Rock core calibration device for stress relief method ground stress test

Abstract

The utility model provides a rock core calibration device for a stress relief method ground stress test. The rock core calibration device comprises a rock core calibration assembly, a pressurizing device and a data acquisition device, the rock core calibration assembly comprises a main pressure-bearing steel pipe, a reinforced rubber sleeve, an upper pressing cover ring and a lower fastening cover ring; the reinforcing rubber sleeve is arranged in an inner cavity of the main pressure-bearing steel pipe, the upper pressing cover ring and the lower fastening cover ring are installed at the two ends of the main pressure-bearing steel pipe in a threaded mode respectively, and meanwhile the upper pressing cover ring and the lower fastening cover ring press the two ends of the reinforcing rubber sleeve and the ends of the main pressure-bearing steel pipe. The rock core calibration device has the following advantages: (1) the rock core calibration device for the ground stress test by the stress relief method, which is simple in structure and convenient to operate, is provided; and (2) oil leakage and oil leakage of the calibration device can be effectively reduced during a test, the efficiency of mounting and dismounting operation and data acquisition is improved, and the pressure control accuracy is improved.

Description

Technical Field

[0001] This utility model belongs to the technical field of stress relief method for geostress testing in hydropower and water conservancy projects, and specifically relates to a rock core calibration device for stress relief method geostress testing. Background Technology

[0002] In stress relief testing, obtaining the elastic modulus of the rock core at the test section is necessary. There are generally two methods: one is to take core samples from near the test section, bring them back to the laboratory, and conduct rock deformation tests on a pressure testing machine to measure the elastic modulus; the other method is to directly calibrate the elastic modulus of the rock core retrieved from the borehole with a stress relief test probe in-situ. The laboratory method of obtaining the elastic modulus through core sample deformation tests will result in parameters that differ from the actual measured section because the core samples are not from the same test section. In-situ calibration of the elastic modulus using a rock core with a stress relief test probe is more accurate and efficient.

[0003] When performing core calibration on-site, a steel cylinder is typically used, with a rubber sleeve embedded inside. The rubber sleeve is sealed and secured at both ends with nearly 20 bolts. The core is then placed inside the rubber sleeve, and a hand pump is used to pressurize the sleeve from the outside to measure the core's elastic modulus. This conventional method suffers from insufficient pressure control with the hand pump, uneven pressurization rates, and a tendency to over-pressurize. Furthermore, the method of securing the rubber sleeve with dozens of bolts is cumbersome to disassemble, prone to incomplete tightening, and susceptible to oil leaks. Utility Model Content

[0004] To address the shortcomings of existing technologies, this invention provides a core calibration device for stress relief testing, which can effectively solve the aforementioned problems.

[0005] The technical solution adopted in this utility model is as follows:

[0006] This utility model provides a core calibration device for stress relief method in-situ stress testing, including: a core calibration component (600), a pressurization device and a data acquisition device;

[0007] The core calibration assembly (600) includes a main pressure-bearing steel pipe (1), a reinforcing rubber sleeve (3), an upper clamping cap ring (4), and a lower fastening cap ring (5); the reinforcing rubber sleeve (3) is installed in the inner cavity of the main pressure-bearing steel pipe (1), and the upper clamping cap ring (4) and the lower fastening cap ring (5) are threaded onto both ends of the main pressure-bearing steel pipe (1). At the same time, the upper clamping cap ring (4) and the lower fastening cap ring (5) press the two ends of the reinforcing rubber sleeve (3) against the ends of the main pressure-bearing steel pipe (1);

[0008] An oil inlet (2) is provided in the middle of the main pressure-bearing steel pipe (1), and the oil inlet (2) is connected to the pressurizing device;

[0009] A stress relief core (500) is inserted inside the reinforcing rubber sleeve (3). The stress relief core (500) contains a stress relief probe (510). The stress relief probe (510) and the pressurizing device are both connected to the data acquisition device.

[0010] Preferably, the core calibration assembly (600) further includes an upper rubber sleeve limiting cone ring (6) and a lower rubber sleeve limiting cone ring (7);

[0011] At the contact position between the top of the reinforcing rubber sleeve (3) and the bottom of the upper pressing cap ring (4), the upper rubber sleeve limiting cone ring (6) is provided;

[0012] At the contact position between the bottom of the reinforcing rubber sleeve (3) and the top of the lower fastening cap ring (5), the lower rubber sleeve limiting cone ring (7) is provided.

