A drop hammer impact test device for pre-tensioned anchor bolts and cables

Abstract

This invention provides a pre-tensioned anchor bolt and anchor cable drop hammer impact test device, including a main frame, a lifting device, a hammer body detachably connected to the lifting device, a lifting rod connected to the main frame, and an anchor bolt simulation assembly and an anchor cable simulation assembly detachably connected to the lifting device. The anchor bolt simulation assembly includes an anchor bolt threaded connection sleeve, an anchor bolt, a locking nut, a steel pipe, a tray, and anchor bolt accessories. The anchor cable simulation assembly includes an anchor cable threaded connection sleeve, an anchor cable, an anchor, a steel pipe, a tray, and anchor cable accessories. Both the anchor bolt threaded connection sleeve and the anchor cable threaded connection sleeve can be detachably connected to the lifting rod. Pressure sensors are installed on both trays, and displacement sensors are installed at the bottom of the anchor bolt and anchor cable. The pre-tensioned anchor bolt and anchor cable drop hammer impact test device of this invention has a reasonable structure and is simple to assemble, enabling more realistic simulation of impact ground pressure conditions and timely acquisition of relevant dynamic data.

Description

Technical Field

[0001] This utility model belongs to the field of impact dynamics experimental equipment, and in particular relates to a pre-tightened anchor bolt and anchor cable drop hammer impact test device. Background Technology

[0002] Rockbursts, a major hazard in deep coal mining, are characterized by their suddenness and destructive power, often causing serious casualties and significant property losses. As mining depths extend to the kilometer level, the complex mechanical environment of the rock mass—characterized by "three highs and one disturbance" (high ground stress, high osmotic pressure, high temperature, and strong mining disturbance)—significantly exacerbates the risk of rockbursts.

[0003] In rockburst prevention systems, pre-tensioned anchor (cable) support systems play a crucial role through active support mechanisms. Dynamic impact experiments are conducted on these support systems in the laboratory to obtain dynamic data. Currently, laboratories primarily employ static testing methods under unpre-tensioned conditions, which cannot accurately reflect the dynamic mechanical response of support components in deep roadways under rockburst conditions. Furthermore, due to the instantaneous and unpredictable nature of rockbursts, existing technologies cannot effectively capture dynamic failure data of the support system. Utility Model Content

[0004] In view of this, in order to solve the above-mentioned technical problems, this utility model proposes a pre-tightened anchor bolt and anchor cable drop hammer impact test device with reasonable structure, simple assembly, and the ability to more realistically simulate the working conditions of impact ground pressure and obtain relevant dynamic data in a timely manner.

[0005] To achieve the above objectives, the technical solution of this utility model is implemented as follows:

[0006] A pre-tensioned anchor bolt and anchor cable drop hammer impact test device includes a main frame, a lifting device installed on the main frame, a hammer body detachably connected to the lifting device, a rod with its upper end connected to the main frame and its lower end passing through the hammer body, an anchor bolt simulation assembly and an anchor cable simulation assembly with their upper ends detachably connected to the lower end of the rod.

[0007] The hammer body is provided with a through hole for the boom to pass through. The diameter of the through hole is larger than the diameter of the boom, to ensure that the hammer body will not rub against the boom during the falling process.

[0008] The simulated anchor bolt assembly includes an anchor bolt threaded connection sleeve, an anchor bolt, a lock nut, a steel pipe, a tray, and anchor bolt accessories. The upper and lower ends of the anchor bolt threaded connection sleeve are detachably connected to the lower end of the lifting rod and the upper end of the anchor bolt via threads, respectively. The lock nut is threaded onto the upper end of the anchor bolt and abuts against the bottom of the anchor bolt threaded connection sleeve. The steel pipe is fitted onto the outside of the anchor bolt. The tray is fitted onto the lower end of the anchor bolt and abuts against the bottom of the steel pipe. The anchor bolt accessories are detachably installed on the lower end of the anchor bolt and abut against the bottom of the tray. A pressure sensor is provided on the tray, and a displacement sensor is provided at the bottom of the anchor bolt.

[0009] The anchor cable simulation assembly includes an anchor cable threaded connection sleeve, an anchor cable, an anchor, a second steel pipe, a second tray, and anchor cable accessories. The upper end of the anchor cable threaded connection sleeve is detachably connected to the lower end of the auger via threads. The upper end of the anchor cable is inserted into the anchor cable threaded connection sleeve and fixed by the anchor. The second steel pipe is sleeved on the outside of the anchor cable. The second tray is sleeved on the lower end of the anchor cable and abuts against the bottom of the second steel pipe. The anchor cable accessories are detachably installed on the lower end of the anchor cable and abut against the bottom of the second tray. A pressure sensor is provided on the second tray, and a displacement sensor is provided at the bottom of the anchor cable.

