A system for preparing samples of cross-flow grouting crushed stone consolidation body.

Abstract

This invention discloses a system for preparing a solidified aggregate sample using pressure-maintaining grouting in a cross-flow zone, comprising a rigid pressure vessel, a pressurizing piston, a servo pressure testing machine, and a grouting unit. The rigid pressure vessel is placed in the middle of the platform of the servo pressure testing machine, directly below the output end of the machine. The rigid pressure vessel is used to hold the aggregate sample. The pressurizing piston can move up and down within the rigid pressure vessel, pressurizing and maintaining the load on the aggregate sample via the press. The grouting unit includes a storage tank, an inert gas cylinder, and a grouting conveying mechanism. The grouting conveying mechanism includes a main grouting pipe, grouting branch pipes, and a grout collection chamber. The grout collection chamber is connected to the rigid pressure vessel via four grouting branch pipes. One end of the main grouting pipe is connected to the grout collection chamber, and the other end is connected to the storage tank. This invention can pressurize and maintain the load on the aggregate sample during the preparation of the solidified aggregate, producing a solidified sample that conforms to the actual stress characteristics.

Description

Technical Field

[0001] This utility model relates to the field of rock mechanical property testing technology, specifically to a sample preparation system for cross-flow zone pressure-maintaining grouting crushed stone consolidation body. Background Technology

[0002] Grouting and backfilling of coal mine caving zones is an important method for controlling surface subsidence. Gangue slurry is transported to the caving zone via pipelines, forming a consolidated aggregate with the crushed rock within the caving zone to restrict the movement of the overlying strata. Therefore, the mechanical bearing capacity of the consolidated aggregate is a key research focus. Since the crushed rock in the caving zone is already under load and possesses initial stress before grouting, current experimental setups rarely consider this, potentially leading to distorted experimental data. Therefore, to realistically simulate the stress environment of the consolidated aggregate, it is necessary to develop a pressure-maintaining grouting system for preparing caving aggregate samples in caving zones. This system should produce consolidated aggregates that meet the required specifications for subsequent mechanical property testing or research. Utility Model Content

[0003] The purpose of this invention is to propose a system for preparing a solidified aggregate sample by pressure-maintaining grouting in a cross-flow zone, which can prepare a solidified aggregate with additional axial pressure and improve the accuracy of subsequent mechanical property tests of the solidified aggregate.

[0004] The technical solution adopted in this utility model is: a system for preparing samples of cross-flow grouting crushed stone consolidation bodies, including...

[0005] A rigid pressure vessel, seated on a vessel base, with an open upper part and a cavity for holding gangue samples;

[0006] The pressurizing piston includes a support plate, a central support frame, and a pressure plate that are fixedly connected in sequence. The pressure plate contacts the inner wall of the rigid pressure vessel and cooperates to generate relative motion.

[0007] A servo pressure testing machine includes a press and a platform for placing the rigid pressure vessel. The press is used to apply axial pressure to a gangue sample inside the rigid pressure vessel. The pressure piston is located below the output end of the press.

[0008] The grouting unit includes a storage tank, an inert gas cylinder, and a grouting conveying mechanism. The grouting conveying mechanism includes a main grouting pipe, at least one grouting branch pipe, and a grout collection chamber. The grouting branch pipe passes through the pressure plate and communicates with the rigid pressure vessel. The grout collection chamber is located in the central support frame and is connected to the grouting branch pipe and the main grouting pipe, respectively. The main grouting pipe and the inert gas cylinder are respectively connected to the storage tank.

[0009] As a further improvement of this utility model, a drain hole is provided in the middle of the container base, and the drain hole communicates with the interior of the rigid pressure vessel.

[0010] As a further improvement of this utility model, permeable stones are laid on the bottom surface of the rigid pressure vessel.

[0011] As a further improvement of this utility model, a pressure gauge and a flow meter are provided on the grouting main pipe.

[0012] As a further improvement of this utility model, a valve is provided on the grouting main pipe.

[0013] As a further improvement of this utility model, it also includes a pressure sensor and a controller. The pressure sensor is located between the output end of the press and the support plate and is fixed on the support plate. The pressure sensor, the pressure gauge, and the flow meter are respectively electrically connected to the controller.

[0014] The beneficial effects of this utility model are:

[0015] (1) This utility model is equipped with a servo pressure testing machine, which can realize axial pressure to maintain the load of gangue in the steel cylinder, and on this basis, grouting and filling can be carried out to obtain accurate grouting and filling data;

[0016] (2) The combined structure of the rigid pressure vessel and the pressurizing piston allows the press to apply axial pressure to the gangue more directly, and can effectively squeeze out excess water during the pressurization process, so that the grout filling body can be quickly formed and consolidated.

