A mold for making a transparent three-dimensional cross-fissure model and a method for making the model

Abstract

The present invention discloses a mold for manufacturing a transparent three-dimensional cross-fracture model and a model manufacturing method. The mold includes a mold-turning frame member, a cross-fracture intact rock specimen, and a mold-turning material specimen. The outside of the mold-turning frame member is a mold-turning enclosure frame. The inside of the mold-turning frame member is partitioned into several spaces for placing the cross-fracture intact rock specimens by partitions. There is a gap between the cross-fracture intact rock specimens and the partitions. The mold-turning material specimen is used to obtain the rock fracture surface morphology characteristics of the cross-fracture intact rock specimens and is used to replicate the three-dimensional morphology of the silicone fracture surface of the solid silicone plate. Transparent cross-fracture models at multiple angles such as 45°, 60°, or 90° can be manufactured according to test requirements; it can be widely applied to the preparation and use of cross-fracture transparent mold-turned specimens and visualization research; the cross-fractures made by the present invention have 4 complete branches, a real rough surface, and cross geometric characteristics. The morphology of the rough fracture wall surface of the mold-turned specimen is basically the same as that of the natural cross-fractures.

Description

Technical Field

[0001] The patent of this invention relates to the fields of underground rock engineering, underground energy development, groundwater environment, etc., and in particular to a mold for making a transparent three-dimensional cross-crack model and a model making method. Background Art

[0002] Fracture media are important carriers of groundwater, and the solute transport issues involved involve important engineering and environmental fields such as geological disposal of nuclear waste, groundwater pollution control, and underground oil and gas storage construction. Since fractured rock mass has a high degree of anisotropy and heterogeneity, the migration and transport process of water or solutes in fractured rock mass is very complex. Using physical model tests for research is an important way to explore the migration and transport mechanisms of various fluids and pollutants in fractured media.

[0003] Fractured rock masses are often composed of fracture networks and rock blocks. At present, single fractures in rocks, as the most basic and simplified component unit of fracture networks, are often the primary research object of scholars, while research on cross fractures is relatively rare. Compared with single fractures, solutes such as fluids and pollutants often produce significant changes in flow direction, flow rate and flow velocity at the intersection of cross fractures, thereby changing the overall solute migration distribution. Therefore, the research conclusions obtained through single fractures may be different from the actual situation of fracture networks. Therefore, further research on cross fractures composed of single fractures is very necessary to understand the solute migration mechanism in fracture networks.

[0004] In order to reveal the solute transport process and mechanism in the fractured medium, real-time observation of seepage characteristics in the laboratory is a very important research method. However, naturally existing fractured rock and artificial fracture specimens (often made of cement mortar) are both opaque materials, and it is impossible to directly observe the specific process of solute migration during the experiment. Therefore, using transparent materials to make cross-fracture specimens and realizing the full process observation of solute migration is the key to solving the above problems.

[0005] In the 6th issue of the Chinese Journal of Geotechnical Engineering in 2017, titled "Experimental Study on Seepage Characteristics of Rock-like Through-Filled Fissures", Zhao Kai et al. obtained cross-cracks made of similar materials by inserting 3D printed inserts into the casting mold and pouring in the cement mortar prepared in advance, vibrating and compacting it, and then removing the inserts after hardening. However, the surface of the cross-cracks obtained by this method is a parallel plate, which does not have three-dimensional roughness, and the non-transparent casting material used cannot observe the seepage characteristics at the intersection.

[0006] The invention patent with the publication number CN106908293A introduces a method for preparing a transparent rock joint replica. The prepared fracture specimen has both transparent properties and rough characteristics. This method proposes a method for making transparent fractures, which can be applied to visualization research. However, the prepared fracture specimen has only a single fracture and cannot meet the requirements for making molds of more complex intersecting fractures.

[0007] The invention patent with the publication number CN111504873A proposes a method for making a simulation model of rock intersecting fractures. The used mold-making method has good transparency and can be used for visualization tests and observations. The made rough intersecting model contains horizontal and vertical fractures of different sizes, which are made separately and then spliced together. However, there is only 1 branch in the "T"-shaped intersecting fracture made by this method, and the morphological characteristics at the intersection are quite different from those of natural "cross"-shaped or irregular-angle intersecting fractures. The contact surface between the horizontal fracture and the vertical fracture is smooth-rough, which is quite different from the actual situation of natural fractures.

[0008] In view of the deficiencies of the above several methods, a three-dimensional intersecting fracture preparation method with transparent characteristics, geometric characteristics at the intersection, and real rough characteristics is urgently needed for further exploring the mechanisms of fluid and solute migration in fractured media. Summary of the Invention

[0009] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a mold and a model-making method for making a transparent three-dimensional intersecting fracture model.

