A triaxial specimen preparation device and test method for rock-like materials

Abstract

The present invention relates to a triaxial sample preparation device and test method for rock-like materials, belonging to the field of geotechnical and hydraulic engineering technology, including a sample preparation frame and a controller, the sample preparation frame is hollow and both front and rear ends are open, the sample preparation frame is provided with an automatic compactor and a mold body used in cooperation with each other and an automatic demolding device for demolding, the automatic compactor is electrically connected to the controller; the automatic compactor includes a reciprocating motor, an output shaft, an adjusting connecting rod and a compacting block connected in sequence from bottom to top, the reciprocating motor is fixed to the top of the sample preparation frame, one end of the output shaft is connected to the reciprocating motor in transmission, and the other end is movably sleeved with the adjusting connecting rod up and down, the compacting block is detachably connected to the free end of the adjusting connecting rod, the adjusting connecting rod is provided with an identification groove along the length direction, and a scale identification is provided in the identification groove. The present invention avoids the deviation caused by manual sample preparation, makes sample preparation more accurate, and is simple to operate and has high work efficiency.

Description

Technical Field

[0001] The invention relates to a triaxial sample preparation device and a test method for rock-like materials, belonging to the technical field of rock, soil and water conservancy engineering. Background Art

[0002] In the process of geotechnical engineering research, various physical and mechanical parameters of rocks and soils need to be tested. However, for some soils and rocks that are difficult or impossible to obtain original samples, it is necessary to reshape the samples for research.

[0003] At present, traditional sample preparation equipment can only prepare samples manually through samplers and compactors, and the number of compaction times and the degree of compaction are determined based on the personal experience of the test personnel. The prepared samples have certain errors and are affected by subjective factors, which in turn affect the test results; secondly, traditional sample preparation equipment needs to continuously use vernier calipers to measure height in all directions during the sample preparation process, which is prone to errors and even leads to sample preparation failure, and the efficiency is low and not precise enough; finally, the traditional method uses a three-petal mold or a two-petal mold for sample preparation. For soft rocks or soils with a high original density, the mold will expand during the sample preparation process, making subsequent test results inaccurate or even leading to test failure.

[0004] A sand triaxial test sample preparation instrument disclosed in the Chinese utility model patent with publication number CN202126369U includes a pressure chamber base, a rubber membrane and a pressure chamber cylinder. The lower end of the pressure chamber cylinder is fixed on the pressure chamber base, and the rubber membrane covers and fits tightly against the inner surface of the pressure chamber cylinder. The characteristic is that the pressure chamber cylinder is a tempered glass split cylinder with scale composed of a double valve membrane, and the outer peripheral wall of the tempered glass split cylinder is provided with a tight hoop. The sample preparation instrument also includes a sample striker, which is composed of a base and a guide rod connected as an integral part.

[0005] The entire sample preparation process of the above reference example is intuitive and visual, simple and convenient to operate, and has strong impact resistance. However, due to the shape limitation of the pressure chamber cylinder, only cylindrical samples can be prepared. When a sample with a higher density needs to be prepared, the sample needs to be repeatedly knocked, which can easily cause the pressure chamber cylinder to expand excessively and make it impossible to remove the tight hoop. At the same time, due to contamination problems, the indication on the cylinder may not be clearly seen during sample preparation, and the sample preparation process still requires manual knocking, with low precision and large errors. Therefore, improvement is urgently needed. Summary of the invention

[0006] In order to overcome the shortcomings of low precision and large errors in the existing manual sample preparation process, the present invention designs a triaxial sample preparation device and test method for rock-like materials, which avoids the deviation caused by manual sample preparation, makes sample preparation more accurate, simple to operate and highly efficient.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] A triaxial sample preparation device for rock-like materials comprises a sample preparation frame and a controller. The sample preparation frame is hollow and has openings at both ends. An automatic compactor and a mold body used in conjunction with each other and an automatic demoulding device for demoulding are arranged in the sample preparation frame. The automatic compactor is electrically connected to the controller. The automatic compactor comprises a reciprocating motor, an output shaft, an adjusting connecting rod and a compacting block connected in sequence from bottom to top. The reciprocating motor is fixed at the top of the sample preparation frame. One end of the output shaft is connected to the reciprocating motor for transmission, and the other end is movably sleeved with the adjusting connecting rod up and down. The compacting block is detachably connected to the free end of the adjusting connecting rod. The adjusting connecting rod is provided with an identification groove along the length direction, and a scale identification is arranged in the identification groove. The mold body comprises a sample preparation mold arranged directly below the compacting block. The shape and size of the compacting block match the inner hole of the sample preparation mold. The bottom end of the sample preparation mold is provided with a mold base fixed in the sample preparation frame. A groove is arranged at the top of the mold base, and the bottom end of the sample preparation mold is embedded in the groove.

