Water-rich soft rock sampling and mechanical property in-situ testing device and testing method

Abstract

The application provides a water-rich soft rock sampling and mechanical property in-situ testing device and testing method, and relates to the technical field of geotechnical engineering. The device comprises a fixing device, a sampling system, a testing system and a transmission system. The bottom of the shell is provided with a protection plate, the protection plate is provided with a telescopic device, the telescopic device is connected with a support seat, the telescopic mechanism of the sampling system is connected with a sampling cylinder through a rotating shaft, the upper end of the telescopic mechanism is connected with a sliding rail, the telescopic assembly of the testing system is connected with a top seat and a pressure head, the pressure head is provided with a pressure sensor and a displacement sensor, the transmission rail of the transmission system is fixed on the protection plate, and the transmission rail is provided with a transmission plate. The device can directly sample the water-rich soft rock in-situ, and the sampled water-rich soft rock is transmitted to the testing system for uniaxial compression test. The mechanical properties of the water-rich soft rock are determined by monitoring and analyzing the test data in real time, thereby providing a reference basis for the deformation law and failure mechanism research of the water-rich soft rock.

Description

Technical Field

[0001] This invention relates to the field of geotechnical engineering technology, and in particular to a device and method for sampling and in-situ testing the mechanical properties of water-rich soft rock. Background Technology

[0002] Water-rich soft rock mines exhibit significant creep characteristics, such as nonlinear large deformation and long deformation duration, due to mining activities. Water-rich soft rock itself has a high water content and low strength, making it susceptible to damage from external environmental factors during sampling and sample preparation. Traditional rock sampling methods for water-rich soft rock often result in fractured samples, leading to incomplete samples and low sample quality.

[0003] In existing technologies, mechanical property tests on water-rich soft rocks are typically conducted in indoor laboratories, making in-situ testing impossible. Furthermore, rock samples lack adequate sealing and preservation devices, frequently resulting in breakage and fragmentation during transportation. Moreover, the response characteristics exhibited by water-rich soft rocks in actual field conditions differ significantly from those tested in laboratory settings. Therefore, it is necessary to conduct sampling and in-situ mechanical property testing of water-rich soft rocks to understand the deformation patterns and failure mechanisms of deep water-rich soft rock surrounding rocks. Summary of the Invention

[0004] To ensure the sampling and shaping accuracy of water-rich soft rock, guarantee that the test results conform to engineering practice, realize in-situ testing of water-rich soft rock, and facilitate the study of deformation laws and failure mechanisms of water-rich soft rock, this invention provides a sampling and in-situ mechanical property testing device and method for water-rich soft rock. The specific technical solution is as follows.

[0005] A sampling and in-situ mechanical property testing device for water-rich soft rock includes a fixing device, a sampling system, a testing system, and a transmission system. The bottom of the device housing is equipped with a protective plate, and a telescopic device is installed on the protective plate, connected to a support base. The telescopic mechanism of the sampling system is connected to a sampling cylinder via a rotating shaft, and a sliding rail is connected to the upper end of the telescopic mechanism. The telescopic component of the testing system connects a top seat and a pressure head, which contains a pressure sensor and a displacement sensor to monitor axial pressure and axial strain. The transmission system's conveying rail is fixed to the protective plate, and a conveying plate is installed on the conveying rail.

[0006] Preferably, the protective plate has multiple telescopic devices fixedly connected to its side, and the support base is fixed to the ground; the protective plate also has through holes.

[0007] Preferably, the base of the sampling system is fixed to the outside of the protective plate, and a cutting blade is embedded below the base; the sampling cylinder is cylindrical and has a double-layer structure.

[0008] Preferably, a drive motor is provided on the outer side of the sliding track, and the drive motor is connected to a telescopic mechanism, which drives the sampling cylinder to pass through the protective plate at the bottom of the housing.

