A rock expansion and degradation characteristics testing device with controllable saturation pressure

Abstract

The present invention discloses a rock expansion and degradation characteristic testing device with controllable saturated pressure, comprising a saturated container, a reaction force clamping mechanism, a water injection mechanism, an expansion detection mechanism and a degradation characteristic testing mechanism, wherein the saturated container has a closed saturated chamber, the saturated chamber is used to place a rock sample, and when the rock sample is placed in the saturated chamber, the reaction force clamping mechanism is pressed on the rock sample. The beneficial effect of the technical solution proposed by the present invention is: water is injected into the saturated chamber by the water injection mechanism and the water pressure in the saturated chamber is maintained at a preset pressure value, so that the rock sample in the saturated chamber is under the set water pressure condition, the position of the rock sample is kept stable by the reaction force clamping mechanism, the expansion rate of the rock sample under the set water pressure condition is detected by the expansion detection mechanism, and the degradation degree of the rock sample under the set water pressure condition is detected by the degradation characteristic testing mechanism, thereby providing data support for the study of rock expansion and degradation laws of high dam foundation rock mass.

Description

Technical Field

[0001] The invention relates to the technical field of rock physical property testing equipment, and in particular to a rock expansion and degradation characteristic testing device with controllable saturation pressure. Background Art

[0002] Rock degradation caused by water-rock interaction is a common inducing factor in water conservancy engineering accidents. At present, the research on the law of rock degradation under water-rock interaction mainly relies on indoor rock mechanics tests, which simulate the actual water-rock environment of engineering rock mass by carrying out dry-wet cycle treatment on rock samples under water conditions.

[0003] With the commissioning of many 300-meter-high dams and reservoirs in my country, the water-rock interaction law of the dam foundation rock mass under high water pressure and high stress environment is a topic of common concern in engineering safety and hydraulic rock mechanics research. At present, indoor rock mechanics tests are carried out without applying water pressure to the rock samples, which makes it difficult to simulate the expansion and property degradation process of the high dam foundation rock mass under high water pressure conditions, and thus it is difficult to analyze the rock expansion and degradation law of the high dam foundation rock mass. Summary of the invention

[0004] In view of this, it is necessary to provide a rock expansion and degradation characteristics testing device with controllable saturation pressure to solve the technical problem that the existing indoor rock mechanics testing equipment is difficult to simulate the expansion and property degradation process of the high dam foundation rock mass under high water pressure conditions, and thus difficult to analyze the rock expansion and degradation laws of the high dam foundation rock mass.

[0005] In order to achieve the above-mentioned objectives, the present invention provides a rock expansion and degradation characteristics testing device with controllable saturated pressure, comprising a saturated container, a reaction force pressing mechanism, a water injection mechanism, an expansion detection mechanism and a degradation characteristics testing mechanism, wherein the saturated container has a closed saturated chamber, the saturated chamber is used to place the rock sample, when the rock sample is placed in the saturated chamber, the reaction force pressing mechanism is pressed on the rock sample, the water injection mechanism injects water into the saturated chamber and keeps the water pressure in the saturated chamber at a preset pressure value, the expansion detection mechanism detects the expansion rate of the rock sample, and the degradation characteristics testing mechanism detects the degree of degradation of the rock sample.

[0006] Preferably, the expansion detection mechanism includes a horizontal expansion rate detection component and a vertical expansion rate detection component, the horizontal expansion rate detection component is connected to the rock sample and used to detect the horizontal expansion rate of the rock sample, and the vertical expansion rate detection component is connected to the rock sample and used to detect the vertical expansion rate of the rock sample.

[0007] Preferably, the horizontal expansion rate detection assembly comprises at least one horizontal displacement sensor, and a sensing rod of the horizontal displacement sensor abuts against a side wall of the rock sample.

[0008] Preferably, the vertical expansion rate detection assembly comprises a pad and a vertical displacement sensor, the pad is clamped between the rock sample and the reaction force pressing mechanism, and the sensing rod of the vertical displacement sensor abuts against the pad.

[0009] Preferably, the degradation characteristic testing mechanism comprises two ultrasonic transducers, and the two ultrasonic transducers are respectively attached to two ends of the rock sample.