[0009] Furthermore, the automatic demoulding device includes a demoulding steel column, a demoulding table and a jack. The demoulding table is fixed in the sample preparation frame and has a structure in which the interior is hollow and the front and rear ends are open. The jack is arranged in the demoulding table and the output end is arranged vertically upward. A through hole penetrating the top of the demoulding table is arranged at the top of the jack. The demoulding steel column is movable up and down and passes through the through hole. The top of the demoulding steel column is arranged with a through hole penetrating the top of the sample preparation frame.

[0010] Furthermore, a heightening mold is connected to the top of the sample making mold, the top of the heightening mold is in an inverted trumpet shape, the bottom end is engaged with the sample making mold, and the shape and size of the inner hole of the bottom end of the heightening mold matches the inner hole of the sample making mold.

[0011] Furthermore, a first mounting groove concentrically arranged with the through hole is provided at the top inner part of the sample preparation frame, a first demoulding pad is detachably fixed in the first mounting groove, and two first stepped holes with diameters increasing sequentially from top to bottom are provided in the first demoulding pad; a second mounting groove concentrically arranged with the through hole is provided at the top inner part of the demoulding table, a second demoulding pad is detachably fixed in the second mounting groove, and two second stepped holes with diameters increasing sequentially from top to bottom are provided in the second demoulding pad, and the demoulding steel column is movably sleeved in the second stepped hole.

[0012] Furthermore, the first demoulding pad and the second demoulding pad are both arranged in a stepped shaft structure, the end of the first demoulding pad with a larger diameter is engaged with the first mounting groove, and the end of the second demoulding pad with a larger diameter is engaged with the second mounting groove.

[0013] Furthermore, a boss is provided in the groove at the top of the mold base, and a top block matching the shape and size of the inner hole of the sample making mold is detachably fixed to the top of the boss.

[0014] Furthermore, a plurality of supporting legs are arranged at the bottom end of the sample preparation frame.

[0015] Furthermore, the output shaft is threadedly sleeved with the adjusting connecting rod.

[0016] Furthermore, the wall thickness of the sample mold is at least 10 mm.

[0017] A test method based on a triaxial specimen preparation device for rock-like materials comprises the following steps:

[0018] S1: Select the corresponding sample mold as required, connect the corresponding heightening mold, and then connect the sample mold with the mold base;

[0019] S2: Prepare and weigh a certain amount of loose specimens and put them into the sample preparation mold;

[0020] S3: Select a compacting block with a flat bottom surface, connect the compacting block to the adjusting connecting rod, and then adjust the sleeve length between the adjusting connecting rod and the output shaft;

[0021] S4: Turn on the controller and adjust the compaction frequency of the reciprocating motor as required to achieve precise control of the compaction degree of the sample. After the adjustment is completed, perform the compaction test;

[0022] S5: After the first layer of the sample is compacted, the compaction is stopped, and the compaction block with a flat bottom surface is replaced with a compaction block with a needle-shaped structure on the bottom surface, and then the reciprocating motor is controlled by the controller to roughen the sample;

[0023] S6: After the roughening is completed, weigh the loose specimens required for the second layer test, put them into the sample preparation mold and perform the compaction test again;

[0024] S7: repeating steps S5 and S6 until the last layer of the sample is compacted to obtain a molded sample;

[0025] S8: Select appropriate first demoulding pads and second demoulding pads, and install the first demoulding pads and second demoulding pads in the first installation groove and the second installation groove respectively, then put the demoulding steel column through the demoulding table and the second demoulding pads on the top of the jack, then put the lower part of the molded specimen on the top of the demoulding steel column, and make the top of the molded specimen push into the first stepped hole;

[0026] S9: Start the jack to embed the top of the molded sample into the first stepped hole of the first demoulding pad for demoulding. After the demoulding is completed, the required sample can be obtained.