[0017] (3) In this utility model, the grouting pipe and the grout collection chamber are integrated into one unit in the pressurized piston. This not only provides axial pressure, but also allows the gangue inside the steel cylinder to be grouted evenly through four branch pipes to create a uniformly filled solidified body inside.

[0018] (4) By setting up a pressure sensor and a controller, the present invention can detect whether the axial pressure is constant in real time through the feedback of the pressure sensor, and control the press to stabilize the pressure when changes occur, thereby improving the quality of solidified body production. Attached Figure Description

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] Figure 1 This is a schematic diagram of the structural preparation system for the cross-flow pressure-maintaining grouting crushed stone consolidation body of this utility model.

[0021] In the diagram: 1-rigid pressure vessel, 2-container base, 3-drainage hole, 4-permeable stone, 5-support plate, 6-central support frame, 7-pressure plate, 8-sealing ring, 9-pressurizer, 10-platform, 11-storage tank, 12-inert gas cylinder, 13-valve, 14-grouting main pipe, 15-grouting branch pipe, 16-grout collection bin, 17-pressure gauge, 18-flow meter, 19-pressure sensor, 20-controller, 21-gangue sample. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the described embodiments of this utility model are within the protection scope of this utility model.

[0023] like Figure 1 As shown, the cross-sectional pressure-maintaining grouting crushed stone consolidation sample preparation system of this utility model includes a rigid pressure vessel 1, a pressure piston, a servo pressure testing machine, and a grouting unit. The rigid pressure vessel 1 is a steel cylinder with an open top and a bottom fixedly connected to a container base 2. Permeable stones 4 are laid on the bottom surface of the steel cylinder, and a drainage hole 3 is provided in the middle of the container base. The permeable stones 4 and drainage hole 3 at the bottom of the steel cylinder allow excess water to be squeezed out of the gangue under axial pressure, thereby achieving rapid solidification of the filling material.

[0024] The pressurizing piston includes a support plate 5, a central support frame 6, and a pressure plate 7. The pressure plate 7 contacts the inner wall of the steel cylinder and can move up and down. The support plate 5 is a circular steel plate, the central support frame 6 is a circular steel cylinder, and the pressure plate 7 is circular. The upper end of the central support frame 6 is welded and fixed to the bottom surface of the support plate 5, and the lower end is welded and fixed to the pressure plate 7. A sealing ring 8 is provided on the pressure plate 7 to prevent slurry leakage.

[0025] The servo pressure testing machine includes a press 9 and a platform 10. The press 9 is mounted on four guide columns vertically fixed to the platform 10 and can slide up and down. The rigid pressure vessel 1 is located in the middle of the platform 10, directly below the output end of the press 9. The output end of the press 9 is the hydraulic cylinder. When the hydraulic cylinder of the press 9 moves downward, it contacts the upper surface of the support plate 5.

[0026] The grouting unit includes a storage tank 11, an inert gas cylinder 12, and a grouting conveying mechanism. The storage tank 11 stores the grouting liquid, and the inert gas cylinder 12 provides power for conveying the grouting liquid from the storage tank 11. The inert gas cylinder 12 contains an inert gas, such as nitrogen or argon, at a certain pressure. The inert gas, when introduced into the storage tank 11, will not react with the grouting material. The grouting conveying mechanism includes a main grouting pipe 14, four branch grouting pipes 15, and a grout collection chamber 16. The branch grouting pipes 15 are evenly distributed circumferentially on the pressure plate 7 and pass through the pressure plate 7, communicating with the rigid pressure vessel 1. The grout collection chamber 16 is located within the central support frame 6 and is connected to both the branch grouting pipes 15 and the main grouting pipe 14. The main grouting pipe 14 and the inert gas cylinder 12 are both connected to the storage tank 11. The grouting unit is equipped with a grout collection chamber 16, which can buffer the impact force generated by high-pressure grouting and stabilize the pressure. Then, grout is injected into the steel cylinder through four evenly distributed grouting branch pipes 15, which can achieve the stability and uniformity of grouting.

[0027] The system also includes a pressure sensor 19 and a controller 20. The pressure sensor 19 is located at the bottom of the cylinder of the press 9 and is fixed on the support plate 5. The controller is a PLC controller. The pressure sensor 19 is electrically connected to the controller 20. A pressure gauge 17, a flow meter 18, and a valve 13 are provided on the grouting main pipe 14. One end of the valve 13 is connected to the storage tank 11, and the other end is connected to the grouting main pipe 14. The pressure gauge 17, the flow meter 18, and the valve 13 are all electrically connected to the controller 20.

