Temperature-confining pressure-tension-torsion coupling anchor cable testing machine and testing method

Abstract

The invention relates to a temperature-confining pressure-tension-torsion coupling anchor cable testing machine and a testing method.The testing machine comprises a base and a door frame installed on the base, an environment simulation assembly is arranged on the lower side of the door frame and comprises a temperature control barrel and a confining pressure barrel, and the confining pressure barrel is arranged in the temperature control barrel and used for applying pressure to a surrounding rock test piece; the temperature control barrel is connected with a temperature control assembly, the confining pressure barrel is connected with a confining pressure control assembly, a connecting plate is arranged on the upper side of the portal frame, the connecting plate and the portal frame are connected through a stretching oil cylinder, a torsion motor is installed on the connecting plate, and the output end of the torsion motor is connected with an anchorage device. A reliable test means is provided for researching the mechanical property and the working mechanism of the anchor cable under the temperature-confining pressure-tension-torsion coupling effect, the test environment simulated by the test better conforms to the actual engineering situation, and the complex stress situation of the anchor cable in the actual engineering can be truly simulated; and mechanical properties, deformation characteristics, failure modes and the like of an anchor cable anchoring system are studied.

Description

Technical Field

[0001] The invention relates to the technical field of civil engineering tests, and in particular to a temperature-confining pressure-tension-torsion coupling anchor cable testing machine and a testing method. Background Art

[0003] In the fields of deep geotechnical engineering, underground engineering, mining engineering, etc., anchor cables are widely used as an important supporting component. The actual working environment of anchor cables is complex, and is subject to the coupling effects of multiple factors such as temperature, confining pressure, tension, torque, etc. Traditional anchor cable testing machines can only conduct single or partial coupling test studies on factors such as tension and torque, and cannot truly simulate the complex stress environment faced by anchor cables in actual engineering. This leads to inaccurate evaluation of the anchoring performance of anchor cables, which is difficult to meet engineering design and actual application requirements. In view of the current research status that traditional testing machines cannot truly simulate such complex working conditions, resulting in inaccurate evaluation of the anchoring performance of anchor cables, in order to ensure the safety and reliability of the project, it is urgent to accurately test and evaluate the performance of anchor cables under complex working conditions. To this end, the present invention proposes a temperature-confining pressure-tension-torsion coupling anchor cable testing machine and test method. Summary of the invention

[0004] In view of the problem that the traditional anchor cable test machine cannot accurately simulate complex working conditions and the evaluation of anchor cable performance is inaccurate, the present invention proposes a temperature-confining pressure-tension-torsion coupling anchor cable test machine and test method. The specific technical scheme is as follows: A temperature-confining pressure-tension-torsion coupled anchor cable testing machine comprises a base and a gantry installed on the base, an environmental simulation component is arranged on the lower side of the gantry, the environmental simulation component comprises a temperature control barrel and a confining pressure barrel arranged in the temperature control barrel for applying pressure to the surrounding rock specimen, the temperature control barrel is connected to the temperature control component, the confining pressure barrel is connected to the confining pressure control component, a connecting plate is arranged on the upper side of the gantry, the connecting plate and the gantry are connected by a stretching cylinder, a torsion motor is installed on the connecting plate, and an anchor for installing an anchor cable is connected to the output end of the torsion motor.

[0005] Furthermore, the temperature control component includes a heat exchange pipeline arranged in the interlayer of the temperature control barrel and a heat exchanger connected to the heat exchange pipeline.

[0006] Furthermore, the confining pressure barrel includes a supporting shell arranged on the outside and a pressure layer made of elastic material arranged on the inside, an oil chamber is formed between the pressure layer and the supporting shell, and the oil chamber has an inlet and an outlet; the confining pressure control component includes a hydraulic pump and an oil tank, the outlet of the hydraulic pump and the inlet of the oil chamber are connected by an oil pipe, a first valve is also provided between the hydraulic pump and the oil chamber, the inlet of the hydraulic pump is connected to the oil tank, the outlet of the oil chamber is connected to the oil tank by an oil pipe, and a second valve is also provided between the oil chamber and the oil tank.

