An in-situ measurement device and test method for the dynamic load impact resistance performance of an anchor body

Abstract

The present invention relates to an in-situ measurement device and test method for the dynamic load impact resistance of an anchor body, and belongs to the technical field of anchor support technology test in mine tunnels. The device includes a launcher, a launch head, a guide rod, a base, a shell, a high-pressure gas cylinder, a pressure sensor, a data acquisition device and a data processing device, wherein the shell is a hollow cylinder, a base is provided at one end of the shell, a pressure sensor is provided in the base, a guide rod is provided on the base, a launch head is provided on the guide rod, a launcher is provided above the launch head, a high-pressure gas cylinder is externally connected to the launcher, the launcher and the pressure sensor are both connected to the data acquisition device, and the data acquisition device is connected to the data processing device. The present invention is easy to install, has strong practicality and operability, applies dynamic load to the anchor rod through the high-pressure gas cylinder and the launcher, and the load is stable and reliable, and the size is adjustable, so as to realize the test of the impact resistance of the anchor rod and the surrounding rock under the action of dynamic load under field conditions.

Description

Technical Field

[0001] The invention relates to an in-situ measuring device and a testing method for the dynamic load impact resistance performance of an anchor body, and belongs to the technical field of mining tunnel anchor support technology testing. Background Art

[0002] In recent years, with the increase in the depth of coal mining, the anchor support structure of the tunnel not only bears large static loads, but also is frequently disturbed by dynamic loads. Under the influence of this strong disturbance and high stress environment, the failure of anchor support has become more and more prominent, and the roof accidents caused by it have become an important issue affecting the safe production of coal mines.

[0003] In order to explore the mechanism of action of dynamic load on anchor rods, a lot of research has been conducted in the prior art, and corresponding test equipment and research methods have been developed. For example, Chinese patent document CN102621013B discloses a dynamic performance test system, which uses a clamping device to fix the top of the specimen and uses the effect of a drop hammer to test the dynamic performance of the anchor rod; Chinese patent document CN103134725B discloses an anchor rod performance test device, which fixes one end of the anchor rod and uses a weight plate and a static hydraulic device to test the impact resistance and static performance of the anchor rod respectively; Chinese patent document CN107084893A discloses a dynamic load test device for jointed rock anchors, in which the anchors and steel pipes are fixed by grouting, a hollow drop weight is released onto an impact plate by a power loading device, and the load generated by the hollow drop weight is collected by a load collection device; Chinese patent document CN107761788B discloses an experimental device suitable for anchor cyclic tensile and dynamic load tensile testing, in which an anchor system consisting of an anchor and a steel pipe is fixed between upper and lower pressure plates, and a tensile test of the anchor system is achieved by converting the compression load into the tensile load.

[0004] However, the above patent has defects such as complex operation, small test range and poor practicality, and cannot accurately reflect the impact resistance of anchor rods in field applications and cannot meet the testing requirements. Therefore, the present invention is proposed. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides an in-situ measurement device for the dynamic load impact resistance of an anchor body, which is easy to install and has strong practicality and operability. Dynamic loads are applied to the anchor rod through a high-pressure gas cylinder and a launching device, and the load is stable and reliable, and the size is adjustable, thereby realizing the test of the impact resistance of the anchor rod and surrounding rock under dynamic loads under field conditions.

[0006] The present invention also provides a testing method for the above-mentioned in-situ measurement device for the dynamic load impact resistance performance of the anchor body.

[0007] The technical solution of the present invention is as follows:

[0008] An in-situ measuring device for the dynamic load impact resistance of an anchor body comprises a launching device, a launching head, a guide rod, a base, a shell, a high-pressure gas cylinder, a pressure sensor, a data acquisition device and a data processing device, wherein:

[0009] The shell is a hollow cylinder, with a base at one end, a pressure sensor in the base, a guide rod on the base, a launch head on the guide rod, a launch device above the launch head, a high-pressure gas cylinder externally connected to the launch device, the launch device and the pressure sensor are connected to a data acquisition device, and the data acquisition device is connected to a data processing device. Nitrogen is filled in the high-pressure gas cylinder.