[0027] Compared with the prior art, the present invention has the following characteristics and beneficial effects:

[0028] 1. The present invention realizes the production of molded specimens through the setting of an automatic compactor and a mold body that cooperate with each other. The automatic compactor realizes precise control of the reciprocating motor by a controller through the setting of a reciprocating motor, an output shaft, an adjusting connecting rod and a compacting block, thereby ensuring the accuracy of the compaction test and avoiding the drawbacks of large sample size error and irregularity caused by manual compaction in traditional devices, and having higher working efficiency. The adjusting connecting rod is threadedly sleeved with the output shaft, and a scale mark is provided on the adjusting connecting rod. The sleeve length of the adjusting connecting rod and the output shaft can be adjusted as needed to achieve the purpose of adjusting the compaction height, thereby achieving effective compaction of multi-layer specimens and improving the quality of the finished specimens. The compacting block can be selected in different sizes and shapes as needed, which is convenient for compacting specimens of different shapes and further improving the applicability of the device. The mold body is set as a hollow and integrally formed sample making mold, which can effectively avoid test failure caused by mold deformation due to insufficient sealing of the mold itself, and the inner hole of the sample making mold can be set in a variety of shapes, which can be coordinated with the compacting block to realize the production of specimens of different shapes and meet the needs of diversified tests.

[0029] 2. The present invention realizes the demoulding operation of the molded sample by setting an automatic demoulding device. By setting a jack and a demoulding steel column, the bottom end of the demoulding steel column is pressed against the jack, and then the top end of the demoulding steel column is pressed against the molded sample, and then the jack is started to realize automatic demoulding, thereby avoiding the problem of damage to the mold and the sample caused by manual demoulding. At the same time, by setting the first demoulding pad and the second demoulding pad, it is possible to increase the demoulding position to avoid insufficient jack range, and it is also convenient to limit the demoulding steel column to ensure the high efficiency of the demoulding process. The first mounting groove and the second mounting groove are used to install the first demoulding pad and the second demoulding pad, which is convenient for positioning and installation, improves installation efficiency, and is also convenient for limiting the first demoulding pad and the second demoulding pad to prevent eccentricity, thereby effectively improving the molding quality and integrity of the demoulding sample.

[0030] 3. The present invention realizes the production of specimens of different shapes by selecting sample making molds with different inner holes, and then compacting them with compacting blocks. In the compaction process, after each layer of specimens is compacted, it is necessary to replace it with a compacting block with a needle-like structure on the bottom for roughening, which greatly improves the tightness between two adjacent layers of specimens, thereby improving the quality of the final product of the specimen, and suitable top blocks (such as steel blocks or permeable stones) can be selected as needed to obtain specimens that better meet the test requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a front view of the present invention;

[0032] Figure 2 is a front cross-sectional view of the present invention;

[0033] Figure 3It is a structural schematic diagram of the adjustable connecting rod of the present invention;

[0034] Figure 4 It is a cross-sectional view of the first demoulding pad of the present invention.

[0035] The accompanying drawings are marked as follows: 1. sample frame; 101. support foot; 2. controller; 301. reciprocating motor; 302. output shaft; 303. adjusting connecting rod; 3031. scale mark; 304. compacting block; 401. heightening mold; 402. sample mold; 403. top block; 5. mold base; 6. first demoulding pad; 7. molded specimen; 8. demoulding steel column; 9. demoulding table; 10. second demoulding pad; 11. jack. DETAILED DESCRIPTION

[0036] The present invention is described in more detail below with reference to the embodiments.