[0010] Preferably, the water-saturated container includes a water-saturated container body and a cover plate, the cover plate is detachably and sealingly connected to the water-saturated container body, and a clearance hole connected to the water-saturated chamber is opened on the cover plate; the reaction force clamping mechanism includes a column, a fastener, a cross beam and a force transmission rod, the column is fixed to the bottom plate of the water-saturated container, the cross beam is fixed to the column via the fastener, one end of the force transmission rod is fixedly connected to the cross beam, and the other end of the force transmission rod passes through the clearance hole and is pressed onto the pad.

[0011] Preferably, the reaction force pressing mechanism further includes a pressure sensor, which is clamped between the cross beam and the force transmission rod and is used to detect the vertical pressure applied to the rock sample.

[0012] Preferably, the reaction force pressing mechanism further includes a first sealing ring, which is sleeved on the force transmission rod and fits against the inner wall of the clearance hole.

[0013] Preferably, the water injection mechanism includes a vacuum tube, a vacuum pump, a water injection tube, a water tank, a pressure tube and a water pressure servo loader, one end of the vacuum tube is connected to the water-saturated chamber, the other end of the vacuum tube is connected to the outlet of the vacuum pump, the vacuum tube is provided with a vacuum valve, one end of the water injection tube is connected to the water-saturated chamber, the other end of the water injection tube is connected to the water tank, the water injection tube is provided with a water injection valve, one end of the pressure tube is connected to the water-saturated chamber, the other end of the pressure tube is connected to the outlet of the water pressure servo loader, and the pressure tube is provided with a pressure valve.

[0014] Preferably, an exhaust hole communicating with the saturated water chamber is provided on the cover plate, and an exhaust valve for controlling the opening or closing of the exhaust hole is provided in the exhaust hole.

[0015] Compared with the prior art, the technical solution proposed in the present invention has the following beneficial effects: water is injected into the saturated chamber through a water injection mechanism and the water pressure in the saturated chamber is maintained at a preset pressure value, so that the rock sample in the saturated chamber is under the set water pressure condition, the position of the rock sample is kept stable through a reaction force clamping mechanism, the expansion rate of the rock sample under the set water pressure condition is detected by an expansion detection mechanism, and the degree of degradation of the rock sample under the set water pressure condition is detected by a degradation characteristic testing mechanism, thereby providing data support for the study of rock expansion and degradation laws of the high dam foundation rock mass. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of an embodiment of a rock expansion and degradation characteristics testing device with controllable saturation pressure provided by the present invention;

[0017] Figure 2 yes Figure 1 A schematic diagram of the structure of the reaction force pressing mechanism, the expansion detection mechanism and the degradation characteristic testing mechanism;

[0018] Figure 3 yes Figure 1 A schematic diagram of the structure of the water injection mechanism;

[0019] Figure 4 yes Figure 1 A top view of the water-saturated container and the reaction force clamping mechanism;

[0020] In the figure: 1-water-saturated container, 2-rock sample, 3-reaction force clamping mechanism, 4-water injection mechanism, 5-expansion detection mechanism, 6-degradation characteristic testing mechanism, 7-processor, 8-display, 11-water-saturated container body, 12-cover plate, 121-exhaust valve, 13-plate buckle, 14-second sealing ring, 31-column, 32-fastener, 321-bolt, 322-nut, 33-crossbeam, 34-force transmission rod, 35-pressure Sensor, 36-first sealing ring, 41-vacuum tube, 42-vacuum pump, 43-water injection pipe, 44-water tank, 45-pressure tube, 46-hydraulic servo loader, 47-vacuum valve, 48-water injection valve, 49-pressure valve, 51-horizontal expansion rate detection component, 511-horizontal displacement sensor, 52-vertical expansion rate detection component, 521-pad, 522-vertical displacement sensor, 61-ultrasonic transducer. DETAILED DESCRIPTION