[0013] Preferably, the reinforcing rubber sleeve (3) adopts a straight cylindrical shape in the middle and a flared shape at both ends; the flared shape at both ends of the reinforcing rubber sleeve (3) matches the step shape inside both ends of the main pressure-bearing steel pipe (1), so that the flared mouth is pressed against the step position.

[0014] Preferably, the reinforcing rubber sleeve (3) is made of steel wire cords arranged in the longitudinal and transverse directions inside.

[0015] Preferably, the pressurization device includes a storage battery (100), an electric oil pump (200), a high-pressure pipeline (220), a pressure sensor (300), and a high-pressure shut-off valve (400);

[0016] The power supply terminal of the electric oil pump (200) is connected to the storage battery (100); the oil supply terminal of the electric oil pump (200) is connected to the oil inlet terminal of the high-pressure pipeline (220); the oil outlet terminal of the high-pressure pipeline (220) is sealed to the oil inlet (2); the pressure sensor (300) is installed in the high-pressure pipeline (220); and the high-pressure shut-off valve (400) is installed in the high-pressure pipeline (220) near the oil inlet (2).

[0017] Preferably, the pressurizing device further includes a pressure gauge (210); the pressure gauge (210) is installed at the oil supply end of the electric oil pump (200).

[0018] Preferably, the data acquisition device includes a digital strain recorder (800) and a laptop computer (900);

[0019] The input terminal of the digital strain recorder (800) is connected to the stress relief probe (510) via a second data line (520); the output terminal of the digital strain recorder (800) is connected to the laptop computer (900) via a third data line (810).

[0020] The laptop (900) is also connected to the pressure sensor (300) via a first data cable (310).

[0021] Preferably, the main pressure-bearing steel pipe (1) has an exhaust port (2.1) on the side away from the oil inlet (2); the exhaust port (2.1) is connected to the exhaust pipe and the high-pressure valve (700).

[0022] The core calibration device for stress relief method in-situ stress testing provided by this utility model has the following advantages:

[0023] (1) A stress relief method core calibration device is provided, which is simple in structure and easy to operate. (2) It can effectively reduce oil leakage and runoff of the calibration device during the test, improve the efficiency of installation and disassembly operations and data acquisition, and improve the accuracy of pressure control. Attached Figure Description

[0024] Figure 1 An overall structural diagram of a rock core calibration device for stress relief method in-situ stress testing provided by this utility model;

[0025] Figure 2 A cross-sectional view of the calibration component provided by this utility model.

[0026] in:

[0027] 1-Main pressure-bearing steel pipe; 2-Oil inlet; 2.1-Exhaust port; 3-Reinforced rubber sleeve; 4-Upper clamping cap ring; 5-Lower fastening cap ring; 6-Upper rubber sleeve limiting cone ring; 7-Lower rubber sleeve limiting cone ring; 100-Battery; 200-Electric oil pump; 210-Pressure gauge; 220-High-pressure pipeline; 300-Pressure sensor; 310-First data line; 400-High-pressure shut-off valve; 500-Core release; 510-Stress relief probe; 520-Second data line; 600-Core calibration assembly; 700-Exhaust pipeline and high-pressure valve; 800-Digital strain recorder; 810-Third data line; 900-Laptop computer. Detailed Implementation

[0028] To make the technical problems solved, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0029] This utility model is applicable to the field of in-situ measurement technology for engineering geology in hydropower, water conservancy, transportation, mining and other fields. In particular, it relates to stress relief method for geostress testing in hydropower and water conservancy projects. It can effectively reduce oil leakage and runoff in the core calibration device during the test, improve the efficiency of installation and disassembly operations and data acquisition, and enhance the accuracy of pressure control. It is a core calibration device for stress relief method geostress testing with simple structure and convenient operation.

[0030] See Figure 1 and Figure 2 This utility model provides a core calibration device for stress relief method in-situ stress testing, including: core calibration component 600, pressurization device and data acquisition device;

[0031] The core calibration assembly 600 includes a main pressure-bearing steel pipe 1, a reinforcing rubber sleeve 3, an upper clamping cap ring 4, and a lower fastening cap ring 5. The reinforcing rubber sleeve 3 is installed in the inner cavity of the main pressure-bearing steel pipe 1. The upper clamping cap ring 4 and the lower fastening cap ring 5 are threaded on both ends of the main pressure-bearing steel pipe 1. At the same time, the upper clamping cap ring 4 and the lower fastening cap ring 5 clamp the two ends of the reinforcing rubber sleeve 3 to the ends of the main pressure-bearing steel pipe 1.

