A true triaxial impact loading device

Abstract

This invention discloses a true triaxial impact loading device, relating to the technical field of rock fracturing test equipment. It includes a frame, with a true triaxial loading device at the bottom and an impact loading device at the top, and a top plate. The true triaxial loading device includes a base, a loading cylinder, a hollow cylinder, a transition weight, and a second crossbeam. The base is located at the bottom of the frame, and the specimen is placed on the base. The impact loading device includes a column, a first crossbeam, a telescopic column, an energy storage spring, an energy storage control cylinder, a first electromagnet, a second electromagnet, a weight, and a lifting cylinder. The true triaxial impact loading device provided by this invention, by setting the true triaxial loading device and the impact loading device to apply static load and impact load to the specimen respectively, achieves the experimental purpose of dynamic and static synchronous loading on the same coal and rock mass, and has the advantages of flexible control and convenient operation.

Description

Technical Field

[0001] The invention relates to the technical field of rock fracturing test equipment, and in particular to a true triaxial impact loading device. Background Art

[0002] With the reduction of shallow coal resources and the continuous increase in mining depth, most mines have entered the deep mining state, and the mining depth of some mines exceeds 1500m. In deep mining, the rock mass is in a complex mechanical environment of "three highs and one disturbance", and the pressure law of the mine is significantly different from that of the shallow part. Among them, coal rock dynamic disasters represented by rock burst have brought new challenges to the safe mining of mines. The frequency and intensity of rock burst under deep mining conditions are much higher than those of shallow mining, and the casualties and economic losses caused also show the characteristics of major malignant accidents, so it must attract people's attention and attention.

[0003] At present, the laboratory mainly conducts experiments on dynamic mechanical testing machines. In static mechanical experiments, MTS material mechanical testing machines are usually used. This testing machine can complete static mechanical tests, normal temperature and pressure tests, high temperature and high pressure tests, and destructive mechanical tests. In terms of dynamic load experimental equipment, drop hammers, light gas guns, and Hopkins pressure bars have been developed successively. However, all of the above can only carry out single static load or dynamic load experiments. In reality, the cause of rock burst is mostly due to the combined action of dynamic and static loads, which leads to the instability and destruction of coal and rock masses. For this reason, it is urgent to study and invent a true triaxial impact loading device to simulate the stress environment characteristics and evolution process when coal and rock dynamic disasters occur, so as to provide a basis for the study of rock burst mechanism. Summary of the invention

[0004] The main purpose of the present invention is to provide a true triaxial impact loading device to solve the problem that there are currently only single-acting impact loading devices and true triaxial loading devices.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A true triaxial impact loading device comprises a frame, wherein the lower part of the frame is provided with a true triaxial loading device, the upper part of the frame is provided with an impact loading device, and the top part is provided with a top plate;

[0007] The true triaxial loading device comprises a base, a loading cylinder, a hollow cylinder, a transition weight and a second cross beam. The base is arranged at the bottom of the frame, and the test piece is placed on the base. The loading cylinder is arranged on the inner wall of the frame, and a first pressure head is arranged at the end thereof and is located around the test piece. The bottom of the hollow cylinder is located above the test piece, and the top is arranged at the bottom of the second cross beam. The second cross beam is arranged on the inner wall of the frame, and an opening is arranged in the middle of the second cross beam. The transition weight is arranged inside the hollow cylinder, and the top passes through the opening of the second cross beam, and a second pressure head is arranged at the bottom thereof.

[0008] The impact loading device includes a column, a first beam, a telescopic column, an energy storage spring, an energy storage control cylinder, a first electromagnet, a second electromagnet, a heavy hammer and a lifting cylinder. The column is arranged between the top plate and the second beam, the first beam is slidably arranged on the column, the telescopic column is arranged between the top plate and the first beam, the energy storage spring is sleeved on the telescopic column, the energy storage control cylinder is arranged at the bottom of the top plate, the first electromagnet is arranged at the bottom of the energy storage control cylinder, the second electromagnet is arranged at the top of the first beam and corresponds to the first electromagnet, the heavy hammer is arranged at the bottom of the first beam, a third pressure head is arranged at the end, and the lifting cylinder is arranged at the top of the second beam.