[0010] To solve the problems of the prior art, the present invention discloses a mold for making a transparent three-dimensional intersecting fracture model, which is characterized in that it includes a mold-making frame member, an intersecting fracture original rock specimen, and a mold-making material specimen. The outside of the mold-making frame member is a mold-making enclosure. The inside of the mold-making frame member is partitioned into several spaces for placing the intersecting fracture original rock specimens by partitions. A gap is reserved between the intersecting fracture original rock specimen and the partition. The mold-making material specimen includes a silicone group mold-making specimen and an epoxy resin group mold-making specimen. The silicone group mold-making specimen fills the gap reserved between the intersecting fracture original rock specimen and the partition for replicating the surface morphological characteristics of the intersecting fracture original rock specimen. After taking out the intersecting fracture original rock specimen, the silicone group mold-making specimen and the partition are combined to form a solid silicone plate. Side plates are respectively arranged on both sides of the solid silicone plate. The epoxy resin group mold-making specimen fills the cavity formed by the solid silicone plate and the side plates, and the epoxy resin group mold-making specimen is used for replicating the silicone fracture surface morphological characteristics of the solid silicone plate to form a transparent three-dimensional intersecting fracture model.

[0011] Further, the mold turning frame includes an L-shaped plate, a peripheral frame, and a bottom plate of the frame. The peripheral frame is a cubic frame. The L-shaped plates are arranged at four corners of the peripheral frame, and the bottom plate of the frame is arranged at the bottom of the peripheral frame.

[0012] Further, the L-shaped plate, the peripheral frame, and the bottom plate of the frame are all made of plexiglass.

[0013] Further, the partition plates are arranged in a cross-cross pattern.

[0014] Correspondingly, a method for manufacturing a transparent three-dimensional cross-fracture model:

[0015] The transparent three-dimensional cross-fracture model is manufactured using the above-mentioned mold.

[0016] Mix silicone liquid and silicone curing agent in a mass ratio of 100:2. After fully stirring, slowly pour the mixture into the reserved gaps between each cross-fracture original rock specimen and the partition plates, so that the rough surfaces of the silicone group mold-turned specimens are in full contact and fit with the rough surfaces of each cross-fracture original rock specimen. Stop pouring after the free surface of the silicone is flush with the top of the cross-fracture original rock specimen, and then let it stand for 1 day. After the silicone group mold-turned specimens are completely solidified and formed, remove the peripheral frame, L-shaped plates, cross-fracture original rock specimens, and the bottom plate of the frame to obtain a solid silicone plate composed of partition plates and silicone group mold-turned specimens. The solid silicone plate contains the morphological characteristics of the cross-fracture surface. Place two side plates on both sides of the solid silicone plate respectively, and mix type A and type B epoxy resin crystal drops in a mass ratio of 3:1. After stirring evenly, slowly pour the mixture onto the two horizontally oriented fracture surfaces of the solid silicone plate. Drain the air bubbles in the epoxy resin, and then let it stand for 1 day to harden and form. Flip the solid silicone plate 90°, 180°, and 270° respectively and repeat the above epoxy resin pouring steps to complete the production of the transparent three-dimensional cross-fracture model.

[0017] The beneficial effects of the present invention are as follows:

[0018] 1. The present invention provides a mold and a model manufacturing method for manufacturing a transparent three-dimensional cross-fracture model. The provided mold turning scheme can manufacture cross-fracture models at multiple angles such as 45°, 60°, or 90° according to test requirements. At the same time, the cross-fractures formed by this scheme have 4 complete branches, real rough surfaces, and cross geometric features. The rough fracture wall surface morphology of the mold-turned specimen is basically the same as that of natural cross-fractures.

[0019] 2. The mold - turning method provided by the present invention features fast forming speed, simple operation during the mold - turning process, and relatively low costs for the required components and specimens. It can be widely applied to the preparation and visualization research of cross - fissure transparent mold - turned specimens. In addition to the advantages of being easy to assemble and form silicone mold - turned specimens with specific shapes, the used surrounding frame and L - shaped plate also overcome the defect that it is difficult to take out the pre - formed crack specimens from the mold - turning surrounding frame during demolding.

[0020] 3. During the mold - turning process of cross - fissure mold - turned specimens, it is not limited to using the silicone and epoxy resin materials adopted in the present invention. According to different test purposes or considerations, other materials focusing on mechanical tests such as cement mortar can also be used. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a three - dimensional structure schematic diagram of the mold of the present invention.

