Preparation method of model test piece for simulating pore fracture structure

Abstract

The invention relates to the technical field of model test piece preparation, and discloses a method for preparing a model test piece for simulating a pore fracture structure, which comprises the following steps: acquiring geometric parameters of the model test piece, and manufacturing a mold for producing the model test piece; obtaining geometric parameters of the hole fracture structure, and manufacturing a hole mold matched with the shape of the hole fracture structure required by the test; the hole die is installed in the die; prefabricated pouring materials are injected into the mold; after the pouring material is solidified, the hole mold is taken out of the pouring body by deforming the hole mold, and the model test piece is obtained. By obtaining the geometric parameters of the pore crack structure, the pore mold with the adaptive shape is prepared, so that the model test piece prepared by the method can form a regular or irregular pore crack shape according to actual working conditions.

Description

Technical Field

[0001] This invention relates to the field of model specimen preparation technology, and in particular to a method for preparing model specimens that simulate pore and crack structures. Background Technology

[0002] The type and distribution of pores and fissures have a significant impact on the overall bearing capacity and stability of rocks. Similarly, building structures containing voids will exhibit specific performance changes. Therefore, preparing model specimens for simulation tests helps to predict and evaluate the performance of engineering geological bodies under external loads and real stress conditions, and to gain a deeper understanding of the mechanism and development process of geological disasters. This has important theoretical and practical value for materials mechanics, rock mechanics and engineering applications.

[0003] Current model specimens are mainly created by drilling regular holes and fissures in the rock to simulate the distribution of pores and fissures in mine roadways and rock strata. Then, cement-based, concrete, polymer and other materials are used to spray the hole walls and fill the pores and fissures to simulate working conditions such as roadway support, pore and fissure sealing and goaf filling in the mine. Through simulation tests, the stress conditions of mine roadways, engineering sites and other places can be predicted and evaluated.

[0004] However, the actual engineering geological environment is complex. Factors such as deep stress, surrounding rock stress, temperature difference, external wind force, rock burst, freeze-thaw, groundwater, rainwater and river corrosion can easily cause the contact surface between concrete and rock, surrounding rock, dams and other materials to loosen, fall off or crack, so that the actual pores and cracks are mostly irregular in shape. Therefore, the traditional model specimens that simulate pore and crack structures with regular pores will cause the pores and cracks of the model specimens to deviate significantly from the actual pore and crack structures, ultimately causing the simulation test results to deviate from reality and fail to accurately support engineering assessment and disaster research. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a method for preparing a model specimen that simulates a pore and crack structure.

[0006] This invention provides a method for preparing a model specimen simulating a pore fracture structure, comprising: Obtain the geometric parameters of the model specimen and manufacture the mold for producing the model specimen; Obtain the geometric parameters of the pore structure and fabricate a pore mold that matches the shape of the pore structure required for the experiment; Install the perforated mold into the mold; The precast casting material is injected into the mold; After the casting material has solidified, the mold is removed from the casting body by deforming the mold to obtain the model specimen.

[0007] Optionally, it also includes a simulation part that can be placed in the mold, the simulation part having through holes; before the hole mold is installed in the mold, the hole mold is first installed in the through holes of the simulation part, and then the hole mold and the simulation part are put into the mold together; after the hole mold is separated from the simulation part and the casting body, a model specimen simulating the hole crack structure passing through different media is made.

[0008] Optionally, the die includes at least one connecting die and at least one support die connected to the connecting die, with one or both ends of the connecting die being detachably connected to the die.

[0009] Optionally, a magnet is provided on the outside of the mold. When the perforated mold is placed in the mold, the magnet contacts the outer wall of the mold. The magnet attracts the connecting mold and limits the end of the connecting mold to the corresponding position on the inner wall of the mold.

[0010] Optionally, the mold sidewall has at least one wall hole, and the end of the connecting mold is inserted into the wall hole.

[0011] Optionally, it also includes an outer mold with a box-like structure and an open top, with the mold located inside the outer mold and multiple mesh holes on the side plate of the outer mold.