[0009] Furthermore, it also includes a monitoring system, which includes a load sensor, a displacement sensor and a load-displacement integrated sensor. The load sensor is arranged between the weight and the third pressure head, the displacement sensor is arranged between the first beam and the second electromagnet, and the load-displacement integrated sensor is arranged between the loading cylinder and the first pressure head, and between the transition weight and the second pressure head.

[0010] Furthermore, the number of the columns, energy storage control cylinders and lifting cylinders are two each, the energy storage control cylinders and lifting cylinders are located inside the two columns, the telescopic column is located in the middle position inside the two energy storage control cylinders, and the weight is located in the middle position inside the two lifting cylinders.

[0011] Furthermore, a shock-absorbing spring is sleeved at the lower part of the column, a protective pad is provided on the top of the shock-absorbing spring, and the bottom is in contact with the second crossbeam.

[0012] Furthermore, the distance between the upper end surface of the protection pad and the second crossbeam is greater than the maximum impact displacement of the first crossbeam.

[0013] Furthermore, it also includes a control system, and the monitoring system, energy storage control cylinder, loading cylinder, first electromagnet, second electromagnet and lifting cylinder are all connected to the control system.

[0014] A test method of a true triaxial impact loading device comprises the following steps:

[0015] S1. Determine the compression deformation of the energy storage spring according to the stiffness coefficient and the designed elastic energy value of the energy storage spring, and determine the stroke of the energy storage control cylinder and the lifting cylinder through the compression deformation.

[0016] S2, open the lifting cylinder to raise the height of the first beam, compress the energy storage spring to deform it to obtain elastic deformation energy, connect the first electromagnet and the second electromagnet, so that the second electromagnet on the first beam is connected to the first electromagnet at the bottom of the top plate, thereby fixing the first beam, and obtain the compression deformation of the energy storage spring through the displacement sensor, and then restore the lifting cylinder to the initial position,

[0017] S3. Place the test piece on the base, apply horizontal static load to the test piece through four loading cylinders, and the load-displacement integrated sensor records the displacement and load data. At the same time, the transition weight is controlled by the hollow cylinder to apply static load to the upper surface of the test piece.

[0018] S4. After the loading cylinder loads the specimen to the set load, the first electromagnet and the second electromagnet are powered off. At this time, the first beam moves downward, and the first beam drives the weight to impact the transition weight. The transition weight impacts the specimen, and the specimen is damaged by the impact.

[0019] S5. The loading cylinder stops loading, the test piece is depressurized, and the monitored data is stored. The size of the static load and impact load on the test piece and the process of destruction are obtained by processing the collected data.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] By setting up a true triaxial loading device and an impact loading device to apply static load and impact load to the specimen respectively, and completing the static load and dynamic load experiments at the same time, the test purpose of dynamic and static synchronous loading of the same coal rock mass is achieved. It has the advantages of flexible control and easy operation, and can better simulate the stress environment characteristics and evolution process when coal rock dynamic disasters occur, thereby providing a basis for the study of rock burst mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the structure of the present invention.

[0023] Figure 2 It is a horizontal cross-sectional view of the true triaxial loading device of the present invention.