[0010] The simulated anchor bolt (cable) assembly with pre-tensioned torque (pre-tension force) is connected to the boom via the anchor bolt (cable) threaded connection sleeve; the hammer is raised to the set height; the hammer is released, and under the action of gravity, it falls freely and impacts tray one (two). The impact force is transmitted to the anchor bolt (cable) through tray one (two) and the anchor bolt (cable) accessories, causing the anchor bolt (cable) to deform under stress until it breaks; the hammer is lifted, and the experimental data is measured and recorded. When the hammer impacts tray one (two), the pressure sensor and displacement sensor acquire real-time impact data and transmit the signals to the external data acquisition instrument and analysis software.

[0011] Furthermore, the main frame includes a base, a top plate, vertical support beams connecting the four corners of the base and the top plate, and two symmetrically arranged guide columns vertically between the base and the bottom plate; the hammer body is sleeved on the guide columns and can slide along the guide columns, and the guide columns guide the hammer body.

[0012] Furthermore, the upper surface of the base is provided with a buffer device to buffer the hammer and the anchor rod (cable) simulation assembly falling from a height, so as to avoid direct impact on the base and cause damage.

[0013] Furthermore, the lifting device includes a lifting motor installed on the top of the main frame, a lifting chain connected to the output end of the lifting motor at its upper end, and a gripping and releasing hammer device connected to the lower end of the lifting chain; there are two lifting motors, symmetrically arranged; there are two lifting chains, each connected to one of the two lifting motors respectively; the gripping and releasing hammer device can be disengaged from the hammer body through an automatic unhooking device.

[0014] Furthermore, it also includes a counterweight, which is detachably assembled onto the hammer body.

[0015] Furthermore, the hammer body is a cuboid structure with symmetrical counterweight cavities on both sides. A horizontally arranged mounting screw is fixed in the counterweight cavity, and a tightening limiting block is threaded onto the mounting screw. The counterweight block is screwed onto the mounting screw by a threaded connection, and the tightening limiting block holds the counterweight block in place.

[0016] The weight of the hammer can be changed by adding or removing counterweights. By changing the weight of the hammer and lowering it at different heights, the height of the hammer can be changed, which can meet the experimental requirements of different impact energies and impact velocities.

[0017] Furthermore, the lower end of the boom is provided with an external thread, and the upper end of the anchor bolt threaded connection sleeve is provided with an internal thread hole that is adapted to the external thread of the lower end of the boom; both the upper and lower ends of the anchor bolt are provided with external threads, and the lower end of the anchor bolt threaded connection sleeve is provided with an internal thread hole that is adapted to the external thread of the upper end of the anchor bolt; the anchor bolt accessory includes a nut, which is screwed onto the external thread at the lower end of the anchor bolt and abuts against the bottom of the tray.

[0018] Various types of anchor bolt threaded connection sleeves can be provided to accommodate anchor bolts of different specifications.

[0019] The assembly sequence of the simulated anchor bolt assembly is as follows: Screw the lock nut to the upper thread of the anchor bolt, screw the upper thread of the anchor bolt into the internal thread hole at the lower end of the threaded connecting sleeve, and tighten the lock nut to simulate the anchoring effect in the well; pass the anchor bolt through steel pipe one, with the end of steel pipe one tightly against the anchor bolt threaded connecting sleeve; install tray one and anchor bolt accessories sequentially at the lower end of the anchor bolt, adjust the positions of steel pipe one, anchor bolt, tray one, and anchor bolt accessories so that tray one is tightly against steel pipe one, ensuring that the anchor bolt, anchor bolt threaded connecting sleeve, and tray one are on the same central axis; finally, use a torque wrench to tighten the nut in the anchor bolt accessories until the experimental preload torque or design preload force is reached;

[0020] The relationship between the preload torque and the anchor bolt preload is as follows:

[0021] F = kM

[0022] Where F is the anchor bolt preload, in kN; k is the preload torque conversion coefficient; and M is the preload torque, in N·m.

[0023] Furthermore, the lower end of the boom is provided with an external thread, and the upper end of the anchor cable threaded connection sleeve is provided with an internal thread hole that is compatible with the external thread of the lower end of the boom; the lower end of the anchor cable threaded connection sleeve is provided with a through hole, the diameter of which is larger than the diameter of the anchor cable and smaller than the diameter of the anchor, the upper end of the anchor cable passes through the through hole and extends into the anchor cable threaded connection sleeve, and is locked by the anchor and secured in the anchor cable threaded connection sleeve; the anchor cable accessory includes an anchor second, which locks the lower end of the anchor cable and abuts against the bottom of the tray second.

[0024] Multiple models of anchor cable threaded connection sleeves can be set to accommodate anchor cables of different specifications.