[0012] Optionally, the support mold is made of flexible material and has a cavity; the connecting mold has an air passage, one end of which is connected to the cavity and the other end is connected to an external air source.

[0013] Optionally, the mold is made of a high-temperature resistant material, and the die is made of a phase change material.

[0014] Optionally, one end of the support mold is detachably connected to the connecting mold, while the other end extends out of the mold.

[0015] Optionally, the formwork is a tubular body with a sliding rod slidably installed inside. One end of the sliding rod extends out of the formwork, and the other end is close to the connecting mold. A connector is provided at the end close to the connecting mold. The two ends of the connector are rotatably connected to a first hook portion via a rotating shaft. A torsion spring is sleeved on each of the two rotating shafts. The two torsion arms of the torsion spring are respectively connected to the connector and the corresponding first hook portion. A first spring is provided between the two first hook portions, and one end of the first spring is connected to the connector. The connecting mold is provided with a protrusion. The two opposite ends of the protrusion form a second hook portion. When the formwork and the connecting mold are detachably connected, the two first hook portions hook together with the corresponding second hook portions, and one end of the first spring abuts against the protrusion.

[0016] The technical solution provided by the embodiments of the present invention has the following advantages compared with the prior art: 1. By obtaining the geometric parameters of the pore and crack structure, a pore mold with a suitable shape is prepared. When the pore mold is removed from the casting body, a model specimen that is close to the actual pore and crack shape can be formed. Therefore, the model specimen prepared by this invention can form regular or irregular pore and crack shapes according to the actual working conditions.

[0017] 2. Since the pore and fracture structure of the model specimen closely matches the actual scene, the simulation test based on the specimen can truly reflect the influence of pore and fracture type and distribution on the bearing capacity and mechanical properties of rock or building structure, and provide accurate test data for the stress prediction of engineering geological bodies, optimization of tunnel support schemes, research and development of pore and fracture sealing technology, and prevention and control of geological disasters.

[0018] 3. By preparing the hole mold, installing and fixing it, pouring and solidifying it, and demolding it, the preparation of irregular hole and crack model specimens is realized. The hole mold can be flexibly customized according to the geometric parameters of different holes and cracks, so that the hole mold can be adapted to any complex shape. Moreover, the hole mold can be removed by deformation, which facilitates demolding on the one hand, and avoids damage to the cast body during demolding on the other hand. Therefore, the preparation method of the present invention has strong adaptability and can meet the needs of diversified hole and crack simulation in different engineering scenarios.

[0019] 4. The preparation method of this invention is not only applicable to the simulation of pores and fractures in geological bodies in the field of rock mechanics, but can also be extended to the performance simulation of building structures with void spaces (such as surrounding rock, dams, concrete components, etc.). Therefore, whether it is the simulation of pores and fractures in deep mine roadways, the study of fracture evolution in natural geological disasters, or the mechanical performance testing of void parts in building structures, accurate simulation can be achieved by customizing and adapting pore molds. This breaks through the limitation of traditional preparation methods that can only adapt to single regular pore and fracture scenarios, and has a wide range of practical application value. Attached Figure Description

[0020] Figure 1 This is a flowchart illustrating a method for preparing a model specimen to simulate a pore-crack structure, as provided in Embodiment 1 of the present invention.

[0021] Figure 2 This is a schematic diagram of the structure of the mold with a hole mold and a simulation part provided in Embodiment 2 of the present invention.

[0022] Figure 3 This is a schematic diagram of the structure of the second fastener provided in Embodiment 2 of the present invention.

[0023] Figure 4 This is a schematic diagram of the structure of the detachable mold with a hole mold provided in Embodiment 2 of the present invention.

[0024] Figure 5 This is a schematic diagram of the detachable mold provided in Embodiment 2 of the present invention.

[0025] Figure 6 This is a schematic diagram of the structure of the airbag as the support provided in Embodiment 3 of the present invention.

[0026] Figure 7This is a schematic diagram of the perforated mold structure when the mold support is an airbag, as provided in Embodiment 3 of the present invention.

[0027] Figure 8 This is a schematic diagram of the structure of the mold provided in the outer mold according to Embodiment 4 of the present invention.