[0007] Furthermore, a supporting cylinder is provided on the lower side of the environmental simulation component.

[0008] Furthermore, a torque sensor and a torsion angle sensor are installed on the torsion motor, and a tension sensor and a displacement sensor are installed on the stretching cylinder.

[0009] Furthermore, it also includes a controller, which is communicatively connected with the torsion motor, the stretching cylinder, the temperature control device, the confining pressure control device, the torque sensor, the torsion angle sensor, the tension sensor and the displacement sensor.

[0010] The temperature-confining pressure-tension-torsion coupling anchor cable test method uses the above-mentioned temperature-confining pressure-tension-torsion coupling anchor cable test machine to conduct a coupling test on the anchor cable, including the following steps: S1. Prepare surrounding rock specimens with anchor cables and place them in a confining pressure barrel, fix the anchor cables on the anchors, and set the test temperature, relay confining pressure, test confining pressure, tensile parameters, and torsion parameters; S2. Start the temperature control component to make the temperature in the temperature control barrel reach the test temperature and keep it stable for a certain period of time; S3, start the confining pressure control component, apply confining pressure to the surrounding rock specimen to the relay confining pressure and keep it stable for a certain period of time, and then continue to pressurize to the test confining pressure and keep it stable for a certain period of time; S4. Control the stretching cylinder and torsion motor to perform tests and record test data.

[0011] Furthermore, the set time for the temperature to remain stable is 1-2 hours, the set time for the relay confining pressure to remain stable is 30 minutes, and the set time for the test confining pressure to remain stable is 1 hour.

[0012] The beneficial effects of the present invention are: It can truly simulate the complex stress conditions of anchor cables in actual engineering projects, and provide a reliable test method for studying the mechanical properties and working mechanism of anchor cables under the coupling of temperature, confining pressure, tension and torsion. The test environment simulated by the test is more in line with the actual engineering conditions, and can more accurately study the mechanical properties, deformation characteristics, failure modes, etc. of the anchor cable anchoring system, providing reliable technical support for the design, construction and engineering application of anchor cable anchoring projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0014] Figure 1It is a structural schematic diagram of the temperature-confining pressure-tension-torsion coupling anchor cable testing machine of the present invention; Figure 2 is a cross-sectional view of the environmental simulation component of the present invention.

[0015] In the figure: 1. base; 2. gantry; 3. hydraulic pump; 4. heat exchanger; 5. tension cylinder; 6. anchor; 7. anchor cable; 8. temperature control barrel; 9. first valve; 10. heat exchange pipeline; 11. surrounding rock specimen; 12. support shell; 13. pressure layer; 14. oil chamber; 15. support cylinder; 16. controller; 17. connecting plate; 18. torsion motor; 19. oil tank. DETAILED DESCRIPTION

[0016] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0017] The present invention provides the following specific embodiments: First, as Figure 1-2 As shown, the present invention provides a temperature-confining pressure-tension-torsion coupled anchor cable testing machine, comprising a base 1 and a gantry 2 installed on the base 1, an environmental simulation component for simulating a temperature environment and a confining pressure environment is arranged at the lower side of the gantry 2, the environmental simulation component comprises a temperature control barrel 8 and a confining pressure barrel arranged in the temperature control barrel 8 for applying pressure to a surrounding rock specimen 11, the temperature control barrel 8 is connected to the temperature control component, the confining pressure barrel is connected to the confining pressure control component, a connecting plate 17 is arranged on the upper side of the gantry 2, the connecting plate 17 and the gantry 2 are connected by a tension cylinder 5, a torsion motor 18 is installed on the connecting plate 17, an anchor 6 for installing an anchor cable 7 is connected to the output end of the torsion motor 18, the torsion motor 18 applies torque to the anchor cable 7 through the anchor 6, and the tension cylinder 5 applies tension to the anchor cable 7 through the torsion motor 18 and the anchor 6.