[0021] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0022] Please refer to Figure 1 , Figure 1The present invention is a schematic structural diagram of an embodiment of a rock expansibility and degradation characteristics testing device with controllable saturated pressure provided by the present invention, wherein the rock expansibility and degradation characteristics testing device with controllable saturated pressure comprises a saturated container 1, a reaction force pressing mechanism 3, a water injection mechanism 4, an expansibility detection mechanism 5 and a degradation characteristics testing mechanism 6, wherein the saturated container 1 has a closed saturated chamber, the saturated chamber is used to place a rock sample 2, when the rock sample 2 is placed in the saturated chamber, the reaction force pressing mechanism 3 is pressed on the rock sample 2, the water injection mechanism 4 injects water into the saturated chamber and keeps the water pressure in the saturated chamber at a preset pressure value, the expansibility detection mechanism 5 detects the expansion rate of the rock sample 2, and the degradation characteristics testing mechanism 6 detects the degree of degradation of the rock sample 2.

[0023] During the experiment, the rock sample 2 is first placed in the water-saturated container 1, and then pressed on the rock sample 2 by the reaction force pressing mechanism 3, and then water is injected into the water-saturated container 1 by the water injection mechanism 4 to keep the water pressure in the water-saturated container 1 at a preset pressure value, and then the expansion rate of the rock sample 2 is detected by the expansion detection mechanism 5 at the set time interval, and the degradation degree of the rock sample 2 is detected by the degradation characteristic testing mechanism 6, so as to provide data support for the study of rock expansion and degradation laws of the high dam foundation rock mass.

[0024] The beneficial effects of the present invention are as follows: water is injected into the saturated chamber through the water injection mechanism 4 and the water pressure in the saturated chamber is maintained at a preset pressure value, so that the rock sample 2 in the saturated chamber is under the set water pressure condition, the position of the rock sample 2 is kept stable through the reaction force clamping mechanism 3, the expansion rate of the rock sample 2 under the set water pressure condition is detected by the expansion detection mechanism 5, and the degradation degree of the rock sample 2 under the set water pressure condition is detected by the degradation characteristic testing mechanism 6, thereby providing data support for the study of rock expansion and degradation laws of the high dam foundation rock mass.

[0025] In order to conduct a comprehensive test of the expansion process of rock sample 2 under the set water pressure conditions, please refer to Figure 1 and Figure 2 In a preferred embodiment, the expansion detection mechanism 5 includes a horizontal expansion rate detection component 51 and a vertical expansion rate detection component 52. The horizontal expansion rate detection component 51 is connected to the rock sample 2 and is used to detect the horizontal expansion rate of the rock sample 2. The vertical expansion rate detection component 52 is connected to the rock sample 2 and is used to detect the vertical expansion rate of the rock sample 2.

[0026] In order to specifically implement the function of the horizontal expansion rate detection component 51, please refer to Figure 1 and Figure 2In a preferred embodiment, the horizontal expansion rate detection component 51 includes at least one horizontal displacement sensor 511, and the sensing rod of the horizontal displacement sensor 511 abuts against the side wall of the rock sample 2. In this embodiment, there are four horizontal displacement sensors 511, which abut against the four side walls of the rock sample 2 respectively, so that the expansion amount of the rock sample 2 in the four side wall directions can be detected.

[0027] To specifically implement the function of the vertical expansion rate detection component 52, please refer to Figure 1 and Figure 2 In a preferred embodiment, the vertical expansion rate detection component 52 includes a pad 521 and a vertical displacement sensor 522. The pad 521 is clamped between the rock sample 2 and the reaction force clamping mechanism 3. The sensing rod of the vertical displacement sensor 522 is in contact with the pad 521. When the rock sample 2 expands vertically, the pad 521 rises, and the displacement of the pad 521 is equal to the vertical expansion amount of the rock sample 2. Therefore, the vertical expansion amount of the rock sample 2 can be determined by detecting the displacement of the pad 521 through the vertical displacement sensor 522.

