Hydraulic fracture propagation testing equipment for jointed rock

Abstract

The utility model belongs to the technical field of rock mechanics tests, and particularly relates to hydraulic fracture propagation testing equipment for jointed rock, which comprises a carrying circuit platform, the sealing clamp mechanism is arranged on the top surface of the carrying circuit platform and is used for clamping the test piece; the heating net is arranged in the side wall of the sealing clamp mechanism; the water injection end of the water injection mechanism is communicated with the sealing clamp mechanism; the glue injection end of the glue injection mechanism is communicated with the sealing clamp mechanism, and the glue injection mechanism is used for visualizing and retaining the experiment result; and the sound wave controller is electrically connected with a sound wave probe, and the detection end of the sound wave probe is attached to the sealing clamp mechanism. According to the utility model, the exquisite design is adopted, test pieces with different sizes can be accurately and flexibly fixed, cracks with different degrees caused by different water pressures formed during pressurization can be recorded, and the final experiment result is completely reserved, so that the subsequent contrast experiment is facilitated.

Description

Technical Field

[0001] This utility model belongs to the field of rock mechanics testing technology, and in particular relates to a device for testing the propagation of hydraulic cracks in jointed rocks. Background Technology

[0002] Most rock masses in nature exhibit microcracks, joints, and cavities. Furthermore, they are composed of various minerals, resulting in anisotropic characteristics. Especially in underground engineering or under high ground stress conditions, fissures in natural rock masses serve as storage and flow spaces for groundwater. Weakened by their own weight and the influence of water, the presence of water significantly reduces the rock mass's strength and bearing capacity, directly impacting its stability. Fissured rock masses are highly susceptible to instability, leading to safety hazards that can damage construction equipment and threaten the lives of workers. When fissures are located in different areas and subjected to varying water pressures, the failure modes and affected areas of the rock differ considerably. Therefore, considering the different water pressures acting on rock fissures and analyzing the fracturing process of fissured rock masses under different water pressure conditions has significant engineering implications.

[0003] Currently, indoor testing equipment for measuring the propagation of hydraulic fractures in jointed rocks has certain shortcomings, such as:

[0004] Firstly, the current apparatus for studying the relationship between jointed rock mass cracking and water pressure is limited in that it cannot visually display experimental results and relies solely on data analysis. This not only weakens the overall understanding of the experimental results but also significantly reduces the intuitive understanding of the degree of damage to the specimens.

[0005] Secondly, the device is cumbersome to operate during demolding, often requiring the specimen to be damaged before it can be removed, which limits the ability to conduct simultaneous spatial and temporal comparative analysis of the specimen under different conditions, affecting the continuity and comparability of experimental results.

[0006] Third, the device lacks the function of recording the degree of cracks caused by different water pressures during the pressurization process in real time, requiring repeated experiments to draw conclusions, which significantly reduces the efficiency of the experiment and the accuracy of data collection. Utility Model Content

[0007] The purpose of this invention is to provide a device for testing the propagation of hydraulic cracks in jointed rocks, in order to solve the above-mentioned problems.

[0008] To achieve the above purpose, the present invention provides the following solutions:

[0009] A device for testing the propagation of hydraulic fractures in jointed rocks, comprising:

[0010] Equipped with a circuit platform;

[0011] A sealing clamp mechanism is provided on the top surface of the circuit mounting platform for clamping the test piece;

[0012] A heating mesh is disposed inside the side wall of the sealing clamp mechanism to enable the specimen to be demolded completely and quickly;

[0013] The water injection mechanism has a water injection end connected to the sealing clamp mechanism, which is used to destroy the specimen;

[0014] The dispensing mechanism has a dispensing end connected to the sealing clamp mechanism, which is used to visualize and preserve the experimental results;

[0015] An acoustic wave controller is electrically connected to an acoustic wave probe, the probe's detection end being attached to the sealing clamp mechanism.

[0016] Preferably, the sealing clamp mechanism includes a sealing plate assembly on the outer side and a spiral extrusion assembly on the inner side;

[0017] The sealing plate assembly includes a bottom plate placed on the circuit mounting platform. Side sealing plates are fixed around the top surface of the bottom plate. The top surfaces of several side sealing plates are covered with the same top cover plate. A sealing strip is provided between the top cover plate and the side sealing plates.