[0037] like Figures 1 to 4 As shown, the triaxial sample preparation device for rock-like materials of this embodiment includes a sample preparation frame 1 and a controller 2. The sample preparation frame 1 is hollow and has openings at both ends. An automatic compactor and a mold body that cooperate with each other and an automatic demolding device for demolding are arranged in the sample preparation frame 1. The automatic compactor is electrically connected to the controller 2; the automatic compactor includes a reciprocating motor 301, an output shaft 302, an adjusting connecting rod 303 and a compacting block 304 that are sequentially connected from bottom to top. The reciprocating motor 301 is fixed to the top of the sample preparation frame 1, one end of the output shaft 302 is connected to the reciprocating motor 301 for transmission up and down, and the other end is threadedly sleeved with the adjusting connecting rod 303, the compacting block 304 is detachably connected to the free end of the adjusting connecting rod 303, and the adjusting connecting rod 303 is connected to the reciprocating motor 301. An identification groove is set along the length direction, and a scale mark 3031 is set in the identification groove; the mold body includes a sample mold 402 set directly below the compaction block 304, the shape and size of the compaction block 304 match the inner hole of the sample mold 402, and the bottom of the sample mold 402 is provided with a mold base 5 fixed in the sample frame 1, and the top of the mold base 5 is provided with a groove, and the bottom end of the sample mold 402 is embedded in the groove, and a boss is also provided in the groove. A pad block 403 matching the shape and size of the inner hole of the sample mold 402 is detachably fixed on the top of the boss. The setting of the boss can reserve a certain space at the bottom of the sample mold 402 after the sample is prepared, so that the demolding steel column 8 can be inserted into the bottom of the sample mold 402 to achieve demolding in the subsequent demolding process.

[0038] Furthermore, the automatic demoulding device includes a demoulding steel column 8, a demoulding table 9 and a jack 11. The jack 11 is electrically connected to the controller 2, and the controller 2 can control the rising rate of the jack 11. The demoulding table 9 is fixed in the sample preparation frame 1 and the demoulding table 9 is hollow inside and has openings at both ends. The jack 11 is arranged in the demoulding table 9 and the output end is arranged vertically upward. A through hole is arranged on the top of the jack 11 to penetrate the top of the demoulding table 9. The demoulding steel column 8 is movable up and down to penetrate the through hole. A through hole is arranged on the top of the demoulding steel column 8 to penetrate the top of the sample preparation frame 1. Automatic demoulding is achieved by the arrangement of the jack 11 and the demoulding steel column 8, thereby avoiding the damage to the integrity of the sample by manual demoulding. The sample is sent out through the through hole to facilitate the removal of the sample.

[0039] Furthermore, the top of the sample making mold 402 is connected to a heightening mold 401, and the top of the heightening mold 401 is in an inverted trumpet shape, and the bottom is engaged with the sample making mold 402, and the shape and size of the inner hole of the bottom of the heightening mold 401 match the inner hole of the sample making mold 402. The trumpet-shaped setting of the upper part of the heightening mold 401 is convenient for operators to add sample materials, effectively reduces the spillage of sample materials, ensures the cleanliness of the interior of the sample making frame 1, and reduces the workload of later cleaning. The lower part of the heightening mold 401 is engaged with the sample making mold 402, which can achieve heightening, and can make samples with higher height to meet the test requirements.

[0040] Furthermore, a first mounting groove concentrically arranged with the through hole is provided at the top of the inner part of the sample preparation frame 1, a first demoulding pad 6 is fixed in the first mounting groove by bolts, and two first stepped holes with increasing diameters from top to bottom are provided in the first demoulding pad 6; a second mounting groove concentrically arranged with the through hole is provided at the top of the inner part of the demoulding platform 9, a second demoulding pad 10 is fixed in the second mounting groove by bolts, and two second stepped holes with increasing diameters from top to bottom are provided in the second demoulding pad 10, and the demoulding steel column 8 is movably sleeved in the second stepped hole. The provision of the first mounting groove and the second mounting groove facilitates the positioning and installation of the first demoulding pad 6 and the second demoulding pad 10, and also serves as a limit for the first demoulding pad 6 and the second demoulding pad 10. Prevent eccentricity and ensure that the demoulding steel column 8 can be accurately aligned with the molded sample 7 for demoulding. At the same time, the setting of the first demoulding pad 6 can raise the molded sample 7 and reduce the stroke required by the jack 11 during the demoulding process to ensure complete demoulding. The setting of the second demoulding pad 10 can be replaced according to the shape and size of the different demoulding steel columns 8, which is convenient for demoulding of molded samples 7 of different shapes and improves the applicability of the device. The first demoulding pad 6, the second demoulding pad 10, the jack 11 and the demoulding steel column 8 cooperate with each other to achieve complete demoulding of the molded sample, with little damage to the sample, thereby ensuring the integrity of the sample. At the same time, the mold can also be well protected to avoid damage to the mold caused by manual demoulding.