[0010] Preferably, the launching device comprises an annular tube, a first launcher and a second launcher, wherein the first launcher and the second launcher are symmetrically arranged in the annular tube, the first launcher and the second launcher have the same structure, and an air inlet is arranged on the annular tube.

[0011] Further preferably, a partition is provided in the first launcher, and the partition divides the first launcher into two upper and lower chambers. A pressure regulating piston is provided in the first launcher, and the piston rod of the pressure regulating piston passes through the partition. The disc of the pressure regulating piston is placed in the chamber above the partition. The chamber above the disc is the first air chamber, and the first air inlet is provided on the side wall of the first air chamber, and the first air outlet is provided on the top of the first air chamber. The first air outlet is directly connected to the outside world, and no air outlet is provided on the ring tube. The chamber below the disc is the second air chamber, and the second air inlet and the second air outlet are provided on the side wall of the second air chamber. The inner diameter of the second air chamber is smaller than that of the first air chamber. The chamber below the partition is the third air chamber, and the third air inlet is provided on the side wall of the third air chamber. A launch chamber is provided at the bottom of the third air chamber, and the inner diameter of the launch chamber is the same as the diameter of the piston rod of the pressure regulating piston. The first air inlet, the first air outlet, the second air inlet, the second air outlet, and the third air inlet are all provided with air intake valves to control the entry of gas.

[0012] Preferably, a pressure valve group is provided between the launching device and the high-pressure gas cylinder, and the pressure valve group includes a pressure gauge and a valve.

[0013] Preferably, a laser speed meter is provided on the shell, and the laser speed meter is connected to a data acquisition device, so that the initial release velocity of the transmitter head is obtained through the laser speed meter.

[0014] Preferably, the emission head is cylindrical, and the diameter of the emission head is the same as the inner diameter of the shell.

[0015] Preferably, a connecting head is provided at the top of the guide rod, and the guide rod is connected to the anchor rod through the connecting head.

[0016] Further preferably, the connecting head is cylindrical, a thread is arranged inside the connecting head, a thread is arranged on the guide rod, the connecting head is connected to the guide rod and the anchor rod through an internal thread, and the bottom of the guide rod is connected to the base through a thread.

[0017] The test method of the above-mentioned in-situ measurement device for the dynamic load impact resistance of the anchor body has the following operating steps:

[0018] (1) Remove the nut of the anchor to be tested to expose the hanging end of the anchor. Use the connector to connect the hanging end of the anchor to the upper end of the guide rod. Install the launcher on the anchor above the connector. Put the launcher head on the guide rod. Connect the launcher head and the launcher through the anchor. Then install the shell and base. Connect the launcher to the high-pressure gas cylinder.

[0019] (2) Open the high-pressure gas cylinder and input the gas pressure value (e.g. 1 MPa). The gas in the high-pressure gas cylinder enters the launch device, the launch device starts, and the launch chamber releases gas instantly, pushing the launch head below to run. The launch head acquires an initial velocity and hits the base;

[0020] (3) If the initial velocity given by the input air pressure value is too large (such as 1 MPa), the base hit by the transmitter drives the anchor rod to move downward. The input air pressure value is reduced (such as 0.9 MPa, 0.8 MPa, etc.), and step (2) is repeated until the critical air pressure value for the impact resistance of the anchor rod is obtained. On the contrary, if the input air pressure value is too small, the position of the anchor rod remains unchanged. The input air pressure value is increased, and step (2) is repeated until the anchor rod is pulled and the critical air pressure value for the impact resistance of the anchor rod is obtained.