[0018] The spiral extrusion assembly includes at least two symmetrically arranged extrusion plates, which are used to clamp the specimen. A spiral column is rotatably connected to the end of the extrusion plate away from the specimen. The spiral column is threadedly connected to the side sealing plate. An adjusting wheel is coaxially fixed to the end of the spiral column away from the extrusion plate.

[0019] Preferably, the heating mesh is fixed inside the side sealing plate.

[0020] Preferably, the water injection mechanism includes a water reservoir placed on the ground, and a water pump is placed inside the water reservoir. The water pump is used for water intake and pressurization and high-pressure drainage.

[0021] The outlet of the water pump is connected to the inlet of the high-pressure water storage chamber, and the outlet of the high-pressure water storage chamber is connected to the inlet of the water inlet opened on the side sealing plate.

[0022] A stepper motor is placed on the top surface of the circuit platform. A screw is connected to the output end of the stepper motor. The output end of the screw is sealed and rotates through the high-pressure water storage chamber and is connected to a pressure plug. The pressure plug is slidably sealed inside the high-pressure water storage chamber.

[0023] Preferably, a second water injection valve is installed on the pipeline connecting the water pump and the high-pressure water storage chamber, and a first water injection valve and a water pressure monitoring sensor are provided on the pipeline connecting the high-pressure water storage chamber and the side sealing plate.

[0024] Preferably, the glue injection mechanism includes a glue storage tank placed on the ground, a glue pump placed inside the glue storage tank, and the glue outlet of the glue pump is connected to a glue injection port opened on the side sealing plate through a glue injection pipe.

[0025] Preferably, the glue injection tube is equipped with a glue injection valve.

[0026] Preferably, the bottom plate has a waste outlet, which is vertically aligned with the wastewater and waste residue collection port. The wastewater and waste residue collection port is located at the top of the wastewater and waste residue collection bucket. The wastewater and waste residue collection bucket is detachably connected to a waste residue filter screen for separating experimental wastewater and waste residue.

[0027] Preferably, the bottom plate has a water outlet and the top cover has an exhaust port.

[0028] Preferably, the bottom plate, the side sealing plate, and the top cover are made of transparent material.

[0029] Compared with the prior art, the present invention has the following advantages and technical effects:

[0030] This invention features a sealing clamp mechanism with a heating mesh on the middle layer of its side, used in conjunction with hot melt adhesive to facilitate specimen demolding and ensure the complete preservation of the experimental specimen. Adhesive is injected into the specimen after testing via an injection mechanism; once the adhesive has solidified, the fissures within the rock mass specimen become clearly visible, making the post-fault changes of the specimen transparent. During water pressurization, an acoustic detection device is activated to record fissure changes under different water pressures in real time, providing valuable guidance for testing the propagation of hydraulic fractures in jointed rocks. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 It is a structural diagram of the utility model;

[0033] Figure 2 This is the front view of the sealing clamp mechanism;

[0034] Figure 3Left view of the sealing clamp mechanism;

[0035] Figure 4 This is a top view of the top cover.

[0036] Figure 5 This is a schematic diagram of the spiral propulsion mechanism for the sealing clamp;

[0037] The components include: 1. Acoustic controller; 2. Circuit platform; 3. Glue storage tank; 4. Acoustic probe; 5. Glue injection valve; 6. Glue pump; 7. Glue injection pipe; 8. Top cover plate; 9. Exhaust port; 10. Side sealing plate; 11. Heating grid; 12. Wastewater and waste residue collection port; 13. Wastewater and waste residue collection bucket; 14. Waste residue filter screen; 15. First water injection valve; 16. Water pressure monitoring sensor; 17. High-pressure water storage chamber; 18. Water pump; 19. Second water injection valve; 20. Water reservoir; 21. Lead screw; 22. Stepper motor; 23. Controller; 24. Extrusion plate; 25. Water injection port; 26. Water outlet; 27. Adjusting wheel; 28. Spiral column; 29. ​​Sealing strip. Detailed Implementation

[0038] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0039] 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 implementation methods.

[0040] Reference Figures 1 to 5 This utility model discloses a device for testing the propagation of hydraulic cracks in jointed rocks, comprising:

[0041] Equipped with circuit platform 2;

[0042] A sealing clamp mechanism is located on the top surface of the circuit mounting platform 2 and is used to clamp the test piece;

[0043] Heating mesh 11 is located inside the side wall of the sealing clamp mechanism and is used to ensure that the specimen is completely and quickly demolded.