[0028] To specifically implement the function of the degradation characteristic test mechanism 6, please refer to Figure 1 and Figure 2 In a preferred embodiment, the degradation characteristic testing mechanism 6 includes two ultrasonic transducers 61, and the two ultrasonic transducers 61 are respectively attached to the two ends of the rock sample 2. In this embodiment, the two ultrasonic transducers 61 are both transceivers, one of which transmits ultrasonic waves to the rock sample 2, and the other ultrasonic transducer 61 receives the ultrasonic waves, so that the longitudinal wave velocity of the rock sample 2 under the set water pressure condition can be tested, and the degradation degree of the rock sample 2 can be characterized by the attenuation of the longitudinal wave velocity.

[0029] In order to realize the function of the reaction force clamping mechanism 3, please refer to Figure 1 , Figure 2 and Figure 4In a preferred embodiment, the water-saturated container 1 includes a water-saturated container body 11 and a cover plate 12, and the cover plate 12 is detachably and hermetically connected to the water-saturated container body 11. In this embodiment, the cover plate 12 is detachably connected to the water-saturated container body 11 through a plate buckle 13, and a clearance hole communicating with the water-saturated chamber is opened on the cover plate 12; the reaction force clamping mechanism 3 includes a column 31, a fastener 32, a beam 33 and a force transmission rod 34, the column 31 is fixed to the bottom plate of the water-saturated container 1, the beam 33 is fixed to the column 31 via the fastener 32, one end of the force transmission rod 34 is fixedly connected to the beam 33, and the other end of the force transmission rod 34 passes through the clearance hole and is pressed onto the pad 521. In this embodiment, the fastener 32 includes a bolt 321 and a nut 322, wherein the bolt 321 is fixed to the column 31, the bolt 321 passes through the beam 33, and the nut 322 is threadedly connected to the bolt 321, thereby fixing the beam 33 to the bolt 321. By adjusting the tightness of the nut 322, the pressure applied by the force transmission rod 34 to the rock sample 2 can be adjusted, thereby simulating the actual stress condition of the dam foundation rock.

[0030] To measure the pressure value applied by the force transmission rod 34 on the rock sample 2, please refer to Figure 1 and Figure 2 In a preferred embodiment, the reaction force clamping mechanism 3 further includes a pressure sensor 35 , which is sandwiched between the cross beam 33 and the force transmission rod 34 and is used to detect the vertical pressure applied to the rock sample 2 .

[0031] To improve the sealing effect of the saturated container 1, please refer to Figure 1 and Figure 2 In a preferred embodiment, the reaction force clamping mechanism 3 also includes a first sealing ring 36, which is sleeved on the force transmission rod 34. The first sealing ring 36 fits the inner wall of the clearance hole. The first sealing ring 36 can achieve a sealed connection between the force transmission rod 34 and the clearance hole, thereby improving the sealing effect of the saturated container 1 and providing the necessary conditions for high water pressure in the saturated chamber.

[0032] In order to realize the function of the water injection mechanism 4, please refer to Figure 1 and Figure 3In a preferred embodiment, the water injection mechanism 4 includes a vacuum tube 41, a vacuum pump 42, a water injection tube 43, a water tank 44, a pressure tube 45 and a water pressure servo loader 46, one end of the vacuum tube 41 is connected to the water-saturated chamber, the other end of the vacuum tube 41 is connected to the outlet of the vacuum pump 42, a vacuum valve 47 is provided on the vacuum tube 41, one end of the water injection tube 43 is connected to the water-saturated chamber, the other end of the water injection tube 43 is connected to the water tank 44, a water injection valve 48 is provided on the water injection tube 43, one end of the pressure tube 45 is connected to the water-saturated chamber, the other end of the pressure tube 45 is connected to the outlet of the water pressure servo loader 46, and a pressure valve 49 is provided on the pressure tube 45.

[0033] To facilitate the discharge of gas from the saturated cavity, please refer to Figure 1 and Figure 2 In a preferred embodiment, the cover plate 12 is provided with an exhaust hole connected to the saturated water chamber, and the exhaust hole is provided with an exhaust valve 121 for controlling the opening or closing of the exhaust hole.

[0034] In order to realize the sealing connection between the water-saturated container body 11 and the cover plate 12, please refer to Figure 1 and Figure 2 In a preferred embodiment, a second sealing ring 14 is provided at the connection between the water-saturated container body 11 and the cover plate 12 .