[0024] Among them, 1-energy storage spring, 2-energy storage control cylinder, 3-first electromagnet, 4-weight, 5-third pressure head, 6-load sensor, 7-lifting cylinder, 8-transition weight, 9-test piece, 10-base, 11-telescopic column, 12-frame, 13-column, 14-displacement sensor, 15-first beam, 16-protective pad, 17-shock-absorbing spring, 18-second beam, 19-hollow cylinder, 20-load-displacement integrated sensor, 21-loading cylinder, 22-second pressure head. DETAILED DESCRIPTION

[0025] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0026] Example 1

[0027] Combination Figure 1 to Figure 2 The present invention provides a true triaxial impact loading device, comprising a frame 12, wherein the frame 12 is provided with a true triaxial loading device at the lower part, an impact loading device at the upper part, and a top plate installed at the top;

[0028] The true triaxial loading device comprises a base 10, a loading cylinder 21, a hollow cylinder 19, a transition weight 8 and a second beam 18. The base 10 is arranged at the bottom of the frame 12, and the specimen 9 is placed on the base 10. The loading cylinder 21 is arranged on the inner wall of the frame 12, and a first pressure head is arranged at the end and is located around the specimen 9. The bottom of the hollow cylinder 19 is located above the specimen 9, and the top is arranged at the bottom of the second beam 18. The second beam 18 is arranged on the inner wall of the frame 12, and an opening is arranged in the middle of the second beam 18. The transition weight 8 is arranged inside the hollow cylinder, and the top passes through the opening of the second beam 18, and the bottom is provided with a second pressure head 22. In this embodiment, there are four loading cylinders 21, and the four horizontal surfaces of the specimen 9 are statically loaded by the loading cylinders 21, and the surface on the top of the specimen 9 is statically loaded by the transition weight 8 controlled by the hollow cylinder 19. The true triaxial loading device can simulate the real stress state of rock stored underground. Since the actual engineering rock mass has a complex stress state underground and there are great differences between the three principal stresses, the true triaxial loading device can better restore the actual stress state of underground coal rock, and can apply principal stresses and impact disturbances in different directions to the coal rock, which is helpful to better study the stress and failure laws of coal rock in the real geographical environment.

[0029] The impact loading device includes a column 13, a first beam 15, a telescopic column 11, an energy storage spring 1, an energy storage control cylinder 2, a first electromagnet 3, a second electromagnet, a heavy hammer 4 and a lifting cylinder 7. The column 13 is arranged between the top plate and the second beam 18, the first beam 15 is slidably arranged on the column 13, the telescopic column 11 is arranged between the top plate and the first beam 15, the energy storage spring 1 is sleeved on the telescopic column 11, the energy storage control cylinder 2 is arranged at the bottom of the top plate, the first electromagnet 3 is arranged at the bottom of the energy storage control cylinder 2, the second electromagnet is arranged at the top of the first beam 15 and is arranged corresponding to the first electromagnet 3, the heavy hammer 4 is arranged at the bottom of the first beam 15, and a third pressure head 5 is provided at the end, and the lifting cylinder 7 is arranged at the top of the second beam 18. In this embodiment, the impact loading device can apply a dynamic load to the specimen 9. When in use, the lifting cylinder 7 is lifted to make the first beam 15 move upward, compressing the energy storage spring 1 on the telescopic column 11 until the second electromagnet on the first beam 15 is attracted and connected with the first electromagnet 3 at the bottom of the energy storage control cylinder 2, so that the first beam 15 is fixedly connected to the top plate, and then the lifting cylinder 7 retracts and descends to the initial position; when it is necessary to apply a dynamic load to the specimen 9, the second electromagnet and the first electromagnet 3 are powered off, so that the first beam 15 is disconnected from the top plate, at which time the first beam 15 will move downward rapidly, and the weight 4 on the top of the first beam 15 will impact the transition weight 8, so that the transition weight 8 impacts the specimen, completing the application of the dynamic load.

[0030] The coal and rock in the mine are not only subjected to the pressure of the upper roof, but also to the disturbance of different degrees such as roof fracture and artificial blasting. It is necessary to study the failure characteristics of coal and rock under dynamic and static combined loading. An impact loading device is designed to apply impact disturbance to coal and rock on the basis of static load loading. The experimental method is used to explore the failure characteristics of coal and rock under combined loading, and provide data support for the prevention and control of rock burst.