[0044] The water injection mechanism has a water injection end connected to the sealing clamp mechanism, which is used to destroy the test specimen;

[0045] The dispensing mechanism has a dispensing end connected to the sealing clamp mechanism, which is used to visualize and preserve experimental results.

[0046] The acoustic wave controller 1 is electrically connected to the acoustic wave probe 4, and the detection end of the acoustic wave probe 4 is attached to the sealing clamp mechanism.

[0047] The sealing clamp mechanism of this invention features a heating mesh 11 on the middle layer of its side, used in conjunction with hot melt adhesive to facilitate specimen demolding and ensure the complete preservation of the experimental specimen. Adhesive is injected into the tested specimen via an injection mechanism, and after the adhesive solidifies, the fractures in the rock mass specimen become clearly visible, making the changes in the specimen after failure visible. During water pressurization, an acoustic detection device is activated to record the changes in fractures under different water pressures in real time, providing guidance for the hydraulic fracture propagation testing of jointed rocks.

[0048] The design has been further optimized, with the sealing clamp mechanism comprising a sealing plate assembly on the outer side and a spiral extrusion assembly on the inner side.

[0049] The sealed plate assembly includes a bottom plate placed on the circuit platform 2. Side sealing plates 10 are fixed around the top surface of the bottom plate. The top surfaces of several side sealing plates 10 are covered with the same top cover plate 8. A sealing strip 29 is provided between the top cover plate 8 and the side sealing plates 10. The sealing strip 29 between the top cover plate 8 and the side sealing plates 10 forms a closed sealed space, which effectively prevents external pollutants or moisture from entering.

[0050] The spiral extrusion assembly includes at least two symmetrically arranged extrusion plates 24. The extrusion plates 24 are used to clamp the specimen. A spiral column 28 is rotatably connected to the end of the extrusion plate 24 away from the specimen. The spiral column 28 is threadedly connected to the side sealing plate 10. An adjusting wheel 27 is coaxially fixed to the end of the spiral column 28 away from the extrusion plate 24.

[0051] By rotating the adjusting wheel 27, specimens of different sizes and shapes can be clamped, thereby improving the applicability and flexibility of the testing device.

[0052] The outer top cover plate 8 of the sealing clamp is made of high-strength polymethyl methacrylate (acrylic) material. The side sealing plate 10 and the bottom sealing plate are designed as three layers: outer, middle and inner. The inner and outer layers are made of high-strength polymethyl methacrylate (acrylic) material, which has high transparency, high melting point and can withstand 20-25 MPa water pressure.

[0053] A rubber gasket is used at the junction of the spiral column 28 and the sealing plate 10 on the side of the sealing fixture to prevent water leakage after pressurization. The spiral column 28 and the extrusion plate 24 are made of high-strength and corrosion-resistant stainless steel, and the two are structurally connected by a precise welding process, thereby ensuring the reliability of the spiral column 28 and the extrusion plate 24 during long-term use.

[0054] The design was further optimized by fixing the heating mesh 11 inside the side sealing plate 10. A heating mesh 11 was installed in the middle layer to facilitate complete and rapid demolding of the experimental specimen.

[0055] The solution is further optimized. The water injection mechanism includes a water storage tank 20 placed on the ground. A water pump 18 is placed inside the water storage tank 20. The water pump 18 is used for water intake and pressurization and high-pressure drainage.

[0056] The outlet of the water pump 18 is connected to the inlet of the high-pressure water storage chamber 17, and the outlet of the high-pressure water storage chamber 17 is connected to the inlet of the water inlet 25 opened on the side sealing plate 10.

[0057] A stepper motor 22 is placed on the top surface of the circuit platform 2. The output end of the stepper motor 22 is connected to a screw 21. The output end of the screw 21 is sealed and passes through the high-pressure water storage chamber 17 and is rotatably connected to a pressure plug. The pressure plug is slidably sealed inside the high-pressure water storage chamber 17.

[0058] To further optimize the design, a second water injection valve 19 is installed on the pipeline connecting the water pump 18 and the high-pressure water storage chamber 17, and a first water injection valve 15 and a water pressure monitoring sensor 16 are installed on the pipeline connecting the high-pressure water storage chamber 17 and the side sealing plate 10.

[0059] The solution is further optimized. The glue injection mechanism includes a glue storage tank 3 placed on the ground. A glue pump 6 is placed inside the glue storage tank 3. The glue outlet of the glue pump 6 is connected to the glue injection port opened on the side sealing plate 10 through the glue injection pipe 7.