[0035] In order to facilitate the automatic control of this device, please refer to Figure 1 In a preferred embodiment, the rock expansion and degradation characteristics testing device with controllable saturation pressure also includes a processor 7 and a display 8. The processor 7 is communicatively connected with the display 8, the pressure sensor 35, the vacuum pump 42, the water pressure servo loader 46, the vacuum valve 47, the water injection valve 48, the pressure valve 49, the horizontal displacement sensor 511, the vertical displacement sensor 522 and the ultrasonic transducer 61, so as to facilitate the control of each component through the processor 7.

[0036] In order to better understand the present invention, the following Figure 1-Figure 4 The working process of the rock expansion and degradation characteristics testing device with controllable saturation pressure provided by the present invention is described in detail:

[0037] (1) A cylindrical rock sample 2 is placed at the center of a water-saturated container body 11, and ultrasonic transducers 61 are placed above and below the rock sample 2;

[0038] (2) placing a pad 521 on the upper ultrasonic transducer 61, making the sensing rod of the horizontal displacement sensor 511 directly contact the side wall of the rock sample 2, and making the sensing rod of the vertical displacement sensor 522 contact the pad 521;

[0039] (3) Place the cover plate 12 and tighten the plate buckle 13. Pass the force transmission rod 34 through the clearance hole of the cover plate 12 to contact the pad 521 on the top of the rock sample 2. Then install the crossbeam 33. By adjusting the tightness of the nut 322 on the bolt 321, a certain contact force is applied to the rock sample 2.

[0040] (4) Close the exhaust valve 121 on the cover plate 12, close the pressure valve 49 and the water injection valve 48, open the vacuum valve 47 and the vacuum pump 42, and evacuate the water-saturated container 1 for 4 hours;

[0041] (5) After the vacuuming is completed, the vacuuming valve 47 and the vacuum pump 42 are closed, and the water injection valve 48 is opened to allow the water in the water tank 44 to be sucked into the saturated water container 1;

[0042] (6) After the water level in the saturated container 1 is above the rock sample 2, the water injection valve 48 is closed, the exhaust valve 121 is opened, the pressure valve 49 is opened, and the hydraulic servo loader 46 is turned on. The hydraulic servo loader 46 is driven by displacement drive to continue adding water to the saturated container 1 until water is discharged from the exhaust valve 121. Then, the water addition is stopped and the exhaust valve 121 is closed;

[0043] (7) Using a pressure control method to drive the water pressure servo loader 46, so that the water-saturated container 1 is loaded to a preset water pressure and the water pressure is kept stable;

[0044] (8) recording the free expansion deformation value of the rock sample 2 under the preset water pressure condition, and displaying the measured values ​​of each displacement sensor on the display 8 in real time;

[0045] (9) transmitting and receiving ultrasonic waves through two ultrasonic transducers 61, testing the longitudinal wave velocity of the rock sample 2 under a preset water pressure condition, and characterizing the degree of degradation of the rock sample 2 through the attenuation of the longitudinal wave velocity;

[0046] (10) Initially, record the displacement value and longitudinal wave velocity value every 10 minutes. When the difference between three consecutive displacement readings is less than 0.001mm, change to reading once every hour. When the difference between three consecutive readings is less than 0.001mm, it can be considered stable. The total test time of pressurized immersion shall not be less than 48 hours.

[0047] The device can also be used to perform side limit and expansion pressure tests under preset water pressure conditions. The specific method is to place the sample in a metal sleeve with water-permeable holes on the side wall of the metal sleeve. The test process refers to existing conventional tests.

[0048] The technical solution provided by the present invention has the beneficial effects of simulating the water pressure environment of the dam foundation rock mass under the condition of reservoir water changes, placing the rock sample in a water pressure change environment, and being able to test the lateral deformation and expansion pressure of the sample in a water pressure change environment. Specifically, water is injected into the saturated chamber by the water injection mechanism 4 and the water pressure in the saturated chamber is maintained at a preset pressure value, so that the rock sample 2 in the saturated chamber is under the set water pressure condition, the position of the rock sample 2 is kept stable by the reaction force clamping mechanism 3, the expansion rate of the rock sample 2 under the set water pressure condition is detected by the expansion detection mechanism 5, and the degradation degree of the rock sample 2 under the set water pressure condition is detected by the degradation characteristic testing mechanism 6, thereby providing data support for the study of rock expansion and degradation laws of the high dam foundation rock mass.