[0031] Preferably, it also includes a monitoring system and a control system, wherein the monitoring system includes a load sensor 6, a displacement sensor 14 and a load-displacement integrated sensor 20, wherein the load sensor 6 is arranged between the weight 4 and the third pressure head 5, and is used to measure the dynamic load applied by the weight 4; the displacement sensor 14 is arranged between the first crossbeam 15 and the second electromagnet, and is used to measure the compression deformation of the energy storage spring 1; the load-displacement integrated sensor 20 is arranged between the loading cylinder 21 and the first pressure head, and between the transition weight 8 and the second pressure head 22, and is used to measure the load and displacement. In this embodiment, the monitoring system, the energy storage control cylinder 2, the loading cylinder 21, the first electromagnet, the second electromagnet and the lifting cylinder 7 are all connected to the control system, and the control system is a controller, which stores and processes the data transmitted by the monitoring system, and performs opening and closing control on the energy storage control cylinder 2, the loading cylinder 21, the first electromagnet, the second electromagnet and the lifting cylinder 7.

[0032] Preferably, the number of the columns 13, the energy storage control cylinder 2 and the lifting cylinder 7 are two each, the energy storage control cylinder 2 and the lifting cylinder 7 are located on the inner sides of the two columns 13, the telescopic column 11 is located in the middle position inside the two energy storage control cylinders 2, and the weight 4 is located in the middle position inside the two lifting cylinders 7.

[0033] Preferably, a shock absorbing spring 17 is sleeved at the lower part of the column 13, a protective pad 16 is provided on the top of the shock absorbing spring 17, and the bottom is in contact with the second cross beam 18. The shock absorbing spring 17 can buffer and reduce the weight of the suddenly descending first cross beam 15, and the protective pad 16 can protect the shock absorbing spring 17.

[0034] Preferably, the distance between the upper end surface of the protection pad 16 and the second cross beam 18 is greater than the maximum impact displacement of the first cross beam 15 .

[0035] Example 2

[0036] A test method of a true triaxial impact loading device comprises the following steps:

[0037] S1. Determine the compression deformation of the energy storage spring 1 according to the stiffness coefficient and the designed elastic energy value of the energy storage spring 1, and determine the stroke of the energy storage control cylinder 2 and the lifting cylinder 7 according to the compression deformation.

[0038] S2, turn on the lifting cylinder 7 to raise the height of the first beam 15, compress the energy storage spring 1 to deform it to obtain elastic deformation energy, turn on the first electromagnet and the second electromagnet, so that the second electromagnet on the first beam 15 is connected to the first electromagnet at the bottom of the top plate, thereby fixing the first beam 15, and obtain the compression deformation of the energy storage spring 1 through the displacement sensor 14, and then restore the lifting cylinder 7 to the initial position,

[0039] S3. Place the test piece on the base 10, apply horizontal static load to the test piece through four loading cylinders 21, and the load-displacement integrated sensor 20 records the data of displacement and load. At the same time, the transition weight 8 is controlled by the hollow cylinder 19 to apply static load to the upper surface of the test piece.

[0040] S4. After the loading cylinder 21 loads the specimen to the set load, the first electromagnet and the second electromagnet are powered off. At this time, the first crossbeam 15 moves downward, and the first crossbeam 15 drives the weight 4 to impact the transition weight 8. The transition weight 8 impacts the specimen, and the specimen is damaged by the impact.

[0041] S5. The loading cylinder 21 stops loading, the test piece is depressurized, and the monitored data is stored. The size of the static load and impact load on the test piece and the process of destruction are obtained by processing the collected data.