[0032] An oil inlet 2 is opened in the middle of the main pressure-bearing steel pipe 1, and the oil inlet 2 is connected to the pressurizing device. A stress relief core 500 is inserted inside the reinforcing rubber sleeve 3. The stress relief core 500 contains a stress relief probe 510. Both the stress relief probe 510 and the pressurizing device are connected to the data acquisition device. An exhaust port 2.1 is opened on the side of the main pressure-bearing steel pipe 1 away from the oil inlet 2. The exhaust port 2.1 is connected to the exhaust pipeline and the high-pressure valve 700. The exhaust port 2.1 on the main pressure-bearing steel pipe 1 can reduce pressure fluctuations caused by timing gas.

[0033] To enhance the ease of operation and sealing performance of the device, the core calibration assembly 600 also includes an upper rubber sleeve limiting cone ring 6 and a lower rubber sleeve limiting cone ring 7; the upper rubber sleeve limiting cone ring 6 is provided at the contact position between the top of the reinforcing rubber sleeve 3 and the bottom of the upper clamping cap ring 4; the lower rubber sleeve limiting cone ring 7 is provided at the contact position between the bottom of the reinforcing rubber sleeve 3 and the top of the lower fastening cap ring 5.

[0034] The reinforcing rubber sleeve 3 adopts a straight cylindrical shape in the middle and a flared shape at both ends. The flared shape at both ends of the reinforcing rubber sleeve 3 matches the step shape inside both ends of the main pressure-bearing steel pipe 1, so that the flared end is pressed against the step position, thereby improving the stability of the reinforcing rubber sleeve 3 structure.

[0035] The reinforced rubber sleeve 3 has steel wire cords installed in the longitudinal and transverse directions inside, which enhances the high pressure resistance of the reinforced rubber sleeve 3.

[0036] In this application, the core calibration component 600 is made of steel. The upper clamping cover ring 4 and the lower fastening cover ring 5 are connected to the main pressure-bearing steel pipe 1 by mechanical threads, instead of the traditional riveting with dozens of bolts, which makes disassembly convenient. At the same time, the reinforcing rubber sleeve 3 of the core calibration component 600 adopts a straight cylindrical shape in the middle and a flared shape at both ends. Rubber sleeve limiting cone rings are set between the flared ends and the upper and lower pressure plates to improve the sealing performance of the entire core calibration component and effectively prevent oil leakage.

[0037] As a specific implementation, the pressurization device includes a storage battery 100, an electric oil pump 200, a high-pressure pipeline 220, a pressure sensor 300, and a high-pressure shut-off valve 400;

[0038] The power supply terminal of the electric oil pump 200 is connected to the storage battery 100; the oil supply terminal of the electric oil pump 200 is connected to the oil inlet terminal of the high-pressure pipeline 220; the oil outlet terminal of the high-pressure pipeline 220 is sealed to the oil inlet port 2; a pressure sensor 300 is installed in the high-pressure pipeline 220; a high-pressure shut-off valve 400 is installed near the oil inlet port 2 in the high-pressure pipeline 220. The pressurization device also includes a pressure gauge 210; the pressure gauge 210 is installed at the oil supply terminal of the electric oil pump 200.

[0039] The pressurization pump is DC driven, with a maximum output pressure of 60MPa and a flow rate of 0.3L / min. The pressure increase and decrease speed is uniform, and the output pressure can be accurately controlled. The pressure sensor 300 has a measurement range of 0-60MPa and a scale value of 0.1MPa.

[0040] The data acquisition device includes a digital strain recorder 800 and a laptop computer 900; the input terminal of the digital strain recorder 800 is connected to the stress relief probe 510 via a second data line 520; the output terminal of the digital strain recorder 800 is connected to the laptop computer 900 via a third data line 810; the laptop computer 900 is also connected to the pressure sensor 300 via a first data line 310.

[0041] This utility model provides a core calibration device for stress relief testing. Its working principle is as follows: the electric oil pump 200 of the pressurization device is started, and the electric oil pump 200 applies pressure to the reinforcing rubber sleeve 3 through the high-pressure pipeline 220. The reinforcing rubber sleeve 3 deforms under stress and applies pressure to the stress relief core 500 inside it. The pressure sensor 300 and the stress relief probe 510 respectively obtain the pressure applied to the stress relief core 500 and the strain data measured by the stress relief probe 510. The elastic modulus of the core can be obtained by calculation.