[0028] The working principle of this system is as follows:

[0029] 1. Processing gangue: Collect gangue from the caving zone of the target coal mine and crush it. First, screen the crushed gangue according to the similar gradation method to make it conform to the particle size distribution on site. Then, pour the screened gangue sample 21 into the rigid pressure vessel 1 (steel cylinder).

[0030] II. Pre-pressurization treatment: The servo pressure testing machine applies pressure to the gangue sample 21 inside the rigid pressure vessel 1 through the press 9, and then holds the load after loading to the target stress.

[0031] 3. Prepare the filling grout. Use gangue and water to prepare the solution. The mass ratio of coarse to fine gangue is 0.5:1.0. The particle size range of coarse gangue is 0.15-2.00 mm, and the particle size range of fine gangue is 0-0.15 mm. The mass ratio of gangue to water is 0.7. Determine the solid content of the grout to be 70%. Other materials, such as cement, can also be used for this filling grout.

[0032] IV. Fabrication of Specimens for Grouting Backfill in the Collapse Zone: The prepared grout is placed in the storage tank 11. The inert gas cylinder 12 is slowly opened, and closed when the required filling ratio t is reached. Excess water is discharged through the permeable stone 4 and the drainage hole 3 at the bottom of the steel cylinder. Ultimately, the pure gangue grout and the fallen gangue form a complete initial stress consolidated backfill in the collapse zone within the steel cylinder. In the formula, m1 and ρ1 are the mass and density of the grouting material, and v1 is the void volume in the gangue after the initial stress.

[0033] 5. Pressure sensor 19 detects the axial pressure of the press in real time. When the pressure value deviates from the set value, the controller 20 controls the press to perform a small compensation to bring the axial pressure back to the set value, thereby ensuring that the pressure remains constant during the test.

[0034] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited thereto. Various changes that can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention are all within the protection scope of the claims of the present invention.

Claims

1. A system for preparing samples of cross-flow grouting aggregate consolidation bodies, characterized in that, include A rigid pressure vessel (1) is mounted on a vessel base (2). The upper part of the rigid pressure vessel (1) is open, and the cavity is used to hold gangue samples (21). The pressurizing piston includes a support plate (5), a central support frame (6) and a pressure plate (7) that are fixedly connected in sequence. The pressure plate (7) contacts the inner wall of the rigid pressure vessel (1) and cooperates to generate relative motion. The servo pressure testing machine includes a press (9) and a platform (10) for placing the rigid pressure vessel (1). The press (9) is used to apply axial pressure to the gangue sample (21) inside the rigid pressure vessel (1). The pressure piston is located below the output end of the press (9). The grouting unit includes a storage tank (11), an inert gas cylinder (12), and a grouting conveying mechanism. The grouting conveying mechanism includes a grouting main pipe (14), at least one grouting branch pipe (15), and a grout collection chamber (16). The grouting branch pipe (15) passes through the pressure plate (7) and communicates with the rigid pressure vessel (1). The grout collection chamber (16) is located in the central support frame (6) and is connected to the grouting branch pipe (15) and the grouting main pipe (14) respectively. The grouting main pipe (14) and the inert gas cylinder (12) are respectively connected to the storage tank (11).

2. The sample preparation system for cross-slope pressure-maintaining grouting crushed stone consolidation body according to claim 1, characterized in that, A drain hole (3) is provided in the middle of the container base (2), and the drain hole (3) communicates with the interior of the rigid pressure vessel (1).

3. The sample preparation system for cross-flow grouting and pressure-maintaining crushed stone consolidation body according to claim 1, characterized in that, Permeable stones (4) are laid on the bottom surface of the rigid pressure vessel (1).

4. The sample preparation system for cross-slope pressure-maintaining grouting crushed stone consolidation body according to claim 1, characterized in that, A pressure gauge (17) and a flow meter (18) are provided on the grouting main pipe (14).

5. The sample preparation system for cross-flow grouting and pressure-maintaining crushed stone consolidation in accordance with claim 1, characterized in that, A valve (13) is provided in the grouting main pipe (14).

6. The sample preparation system for cross-flow grouting and pressure-maintaining crushed stone consolidation body according to claim 4, characterized in that, It also includes a pressure sensor (19) and a controller (20). The pressure sensor (19) is located between the output end of the press (9) and the support plate (5) and is fixed on the support plate (5). The pressure sensor (19), the pressure gauge (17), and the flow meter (18) are electrically connected to the controller (20) respectively.

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