[0041] Furthermore, the first demoulding pad 6 and the second demoulding pad 10 are both arranged in a stepped shaft structure, the end of the first demoulding pad 6 with a larger diameter is engaged with the first mounting groove, and the end of the second demoulding pad 10 with a larger diameter is engaged with the second mounting groove. The first demoulding pad 6 and the second demoulding pad 10 are respectively connected to the sample preparation frame 1 and the demoulding table 9 by bolts. Due to the setting of the stepped shaft structure, the bolts only need to axially penetrate a section with a larger diameter to achieve connection, without having to penetrate the entire first demoulding pad 6 and the second demoulding pad 10, so the connection is quicker and more convenient.

[0042] Furthermore, a plurality of supporting legs 101 are provided at the bottom end of the sample preparation frame 1 .

[0043] Furthermore, the wall thickness of the sample mold 402 is at least 10 mm.

[0044] A test method based on a triaxial specimen preparation device for rock-like materials comprises the following steps:

[0045] S1: Select the corresponding sample mold 402 as required, connect the corresponding heightening mold 401, and then connect the sample mold 402 with the mold base 5;

[0046] S2: Prepare and weigh a certain amount of loose samples and put them into the sample preparation mold 402;

[0047] S3: Select a compacting block 304 with a flat bottom surface, connect the compacting block 304 to the adjusting connecting rod 303, and then adjust the sleeve length between the adjusting connecting rod 303 and the output shaft 302;

[0048] S4: Turn on the controller 2 to adjust the compaction frequency of the reciprocating motor 301 as required to achieve accurate control of the compaction degree of the sample, and perform a compaction test after the adjustment is completed;

[0049] S5: After the compaction of the first layer of the sample is completed, the compaction is stopped, and the compaction block 304 with a flat bottom surface is replaced with a compaction block 304 with a needle-shaped structure on the bottom surface, and the reciprocating motor 301 is controlled by the controller 2 to roughen the sample. The roughening of the compaction block 304 with a needle-shaped structure on the bottom surface can make the samples between different layers more tightly combined, and finally obtain a high-quality sample;

[0050] S6: After the roughening is completed, the loose sample required for the second layer test is weighed and placed into the sample preparation mold 402 and the compaction test is performed again;

[0051] S7: repeating steps S5 and S6 until the last layer of the sample is compacted to obtain a molded sample 7;

[0052] S8: Select a suitable first demoulding pad 6 and a second demoulding pad 10, and install the first demoulding pad 6 and the second demoulding pad 10 in the first installation groove and the second installation groove respectively, then pass the demoulding steel column 8 through the demoulding table 9 and the second demoulding pad 10 and place them on the top of the jack 11, then put the lower part of the molded sample 7 on the top of the demoulding steel column 8, and make the top of the molded sample 7 push into the first stepped hole;

[0053] S9: Start the jack 11 to embed the top of the molded sample 7 into the first stepped hole of the first demoulding pad 6 for demoulding. After the demoulding is completed, the required sample can be obtained.

[0054] Embodiment 1

[0055] A test method based on a triaxial specimen preparation device for rock-like materials comprises the following steps:

[0056] S1: Select a sample mold 402 with a circular inner hole as required, and connect the corresponding heightening mold 401, then connect the sample mold 402 with the mold base 5, and the top block 403 at the top of the boss is a steel block;

[0057] S2: Prepare and weigh a certain amount of loose samples and put them into the sample preparation mold 402;

[0058] S3: Select a compacting block 304 with a flat bottom surface, connect the compacting block 304 to the adjusting connecting rod 303, and then adjust the sleeve length between the adjusting connecting rod 303 and the output shaft 302;

[0059] S4: Turn on the controller 2 to adjust the compaction frequency of the reciprocating motor 301 as required to achieve accurate control of the compaction degree of the sample, and perform a compaction test after the adjustment is completed;