[0009] Preferably, the conveyor rails are fixed to the protective plates inside the housing, the conveyor plates are connected to the conveyor rails via sliders, and pressure sensors are installed on the conveyor plates.

[0010] Preferably, an air inlet valve is provided between the two layers of the sampling cylinder, and a high-pressure gas pipeline is connected to the air inlet valve, the high-pressure gas pipeline being arranged along the telescopic mechanism.

[0011] Preferably, the transmission system delivers the specimen to the underside of the indenter, and the control device starts the uniaxial compression testing machine to output monitoring data from the indenter, pressure sensor, and displacement sensor.

[0012] A method for sampling and in-situ testing of the mechanical properties of water-rich soft rock, utilizing the aforementioned in-situ testing device for sampling and mechanical properties of water-rich soft rock, includes the following steps:

[0013] After the device is fixed at the sampling point, the sampling surface is parallel to the device. The sampling cylinder is filled with high-pressure gas between layers. The sampling cylinder is extended to the sampling point by the telescopic mechanism, and the rotating shaft rotates up and down to take samples. After sampling, the telescopic mechanism controls the sampling cylinder to retract. When it passes the base, the cutting blade cuts the end face of the sample. The transmission system transmits the sample to the pressure head through the transmission track to perform a uniaxial compression test and record the monitoring data.

[0014] A further preferred embodiment is that the high-pressure gas between the sampling cylinder layers is released during the process of the transmission system transporting the sample.

[0015] Further preferred is that the uniaxial compressive strength, elastic modulus, and Poisson's ratio of the rock are obtained from the monitoring data analysis.

[0016] The beneficial effects of the sampling and in-situ mechanical property testing device and method for water-rich soft rock provided by the present invention are that the device, through the cooperation of the sampling system, the testing system and the transmission system, realizes on-site sampling of water-rich soft rock and can perform in-situ mechanical property testing, reducing the transportation process of soft rock; using the device for in-situ testing realizes the automation of in-situ testing, improves testing efficiency, and the test results are more in line with engineering practice. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a device for sampling and in-situ testing of the mechanical properties of water-rich soft rock.

[0018] Figure 2 This is a schematic diagram of the internal structure of a water-rich soft rock sampling and in-situ mechanical property testing device.

[0019] Figure 3This is a three-dimensional structural diagram of a device for sampling and in-situ testing of the mechanical properties of water-rich soft rock.

[0020] Figure 4 This is a flowchart of the method for sampling and in-situ testing of the mechanical properties of water-rich soft rock;

[0021] In the diagram: 4-protective plate, 5-telescopic device, 6-support base, 7-base, 8-sampling cylinder, 9-telescopic mechanism, 10-sliding rail, 11-drive motor, 12-top seat, 13-high pressure gas pipeline, 14-inlet valve, 15-through hole, 16-telescopic device, 17-pressure head, 18-drive motor, 19-pressure sensor, 20-displacement sensor, 21-transfer rail, 22-control device, 23-transfer plate, 24-pressure sensor, 26-rotating shaft, 27-controller. Detailed Implementation

[0022] Combination Figures 1 to 4 As shown, the specific implementation of the sampling and in-situ mechanical property testing device and method for water-rich soft rock provided by the present invention will be described.

[0023] A sampling and in-situ mechanical property testing device for water-rich soft rock includes a fixing device, a sampling system, a testing system, and a transmission system. The fixing device facilitates the fixation of the device and in-situ testing. The sampling system enables automatic on-site sampling of water-rich soft rock. The transmission system transfers the sample to the testing system, which performs on-site testing on the sampled specimen to determine its mechanical properties. The bottom of the device housing 3 is equipped with a protective plate 4, on which a telescopic device 5 is installed to adjust the relationship between the device and the sampling surface. The telescopic device 5 is connected to a support base 6, which can be fixedly installed on the sampling surface. The telescopic mechanism of the sampling system 1 is connected to the sampling cylinder 8 via a rotating shaft, and the upper end of the telescopic mechanism 9 is connected to a sliding rail 10. The telescopic component of the testing system connects a top seat 12 to a pressure head 17. The pressure head 17 is equipped with a pressure sensor 19 and a displacement sensor 20 to monitor axial pressure and axial strain. The transmission system 2 has a transmission track fixed on the protective plate 4. A transmission plate 23 is installed on the transmission track. The transmission plate 23 moves along the transmission track 21, driving the sample specimen to move.