[0042] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any slight modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A true triaxial impact loading device, characterized in that: It comprises a frame, wherein a true triaxial loading device is provided at the lower part of the frame, an impact loading device is provided at the upper part, and a top plate is installed at the top; The true triaxial loading device comprises a base, a loading cylinder, a hollow cylinder, a transition weight and a second cross beam. The base is arranged at the bottom of the frame, and the test piece is placed on the base. The loading cylinder is arranged on the inner wall of the frame, and a first pressure head is arranged at the end thereof and is located around the test piece. The bottom of the hollow cylinder is located above the test piece, and the top is arranged at the bottom of the second cross beam. The second cross beam is arranged on the inner wall of the frame, and an opening is arranged in the middle of the second cross beam. The transition weight is arranged inside the hollow cylinder, and the top passes through the opening of the second cross beam, and a second pressure head is arranged at the bottom thereof. The impact loading device includes a column, a first beam, a telescopic column, an energy storage spring, an energy storage control cylinder, a first electromagnet, a second electromagnet, a heavy hammer and a lifting cylinder, wherein the column is arranged between the top plate and the second beam, the first beam is slidably arranged on the column, the telescopic column is arranged between the top plate and the first beam, the energy storage spring is sleeved on the telescopic column, the energy storage control cylinder is arranged at the bottom of the top plate, the first electromagnet is arranged at the bottom of the energy storage control cylinder, the second electromagnet is arranged at the top of the first beam and is arranged corresponding to the first electromagnet, the heavy hammer is arranged at the bottom of the first beam, a third pressure head is arranged at the end, and the lifting cylinder is arranged at the top of the second beam; It also includes a monitoring system, which includes a load sensor, a displacement sensor and a load-displacement integrated sensor. The load sensor is arranged between the weight and the third pressure head, the displacement sensor is arranged between the first beam and the second electromagnet, and the load-displacement integrated sensor is arranged between the loading cylinder and the first pressure head, and between the transition weight and the second pressure head.

2. A true triaxial impact loading device as claimed in claim 1, characterized in that: The number of the columns, energy storage control cylinders and lifting cylinders are all two. The energy storage control cylinders and lifting cylinders are located on the inner sides of the two columns. The telescopic column is located in the middle position of the inner sides of the two energy storage control cylinders. The heavy hammer is located in the middle position of the inner sides of the two lifting cylinders.

3. A true triaxial impact loading device as claimed in claim 1, characterized in that: A shock absorbing spring is sleeved at the lower part of the column, a protective pad is arranged on the top of the shock absorbing spring, and the bottom is in contact with the second cross beam.

4. A true triaxial impact loading device as claimed in claim 3, characterized in that: The distance between the upper end surface of the protection pad and the second crossbeam is greater than the maximum impact displacement of the first crossbeam.

5. A true triaxial impact loading device as claimed in claim 1, characterized in that: It also includes a control system, and the monitoring system, the energy storage control cylinder, the loading cylinder, the first electromagnet, the second electromagnet and the lifting cylinder are all connected to the control system.

6. A test method of a true triaxial impact loading device, using the true triaxial impact loading device as claimed in claim 1, characterized in that: The following steps are involved: S1. Determine the compression deformation of the energy storage spring according to the stiffness coefficient and the designed elastic energy value of the energy storage spring, and determine the stroke of the energy storage control cylinder and the lifting cylinder through the compression deformation. S2, open the lifting cylinder to raise the height of the first beam, compress the energy storage spring to deform it to obtain elastic deformation energy, connect the first electromagnet and the second electromagnet, so that the second electromagnet on the first beam is connected to the first electromagnet at the bottom of the top plate, thereby fixing the first beam, and obtain the compression deformation of the energy storage spring through the displacement sensor, and then restore the lifting cylinder to the initial position, S3. Place the test piece on the base, apply horizontal static load to the test piece through four loading cylinders, and the load-displacement integrated sensor records the displacement and load data. At the same time, the transition weight is controlled by the hollow cylinder to apply static load to the upper surface of the test piece. S4. After the loading cylinder loads the specimen to the set load, the first electromagnet and the second electromagnet are powered off. At this time, the first beam moves downward, and the first beam drives the weight to impact the transition weight. The transition weight impacts the specimen, and the specimen is damaged by the impact. S5. The loading cylinder stops loading, the test piece is depressurized, and the monitored data is stored. The size of the static load and impact load on the test piece and the process of destruction are obtained by processing the collected data.

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