[0028] Figure 9 This is a schematic diagram of the structure provided in Embodiment 5 of the present invention, showing the connecting mold and the die connected by a magnet.

[0029] Figure 10 This is a schematic diagram of the through-mold structure provided in Embodiment Six of the present invention.

[0030] Figure 11 This is a schematic diagram of the structure provided in Embodiment 6 of the present invention, showing the connection between the connecting mold and the die through a first fixing member.

[0031] Figure 12 This is a schematic diagram of the structure provided in Embodiment Six of the present invention, showing that the formwork support and the connecting formwork can be detachably connected by a first hook structure.

[0032] Figure 13 This is a schematic diagram of the hook structure when it is separated, as provided in Embodiment Six of the present invention.

[0033] Figure 14 This is a schematic diagram of the structure of the formwork support and connecting formwork provided in Embodiment 6 of the present invention, which are connected by tenons and mortises.

[0034] Figure 15 This is a schematic diagram of the structure provided in Embodiment 6 of the present invention, showing that the support mold and the connecting mold can be detachably connected by a second hook structure.

[0035] Explanation of reference numerals in the attached drawings: 1. Mold; 11. Wall hole; 12. Base plate; 13. First rectangular frame; 14. Side plate; 15. Second rectangular frame; 2. Hole mold; 21. Connecting mold; 22. Support mold; 23. Slide rod; 24. Connecting piece; 25. First hook part; 26. First spring; 27. Protrusion part; 28. Second hook part; 29. ​​Rotating shaft; 3. Limiting piece; 31. Magnet; 32. First fixing piece; 33. First pressure plate; 34. First handle; 4. Outer mold; 5. Simulation piece; 6. Cast body; 7. Second fixing piece; 71. Second handle; 72. Second pressure plate; 73. Threaded rod; 74. Threaded hole; 8. Hook piece; 81. Second spring; 82. Connecting rod; 83. Third spring. Detailed Implementation

[0036] The following detailed description of a specific embodiment of the present invention is provided in conjunction with the accompanying drawings. However, it should be understood that the scope of protection of the present invention is not limited to the specific embodiment.

[0037] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the technical solution of this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0038] Example 1: like Figure 1 As shown, this embodiment provides a method for preparing a model specimen simulating a pore fracture structure, including: Step 1: Obtain the geometric parameters of the model specimen and make mold 1 for producing the model specimen; Step 2: Obtain the geometric parameters of the pore fracture structure and fabricate a pore mold 2 that matches the shape of the pore fracture structure required for the experiment; Step 3: Install the hole mold 2 into the mold 1; Step 4: Pour the precast casting material into mold 1; Step 5: After the casting material has solidified, the mold 2 is removed from the casting body by deforming it to obtain the model specimen.

[0039] Example 2: like Figure 2 As shown, this embodiment provides a method for preparing a model specimen simulating a pore fracture structure. The difference from Embodiment 1 is that it also includes a simulation part 5 that can be placed in the mold 1, and the simulation part 5 has a through hole. Before the hole mold 2 is installed in the mold 1, the hole mold 2 is first installed in the through hole of the simulation part 5, and then the hole mold 2 and the simulation part 5 are put into the mold 1 together. After the hole mold 2 is separated from the simulation part 5 and the casting body, a model specimen simulating a pore fracture structure passing through different media is made.

[0040] In actual working conditions, pore-fracture structures often pass through different media. Therefore, one or more simulation parts 5 are made according to actual needs. The simulation parts are then installed on the hole mold 2, and then both are placed into the mold. In the mold, the position of the simulation part 5 matches the actual position. Then, the casting body is injected into the space in the mold where the simulation part and hole mold are not set. After the casting body solidifies, the simulation part 5 and the casting body are connected as one, forming a model specimen. This model specimen will simulate the working conditions of the pore-fracture structure passing through different media.

[0041] like Figure 3As shown in this embodiment, the simulated part 5 is prone to displacement when the casting body 6 has not yet solidified. Therefore, the simulated part 5 is fixed by setting a second fixing part 7 on the mold 1.