[0021] Preferably, in step (2), the starting process of the transmitting device is as follows:

[0022] a. The first air inlet is opened, and the high-pressure gas enters the first air chamber, pushing the pressure regulating piston to move to the lowest end, and then the first air inlet is closed;

[0023] b. The second air inlet is opened, and the high-pressure gas enters the second air cavity. The air pressure of the first air cavity is the same as that of the second air cavity, and the inner diameter of the second air cavity is smaller than that of the first air cavity. Therefore, the air flow pushes the pressure regulating piston upward. When the gas does not enter the second air cavity, the second air inlet is closed;

[0024] c. The third air inlet is opened, and the high-pressure gas enters the third air cavity. When the gas does not enter the third air cavity, the third air inlet is closed;

[0025] d. Open the first air outlet, the air pressure in the first air chamber suddenly drops, the pressure regulating piston quickly moves to the top of the first air chamber, the piston rod of the pressure regulating piston moves out of the launch chamber, the high-pressure gas is released instantly, pushing the launch head downward and hitting the base;

[0026] e. Open the second air outlet to release the gas in the second air cavity, and the launch is completed.

[0027] The beneficial effects of the present invention are:

[0028] 1. The present invention is easy to install, has strong practicality and operability, applies dynamic load to the anchor rod through a high-pressure gas cylinder and a launching device, and the load is stable and reliable, and the size is adjustable, so as to realize the test of the impact resistance of the anchor rod and the surrounding rock under the action of dynamic load under field conditions.

[0029] 2. The present invention can connect anchor rods of different models to the device by replacing connecting heads of different models, thereby applying dynamic loads to anchor rods of different models and angles.

[0030] 3. The present invention can measure the impact resistance of anchor rods under dynamic loads under field conditions, and can well simulate the destructive characteristics of anchor bodies under dynamic loads under deep mining conditions. It is easy to operate and highly practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of the present invention;

[0032] Figure 2 It is a top view schematic diagram of the launch device of the present invention;

[0033] Figure 3 It is a schematic side cross-sectional view of the launch device of the present invention;

[0034] Figure 4 is a schematic structural diagram of a first transmitter of the present invention;

[0035] Figure 5 It is a schematic diagram of the application of the present invention.

[0036] Among them: 1. anchor rod; 2. launching device; 3. first launcher; 4. second launcher; 5. air inlet; 6. connecting head; 7. launching head; 8. guide rod; 9. base; 10. shell; 11. laser velocimeter; 12. air inlet hose; 13. pressure valve group; 14. high-pressure gas cylinder; 15. first air cavity; 16. first air inlet; 17. first air outlet; 18. second air cavity; 19. second air inlet; 20. second air outlet; 21. third air cavity; 22. third air inlet; 23. pressure regulating piston; 24. launching cavity; 25. data acquisition device; 26. data processing device; 27. pressure sensor; 28. wire; 29. ​​partition; 30. disc; 31. overlying stratum; 32. basic top; 33. direct top; 34. coal body. DETAILED DESCRIPTION

[0037] The present invention will be further described below by way of embodiments in conjunction with the accompanying drawings, but is not limited thereto.

[0038] Embodiment 1:

[0039] like Figure 1-5As shown, this embodiment provides an in-situ measurement device for the dynamic load impact resistance of an anchor body, including a launch device 2, a launch head 7, a guide rod 8, a base 9, a shell 10, a high-pressure gas cylinder 14, a pressure sensor 27, a data acquisition device 25 and a data processing device 26, wherein:

[0040] The housing 10 is a hollow cylinder, with a base 9 at one end thereof, a pressure sensor 27 disposed in the base 9, a guide rod 8 disposed on the base 9, a launch head 7 disposed on the guide rod 8, a launch device 2 disposed above the launch head 7, the launch device 2 is externally connected to a high-pressure gas cylinder 14, the launch device 2 and the pressure sensor 27 are both connected to a data acquisition device 25, and the data acquisition device 25 is connected to a data processing device 26. The high-pressure gas cylinder is filled with nitrogen.

