Experimental system for testing cracking performance of rock after impact presplitting

Abstract

The invention belongs to the technical field of rock mechanics and mine engineering, and discloses an experiment system for testing cracking performance of rock after impact presplitting, which comprises a rock sample clamping device for clamping rock samples with different sizes and specifications; a loading part of the static loading device is propped against the outer wall of the rock sample for static loading; the dynamic loading device comprises a plurality of movably arranged hydraulic impact cutting teeth, and performs multi-working-condition pre-splitting impact on the rock sample under hydraulic driving; and the control device comprises a crack monitoring module and a data acquisition and analysis module which are electrically connected. The device is easy to operate and convenient to use, through combination of dynamic loading and static loading, the stress condition of rock under the underground cutting working condition is simulated more truly, synchronous acquisition and processing of experimental parameters are achieved, the integrity and reliability of experimental data are ensured, and more accurate data support is provided for mine engineering.

Description

Technical Field

[0001] The invention relates to the technical field of rock mechanics and mining engineering, and in particular to an experimental system for testing the cracking performance of rocks after impact pre-cracking. Background Art

[0002] The study of rock cracking properties is of great significance for mining, tunnel construction and geological disaster prediction. In the actual mining process, rocks are often subjected to complex dynamic impact loads. This impact load may come from tunnel excavation, coal mining machine cutting, etc., causing cracks and cracking inside the rock.

[0003] Existing research methods are mostly limited to single static or dynamic loading experiments, which cannot effectively simulate the entire process of rock from impact pre-cracking to subsequent cracking; in addition, the test accuracy and multi-parameter synchronous acquisition capabilities of dynamic experimental equipment are weak, and real-time monitoring of the crack propagation process cannot be achieved, resulting in low reliability and repeatability of experimental results.

[0004] Therefore, an experimental system for testing the cracking performance of rocks after impact pre-cracking is urgently needed to meet the needs of studying the mechanical behavior of complex rocks. Summary of the invention

[0005] The purpose of the present invention is to provide an experimental system for testing the cracking performance of rocks after impact pre-cracking, which integrates dynamic impact loading, static loading, crack monitoring and data acquisition functions, and can provide experimental support for the study of rock dynamic behavior and mechanical properties.

[0006] To achieve the above object, the present invention provides the following solution: The present invention provides an experimental system for testing the cracking performance of rocks after impact pre-cracking, comprising:

[0007] A rock sample clamping device, which is limitedly slidable on the aluminum alloy platform and is used to clamp rock samples of different sizes and specifications;

[0008] A static loading device, the static loading device is arranged corresponding to the rock sample clamping device, and a loading component of the static loading device abuts against the outer wall of the rock sample to perform static loading;

[0009] A dynamic loading device, the dynamic loading device comprising a rotating disc rotatably connected to the aluminum alloy platform, the rotating disc being provided with a plurality of hydraulic impact picks, which are driven by hydraulic pressure to perform multi-condition pre-cracking impact on the rock sample;

[0010] The control device comprises an electrically connected crack monitoring module and a data acquisition and analysis module, wherein the crack monitoring module is used to monitor the state of the rock sample, and the data acquisition and analysis module records the dynamic behavior of the crack in real time.

[0011] Preferably, the crack monitoring module includes a high-speed camera, an acoustic emission sensor and a laser displacement sensor which are electrically connected to the data acquisition and analysis module respectively, and the high-speed camera, the acoustic emission sensor and the laser displacement sensor are respectively arranged corresponding to the rock sample.

[0012] Preferably, a plurality of sliding rails are provided on the aluminum alloy platform, the rock sample clamping device is slidably connected to the sliding rails, the rotating disc is hinged to the sliding rails, and the static loading device is arranged at one end of the sliding rail away from the rotating disc.

[0013] Preferably, a tooth seat corresponding to the hydraulic impact pick is fixedly connected to the rotating disc, the hydraulic impact pick is embedded in the end connected to the tooth seat, and the hydraulic impact pick is connected to an independently arranged oil inlet hydraulic branch pipe and an oil return hydraulic branch pipe.