[0042] The second fixing component 7 includes a second handle 71, a threaded rod 73 connected to the second handle 71, and a second pressure plate 72 connected to the threaded rod 73. A threaded hole 74 is provided at a corresponding position on the side plate of the mold 1. The threaded rod 73 and the threaded hole 74 are threadedly connected. The second pressure plate 72 is located inside the mold 1, and the second handle 71 is located outside the mold 1. By rotating the second handle 71, the second pressure plate 72 moves toward the simulation component 5 and squeezes the simulation component 5, thereby preventing the simulation component 5 from shifting.

[0043] like Figure 4 and Figure 5 As shown, if there are many parts in the mold such as simulation part 5, or if there is a problem of inconvenience in demolding, the above problems can be solved by setting a detachable mold.

[0044] The detachable mold 1 includes a base plate 12 and four side plates 14, which are connected end to end to form a closed ring structure; the base plate 12 and the side plates 14, as well as the two adjacent side plates 14, can be detachably connected.

[0045] like Figure 5 As shown, a first rectangular frame 13 is provided on the base plate 12, and four side plates 14 are confined within the first rectangular frame 13. The cross-section of the end of the four side plates 14 that contacts each other is a right triangle (one angle is 45 degrees). A second rectangular frame 15 is provided on the outer periphery of the top of the four side plates 14. The four side plates 14 are enclosed and confined into a cuboid shape by the first rectangular frame 13 and the second rectangular frame 15.

[0046] Example 3: like Figure 6 and Figure 7 As shown, this embodiment provides a method for preparing a model specimen simulating a pore fracture structure. The difference from Embodiment 1 is that the pore mold 2 includes a connecting mold 21 and a plurality of support molds 22 connected to the connecting mold 21. One end of the connecting mold 21 is detachably connected to the mold 1.

[0047] The support mold 22 is made of flexible material and has a cavity; the connecting mold 21 has an air passage, one end of which is connected to the cavity and the other end is connected to an external air source.

[0048] In this embodiment, the support mold 22 is an air bladder. By inflating multiple air bladders with an external air source, a hole mold 2 that is compatible with the pore and fissure structure can be formed.

[0049] In this embodiment, a wall hole 11 is provided on the side wall of the mold 1, and the end of the connecting mold 21 is inserted into the wall hole 11. The connecting mold 21 is detachably limited in the wall hole by a limiting device.

[0050] Working principle: When the casting material is injected into the mold 1, the support mold 22 expands due to the air supply from the external air source; after the casting material solidifies, the air is released from the support mold 22, and the connecting mold 21 and the shrinking support mold 22 are removed, forming a space in the casting body that simulates a pore and crack structure.

[0051] Example 4: like Figure 8 As shown, this embodiment provides a method for preparing a model specimen simulating a pore fracture structure. The difference from Embodiment 1 is that it also includes an outer mold 4 with a box structure and an open top. The mold 1 is located inside the outer mold 4, and multiple mesh holes are opened on the side plate of the outer mold 4.

[0052] In this embodiment, the side wall of the mold 1 has at least one wall hole 11. The end of the connecting mold 21 is inserted into the wall hole 11 and also into the mesh hole. The outer mold 4 with the mesh hole is provided to facilitate the positioning of the hole mold 2.

[0053] Example 5: like Figure 9 As shown, this embodiment provides a method for preparing a model specimen simulating a pore-crack structure, which differs from Embodiment 1 in that: The die 2 includes a connecting die 21 and a support die 22 connected to the connecting die 21. The two ends of the connecting die 21 are detachably connected to the die 1.

[0054] In this embodiment, the two ends of the connecting mold 21 are detachably connected to the mold 1 by magnets. The mold 1 is provided with a magnet 31. When the hole mold 2 is placed in the mold 1, the magnet 31 contacts the outer wall of the mold 1. The magnet 31 attracts the connecting mold 21 and limits the end of the connecting mold 21 to the corresponding position on the inner wall of the mold 1.

[0055] In other embodiments, the two ends of the connecting mold 21 can also be connected to the mold 1 by glue. When the glue solidifies, the connecting mold 21 is separated from the mold 1 by baking the location where the glue is placed.