[0018] Furthermore, the temperature control component includes a heat exchange pipe 10 disposed in the interlayer of the temperature control barrel 8 and a heat exchanger 4 connected to the heat exchange pipe 10, and the heat exchanger 4 controls the temperature by inputting cold water, ultra-low temperature liquid nitrogen or hot water into the heat exchange pipe 10. In addition, the temperature control component can also use electromagnetic eddy current to regulate the temperature in the temperature control barrel 8.

[0019] Furthermore, the confining pressure barrel includes a support shell 12 arranged on the outside and a pressure layer 13 made of elastic material arranged on the inside, an oil chamber 14 is formed between the pressure layer 13 and the support shell 12, and the oil chamber 14 has an inlet and an outlet; the confining pressure control assembly includes a hydraulic pump 3 and an oil tank 19, the outlet of the hydraulic pump 3 is connected to the inlet of the oil chamber 14 through an oil pipe, a first valve 9 is also provided between the hydraulic pump 3 and the oil chamber 14, the inlet of the hydraulic pump 3 is connected to the oil tank 19, the outlet of the oil chamber 14 is connected to the oil tank 19 through an oil pipe, and a second valve is also provided between the oil chamber 14 and the oil tank 19. By injecting hydraulic oil into the oil chamber 14, the pressure layer 13 is deformed and squeezed to apply pressure to the confining pressure.

[0020] Furthermore, a supporting cylinder 15 is provided on the lower side of the environmental simulation component, and the supporting cylinder 15 is used to push the confining pressure to the test position before the test.

[0021] Furthermore, a torsion angle sensor and a torque sensor are installed on the torsion motor 18, and a torsion angle sensor, a torque sensor, a tension sensor and a displacement sensor are installed on the stretching cylinder 5 to measure the torsion angle, torque, tension and displacement of the anchor cable 7 during the test. A temperature sensor is also installed in the temperature control barrel 8.

[0022] Furthermore, it also includes a controller 16, which is respectively communicatively connected with the torsion motor 18, the stretching cylinder 5, the temperature control device, the temperature sensor, the torque sensor, the torsion angle sensor, the tension sensor, the displacement sensor and the confining pressure control device.

[0023] In a second aspect, the present invention provides a temperature-confining pressure-tension-torsion coupling anchor cable test method, which uses the above-mentioned temperature-confining pressure-tension-torsion coupling anchor cable test machine to perform a coupling test on the anchor cable 7, comprising the following steps: S1. According to the test requirements, suitable anchor cable materials and surrounding rock materials are selected to make surrounding rock specimens 11. The size and shape of the specimens are processed according to the research needs, and the surface of the anchor cable 7 is pre-treated by grinding to facilitate the installation of strain gauges and displacement sensors. The surrounding rock specimen 11 anchored with the anchor cable 7 is placed in the confining pressure barrel of the environmental simulation component, and the upper end of the surrounding rock specimen 11 protrudes from the confining pressure barrel. The supporting oil cylinder 15 is started to push the upper plane of the surrounding rock specimen 11 to contact with the portal frame 2, and the anchor cable 7 is fixed to the anchor 6 when the anchor cable 7 is straightened. Set temperature parameters, including test temperature, temperature change rate, etc. For example, to simulate seasonal temperature changes in underground projects or the impact of some extreme environments on anchor cables, the test temperature can be set between -50℃ and +80℃, and the temperature change rate can be set to 5℃ / hour; Set the confining pressure parameters, such as the intermediate confining pressure, confining pressure loading rate, and test confining pressure. If simulating a deep geotechnical engineering environment, the intermediate confining pressure can be set to 15 MPa, increasing to a final confining pressure of 30 MPa at a certain loading rate (such as 0.5 MPa / minute); Set the tensile and torsion loading parameters: For tensile loading tests, set the maximum tensile force, tensile force loading rate, etc. For example, the tensile force loading rate is set to 10kN / min, the maximum tensile force is set to 500kN, and the load is from 0kN to 500kN. For torsion loading tests, set the maximum torque, torque loading rate, etc. For example, the torque loading rate is set to 500N・m / min, the maximum torque is 2000N・m, and the load is from 0N・m to 2000N・m. For coupling tests, set the corresponding tensile and torsion loading parameters according to the coupling ratio, such as a tension-torsion ratio of 2:1.