[0022] Figure 2 It is a top - view structure diagram of the mold of the present invention.

[0023] Figure 3 It is a side - view diagram of the solid silicone plate in the present invention.

[0024] Figure 4 It is a partial three - dimensional structure diagram of the solid silicone plate in the present invention.

[0025] REFERENCE NUMERALS:

[0026] 1. Mold - turning frame member; 2. Cross - fissure original rock specimen; 3. Partition board; 4. L - shaped plate; 5. Peripheral surrounding frame; 6. Surrounding frame bottom plate; 7. Silicone group mold - turned specimen; 8. Epoxy resin group mold - turned specimen; 9. Rock fissure; 10. Rock matrix; 11. Solid silicone plate; 12. Side plate. EMBODIMENTS

[0027] The present invention will be further described below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and cannot be used to limit the protection scope of the present invention.

[0028] As Figures 1-4As shown in the figure, the present invention provides a mold for making a transparent three-dimensional cross-fracture model, which includes a mold-turning frame member 1, a cross-fracture original rock specimen 2 and a mold-turning material specimen. The outside of the mold-turning frame member 1 is a mold-turning enclosure frame. The inside of the mold-turning frame member 1 is divided into several spaces for placing the cross-fracture original rock specimens 2 by a partition plate 3, and a gap is reserved between the cross-fracture original rock specimen 2 and the partition plate 3. The mold-turning material specimens include a silicone group mold-turning specimen 7 and an epoxy resin group mold-turning specimen 8, which are respectively used to replicate the surface three-dimensional topography of the cross-fracture original rock specimen 2 and the solid silicone plate 11. The silicone group mold-turning specimen 7 is filled in the reserved gap between the cross-fracture original rock specimen 2 and the partition plate 3, and the epoxy resin group mold-turning specimen 8 is filled in the cavity formed by the solid silicone plate 11 and the side plate 12. The partition plate 3 is preferably a cross-shaped plate. The solid silicone plate 11 is composed of the silicone group mold-turning specimen 7 and the partition plate 3, and side plates 12 are respectively arranged on both sides of the solid silicone plate 11.

[0029] Taking a cube granite rock with dimensions of 21.0 cm×21.0 cm×21.0 cm as the raw material, it is split into four independent cross-fracture original rock specimens 2 by a series of technical means. In fact, according to the cross angle of the cross-fracture original rock specimen 2, in this solution, only the cross-shaped plate needs to be adjusted at the corresponding angle to make cross-fracture models at multiple angles such as 45°, 60° or 90°. In this embodiment, the manufacturing method of the 90° cross-fracture is introduced in detail, and the size of each cross-fracture original rock specimen is about 10.5 cm×10.5 cm×21.0 cm (length×width×height). The rock fracture 9 obtained by splitting has a natural rough surface, and the included angle formed between two adjacent fracture surfaces is 90°, thereby obtaining a "cross"-shaped rough cross-fracture.

[0030] The mold-turning enclosure frame includes an L-shaped plate 4, a peripheral enclosure frame 5 and an enclosure bottom plate 6, all of which are made of plexiglass plates with a thickness of about 2.0 cm. The size of the enclosure frame is mainly designed according to the size of the cross-fracture original rock specimen. In the present invention, the overall internal size of the peripheral enclosure frame 5 is 30.0 cm×30.0 cm×21.0 cm (length×width×height); the planar size of the enclosure bottom plate 6 is 32.0 cm×32.0 cm, and the thickness is 2.0 cm. The L-shaped plate 4 is arranged at the four corners of the peripheral enclosure frame 5, and the enclosure bottom plate 6 is arranged at the bottom of the peripheral enclosure frame 5.

[0031] The cross plate is composed of two 1.0 cm thick organic glass plates with a size of 30.0 cm × 21.0 cm, which are vertically crossed and placed in the middle of the peripheral frame 5. The L-shaped plate 4 is made of a 2.0 cm thick glass plate, with a single-side outer frame size of 8.5 cm × 21.0 cm and an inner frame size of 6.5 cm × 21.0 cm, and is placed in the four corners of the peripheral frame 5.

[0032] After the above components are assembled, a waterproof film is pasted on the outer frame of the peripheral frame 5 and the junction with the frame bottom plate 6 to prevent material leakage that may occur when the silicone group mold material is subsequently poured.

[0033] In order to facilitate the separation of the silicone group mold specimen 7 and the rock fissure 9, the surface of the rock fissure 9 is evenly coated with a silicone release agent, and four cross-crack original rock specimens 2 are placed around the cross plate in the frame.