[0056] Example 6: like Figure 10 As shown, this embodiment provides a method for preparing a model specimen simulating a pore-crack structure, which differs from Embodiment 1 in that: The die 2 includes a connecting die 21 and a support die 22 connected to the connecting die 21. The two ends of the connecting die 21 are detachably connected to the die 1.

[0057] like Figure 10 and Figure 11 As shown, in this embodiment, the mold 1 has three wall holes 11, and the two ends of the connecting mold 21 are inserted into the corresponding two wall holes 11. One end of the support mold 22 extends out of the mold 1 from one wall hole 11. By setting a first fixing member 32 at each end of the connecting mold 21, the two ends of the connecting mold 21 are detachably connected to the mold 1 through the first fixing member.

[0058] like Figure 11 As shown, the first fixing member 32 includes a first handle 34, a first pressure plate 33 connected to the first handle 34, and a threaded hole at the end of the connecting mold 21. One end of the first handle 34 passes through the wall hole 11 and is threadedly connected to the threaded hole. When the first pressure plate 33 abuts against the mold 1, the end of the connecting mold 21 is detachably connected to the mold 1.

[0059] One end of the support mold 22 is detachably connected to the connecting mold 21, and the other end extends out of the mold 1.

[0060] In this embodiment, one end of the support mold 22 is detachably connected to the connecting mold 21, which is implemented in four ways.

[0061] like Figure 12 and Figure 13 As shown, firstly, the support mold 22 is a tubular body, and a sliding rod 23 is slidably arranged inside the support mold 22. One end of the sliding rod 23 extends out of the support mold 22, and the other end is close to the connecting mold 21. A connector 24 is provided at the end close to the connecting mold 21. The two ends of the connector 24 are rotatably connected to the first hook part 25 through the rotating shaft 29. A torsion spring is sleeved on each of the two rotating shafts 25. The two torsion arms of the torsion spring are respectively connected to the connector 24 and the corresponding first hook part 25. A first spring 26 is provided between the two first hook parts 25. One end of the first spring 26 is connected to the connector 24. A protrusion 27 is provided on the connecting mold 21. The two opposite ends of the protrusion form the second hook part 28. When the support mold 22 and the connecting mold 21 are detachably connected, the two first hook parts 25 are hooked together with the corresponding second hook parts 28, and one end of the first spring 26 abuts against the protrusion 27.

[0062] In this embodiment, the protrusion height of the protrusion 27 does not exceed the outer wall of the connecting mold 21. That is, a groove is first opened on the connecting mold 21, and then the protrusion 27 is set in the groove to prevent the protrusion 27 from obstructing demolding during demolding.

[0063] After the casting material solidifies, the formwork 22 and the connecting mold 21 are separated and removed from the casting body, thus separating the perforated mold 2 from the casting body.

[0064] like Figure 14As shown, secondly, by opening a mortise in the connecting mold 21 and setting a tenon at the end of the support mold 22, the tenon and the mortise are engaged to make the two detachably connected.

[0065] like Figure 15 As shown, thirdly, the support mold 22 is a tubular body, and a hook 8 is inserted into the support mold 22. The hook 8 includes a connecting rod 82 inserted into the support mold 22. A second spring 81 is provided between the first side of one end of the connecting rod 82 and the inner wall of the support mold, and a third spring 83 is provided between the second side of the other end of the connecting rod 82 and the inner wall of the support mold. A third hook portion is formed at the end of the connecting rod 82. A slot is opened on the connecting mold 21, and a fourth hook portion is formed in the slot. When the third hook portion hooks the fourth hook portion, one end of the support mold 22 is detachable from the connecting mold 21. When demolding, the upper end of the connecting rod 82 is pressed upward to separate the third hook portion and the fourth hook portion, and then the two can be separated.

[0066] Fourth, the connecting mold 21 and the supporting mold 22 are connected by threads, that is, one has a threaded hole and the other has a threaded rod, and then the two are connected by threads.

