three directions perpendicular to each of the three pairs of outer wall surfaces of the cube that constitutes the test specimen 1.

[0063] According to this, when the dividing surface DP is a plane, the distance between the constituent elements constituting the dividing surface DP can be adjusted with high precision regardless of the direction of the normal to the dividing surface DP. Also, when the dividing surface DP is a curved surface, the distance between the constituent elements constituting the dividing surface DP can be adjusted with high precision.

[0064] Furthermore, in the test piece 1 of the first embodiment, the multiple constituent bodies 10-1a to 10-8b have shapes obtained by dividing the cube constituting the test piece 1 into n equal parts in each of three directions perpendicular to each of the three pairs of outer wall surfaces of the cube, and then dividing the cube along the dividing plane DP.

[0065] According to this, by changing the number of constituent elements that make up the test specimen 1, it is possible to easily manufacture a test specimen 1 of any size.

[0066] The specimen 1 may have a plurality of dividing planes DP, and in this case, the dividing planes DP may intersect with each other.

[0067] 12, in test specimen 1D of the first modified example of the first embodiment, test specimen 1D includes compression springs 23 between head 21a and the bottom surface of countersunk hole forming portion 11a, and between nut 22 and the bottom surface of countersunk hole forming portion 11a. Compression springs 23 bias the components in a direction that shortens the distance between the components. FIG. 12 is a cross-sectional view of specimen 1D.

[0068] In addition, the test specimen 1D may be provided with a washer at least in one of the following locations: between the head 21a and the compression spring 23, between the nut 22 and the compression spring 23, and between the compression spring 23 and the bottom surface of the countersunk hole forming portion 11a. Furthermore, the test specimen 1D may have a compression spring 23 only between the head 21a and the bottom surface of the countersunk hole forming portion 11a, or between the nut 22 and the bottom surface of the countersunk hole forming portion 11a.

[0069] As shown in FIGS. 13 and 14, in the specimen 1A of the second modified example of the first embodiment, the dividing plane DP is a curved surface. Fig. 13 is a left-front upper perspective view of the test body 1A. Fig. 14 is a right-front lower perspective view of the test body 1A.

[0070] 15 to 17, in the test specimen 1B of the third modified example of the first embodiment, each small cube of each through-hole forming portion 11 is provided with a bolt 21 and a nut 22. In this case, the test specimen 1B may be bonded to each other so that the small cubes 10-1 to 10-8 do not separate from the other small cubes. In this case, the test specimen 1B may be housed in a case or cover so that the small cubes 10-1 to 10-8 do not separate from the other small cubes.

[0071] Second Embodiment Next, a test specimen of the second embodiment will be described. The test specimen of the second embodiment differs from the test specimen of the first embodiment in that the multiple constituents have a shape obtained by dividing a cube along the dividing plane. The following description will focus on the differences. In the description of the second embodiment, components that are assigned the same reference numerals as those used in the first embodiment are the same or substantially similar.

[0072] (composition) As shown in FIGS. 18 to 26, a test specimen 1C of the second embodiment includes two components 10-1a and 10-1b.

[0073] Fig. 18 is a left-front upper perspective view of test specimen 1C. Fig. 19 is a right-front lower perspective view of test specimen 1C. Fig. 20 is a plan view of test specimen 1C. Fig. 21 is a bottom view of test specimen 1C. Fig. 22 is a cross-section of test specimen 1C cut by the plane represented by line XXI-XXI in Fig. 21, viewed in the positive direction of the x-axis.

[0074] Fig. 23 is a right side view of specimen 1C. Fig. 24 is a cross-section of specimen 1C cut along a plane represented by line XXIII-XXIII in Fig. 23, viewed in the positive direction of the z-axis. Fig. 25 is a front view of specimen 1C. Fig. 26 is a cross-section of specimen 1C cut along a plane represented by line XXV-XXV in Fig. 25, viewed in the positive direction of the x-axis.

[0075] 18 and 19, the two components 10-1a and 10-1b have shapes obtained by dividing the cube constituting the specimen 1C along a predetermined dividing plane DP in three directions (in this example, the x-axis direction, the y-axis direction, and the z-axis direction) perpendicular to the three pairs of outer wall surfaces of the cube. In this example, the dividing plane DP is a plane.