[0014] Preferably, the hydraulic impact pick is provided with an oil inlet chamber and an oil return chamber which are independent of each other, the oil inlet chamber is communicated with the oil inlet hydraulic branch pipe, and the oil return chamber is communicated with the oil return hydraulic branch pipe.

[0015] Preferably, there are a plurality of rock sample impact pre-cracks in the rock sample, and the rock sample impact pre-cracks are obtained by the impact of the hydraulic impact pick.

[0016] Preferably, an adjustable limit device is movably provided on the aluminum alloy platform, and the adjustable limit device is limit-connected to the rock sample clamping device.

[0017] Preferably, a sliding block is provided on the sliding guide rail for sliding limit sliding, and the rock sample clamping device is fixedly connected to the sliding block.

[0018] Compared with the prior art, the present invention has the following advantages and technical effects: the present invention discloses an experimental system for testing the cracking performance of rocks after impact pre-cracking. The system can fully simulate the stress conditions of rocks under underground cutting conditions, simulate the rock pre-cracking process through dynamic impact loading, and further test the cracking performance of pre-cracked rocks in combination with a static loading device, thereby fully reflecting the mechanical behavior of rocks after impact pre-cracking, including residual strength, crack propagation path and cracking mode; the system consists of a rock sample clamping device, a dynamic impact loading device, a static loading device, a crack monitoring module, and a data acquisition and analysis module. The rock sample clamping device can firmly clamp rock samples of different shapes and sizes to adapt to different experimental conditions, thereby increasing the applicable scope of the experiment and improving the applicability of the device; the dynamic impact loading device is used to apply dynamic impact loads to rocks to simulate the actual working conditions of underground coal mining machines cutting coal and rocks. The device adopts several hydraulic shock The pick is loaded, and the number and angle of impact loading can be adjusted by rotating the disc, which can simulate single-point and multi-point impact pre-cracking conditions and accurately control the impact energy and loading direction; after impact pre-cracking, the static loading device is used to apply load to the rock to further test its cracking performance, including residual strength, elastic modulus and crack propagation path; the crack monitoring module is used to record the dynamic process of rock crack propagation in real time, realize accurate measurement of crack position, propagation speed, number of cracks and distribution characteristics, provide key data such as crack initiation, propagation speed and number of cracks, and provide a reliable experimental basis for in-depth research on rock cracking mechanism; the data acquisition and analysis module is electrically connected to the crack monitoring module, records the stress-strain curve and crack dynamic behavior in real time, processes, fits and visualizes the collected data to ensure the integrity and reliability of the experimental data, and generates intuitive experimental reports through visualization analysis tools.

[0019] The invention is simple to operate and easy to use. Through the combination of dynamic loading and static loading, it can more realistically simulate the stress conditions of rocks under underground cutting conditions, and realize the synchronous collection and processing of experimental parameters, thereby ensuring the integrity and reliability of experimental data and providing more accurate data support for the implementation of mining projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0021] Figure 1 This is a schematic diagram of an experimental system for testing the cracking performance of rocks after impact pre-cracking according to the present invention;

[0022] Figure 2 This is a schematic diagram of static loading of rock samples of the present invention;

[0023] Figure 3 This is a schematic diagram of dynamic loading of rock samples of the present invention;

[0024] Figure 4 It is a schematic diagram of the stress-strain curve of the rock sample during the dynamic loading process of the present invention;

[0025] Figure 5 It is a schematic diagram of a dynamic impact loading device and a static loading device of the present invention;

[0026] Figure 6 This is a schematic diagram of a crack monitoring module of the present invention;

[0027] Figure 7 This is a schematic diagram of the hydraulic impact pick structure of the present invention;

[0028] Figure 8 A side view of a hydraulic impact pick according to the present invention;

[0029] Fig. 9 This is a design diagram of the impact pick hydraulic system of the present invention;

[0030] Fig.10 It is the work flow chart of the present invention;

[0031] In the figure: 1. static loading device; 2. adjustable limit device; 3. rock sample clamping device; 4. rotating disc; 5. dynamic impact loading device; 6. rock sample impact pre-crack; 7. rock sample; 8. high-speed camera; 9. acoustic emission sensor; 10. laser displacement sensor; 11. hydraulic impact pick; 12. return oil chamber; 13. oil inlet chamber; 14. tooth seat; 15. oil inlet hydraulic branch pipe; 16. return oil hydraulic branch pipe; 17. crack monitoring module; 18. aluminum alloy platform; 19. sliding guide rail. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the 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.