[0060] S5: After the first layer of the sample is compacted, the compaction is stopped, and the compaction block 304 with a flat bottom surface is replaced with a compaction block 304 with a needle-shaped structure on the bottom surface, and then the reciprocating motor 301 is controlled by the controller 2 to roughen the sample;

[0061] S6: After the roughening is completed, the loose sample required for the second layer test is weighed and placed into the sample preparation mold 402 and the compaction test is performed again;

[0062] S7: repeating steps S5 and S6 until the last layer of the sample is compacted to obtain a molded sample 7;

[0063] S8: Select a suitable first demoulding pad 6 and a second demoulding pad 10, and install the first demoulding pad 6 and the second demoulding pad 10 in the first installation groove and the second installation groove respectively, then pass the demoulding steel column 8 through the demoulding table 9 and the second demoulding pad 10 and place them on the top of the jack 11, then put the lower part of the molded sample 7 on the top of the demoulding steel column 8, and make the top of the molded sample 7 push into the first stepped hole;

[0064] S9: Start the jack 11 to embed the top of the molded sample 7 into the first stepped hole of the first demoulding pad 6 for demoulding. After the demoulding is completed, a cylindrical sample can be obtained.

[0065] Embodiment 2

[0066] The rest is the same as the first embodiment, except that, in step S1, a sample-making mold 402 with a rectangular inner hole is selected as required, and the top block 403 on the top of the boss is a permeable stone, and finally a square sample can be obtained after demolding is completed; the purpose of preparing samples of different shapes is achieved by replacing the sample-making mold 402 with different inner hole shapes, thereby improving the applicability of the device, and the top block 403 is selected from permeable stone, which can effectively control the water content of the finished sample, thereby obtaining a finished sample that better meets the experimental requirements.

[0067] Working principle of the present invention: The present invention provides a framework for sample making and demolding through the setting of the sample preparation frame 1, which is convenient for sample making and demolding at different locations, and then through the cooperation of the automatic compactor and the mold body, the automatic compactor compacts the sample, and the mold body places the sample, and finally a molded sample that meets the test requirements is obtained, and then the molded sample is demolded by the automatic demolding device to obtain a complete sample that meets the requirements. The automatic compactor, the mold body and the automatic demolding device can work at the same time to realize sample making and sample demolding at the same time, which greatly improves the sample making efficiency.

[0068] In the description of the present invention, it should be noted that the terms "inside", "outside", "upper", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are 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 on the present invention.

[0069] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0070] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Claims