[0060] The design was further optimized by installing an injection valve 5 on the injection tube 7.

[0061] The design is further optimized by providing a waste outlet on the bottom plate, which is vertically aligned with the wastewater and waste residue collection port 12. The wastewater and waste residue collection port 12 is located at the top of the wastewater and waste residue collection tank 13. The wastewater and waste residue collection tank 13 is detachably connected to a waste residue filter screen 14 for separating experimental wastewater and waste residue.

[0062] The design has been further optimized by providing a water outlet 26 on the bottom flat plate and an exhaust port 9 on the top cover plate 8.

[0063] The top cover plate 8 of the sealing fixture has a reserved vent 9, which is sealed with a safety valve. The bottom plate has a reserved water outlet 26, and the circuit platform 2 also has a reserved water outlet. The two are the same size. During installation, the reserved water outlet 26 on the bottom plate of the sealing fixture coincides with the reserved water outlet on the circuit platform 2, and is sealed with a safety valve. The bottom is equipped with a wastewater and waste residue collection device. The upper part of the device is a funnel-shaped wastewater and waste residue collection port 12, and the lower part is a wastewater and waste residue collection bucket 13. The wastewater and waste residue collection bucket 13 is equipped with a pull-out waste residue filter screen 14, which can quickly separate experimental wastewater and waste residue, so that the experimental equipment can be reused efficiently.

[0064] The design has been further optimized so that the bottom plate, the side sealing plate 10, and the top cover plate 8 are made of transparent material.

[0065] A controller 23 is placed on the ground. Controller 23 is electrically connected to the acoustic controller 1, the first water injection valve 15, the water pressure monitoring sensor 16, the second water injection valve 19, and the stepper motor 22. Controller 23 is used to control the motor operation and record the water pressure data monitored by the water pressure monitoring sensor 16. The controller 23 also includes the acoustic controller 1 and the acoustic probe 4 connected via data wires. The acoustic controller 1 is connected to controller 23 via data wires and can be adjusted centrally by controller 23 or individually by acoustic controller 1. Data is transmitted to controller 23 via data wires in the circuit platform 2.

[0066] The usage process of this utility model is as follows:

[0067] S1. Adjust the sealing clamp according to the actual dimensions of the experimental specimen. Place the experimental specimen in the sealing clamp and apply a thin layer of hot melt adhesive to the side and bottom sealing plates. Adjust the positions of the four extrusion plates 24 by rotating the adjusting wheel 27 to fix the jointed rock mass specimen to a compacted state. Connect the water outlet of the water injection mechanism to the water injection port 25 of the sealing clamp through the water outlet pipe. Use the stepper motor 22 to push the pressurized water into the jointed rock mass specimen. Open the water injection valve and the vent 9 to expel the air from the sealing clamp through water injection, and then seal the vent 9.

[0068] S2. Experimental data on the hydraulic crack propagation test of jointed rock is collected using the water pressure monitoring sensor 16. The water pressure value is transmitted to the main controller 23 in real time. Simultaneously, the acoustic controller 1 is turned on, and the acoustic probe 4 is placed tightly against the side wall of the sealing fixture to transmit the crack status of the jointed rock specimen to the main controller 23 in real time. When the water pressure monitoring sensor 16 value rises to a certain level and begins to decline, the changes in the acoustic detection device value are observed, and the cracking of the jointed rock specimen along the joint is observed until a significant change in the acoustic monitoring data occurs. Then, the stepper motor 22 is stopped, and the acoustic detection device is turned off.

[0069] S3. Open outlet 26 to drain the water from the sealing clamp, then seal outlet 26. Open injection valve 5 until the colored adhesive submerges the experimental specimen. After the colored adhesive solidifies, turn on heating net 11 to heat and facilitate demolding. Remove excess adhesive and retain the experimental specimen. Observe the changes in the experimental specimen and analyze the collected data to analyze the relationship between jointed rock mass cracking and water pressure, as well as the failure morphology of the rock mass.

[0070] In the description of this utility model, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., 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 this utility model 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 utility model.

[0071] The embodiments described above are merely preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model. Various modifications and improvements made to the technical solutions of the present utility model by those skilled in the art without departing from the spirit of the present utility model should fall within the protection scope defined by the claims of the present utility model.