[0033] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] Reference Figure 1-10 As shown, this embodiment provides an experimental system for testing the cracking performance of rocks after impact pre-cracking, comprising:

[0035] A rock sample clamping device 3, which is limitedly slidable on the aluminum alloy platform 18 and is used to clamp rock samples 7 of different sizes and specifications;

[0036] A static loading device 1, which is arranged corresponding to the rock sample clamping device 3, and a loading component of the static loading device 1 abuts against the outer wall of the rock sample 7 for static loading;

[0037] A dynamic loading device, the dynamic loading device comprises a rotating disc 4 rotatably connected to an aluminum alloy platform 18, a plurality of hydraulic impact picks 11 are arranged on the rotating disc 4, and a multi-condition pre-cracking impact is performed on the rock sample 7 under hydraulic drive;

[0038] The control device includes an electrically connected crack monitoring module 17 and a data acquisition and analysis module. The crack monitoring module 17 is used to monitor the state of the rock sample 7, and the data acquisition and analysis module records the dynamic behavior of the crack in real time.

[0039] The present invention discloses an experimental system for testing the cracking performance of rocks after impact pre-cracking. The system can fully simulate the stress conditions of rocks under underground cutting conditions, simulate the rock pre-cracking process through dynamic impact loading, and further test the cracking performance of pre-cracking rocks in combination with a static loading device 1, thereby fully reflecting the mechanical behavior of rocks after impact pre-cracking, including residual strength, crack propagation path and cracking mode; the system consists of a rock sample clamping device 3, a dynamic impact loading device 5, a static loading device 1, a crack monitoring module 17, and a data acquisition and analysis module. The rock sample clamping device 3 can firmly clamp rock samples 7 of different shapes and sizes to adapt to different experimental conditions, thereby increasing the applicable scope of the experiment and improving the applicability of the device; the dynamic impact loading device 5 is used to apply dynamic impact loads to rocks to simulate the actual working conditions of underground coal mining machines cutting coal and rocks. The device adopts a plurality of hydraulic impact picks 11 for loading, and can By rotating the disc 4 to adjust the number and angle of impact loading, single-point and multi-point impact pre-cracking conditions can be simulated, and the impact energy and loading direction can be accurately controlled; after impact pre-cracking, the static loading device 1 is used to apply load to the rock to further test its cracking performance, including residual strength, elastic modulus and crack propagation path; the crack monitoring module 17 is used to record the dynamic process of rock crack propagation in real time, realize accurate measurement of crack position, propagation speed, number of cracks and distribution characteristics, provide key data such as crack initiation, propagation speed and number of cracks, and provide a reliable experimental basis for in-depth research on the rock cracking mechanism; the data acquisition and analysis module is electrically connected to the crack monitoring module 17, records the stress-strain curve and crack dynamic behavior in real time, processes, fits and visualizes the collected data, ensures the integrity and reliability of the experimental data, and generates an intuitive experimental report through a visualization analysis tool. The invention is simple to operate and easy to use. Through the combination of dynamic loading and static loading, it can more realistically simulate the stress conditions of rocks under underground cutting conditions, and realize the synchronous collection and processing of experimental parameters, thereby ensuring the integrity and reliability of experimental data and providing more accurate data support for the implementation of mining projects.

[0040] In one embodiment of the present application, the static loading device 1 applies a load to the pre-cracked rock sample 7 to further test its cracking performance, including residual strength, elastic modulus and crack propagation path.

[0041] Further optimizing the scheme, the crack monitoring module 17 includes a high-speed camera 8, an acoustic emission sensor 9 and a laser displacement sensor 10 which are electrically connected to the data acquisition and analysis module, respectively. The high-speed camera 8, the acoustic emission sensor 9 and the laser displacement sensor 10 are respectively set corresponding to the rock sample 7. The crack monitoring module 17 is composed of a high-speed camera 8, an acoustic emission sensor 9 and a laser displacement sensor 10, which are used to record the dynamic process of rock crack expansion in real time; the high-speed camera 8 is used to record the dynamic image of the rock sample impact pre-crack 6 in real time to ensure that the crack expansion can be accurately captured during high dynamic loading; the acoustic emission sensor 9 is used to monitor the sound wave signal released during the expansion of the rock sample impact pre-crack 6, and can accurately capture the process of crack initiation, expansion and merging; the laser displacement sensor 10 is used to accurately measure the expansion length and speed of the crack to provide more detailed crack expansion data.