1. A triaxial specimen preparation device for rock-like materials, characterized by: The invention comprises a sample preparation frame (1) and a controller (2); the sample preparation frame (1) is hollow and has openings at both the front and rear ends; an automatic compactor and a mold body and an automatic demoulding device for demoulding are arranged in the sample preparation frame (1) and are used in coordination with each other; the automatic compactor is electrically connected to the controller (2); the automatic compactor comprises a reciprocating motor (301), an output shaft (302), an adjusting connecting rod (303) and a compacting block (304) which are connected in sequence from bottom to top; the reciprocating motor (301) is fixed at the top of the sample preparation frame (1); one end of the output shaft (302) is drivingly connected to the reciprocating motor (301); and the other end is connected to the adjusting connecting rod (303) is movably sleeved up and down, the compacting block (304) is detachably connected to the free end of the adjusting connecting rod (303), the adjusting connecting rod (303) is provided with a marking groove along the length direction, and a scale mark (3031) is provided in the marking groove; the mold body comprises a sample making mold (402) arranged directly below the compacting block (304), the shape and size of the compacting block (304) match the inner hole of the sample making mold (402), the bottom end of the sample making mold (402) is provided with a mold base (5) fixed in the sample making frame (1), the top end of the mold base (5) is provided with a groove, and the bottom end of the sample making mold (402) is embedded in the groove; The automatic demoulding device comprises a demoulding steel column (8), a demoulding table (9) and a jack (11); the demoulding table (9) is fixed in the sample preparation frame (1) and is hollow inside with openings at both ends; the jack (11) is arranged in the demoulding table (9) and the output end is arranged vertically upward; a through hole penetrating the top of the demoulding table (9) is arranged at the top of the jack (11); the demoulding steel column (8) is movable up and down through the through hole; and a through hole penetrating the top of the sample preparation frame (1) is arranged at the top of the demoulding steel column (8); Also included is the following test method: comprising the following steps: S1: Select the corresponding sample making mold (402) as required, connect the corresponding heightening mold (401), and then connect the sample making mold (402) to the mold base (5); S2: Prepare and weigh a certain amount of loose sample and put it into the sample preparation mold (402); S3: Select a compacting block (304) with a flat bottom surface, connect the compacting block (304) to the adjusting connecting rod (303), and then adjust the sleeve length between the adjusting connecting rod (303) and the output shaft (302); S4: turning on the controller (2) to adjust the compaction frequency of the reciprocating motor (301) as required to achieve accurate control of the compaction degree of the sample, and performing a compaction test after the adjustment is completed; S5: After the compaction of the first layer of the sample is completed, the compaction is stopped, and the compaction block (304) with a flat bottom surface is replaced with a compaction block (304) with a needle-shaped structure on the bottom surface, and then the reciprocating motor (301) is controlled by the controller (2) to roughen the sample; S6: After the roughening is completed, the loose specimen required for the second layer test is weighed and placed into the sample preparation mold (402) and the compaction test is performed again; S7: repeating steps S5 and S6 until the last layer of the sample is compacted to obtain a molded sample (7); S8: Select a suitable first demoulding pad (6) and a second demoulding pad (10), and install the first demoulding pad (6) and the second demoulding pad (10) in the first installation groove and the second installation groove respectively, then place the demoulding steel column (8) through the demoulding table (9) and the second demoulding pad (10) on the top of the jack (11), and then put the lower part of the molded specimen (7) on the top of the demoulding steel column (8), and make the top of the molded specimen (7) push into the first stepped hole; S9: Start the jack (11) to embed the top of the molded sample (7) into the first stepped hole of the first demoulding pad (6) for demoulding. After the demoulding is completed, the desired sample can be obtained.

2. A triaxial specimen preparation device for rock-like materials according to claim 1, characterized in that: The top of the sample making mold (402) is connected to the heightening mold (401), the top of the heightening mold (401) is arranged in an inverted trumpet shape, the bottom of the heightening mold (401) is engaged with the sample making mold (402), and the shape and size of the inner hole at the bottom of the heightening mold (401) match the inner hole of the sample making mold (402).

3. A triaxial specimen preparation device for rock-like materials according to claim 2, characterized in that: The sample preparation frame (1) is provided with a first mounting groove concentrically arranged with the through hole at the top inner side, a first demoulding pad (6) is detachably fixed in the first mounting groove, and two first stepped holes whose diameters increase sequentially from top to bottom are provided in the first demoulding pad (6); the demoulding table (9) is provided with a second mounting groove concentrically arranged with the through hole at the top inner side, a second demoulding pad (10) is detachably fixed in the second mounting groove, and two second stepped holes whose diameters increase sequentially from top to bottom are provided in the second demoulding pad (10), and the demoulding steel column (8) is movably sleeved in the second stepped hole.

4. A triaxial specimen preparation device for rock-like materials according to claim 3, characterized in that: The first demoulding pad (6) and the second demoulding pad (10) are both arranged in a stepped shaft structure; the end with a larger diameter of the first demoulding pad (6) is engaged with the first mounting groove, and the end with a larger diameter of the second demoulding pad (10) is engaged with the second mounting groove.

5. The triaxial specimen preparation device for rock-like materials according to claim 1, characterized in that: A boss is also provided in the groove at the top of the mold base (5), and a top block (403) matching the shape and size of the inner hole of the sample making mold (402) is detachably fixed to the top of the boss.

6. The triaxial specimen preparation device for rock-like materials according to claim 1, characterized in that: A plurality of supporting feet (101) are arranged at the bottom end of the sample preparation frame (1).

7. The triaxial specimen preparation device for rock-like materials according to claim 1, characterized in that: The output shaft (302) is threadably sleeved with the adjusting connecting rod (303).

8. The triaxial specimen preparation device for rock-like materials according to claim 1, characterized in that: The wall thickness of the sample making mold (402) is at least 10 mm.

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