[0076] Specimen 1C has a plurality of through-hole forming portions 11 (24 in this example) that form through-holes that penetrate the cube in three directions (x-axis direction, y-axis direction, and z-axis direction in this example) that are perpendicular to the three pairs of outer wall surfaces of the cube that constitutes specimen 1C. The number of through-hole forming portions 11 that specimen 1C has may be 1 to 23, or may be 25 or more.

[0077] Each of the through-hole forming portions 11 of the specimen 1C has a position where it does not intersect with other through-hole forming portions 11. 23 and 24, in this example, specimen 1C has eight through-hole formation portions 11 in the x-axis direction. Note that the number of through-hole formation portions 11 in the x-axis direction that specimen 1C has may be one to seven, or may be nine or more.

[0078] The eight through hole forming portions 11 in the x-axis direction are located in a cross section of the test specimen 1C taken along a plane perpendicular to the x-axis, with four of them lined up along the y-axis direction between each of the two ends and the center in the z-axis direction.

[0079] 25 and 26, in this example, the specimen 1C has eight through-hole formation portions 11 in the y-axis direction. Note that the number of through-hole formation portions 11 in the y-axis direction that the specimen 1C has may be one to seven, or may be nine or more.

[0080] Of the eight through-hole forming portions 11 in the y-axis direction, four are positioned at each end in the z-axis direction in a cross section of the specimen 1C taken along a plane perpendicular to the y-axis, aligned along the x-axis direction.

[0081] 21 and 22, in this example, the specimen 1C has eight through-hole forming portions 11 in the z-axis direction. Note that the number of through-hole forming portions 11 in the z-axis direction that the specimen 1C has may be one to seven, or may be nine or more.

[0082] Of the eight through-hole forming portions 11 in the z-axis direction, four are positioned at each end in the y-axis direction in a cross section of the specimen 1C taken along a plane perpendicular to the z-axis, so as to be aligned along the x-axis direction.

[0083] The test specimen 1C of the second embodiment can also achieve the same functions and effects as the test specimen 1 of the first embodiment.

[0084] The present invention is not limited to the above-described embodiment. For example, various modifications that can be understood by those skilled in the art may be made to the above-described embodiment without departing from the spirit of the present invention. [Explanation of symbols]

[0085] 1, 1A, 1B, 1C, 1D test specimens 10-1~10-8 small cube 10-1a~10-8b Constituent 11 Through hole forming part 11a Counterbored hole forming part 11b Communication hole forming part 21 volts 21a Head 21b Shaft 22 Nut 23 Compression spring DP split plane

Claims

1. A test specimen used to perform at least one of a hydraulic test for investigating hydraulic characteristics, a permeability test for investigating hydraulic conductivity, and a hydraulic fracturing test for investigating fracture characteristics due to hydraulic pressure, A test specimen comprising a plurality of constituents each having a shape that is obtained by dividing a cube along a predetermined dividing plane, the plurality of constituents being configured such that the distance between the constituents is adjustable.

2. 2. The test specimen according to claim 1, the test specimen includes a through-hole forming portion that forms a through-hole penetrating the cube in a direction perpendicular to a pair of outer wall surfaces of the cube, the through hole has a pair of openings that open on the pair of outer wall surfaces, respectively, and a communicating portion that communicates the pair of openings and has a cross-sectional area of ​​at least a portion that is connected to the openings that is smaller than that of the openings, The test specimen comprises a pair of heads each having a cross-sectional area larger than that of the portion of the communicating portion that connects to the opening and that are accommodated in the pair of openings, and a connecting portion that is inserted into the communicating portion and connects the pair of heads, and is configured so that the distance between the heads is changeable.

3. The test specimen according to claim 1 or claim 2, A test specimen configured such that the distance between the constructs is adjustable in each of three directions perpendicular to each of the three pairs of outer wall surfaces of the cube.

4. The test specimen according to claim 1 or claim 2, A test specimen in which the multiple constituent bodies have shapes obtained by dividing the cube into n equal parts in each of three directions perpendicular to each of the three pairs of outer wall surfaces of the cube and dividing the cube along the division surfaces.

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