[0042] In one embodiment of the present application, a high-speed camera 8, an acoustic emission sensor 9 and a laser displacement sensor 10 are respectively installed at appropriate positions of a rock sample holding device 3 via an adjustable tripod and a positioning fixture, so as to facilitate the extraction of real-time cracking development characteristics of a rock sample 7; the installation method is a prior art, and technicians in this field can select it according to their needs.

[0043] In one embodiment of the present application, the data acquisition and analysis module uses a multi-channel data acquisition system to record the dynamic behavior of cracks in real time, including: crack location / number, crack development speed, and processes, fits and visualizes the real-time collected data to generate a stress-strain curve of the cracking process of the pre-cracked rock sample 7.

[0044] Further optimization scheme, a plurality of sliding rails 19 are arranged on the aluminum alloy platform 18, the rock sample clamping device 3 is slidably connected with the sliding rails 19, the rotating disc 4 is hinged with the sliding rails 19, and the static loading device 1 is arranged at the end of the sliding rails 19 away from the rotating disc 4. The sliding rails 19 are arranged in the middle of the aluminum alloy platform 18 by welding, the rock sample clamping device 3 is connected with the lower sliding rails 19 by sliding connection, and the tail of the sliding rails 19 is connected with the static loading device 1, so that the rock sample 7 after impact pre-cracking can be subjected to the next step of loading cracking development analysis; the lower part of the rotating disc 4 is hingedly connected with the sliding rails 19, and the loading direction and position of the hydraulic impact pick 11 can be adjusted by rotation to meet different dynamic impact loading pre-cracking requirements.

[0045] In one embodiment of the present application, the rotating disc 4 can rotate 360° around the normal axis on its own center, thereby adjusting the impact angle of the hydraulic impact pick 11 to simulate single-point and multi-point impact pre-cracking conditions.

[0046] In one embodiment of the present application, the rotating disc 4 can adjust the elevation angle with respect to the sliding guide rail 19, thereby adjusting the impact elevation angle of the hydraulic impact pick 11 to simulate single-point and multi-point impact pre-cracking working conditions.

[0047] A further optimized solution is that a tooth seat 14 corresponding to the hydraulic impact pick 11 is fixedly connected to the rotating disc 4, the hydraulic impact pick 11 is embedded in the end portion connected to the tooth seat 14, and the hydraulic impact pick 11 is connected to an independently arranged oil inlet hydraulic branch pipe 15 and an oil return hydraulic branch pipe 16; the hydraulic impact pick 11 is provided with mutually independent oil inlet chamber 13 and oil return chamber 12, the oil inlet chamber 13 is connected to the oil inlet hydraulic branch pipe 15, and the oil return chamber 12 is connected to the oil return hydraulic branch pipe 16. The dynamic impact loading device 5 applies an impact load to the rock sample 7 through the hydraulic impact pick 11. The hydraulic impact pick 11 is fixed on the tooth seat 14. The hydraulic impact pick 11 is driven by internal hydraulic power and can accurately control the impact energy and release speed. Hydraulic oil is injected into the oil inlet chamber 13 inside the hydraulic impact pick 11 through the oil inlet hydraulic branch pipe 15 to realize the impact movement of the hydraulic impact pick 11. And hydraulic oil is injected into the return oil chamber 12 inside the hydraulic impact pick 11 through the return oil hydraulic branch pipe 16, and the impact stroke of the hydraulic impact pick 11 is retracted.