[0067] Example 6: This embodiment provides a method for preparing a model specimen simulating a pore fracture structure, which differs from Embodiment 1 in that: Mold 1 is made of high-temperature resistant material, and die 2 is made of phase change material.

[0068] Solid materials with a certain hardness at the corresponding temperature, such as waxes, fatty acids, polymer gels, and other low-melting-point materials, are selected. These materials should melt into a liquid state at 50 to 150 degrees Celsius. Phase transformation pore molds are prepared according to the required vacancy structure. Alternatively, ice can be selected as a phase change material.

[0069] After the casting material solidifies, the mold 2 melts by heating and flows out of the casting body, forming a space in the casting body that simulates rock pores and fissures.

[0070] In addition, existing technologies such as 3D printing and CNC machine tool processing can be used to prepare the hole mold.

[0071] The above inventions are merely a few specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A method for preparing a model specimen simulating a pore fracture structure, characterized in that, include: Obtain the geometric parameters of the model specimen and manufacture the mold for producing the model specimen; Obtain the geometric parameters of the pore structure and fabricate a pore mold that matches the shape of the pore structure required for the experiment; Install the perforated mold into the mold; The precast casting material is injected into the mold; After the casting material has solidified, the mold is removed from the casting body by deforming the mold to obtain the model specimen.

2. The method for preparing a model specimen simulating a pore-crack structure as described in claim 1, characterized in that, It also includes a simulation component that can be placed inside the mold, and the simulation component has through holes; Before installing the hole mold into the mold, the hole mold is first installed in the through hole of the simulation part, and then the hole mold and the simulation part are put into the mold together; after the hole mold is separated from the simulation part and the casting body, a model specimen simulating the hole crack structure passing through different media is made.

3. The method for preparing a model specimen simulating a pore-crack structure as described in claim 1, characterized in that, The die includes at least one connecting die and at least one supporting die connected to the connecting die, with one or both ends of the connecting die detachably connected to the die.

4. The method for preparing a model specimen simulating a pore-crack structure as described in claim 3, characterized in that, The mold is equipped with a magnet. When the perforated mold is placed in the mold, the magnet contacts the outer wall of the mold. The magnet attracts the connecting mold and limits the end of the connecting mold to the corresponding position on the inner wall of the mold.

5. The method for preparing a model specimen simulating a pore-crack structure as described in claim 3, characterized in that, The mold sidewall has at least one wall hole, and the end of the connecting mold is inserted into the wall hole.

6. The method for preparing a model specimen simulating a pore-crack structure as described in claim 5, characterized in that, It also includes an outer mold with a box-like structure and an open top, with the mold located inside the outer mold and multiple mesh holes on the side plate of the outer mold.

7. The method for preparing a model specimen simulating a pore-crack structure as described in claim 5, characterized in that, The support mold is made of flexible material and has a cavity; the connecting mold has an air passage, one end of which is connected to the cavity and the other end is connected to an external air source.

8. The method for preparing a model specimen simulating a pore-crack structure as described in claim 5, characterized in that, The mold is made of high-temperature resistant material, and the pore mold is made of phase change material.

9. The method for preparing a model specimen of a simulated pore and crack structure as described in claim 5, characterized in that, One end of the support mold is detachably connected to the connecting mold, and the other end extends out of the mold.

10. The method for preparing a model specimen simulating a pore-crack structure as described in claim 9, characterized in that, The formwork is a tubular body, and a sliding rod is slidably installed inside the formwork. One end of the sliding rod extends out of the formwork, and the other end is close to the connecting mold. A connector is provided at the end close to the connecting mold. The two ends of the connector are rotatably connected to the first hook part through a rotating shaft. A torsion spring is sleeved on each of the two rotating shafts. The two torsion arms of the torsion spring are respectively connected to the connector and the corresponding first hook part. A first spring is provided between the two first hook parts, and one end of the first spring is connected to the connector. The connecting mold has a protrusion, and the two opposite ends of the protrusion are respectively formed with second hooks. When the support mold and the connecting mold are detachably connected, the two first hooks are hooked together with the corresponding second hooks, and one end of the first spring abuts against the protrusion.

Images