[0024] Multiple telescopic devices 5 are fixedly connected to the side of the protective plate 4, and the support base 6 is fixed to the ground to ensure stable operation of the equipment during water-rich soft rock sampling, preventing the rock sample from breaking due to equipment vibration. The protective plate also has through holes to facilitate the extension of the sampling cylinder 8 for sampling and the retraction of the sample. The base 7 of the sampling system is fixed to the outside of the protective plate, and a cutting blade is embedded below the base 7 for cutting the end face of the sample, ensuring a flat end face for the soft rock sample. The sampling cylinder 8 is cylindrical and has a double-layer structure, with an air inlet valve 14 located between the two layers.

[0025] A drive motor is installed on the outer side of the sliding track 10. The drive motor is connected to a telescopic mechanism 9. The telescopic mechanism 9 drives the sampling cylinder 8 through the protective plate 4 at the bottom of the shell to the sampling surface. The sampling cylinder 8 rotates to achieve sampling of water-rich soft rock. An air inlet valve 14 is installed between the two layers of the sampling cylinder 8. A high-pressure gas pipeline is connected to the air inlet valve, and the high-pressure gas pipeline 13 is arranged along the telescopic mechanism. The space between the two layers of the sampling cylinder is filled with high-pressure gas during sampling. After the sampling cylinder 8 takes a sample, it enters the shell and the high-pressure gas is released to complete the sampling.

[0026] Two conveyor tracks 10 are fixed on the protective plate 4 inside the housing. The conveyor plate 23 is connected to the conveyor track 21 via a slider. A pressure sensor is installed on the conveyor plate.

[0027] The transmission system 2 delivers the specimen to the underside of the pressure head 17. The control device 22 starts the uniaxial compression testing machine and exports the monitoring data from the pressure head, pressure sensor, and displacement sensor. Mechanical parameters such as axial pressure and axial deformation of water-rich soft rock can be measured and displayed in real time. These mechanical parameters are displayed via external devices, and the data can be exported via relevant software. The controller 27 built into the top seat 12 can also control the extension and retraction speed and displacement of the sampling cylinder via external devices.

[0028] A method for in-situ sampling and mechanical property testing of water-rich soft rock utilizes a aforementioned in-situ sampling and mechanical property testing device. The process includes: fixing the device at the sampling point with the sampling surface parallel to the device; filling the interlayer of the sampling cylinder with high-pressure gas; extending the sampling cylinder to the sampling point via a telescopic mechanism; and rotating the shaft up and down to collect the sample. After sampling, the telescopic mechanism retracts the sampling cylinder, and a cutting blade cuts the sample end face as it passes the base. The transmission system transports the sample to below the indenter via a conveyor track for uniaxial compression testing and data recording. During sample transport, the high-pressure gas in the interlayer of the sampling cylinder is released. Analysis of the monitoring data yields the uniaxial compressive strength, elastic modulus, and Poisson's ratio of the rock.