[0048] In one embodiment of the present application, the hydraulic driving circuit of the hydraulic impact pick 11 is as follows: Fig. 9 In actual work, after the hydraulic oil in the system circuit is ready, the plunger pump is started, the hydraulic system is running, and the hydraulic oil passes through the gear flow distributor and the accumulator, and then enters the cylinder front chamber of the hydraulic impact pick 11 through the three-position four-way electromagnetic reversing valve, driving the hydraulic impact pick 11 to work; when the hydraulic impact system is working, the adjustment of the impact frequency of the impact pick is achieved by controlling the plunger pump, and the plunger pump is controlled by adjusting the speed of the motor. When the motor speed is faster, the plunger pump will inhale more hydraulic oil, and when the motor speed is slower, the hydraulic oil will be inhaled less.

[0049] In one embodiment of the present application, the hydraulic system can select the hydraulic closed circuit pressure value according to the different strengths of the rock samples through a controller. The closed circuit pressure value of the hydraulic system can be set within the range of 30-50MPa to ensure the effect of the hydraulic impact pick 11 on the impact pre-cracking of the coal rock.

[0050] In one embodiment of the present application, the impact loading process is synchronously recorded by a data acquisition and analysis device to capture stress and strain data during the impact process.

[0051] According to a further optimization scheme, there are a plurality of rock sample impact pre-cracks 6 in the rock sample 7, and the rock sample impact pre-cracks 6 are obtained by impacting the hydraulic impact pick 11. After the rock sample 7 is clamped in the rock sample clamping device 3, the hydraulic impact pick 11 performs impact loading according to the designed number, strength and angle, and the impact pre-cracks produce the rock sample impact pre-cracks 6.

[0052] Further optimization scheme, the aluminum alloy platform 18 is provided with an adjustable limit device 2, and the adjustable limit device 2 is limitedly connected with the rock sample clamping device 3. The adjustable limit device 2 is fixed to the upper part of the aluminum alloy platform 18 by bolt connection, and the clamping size of the rock sample clamping device 3 is adjusted to adapt to rock samples 7 of different sizes; at the same time, the stability of the rock sample clamping device 3 can be ensured when impact loading is performed.

[0053] In a further optimized solution, a sliding block is provided on the sliding guide rail 19 to limit the sliding movement, and the rock sample clamping device 3 is fixedly connected to the sliding block. The sliding block is slidably connected to the sliding guide rail 19, and can drive the rock sample clamping device 3 fixed on the sliding block to slide horizontally on the aluminum alloy platform 18, so that the rock sample 7 after impact loading pre-cracked can be smoothly transferred to the static loading device 1.

[0054] In one embodiment of the present application, the rock sample holding device 3 is made of high-strength material and can stably fix rock samples 7 of different shapes and sizes to ensure that the rock samples 7 will not slide or shift during the experiment, thereby ensuring the accuracy of loading.

[0055] Furthermore, the static loading device 1 supports multiple loading modes, such as uniaxial loading, triaxial loading and cyclic loading.

[0056] According to the attached Fig.10 , the test process of this application is as follows:

[0057] The rock samples 7 of different shapes and sizes are stably fixed to ensure that the rock samples 7 do not slide or move during the experiment, thereby ensuring the accuracy of loading.

[0058] The dynamic impact loading device 5 is fixed on the top of the rotating disc 4 by bolt connection, and then the impact load is applied to the rock sample 7 through the hydraulic impact pick 11, which can simulate single-point and multi-point impact pre-cracking conditions, and can accurately adjust the loading direction and position of the hydraulic impact pick 11 to meet different dynamic impact loading pre-cracking requirements, and the impact pre-cracking produces rock sample impact pre-cracking cracks 6.

[0059] After the impact loading is completed, the rock sample 7 enters the static loading device 1 for static or quasi-dynamic loading test. The static loading device 1 applies pressure to the rock sample 7 through the servo hydraulic system, and the loading rate can be adjusted in the range of 0.01mm / min to 5mm / min. During the loading process, parameters such as the stress-strain curve, crack extension behavior, and residual strength of the rock sample 7 will be collected in real time and transmitted to the data acquisition device for analysis. In order to monitor the crack extension process in real time, the crack monitoring module 17 uses a variety of sensors. The high-speed camera 8 is used to record the dynamic image of the crack in real time to ensure that the crack extension can be accurately captured during high dynamic loading; the acoustic emission sensor 9 is used to monitor the acoustic wave signal released during the crack extension process, and can accurately capture the process of crack initiation, extension and merging; the laser displacement sensor 10 is used to accurately measure the crack extension length and speed to provide more detailed crack extension data.