[0042] This utility model has the following beneficial effects:

[0043] (1) A stress relief method core calibration device is provided, which is simple in structure and easy to operate. (2) It can effectively reduce oil leakage and runoff of the calibration device during the test, improve the efficiency of installation and disassembly operations and data acquisition, and improve the accuracy of pressure control.

[0044] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A core calibration device for stress relief testing, characterized in that, include: Core calibration assembly (600), pressurization device, and data acquisition device; The core calibration assembly (600) includes a main pressure-bearing steel pipe (1), a reinforcing rubber sleeve (3), an upper clamping cap ring (4), and a lower fastening cap ring (5); the reinforcing rubber sleeve (3) is installed in the inner cavity of the main pressure-bearing steel pipe (1), and the upper clamping cap ring (4) and the lower fastening cap ring (5) are threaded onto both ends of the main pressure-bearing steel pipe (1). At the same time, the upper clamping cap ring (4) and the lower fastening cap ring (5) press the two ends of the reinforcing rubber sleeve (3) against the ends of the main pressure-bearing steel pipe (1); An oil inlet (2) is provided in the middle of the main pressure-bearing steel pipe (1), and the oil inlet (2) is connected to the pressurizing device; A stress relief core (500) is inserted inside the reinforcing rubber sleeve (3). The stress relief core (500) contains a stress relief probe (510). The stress relief probe (510) and the pressurizing device are both connected to the data acquisition device.

2. The core calibration device for stress relief method in-situ stress testing according to claim 1, characterized in that, The core calibration assembly (600) also includes an upper rubber sleeve limiting cone ring (6) and a lower rubber sleeve limiting cone ring (7); At the contact position between the top of the reinforcing rubber sleeve (3) and the bottom of the upper pressing cap ring (4), the upper rubber sleeve limiting cone ring (6) is provided; At the contact position between the bottom of the reinforcing rubber sleeve (3) and the top of the lower fastening cap ring (5), the lower rubber sleeve limiting cone ring (7) is provided.

3. The core calibration device for stress relief method in-situ stress testing according to claim 1, characterized in that, The reinforcing rubber sleeve (3) adopts a straight cylindrical shape in the middle and a flared shape at both ends; the flared shape at both ends of the reinforcing rubber sleeve (3) matches the step shape inside both ends of the main pressure-bearing steel pipe (1), so that the flared mouth is pressed against the step position.

4. The core calibration device for stress relief method in-situ stress testing according to claim 1, characterized in that, The reinforced rubber sleeve (3) is made of steel wire cords arranged in the longitudinal and transverse directions inside.

5. A core calibration device for stress relief method in-situ stress testing according to claim 1, characterized in that, The pressurization device includes a storage battery (100), an electric oil pump (200), a high-pressure pipeline (220), a pressure sensor (300), and a high-pressure shut-off valve (400); The power supply terminal of the electric oil pump (200) is connected to the storage battery (100); the oil supply terminal of the electric oil pump (200) is connected to the oil inlet terminal of the high-pressure pipeline (220); the oil outlet terminal of the high-pressure pipeline (220) is sealed to the oil inlet (2); the pressure sensor (300) is installed in the high-pressure pipeline (220); and the high-pressure shut-off valve (400) is installed in the high-pressure pipeline (220) near the oil inlet (2).

6. A core calibration device for stress relief method in-situ stress testing according to claim 5, characterized in that, The pressurization device also includes a pressure gauge (210); the pressure gauge (210) is installed at the oil supply end of the electric oil pump (200).

7. A core calibration device for stress relief method in-situ stress testing according to claim 5, characterized in that, The data acquisition device includes a digital strain recorder (800) and a laptop computer (900); The input terminal of the digital strain recorder (800) is connected to the stress relief probe (510) via a second data line (520); the output terminal of the digital strain recorder (800) is connected to the laptop computer (900) via a third data line (810). The laptop (900) is also connected to the pressure sensor (300) via a first data cable (310).

8. A core calibration device for stress relief method in-situ stress testing according to claim 1, characterized in that, The main pressure-bearing steel pipe (1) has an exhaust port (2.1) on the side away from the oil inlet (2); the exhaust port (2.1) is connected to the exhaust pipe and the high-pressure valve (700).

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