[0029] The method involves first fixing the water-rich soft rock sampling and in-situ mechanical property testing device at the sampling point, adjusting the support base to ensure the sampling surface is parallel to the equipment, and simultaneously adjusting the telescopic device to maintain equipment stability. High-pressure gas is then filled between the two layers of the sampling cylinder through the air inlet valve. Next, the drive motor is started via the screen display control device, controlling the electric telescopic device to move downwards, allowing the sampling cylinder to extend beyond the bottom protective plate of the housing. Once the sampling cylinder reaches the sampling point, it rotates up and down via a rotating shaft to collect the sample. After sampling, the drive motor controls the electric telescopic device to retract upwards. As the upper and lower ends of the sampling cylinder pass the base, the screen display control device controls the embedded cutting blade in the base to extend and cut the sample end face, ensuring the water-rich soft rock sample end face remains flat. After cutting, the sampling cylinder extends and retracts into the housing through the through-hole. Then, the electric telescopic device is controlled to slide along the sliding rail to above the conveyor plate. The air outlet valve is then opened to slowly release the high-pressure gas between the sampling cylinder layers, while simultaneously controlling the electric telescopic device to move the water-rich soft rock sample to the center of the conveyor plate. An automatic control device drives the conveyor rail, causing the conveyor plate to move below the pressure head. The drive motor is started by the screen display control device and reasonable parameters are set to conduct a uniaxial compression test on the water-rich soft rock sample. Then, the data obtained by the pressure sensor and displacement sensor in the indenter are exported by external equipment and analyzed by the controller using software. This method has higher testing efficiency and the test results are more consistent with engineering practice.

[0030] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A method for sampling and in-situ testing of the mechanical properties of water-rich soft rock, characterized in that, An in-situ sampling and mechanical property testing device for water-rich soft rock is disclosed. The device includes a fixing device, a sampling system, a testing system, and a transmission system. A protective plate is installed at the bottom of the device's casing, and a telescopic device is mounted on the protective plate, connected to a support base. The telescopic mechanism of the sampling system is connected to a sampling cylinder via a rotating shaft, and a sliding rail is connected to the upper end of the telescopic mechanism. The telescopic component of the testing system connects a top seat and a pressure head, which is equipped with a pressure sensor and a displacement sensor to monitor axial pressure and axial strain. Two transmission rails of the transmission system are fixed to the protective plate, and transmission plates are mounted on the rails. Multiple telescopic devices are fixedly connected to the sides of the protective plate, and the support base is fixed to the ground. The protective plate also includes… A through hole is provided; the base of the sampling system is fixed to the outside of the protective plate, and a cutting blade is embedded below the base; the sampling cylinder is cylindrical and has a double-layer structure; an air inlet valve is provided between the double layers of the sampling cylinder, and a high-pressure gas pipeline is connected to the air inlet valve, which is arranged along the telescopic mechanism; a drive motor is provided on the outside of the sliding track, and the drive motor is connected to the telescopic mechanism, which drives the sampling cylinder through the protective plate at the bottom of the shell; two conveying tracks are respectively fixed to the protective plate inside the shell, and the conveying plate is connected to the conveying track through a slider, and a pressure sensor is provided on the conveying plate; the transmission system delivers the sample to the bottom of the pressure head, and the control device starts the uniaxial compression testing machine and outputs the monitoring data of the pressure head, pressure sensor, and displacement sensor; The in-situ testing method includes: after the in-situ testing device is fixed at the sampling point, the sampling surface is parallel to the in-situ testing device, the space between the layers of the double-layered sampling cylinder is filled with high-pressure gas, the sampling cylinder is extended to the sampling point by the telescopic mechanism, and the rotating shaft rotates up and down to collect the sample; after sampling, the telescopic mechanism controls the sampling cylinder to retract, and when it passes the base, the cutting blade cuts the end face of the sample; the transmission system transmits the sample to the underside of the indenter through the conveying track, performs a uniaxial compression test, and records the monitoring data. After the sampling tube takes a sample, it enters the shell to release the high-pressure gas between the two layers of the sampling tube's double-layer structure.

2. The method for sampling and in-situ testing of the mechanical properties of water-rich soft rock according to claim 1, characterized in that, The monitoring data analysis yielded the uniaxial compressive strength, elastic modulus, and Poisson's ratio of the rock.

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