[0024] S2, start the temperature control component, make the temperature in the temperature control barrel 8 reach the set value and keep it stable for a certain period of time, so that the temperature of the surrounding rock specimen 11 is stably distributed; in this embodiment, the temperature is kept stable for 1-2 hours, and the specific time can be set according to the test requirements. S3, start the confining pressure control component, open the first valve 9, close the second valve, apply confining pressure to the surrounding rock specimen 11 until the relay confining pressure value, that is, the hydraulic oil pressure in the oil chamber 14 reaches the relay value and remains stable for a certain period of time, and then continue to pressurize to the set confining pressure value, that is, the hydraulic oil pressure in the oil chamber 14 reaches the set value and remains stable for a certain period of time, and observe the state of the surrounding rock specimen 11 under the combined action of the set confining pressure and the set temperature; in this embodiment, the relay confining pressure remains stable for 30 minutes, and the test confining pressure remains stable for 1 hour. The specific duration can be set according to the test requirements. S4. Conduct the test: For the tensile loading test, start the tensile cylinder 5, and load the tensile force according to the set tensile loading rate. During the loading process, collect the strain, displacement, force and other measurement data in real time, and observe the deformation and damage of the specimen until the specimen is damaged or the set maximum tensile force is reached. For the torsion loading test, start the torsion motor 18 and collect relevant data. In the coupling test, start the tensile cylinder 5 and the torsion motor 18 at the same time, load according to the set tension-torsion coupling parameters, pay close attention to the test data and the state of the specimen, conduct the test and record the test data.

[0025] After the test, the first valve 9 is closed and the second valve is opened, and the hydraulic oil in the oil chamber returns to the oil tank.

[0026] Finally, the various collected data (temperature, confining pressure, tensile force, torque, torsion angle, strain, displacement, etc.) are stored and displayed in real time by computer, so as to timely analyze the phenomena and results during the test.

[0027] For example, based on the collected strain data, the strain-time curve, strain-load curve, etc. are drawn to analyze the strain variation law of the anchor cable specimen under the coupling of temperature-confining pressure-tension-torsion. For another example, the growth trend of tensile and torsional strains and their mutual influence relationship under different temperature and confining pressure conditions can be observed.

[0028] Through displacement data, the overall deformation of the specimen is analyzed, including axial elongation, radial contraction or expansion, etc., and the relationship between deformation and various loading parameters is studied. Combined with force and torque data, the mechanical performance parameters such as strength and stiffness of the anchor cable are calculated, and the influence of temperature and confining pressure on the tensile and torsion mechanical properties of the anchor cable is evaluated. For example, the changes in the ultimate tensile strength, yield torque and other parameters of the anchor cable under different temperatures and confining pressures are compared.

[0029] Observe the failure morphology of the specimens, such as whether untwisting, necking, fracture, shear failure, torsion failure, torsion-shear failure, etc. occur, and analyze the correlation between the failure mode and the temperature-confining pressure-tension-torsion coupled loading conditions, to provide a theoretical basis for the design and application of anchor cables in complex engineering environments.

[0030] The temperature-confining pressure-tension-torsion coupling anchor cable tester and test method proposed in the present invention can truly simulate the complex stress conditions of the anchor cable 7 in actual engineering, and provide a reliable test method for studying the mechanical properties and working mechanism of the anchor cable 7 under the temperature-confining pressure-tension-torsion coupling. The test environment simulated by the test is more in line with the actual engineering situation, and the mechanical properties, deformation characteristics, failure mode, etc. of the anchor cable anchoring system can be studied more accurately, providing a reliable theoretical basis for the design, construction and engineering application of the anchor cable anchoring project.