[0041] The launching device 2 comprises an annular tube, a first launcher 3 and a second launcher 4. The first launcher 3 and the second launcher 4 are symmetrically arranged in the annular tube. The first launcher 3 and the second launcher 4 have the same structure. An air inlet 5 is arranged on the annular tube.

[0042] The first launcher 3 is provided with a partition 29, which divides the first launcher 3 into an upper and lower cavity. The first launcher 3 is provided with a pressure regulating piston 23, the piston rod of the pressure regulating piston 23 passes through the partition 29, the disk 30 of the pressure regulating piston 23 is placed in the cavity above the partition 29, the cavity above the disk 30 is the first air cavity 15, the side wall of the first air cavity 15 is provided with a first air inlet 16, the top of the first air cavity 15 is provided with a first air outlet 17, and the first air outlet 17 is provided. It is directly connected to the outside world, and no air outlet is set on the ring tube. The cavity below the disc 30 is the second air cavity 18, and the second air inlet 19 and the second air outlet 20 are set on the side wall of the second air cavity 18. The inner diameter of the second air cavity 18 is smaller than that of the first air cavity 15. The cavity below the partition 29 is the third air cavity 21, and the third air inlet 22 is set on the side wall of the third air cavity 21. The bottom of the third air cavity 21 is provided with a firing cavity 24, and the inner diameter of the firing cavity 24 is the same as the piston rod diameter of the pressure regulating piston 23. The first air inlet, the first air outlet, the second air inlet, the second air outlet, and the third air inlet are all provided with air inlet valves to control the gas entry.

[0043] The launching device 2 is connected to the high-pressure gas cylinder 14 through an air intake hose 12, and a pressure valve group 13 is arranged on the air intake hose 12, and the pressure valve group includes a pressure gauge and a valve.

[0044] A laser velocimeter 11 is provided on the housing 10 , and the laser velocimeter is connected to a data acquisition device, and the initial release velocity of the transmitter head is obtained through the laser velocimeter.

[0045] The transmitting head 7 is cylindrical, and the diameter of the transmitting head 7 is the same as the inner diameter of the housing 10 .

[0046] A connecting head 6 is provided on the top of the guide rod 8 , and the guide rod 8 is connected to the anchor rod 1 via the connecting head 6 .

[0047] The test method of the above-mentioned in-situ measurement device for the dynamic load impact resistance of the anchor body has the following operating steps:

[0048] (1) Remove the nut of the anchor rod 1 to be tested to expose the hanging end of the anchor rod, connect the hanging end of the anchor rod 1 to the upper end of the guide rod 8 using the connecting head 6, install the launching device 2 on the anchor rod above the connecting head 6, and sleeve the launching head 7 on the guide rod 8. The launching head 7 and the launching device 2 are connected by an anchoring agent, and then the housing 10 and the base 9 are installed. The launching device 2 is externally connected to a high-pressure gas cylinder 14;

[0049] (2) Open the high-pressure gas cylinder 14 and input a gas pressure value of 1 MPa. The gas in the high-pressure gas cylinder 14 enters the launching device 2, the launching device 2 is started, and the launching chamber 24 releases gas instantly, pushing the launching head 7 below to run. The launching head 7 obtains an initial velocity and hits the base 9;

[0050] (3) If the initial velocity given by the input air pressure value is too large, the base 9 hit by the transmitter 7 drives the anchor rod to move downward, and the input air pressure value is reduced to 0.9 MPa, 0.8 MPa, and step (2) is repeated until the critical air pressure value for the impact resistance of the anchor rod is obtained. On the contrary, if the input air pressure value is too small, the position of the anchor rod remains unchanged, and the input air pressure value is increased, and step (2) is repeated until the anchor rod is pulled, and the critical air pressure value for the impact resistance of the anchor rod is obtained.