[0034] The relative positions of the specimens were adjusted so that a 2.0 cm reserved gap existed between the rough surface of the cross-crack original rock specimen 2 and the cross plate for filling the silica gel group mold specimen 7.

[0035] To make a three-dimensional cross-crack model, mix the silicone liquid and silicone curing agent in a mass ratio of 100:2, stir thoroughly (about 5 min), and then slowly pour it into the reserved gap between the cross-crack original rock specimen 2 and the cross-cross plate, so that the silicone group mold specimen is in full contact and fit with the rough surface of each cross-crack original rock specimen, and stop pouring when the free surface of the liquid silicone is flush with the top of each fracture specimen.

[0036] After standing for 1 day in a constant temperature environment indoors, the liquid silicone solidifies into solid silicone. The surrounding frame 5, L-shaped plate 4, cross-crack original rock specimen 2 and frame bottom plate 6 are removed in sequence to obtain solid silicone containing the rough surface morphology of each cross crack, which together with the cross plate constitutes a solid silicone plate 11. The crack surface and the solid silicone should be separated slowly to avoid stress concentration caused by too fast a separation speed, resulting in damage to the crack or solid silicone surface, which affects the accuracy of subsequent tests.

[0037] The solid silicone plate 11 has 4 branches, one of which is fixed on the horizontal plane, and the side plates 12 are fixed on both sides of the solid silicone plate 11. At the same time, a waterproof film is pasted at the junction to prevent leakage when pouring the epoxy resin group mold material. Mix the A-type epoxy resin crystal glue and the B-type epoxy resin crystal glue in a mass ratio of 3:1, stir thoroughly (about 5 minutes), and then slowly pour a certain thickness on the two horizontal silicone crack surfaces to ensure that the epoxy resin mold group material submerges the highest point of the silicone crack surface by about 2.0 cm.

[0038] Use a multi-function spray gun (spot spray) to expel the bubbles in the epoxy resin, and after standing for 1 day in a constant temperature environment, it can be molded into a solid epoxy resin. Flip the solid silicone plate 11 clockwise by 90°, 180°, and 270°, and complete the casting process of all cross-crack specimens in turn according to the previous steps (wherein, two crack surfaces can be cast each time it is flipped, and a total of 8 surfaces can be cast).

[0039] The molded samples are taken out from the solid silica gel plate 11 in sequence, and the transparent three-dimensional cross-crack model is obtained according to the corresponding combination of each crack surface. The model contains 4 branches and has the same rough surface morphology as the "cross"-shaped rough cross original rock cracks.

[0040] The present invention also provides a method for making a transparent three-dimensional cross-crack model using the above mold, and the specific steps are as follows:

[0041] Step 1: According to the experimental requirements, determine the size of the cross-crack original rock specimen, and obtain cross-cracks of a specific angle (90° is taken as an example in this article) through the Brazilian splitting method, and the splitting surface is a rough surface.

[0042] Step 2: Make a mold frame that matches the size of the cross-fracture original rock specimen, place the cross plate in the center of the mold perimeter frame, and divide the frame into 4 areas; place the L-shaped plate at the 4 corners of the perimeter frame.

[0043] Step 3: Paste a waterproof film on the outer frame of the frame and its connection with the base plate to prevent leakage of the mold material, then evenly apply the release agent to the inside of the mold frame and the rough surface of the cross-crack original rock specimens, and place 4 fractured original rock specimens in 4 areas in the frame respectively.

[0044] Step 4: Adjust the relative positions of the specimens to ensure that there is a 2.0 cm gap between each fractured original rock specimen and the cross plate for filling the silicone group molded specimen.

[0045] Step 5: Mix the silicone liquid and silicone curing agent in a mass ratio of 100:2, stir thoroughly and then slowly pour it into the reserved gaps between each cross-crack original rock specimen and the cross-cross plate, so that the silicone group mold specimen is in full contact and fit with the rough surface of each crack specimen.

[0046] Step 6: Stop pouring when the free surface of the silica gel is flush with the top of the cross-fracture original rock specimen, and then leave the above components to stand in a constant temperature environment for 1 day.

[0047] Step 7: After the silicone rubber group die-casting specimen is completely solidified and formed, remove the peripheral surrounding frame, L-shaped plate, cross-fissure original rock specimen, and the bottom plate of the surrounding frame in sequence, and then a solid silicone rubber plate composed of the cross-shaped plate and the silicone rubber group die-casting material can be obtained. This silicone rubber plate contains the morphological characteristics of the cross-fissure surface.