[0031] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. Temperature-confining pressure-tension-torsion coupling anchor cable testing machine, characterized by: The invention comprises a base (1) and a gantry (2) mounted on the base (1); an environmental simulation component is arranged on the lower side of the gantry (2); the environmental simulation component comprises a temperature control barrel (8) and a confining pressure barrel arranged in the temperature control barrel (8) for applying pressure to a surrounding rock specimen (11); the temperature control barrel (8) is connected to the temperature control component; the confining pressure barrel is connected to the confining pressure control component; a connecting plate (17) is arranged on the upper side of the gantry (2); the connecting plate (17) and the gantry (2) are connected via a tension cylinder (5); a torsion motor (18) is mounted on the connecting plate (17); an output end of the torsion motor (18) is connected to an anchor (6) for mounting an anchor cable (7).

2. The temperature-confining pressure-tension-torsion coupled anchor cable testing machine according to claim 1, characterized in that: The temperature control component comprises a heat exchange pipeline (10) arranged in the interlayer of the temperature control barrel (8) and a heat exchanger (4) connected to the heat exchange pipeline (10).

3. The temperature-confining pressure-tension-torsion coupled anchor cable testing machine according to claim 1, characterized in that: The confining pressure barrel comprises a support shell (12) arranged on the outside and a pressure layer (13) made of elastic material arranged on the inside, an oil chamber (14) is formed between the pressure layer (13) and the support shell (12), and the oil chamber (14) has an inlet and an outlet; the confining pressure control component comprises a hydraulic pump (3) and an oil tank (19), the outlet of the hydraulic pump (3) and the inlet of the oil chamber (14) are connected via an oil pipe, a first valve (9) is further provided between the hydraulic pump (3) and the oil chamber (14), the inlet of the hydraulic pump (3) is connected to the oil tank (19), the outlet of the oil chamber (14) and the oil tank (19) are connected via an oil pipe, and a second valve is further provided between the oil chamber (14) and the oil tank (19).

4. The temperature-confining pressure-tension-torsion coupled anchor cable testing machine according to claim 1, characterized in that: A supporting oil cylinder (15) is also provided on the lower side of the environmental simulation component.

5. The temperature-confining pressure-tension-torsion coupled anchor cable testing machine according to claim 1, characterized in that: A torque sensor and a torsion angle sensor are mounted on the torsion motor (18), and a tension sensor and a displacement sensor are mounted on the stretching cylinder (5).

6. The temperature-confining pressure-tension-torsion coupled anchor cable testing machine according to claim 5, characterized in that: It also includes a controller (16), which is communicatively connected to the torsion motor (18), the stretching cylinder (5), the temperature control device, the confining pressure control device, the torque sensor, the torsion angle sensor, the tension sensor, and the displacement sensor.

7. A temperature-confining pressure-tension-torsion coupling anchor cable test method, using a temperature-confining pressure-tension-torsion coupling anchor cable test machine as claimed in any one of claims 1 to 6 to perform a coupling test on an anchor cable (7), characterized in that: The following steps are included: S1. Prepare a surrounding rock specimen (11) anchored with an anchor cable (7) and place the surrounding rock specimen (11) in a confining pressure barrel, fix the anchor cable (7) on the anchor (6), and set the test temperature, relay confining pressure, test confining pressure, tensile parameters, and torsion parameters; S2, start the temperature control component to make the temperature in the temperature control barrel (8) reach the test temperature and keep it stable for a certain period of time; S3, starting the confining pressure control component, applying confining pressure to the surrounding rock specimen (11) to the relay confining pressure and keeping it stable for a certain period of time, and then continuing to pressurize to the test confining pressure and keeping it stable for a certain period of time; S4, controlling the stretching cylinder (5) and the torsion motor (18) to operate, conducting a test and recording the test data.

8. The temperature-confining pressure-tension-torsion coupled anchor cable test method according to claim 7, characterized in that: The set time for the temperature to remain stable is 1-2 hours, the set time for the relay confining pressure to remain stable is 30 minutes, and the set time for the test confining pressure to remain stable is 1 hour.

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