[0051] The analysis data specifically includes: ① The critical air pressure value P0 for impact resistance makes the transmitter head 7 produce an impact speed v0. The laser velocimeter 11 carried by the shell 10 is used to measure the speed v0 of the transmitter head 7, and then the initial kinetic energy E0 of the transmitter head 7 can be obtained. The energy c dissipated by the transmitter head 7 in the movement process in the shell 10 is not considered. Therefore, the sum of the initial kinetic energy E0 of the transmitter head 7 and the gravitational potential energy G is fully converted into the dynamic load impact energy E received by the anchor rod. The dynamic load impact energy E obtained here is the critical value E of the dynamic load impact resistance performance of the anchor rod, that is, it satisfies the formula: E=E0+G. ② The pressure sensor 27 and the data acquisition device 25 can monitor, record and record the impact energy changes received by the base 9 during each impact test in real time. The data processing device 26 generates different stress curves, and finally obtains the dynamic load impact energy value and damage characteristics of the anchor rod.

[0052] Embodiment 2:

[0053] An in-situ measurement device for the dynamic load impact resistance of an anchor body has a structure as described in Example 1, except that the connecting head 6 is cylindrical, a thread is provided inside the connecting head 6, a thread is provided on the guide rod 8, the connecting head 6 is connected to the guide rod 8 and the anchor rod 1 through an internal thread, and the bottom of the guide rod is connected to a base through a thread.

[0054] Embodiment 3:

[0055] A method for testing an in-situ measurement device for anti-dynamic impact performance of an anchor body as described in Example 1, except that, in step (2), the starting process of the launch device is as follows:

[0056] a. The first air inlet 16 is opened, and the high-pressure gas enters the first air chamber 15, pushing the pressure regulating piston 23 to move to the lowermost end, and then the first air inlet 16 is closed;

[0057] b. The second air inlet 19 is opened, and the high-pressure gas enters the second air cavity 18. The air pressure of the first air cavity 15 is the same as that of the second air cavity 18, and the inner diameter of the second air cavity 18 is smaller than that of the first air cavity 15. Therefore, the air flow pushes the pressure regulating piston 23 upward. When the gas does not enter the second air cavity, the second air inlet 19 is closed;

[0058] c. The third air inlet 22 is opened, and the high-pressure gas enters the third air cavity 21. When the gas does not enter the third air cavity 21, the third air inlet 22 is closed;

[0059] d. Open the first gas outlet 17, the air pressure in the first air chamber 15 drops suddenly, the pressure regulating piston 23 quickly moves to the top of the first air chamber 15, the piston rod of the pressure regulating piston 23 moves out of the launch chamber 24, and the high-pressure gas is released instantly, pushing the launch head 7 downward and hitting the base 9;

[0060] e. Open the second gas outlet 20 to release the gas in the second gas cavity 18, and the launch is finished.

[0061] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. It should be noted that all equivalent substitutions and obvious deformation forms made by any technician familiar with the field under the guidance of this specification fall within the substantive scope of this specification and should be protected by the present invention.