[0060] All monitoring data are connected to the data acquisition and analysis device via cables. The device is responsible for recording all experimental data in real time, including impact energy, loading force, crack propagation process, stress-strain curve, etc. The data acquisition and analysis device uses a synchronous trigger system to ensure that all sensor data starts to be collected at the same time point to ensure the consistency and accuracy of the experimental data. The collected data will be processed and fitted by computer analysis software to generate an experimental report, including stress-strain curve, crack propagation path, cracking mode, etc. During the experiment, all devices work together through a unified control platform. The entire experimental system is installed on a steel base and is equipped with shock-absorbing pads to absorb impact vibrations. It can effectively absorb the vibrations generated during the impact loading process to ensure the stability of the equipment and the repeatability of the experimental results.

[0061] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0062] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. An experimental system for testing the cracking performance of rocks after impact pre-cracking, characterized in that: include: A rock sample clamping device (3), wherein the rock sample clamping device (3) is limitedly slidable on the aluminum alloy platform (18) and is used to clamp rock samples (7) of different sizes and specifications; A static loading device (1), wherein the static loading device (1) is arranged corresponding to the rock sample clamping device (3), and a loading component of the static loading device (1) abuts against an outer wall of the rock sample (7) to perform static loading; A dynamic loading device, the dynamic loading device comprising a rotating disc (4) rotatably connected to the aluminum alloy platform (18), the rotating disc (4) being provided with a plurality of hydraulic impact picks (11) for performing multi-condition pre-cracking impact on the rock sample (7) under hydraulic drive; The control device comprises an electrically connected crack monitoring module (17) and a data acquisition and analysis module, wherein the crack monitoring module (17) is used to monitor the state of the rock sample (7), and the data acquisition and analysis module records the dynamic behavior of the crack in real time.

2. The rock cracking performance test system after impact pre-cracking according to claim 1 is characterized by: The crack monitoring module (17) comprises a high-speed camera (8), an acoustic emission sensor (9) and a laser displacement sensor (10) which are electrically connected to the data acquisition and analysis module respectively; the high-speed camera (8), the acoustic emission sensor (9) and the laser displacement sensor (10) are respectively arranged corresponding to the rock sample (7).

3. The rock cracking performance test system after impact pre-cracking according to claim 1 is characterized by: A plurality of sliding guide rails (19) are arranged on the aluminum alloy platform (18), the rock sample clamping device (3) is slidably connected to the sliding guide rails (19), the rotating disc (4) is hinged to the sliding guide rails (19), and the static loading device (1) is arranged at one end of the sliding guide rail (19) away from the rotating disc (4).

4. The rock cracking performance test system after impact pre-cracking according to claim 1 is characterized in that: The rotating disc (4) is fixedly connected with a tooth seat (14) corresponding to the hydraulic impact pick (11); the hydraulic impact pick (11) is embedded in an end portion connected to the tooth seat (14); and the hydraulic impact pick (11) is connected to an independently arranged oil inlet hydraulic branch pipe (15) and an oil return hydraulic branch pipe (16).

5. The rock cracking performance test system after impact pre-cracking according to claim 4 is characterized in that: The hydraulic impact pick (11) is provided with an oil inlet chamber (13) and an oil return chamber (12) which are independent of each other. The oil inlet chamber (13) is communicated with the oil inlet hydraulic branch pipe (15), and the oil return chamber (12) is communicated with the oil return hydraulic branch pipe (16).

6. The rock cracking performance test system after impact pre-cracking according to claim 1 is characterized by: There are a plurality of rock sample impact pre-cracks (6) in the rock sample (7), and the rock sample impact pre-cracks (6) are obtained by impacting the hydraulic impact pick (11).

7. The rock cracking performance test system after impact pre-cracking according to claim 3 is characterized by: An adjustable limit device (2) is movably provided on the aluminum alloy platform (18), and the adjustable limit device (2) is limit-connected to the rock sample clamping device (3).

8. The rock cracking performance test system after impact pre-cracking according to claim 3 is characterized by: A sliding block is provided on the sliding guide rail (19) for sliding limit movement, and the rock sample clamping device (3) is fixedly connected to the sliding block.

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