[0049] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A rock expansion and degradation characteristics testing device with controllable saturation pressure, characterized in that: It comprises a water-saturated container, a reaction force pressing mechanism, a water injection mechanism, an expansion detection mechanism and a degradation characteristic testing mechanism, wherein the water-saturated container has a closed water-saturated chamber, the water-saturated chamber is used to place a rock sample, when the rock sample is placed in the water-saturated chamber, the reaction force pressing mechanism is pressed on the rock sample, the water injection mechanism injects water into the water-saturated chamber and keeps the water pressure in the water-saturated chamber at a preset pressure value, the expansion detection mechanism detects the expansion rate of the rock sample, and the degradation characteristic testing mechanism detects the degree of degradation of the rock sample; The expansion detection mechanism includes a horizontal expansion rate detection component and a vertical expansion rate detection component, the horizontal expansion rate detection component is connected to the rock sample and used to detect the horizontal expansion rate of the rock sample, and the vertical expansion rate detection component is connected to the rock sample and used to detect the vertical expansion rate of the rock sample; The horizontal expansion rate detection assembly includes at least one horizontal displacement sensor, and the sensing rod of the horizontal displacement sensor abuts against the side wall of the rock sample; The vertical expansion rate detection assembly includes a pad and a vertical displacement sensor, the pad is clamped between the rock sample and the reaction force pressing mechanism, and the sensing rod of the vertical displacement sensor abuts against the pad; The water injection mechanism includes a vacuum tube, a vacuum pump, a water injection tube, a water tank, a pressure tube and a water pressure servo loader, one end of the vacuum tube is connected to the water-saturated chamber, the other end of the vacuum tube is connected to the outlet of the vacuum pump, and a vacuum valve is provided on the vacuum tube, one end of the water injection tube is connected to the water-saturated chamber, the other end of the water injection tube is connected to the water tank, and a water injection valve is provided on the water injection tube, one end of the pressure tube is connected to the water-saturated chamber, the other end of the pressure tube is connected to the outlet of the water pressure servo loader, and a pressure valve is provided on the pressure tube.

2. The rock expansion and degradation characteristics testing device with controllable saturation pressure according to claim 1 is characterized in that: The degradation characteristic testing mechanism comprises two ultrasonic transducers, and the two ultrasonic transducers are respectively attached to two ends of the rock sample.

3. The rock expansion and degradation characteristics testing device with controllable saturation pressure according to claim 1 is characterized in that: The water-saturated container comprises a water-saturated container body and a cover plate, wherein the cover plate is detachably and sealedly connected to the water-saturated container body, and a clearance hole communicating with the water-saturated cavity is provided on the cover plate; The reaction force clamping mechanism includes a column, a fastener, a cross beam and a force transmission rod. The column is fixed to the bottom plate of the water-saturated container, the cross beam is fixed to the column via the fastener, one end of the force transmission rod is fixedly connected to the cross beam, and the other end of the force transmission rod passes through the clearance hole and is pressed onto the pad.

4. The rock expansion and degradation characteristics testing device with controllable saturation pressure according to claim 3 is characterized in that: The reaction force pressing mechanism also includes a pressure sensor, which is clamped between the crossbeam and the force transmission rod and is used to detect the vertical pressure applied to the rock sample.

5. The rock expansion and degradation characteristics testing device with controllable saturation pressure according to claim 3 is characterized in that: The reaction force pressing mechanism also includes a first sealing ring, which is sleeved on the force transmission rod and fits the inner side wall of the clearance hole.

6. The rock expansion and degradation characteristics testing device with controllable saturation pressure according to claim 3 is characterized in that: The cover plate is provided with an exhaust hole connected with the saturated water cavity, and the exhaust hole is provided with an exhaust valve for controlling the opening or closing of the exhaust hole.

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