Claims

1. An in-situ measurement device for the dynamic load impact resistance of an anchor body, characterized in that: It includes a launching device, a launching head, a guide rod, a base, a shell, a high-pressure gas cylinder, a pressure sensor, a data acquisition device and a data processing device, wherein: The shell is a hollow cylinder, one end of the shell is provided with a base, a pressure sensor is provided in the base, a guide rod is provided on the base, a launch head is provided on the guide rod, a launch device is provided above the launch head, the launch device is externally connected to a high-pressure gas cylinder, the launch device and the pressure sensor are both connected to a data acquisition device, and the data acquisition device is connected to a data processing device; The launching device comprises an annular tube, a first launcher and a second launcher. The first launcher and the second launcher are symmetrically arranged in the annular tube. The first launcher and the second launcher have the same structure. An air inlet is arranged on the annular tube. A partition is provided in the first launcher, and the partition divides the first launcher into two upper and lower chambers. A pressure-regulating piston is provided in the first launcher, and the piston rod of the pressure-regulating piston passes through the partition. The disk of the pressure-regulating piston is placed in the chamber above the partition. The chamber above the disk is a first air chamber, and a first air inlet is provided on the side wall of the first air chamber, and a first air outlet is provided on the top of the first air chamber. The chamber below the disk is a second air chamber, and a second air inlet and a second air outlet are provided on the side wall of the second air chamber. The inner diameter of the second air chamber is smaller than that of the first air chamber. The chamber below the partition is a third air chamber, and a third air inlet is provided on the side wall of the third air chamber. A launching chamber is provided at the bottom of the third air chamber, and the inner diameter of the launching chamber is the same as the diameter of the piston rod of the pressure-regulating piston. A pressure valve group is provided between the launch device and the high-pressure gas cylinder, and the pressure valve group includes a pressure gauge and a valve; A laser velocimeter is arranged on the shell, and the laser velocimeter is connected to a data acquisition device, and the initial release velocity of the transmitter head is obtained through the laser velocimeter; A coupling head is provided at the top of the guide rod, and the guide rod is connected to the anchor rod through the coupling head. The coupling head is cylindrical, and threads are provided inside the coupling head. Threads are provided on the guide rod. The coupling head connects the guide rod and the anchor rod through internal threads, and the bottom of the guide rod is connected to a base through threads.

2. The in-situ measuring device for the dynamic load impact resistance of an anchor body according to claim 1, characterized in that: The transmitter head is cylindrical, and the diameter of the transmitter head is the same as the inner diameter of the shell.

3. A method for testing the in-situ measurement device for the dynamic load impact resistance of an anchor body according to claim 1, characterized in that: The steps are as follows: (1) Remove the nut of the anchor to be tested to expose the anchor end, connect the anchor end to the upper end of the guide rod using a connector, install the launcher on the anchor above the connector, put the launcher head on the guide rod, connect the launcher head to the launcher through an anchoring agent, then install the housing and base, and connect the launcher to a high-pressure gas cylinder; (2) Open the high-pressure gas cylinder and input the gas pressure value. The gas in the high-pressure gas cylinder enters the launch device, the launch device starts, and the launch chamber releases gas instantly, pushing the launch head below to run. The launch head acquires an initial velocity and hits the base; The launcher startup process is as follows: a. The first air inlet is opened, and the high-pressure gas enters the first air chamber, pushing the pressure regulating piston to move to the lowest end, and then the first air inlet is closed; b. The second air inlet is opened, and the high-pressure gas enters the second air cavity. The air pressure of the first air cavity is the same as that of the second air cavity, and the inner diameter of the second air cavity is smaller than that of the first air cavity. Therefore, the air flow pushes the pressure regulating piston upward, and when the gas no longer enters the second air cavity, the second air inlet is closed; c. The third air inlet is opened, and the high-pressure gas enters the third air cavity. When the gas no longer enters the third air cavity, the third air inlet is closed; d. Open the first air outlet, the air pressure in the first air chamber suddenly drops, the pressure regulating piston quickly moves to the top of the first air chamber, the piston rod of the pressure regulating piston moves out of the launch chamber, the high-pressure gas is released instantly, pushing the launch head downward and hitting the base; e. Open the second air outlet to release the gas in the second air cavity, and the launch ends; (3) If the initial velocity given by the input air pressure value is too large, the base hit by the transmitter will drive the anchor rod to move downward. The input air pressure value is reduced and step (2) is repeated until the critical air pressure value for the impact resistance of the anchor rod is obtained. On the contrary, if the input air pressure value is too small, the position of the anchor rod remains unchanged. The input air pressure value is increased and step (2) is repeated until the anchor rod is pulled and the critical air pressure value for the impact resistance of the anchor rod is obtained.

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