[0048] Step 8: Place the two side plates on both sides of the solid silicone rubber plate respectively, mix type A and type B epoxy resin crystal drip glue according to a mass ratio of 3:1, stir evenly, and slowly pour it onto the two fissure surfaces facing horizontally on the solid silicone rubber plate.

[0049] Step 9: Use a multi-functional spray gun to discharge the air bubbles in the epoxy resin, and then leave the above components in a constant temperature environment for 1 day to harden and form.

[0050] Step 10: Flip the solid silicone rubber plate by 90°, 180°, and 270°, and repeat steps 8 and 9 to complete the production of all transparent specimens of the three-dimensional cross-fissure model in sequence.

[0051] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. At the same time, in the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. And in the drawings of the present invention, the filling pattern is only for distinguishing layers and is not limited in any other way.

[0052] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A mold for making a transparent three-dimensional cross-fissure model, characterized in that, The invention comprises a mold frame component (1), a cross-crack original rock specimen (2) and a mold material specimen, wherein the exterior of the mold frame component (1) is a mold enclosure, the interior of the mold frame component (1) is partitioned into a plurality of spaces for placing the cross-crack original rock specimen (2) by a partition (3), a gap is reserved between the cross-crack original rock specimen (2) and the partition (3), and the mold material specimen comprises a silicone group mold specimen (7) and an epoxy resin group mold specimen (8), wherein the silicone group mold specimen (7) is filled in the pre-reserved gap between the cross-crack original rock specimen (2) and the partition (3). A gap is left for replicating the surface morphology of the cross-crack original rock specimen (2); after the cross-crack original rock specimen (2) is taken out, the silicone group mold specimen (7) is combined with the partition (3) to form a solid silicone plate (11); side plates (12) are respectively provided on both sides of the solid silicone plate (11); the epoxy resin group mold specimen (8) is filled in the cavity formed by the solid silicone plate (11) and the side plates (12); the epoxy resin group mold specimen (8) is used to replicate the surface morphology of the silicone cracks of the solid silicone plate (11) to form a transparent three-dimensional cross-crack model.

2. The mold for fabricating a transparent three-dimensional cross fracture model according to claim 1, characterized in that, The molded enclosure frame comprises an L-shaped plate (4), a peripheral enclosure frame (5) and an enclosure frame bottom plate (6); the peripheral enclosure frame (5) is a cubic frame; the L-shaped plate (4) is arranged at the four corners of the peripheral enclosure frame (5); and the enclosure frame bottom plate (6) is arranged at the bottom of the peripheral enclosure frame (5).

3. The mold for manufacturing a transparent three-dimensional cross fracture model according to claim 2, characterized in that, The L-shaped plate (4), the peripheral frame (5) and the frame bottom plate (6) are all made of organic glass.

4. The mold for manufacturing a transparent three-dimensional cross-fissure model according to claim 1, characterized in that, The partitions (3) are arranged in a cross pattern.

5. A method for making a transparent three-dimensional cross-crack model, characterized in that: The transparent three-dimensional cross-crack model is made by using the mold described in any one of claims 1 to 4; The silicone liquid and the silicone curing agent are mixed in a mass ratio of 100:2, and after being fully stirred, the mixture is slowly poured into the reserved gap between each cross-crack original rock specimen (2) and the partition (3), so that the silicone group mold specimen (7) is fully in contact with and fits the rough surface of each cross-crack original rock specimen (2); the pouring is stopped when the free surface of the silicone is flush with the top of the cross-crack original rock specimen (2), and then left to stand for 1 minute. d time; after the silicone group molded specimen (7) is completely solidified, the surrounding frame (5), L-shaped plate (4), cross-crack original rock specimen (2) and frame bottom plate (6) are removed to obtain a solid silicone plate (11) composed of the partition plate (3) and the silicone group molded specimen (7), and the solid silicone plate (11) includes cross-crack surface morphology features; two side plates (12) are placed on both sides of the solid silicone plate (11), and type A and type B epoxy resin crystal glue are mixed in a mass ratio of 3:1, stirred evenly, and then slowly poured onto the two horizontal crack surfaces on the solid silicone plate (11); the bubbles in the epoxy resin are discharged, and then it is left to stand for 1 day to harden and form; the solid silicone plate (11) is turned over and the above epoxy resin pouring steps are repeated to complete the production of a transparent three-dimensional cross-crack model.

6. The method for fabricating a transparent three-dimensional cross-fracture model according to claim 5, wherein: The flipping angles of the solid silicone plate (11) are 90°, 180° and 270°.

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