Claims

1. A device for testing the propagation of hydraulic fractures in jointed rocks, characterized in that, include: Equipped with a circuit platform (2); A sealing clamp mechanism is provided on the top surface of the circuit mounting platform (2) for clamping the test piece; Heating mesh (11), the heating mesh (11) is disposed inside the side wall of the sealing clamp mechanism, for the purpose of making the specimen completely and quickly demolded; A water injection mechanism, wherein the water injection end of the water injection mechanism is connected to the sealing clamp mechanism, is used to destroy the specimen; The dispensing mechanism has a dispensing end connected to the sealing clamp mechanism, which is used to visualize and preserve the experimental results; A sound wave controller (1) is electrically connected to a sound wave probe (4), and the detection end of the sound wave probe (4) is attached to the sealing clamp mechanism.

2. The hydraulic fracture propagation testing device for jointed rocks according to claim 1, characterized in that: The sealing clamp mechanism includes a sealing plate assembly on the outer side and a spiral extrusion assembly on the inner side. The sealing plate assembly includes a bottom plate placed on the circuit platform (2), and side sealing plates (10) are fixed around the top surface of the bottom plate. The top surfaces of several side sealing plates (10) are covered with the same top cover plate (8), and a sealing strip (29) is provided between the top cover plate (8) and the side sealing plates (10). The spiral extrusion assembly includes at least two symmetrically arranged extrusion plates (24), which are used to clamp the specimen. A spiral column (28) is rotatably connected to one end of the extrusion plate (24) away from the specimen. The spiral column (28) is threadedly connected to the side sealing plate (10). An adjusting wheel (27) is coaxially fixed to one end of the spiral column (28) away from the extrusion plate (24).

3. The hydraulic fracture propagation testing device for jointed rocks according to claim 2, characterized in that: The heating mesh (11) is fixed inside the side sealing plate (10).

4. The hydraulic fracture propagation testing device for jointed rocks according to claim 2, characterized in that: The water injection mechanism includes a water reservoir (20) placed on the ground, and a water pump (18) is placed inside the water reservoir (20). The water pump (18) is used for water intake and pressurization and high-pressure drainage. The outlet of the water pump (18) is connected to the inlet of the high-pressure water storage chamber (17), and the outlet of the high-pressure water storage chamber (17) is connected to the inlet of the water inlet (25) opened on the side sealing plate (10). A stepper motor (22) is placed on the top surface of the circuit platform (2). A screw (21) is axially connected to the output end of the stepper motor (22). The output end of the screw (21) is sealed and rotatably connected to a pressure plug through the high-pressure water storage chamber (17). The pressure plug is slidably sealed inside the high-pressure water storage chamber (17).

5. The hydraulic fracture propagation testing device for jointed rocks according to claim 4, characterized in that: A second water injection valve (19) is installed on the pipeline connecting the water pump (18) and the high-pressure water storage chamber (17). A first water injection valve (15) and a water pressure monitoring sensor (16) are provided on the pipeline connecting the high-pressure water storage chamber (17) and the side sealing plate (10).

6. The hydraulic fracture propagation testing device for jointed rocks according to claim 2, characterized in that: The glue injection mechanism includes a glue storage tank (3) placed on the ground, and a glue pump (6) is placed inside the glue storage tank (3). The glue outlet of the glue pump (6) is connected to the glue injection port opened on the side sealing plate (10) through the glue injection pipe (7).

7. A testing device for hydraulic fracture propagation in jointed rock according to claim 6, characterized in that: The glue injection tube (7) is equipped with a glue injection valve (5).

8. The hydraulic fracture propagation testing device for jointed rocks according to claim 2, characterized in that: The bottom plate has a waste outlet, and a wastewater and waste residue collection bucket (13) is provided below the bottom plate. The top of the wastewater and waste residue collection bucket (13) is connected to a wastewater and waste residue collection port (12). The waste outlet and the wastewater and waste residue collection port (12) are vertically aligned. A waste residue filter screen (14) is detachably connected inside the wastewater and waste residue collection bucket (13) for separating experimental wastewater and waste residue.

9. A testing device for hydraulic crack propagation in jointed rock according to claim 2, characterized in that: The bottom plate is provided with a water outlet (26) and the top cover plate (8) is provided with an exhaust port (9).

10. A testing device for hydraulic fracture propagation in jointed rocks according to claim 2, characterized in that: The bottom plate, the side sealing plate (10), and the top cover plate (8) are made of transparent material.

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