[0025] The assembly sequence of the anchor cable simulation assembly is as follows: Install the matching anchor at one end of the anchor cable, tighten the anchor clamp, and fix the anchor cable and anchor; pass the lower end of the anchor cable through the through hole of the anchor cable threaded connection sleeve, and clamp the end of the anchor cable with the anchor installed into the anchor cable threaded connection sleeve, with the anchor placed inside the anchor cable threaded connection sleeve to simulate the underground anchoring effect; insert the anchor cable into steel pipe II, with the end of steel pipe II tightly attached to the anchor cable threaded connection sleeve; install tray II and anchor cable accessories in sequence at the lower end of the anchor cable, and adjust the positions of steel pipe II, anchor cable, tray II, and anchor cable accessories so that tray II is tightly attached to steel pipe II, ensuring that the anchor cable, anchor cable threaded connection sleeve, and tray II are on the same central axis; finally, use a tensioning jack to lock anchor II in the anchor cable accessories until the experimental design preload is reached.

[0026] Compared with existing technologies, the pre-tensioned anchor bolt and anchor cable drop hammer impact test device of this utility model has the following advantages:

[0027] The pre-tightened anchor bolt and anchor cable drop hammer impact test device of this utility model has a reasonable structure and simple assembly. The anchor bolt (cable) simulation assembly is convenient to assemble and can apply pre-tightening force. It can simulate the working condition of pre-tightened anchor bolts (cables) under impact load in underground working conditions. In addition, it is equipped with pressure sensors and displacement sensors to obtain relevant dynamic data in a timely manner, providing data support for the support design of mines with rockburst tendency. Attached Figure Description

[0028] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an undue limitation of the utility model. In the drawings:

[0029] Figure 1 This is a schematic diagram of the pre-tightening anchor bolt drop hammer impact test device described in Embodiment 1 of this utility model;

[0030] Figure 2 This is a schematic diagram of the structure of the anchor bolt simulation assembly described in Embodiment 1 of this utility model;

[0031] Figure 3 This is a schematic diagram of the structure of the anchor cable simulation assembly described in Embodiment 2 of this utility model;

[0032] Figure 4 This is a schematic diagram of the internal structure of the hammer body described in Embodiment 3 of this utility model.

[0033] Explanation of reference numerals in the attached figures:

[0034] 1-Main frame, 2-Hammer body, 3-Hanging rod, 4-Anchor bolt simulation assembly, 5-Guide column, 6-Lifting motor, 7-Lifting chain, 8-Grab and release hammer device, 9-Anchor bolt threaded connection sleeve, 10-Anchor bolt, 11-Locking nut, 12-Steel pipe one, 13-Plate one, 14-Anchor bolt accessories, 15-Anchor cable simulation assembly, 16-Anchor cable threaded connection sleeve, 17-Anchor cable, 18-Anchor, 19-Steel pipe two, 20-Plate two, 21-Anchor cable accessories, 22-Counterweight block, 23-Counterweight cavity, 24-Mounting screw, 25-Tightening limit block. Detailed Implementation

[0035] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0036] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0037] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0038] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0039] Example 1

[0040] like Figure 1 and 2 As shown, a pre-tensioned anchor bolt drop hammer impact test device includes a main frame 1, a lifting device installed on the main frame 1, a hammer body 2 that can be detached from the lifting device, a hanging rod 3 whose upper end is connected to the main frame 1 and whose lower end passes through the hammer body 2, and an anchor bolt simulation assembly 4 whose upper end is detachably connected to the lower end of the hanging rod 3.

[0041] The main frame 1 includes a base, a top plate, vertical support beams connecting the base and the top plate at the four corners, and two symmetrically arranged guide columns 5 vertically between the base and the bottom plate; a buffer device is provided on the upper surface of the base.

[0042] The lifting device includes a lifting motor 6 installed on the top of the main frame, a lifting chain 7 connected to the output end of the lifting motor 6 at the top, and a grabbing hammer device 8 connected to the lower end of the lifting chain 7; there are two lifting motors 6, which are symmetrically arranged; there are two lifting chains 7, which are respectively connected to the two lifting motors 6; the grabbing hammer device 8 and the hammer body 2 can be disengaged and connected via an automatic unhooking device.

[0043] The hammer body 2 is sleeved on the guide column 5 and can slide along the guide column 5; the hammer body 2 is provided with a through hole for the lifting rod 3 to pass through, and the diameter of the through hole is larger than the diameter of the lifting rod 3;

[0044] The lower end of the lifting rod 3 is provided with an external thread;

[0045] The anchor bolt simulation assembly 4 includes an anchor bolt threaded connection sleeve 9, an anchor bolt 10, a locking nut 11, a steel pipe 12, a tray 13, and an anchor bolt accessory 14. The upper end of the anchor bolt threaded connection sleeve 9 has an internal threaded hole that matches the external thread at the lower end of the hanger 3. The upper end of the anchor bolt threaded connection sleeve 9 is detachably connected to the lower end of the hanger 3 via threads. Both the upper and lower ends of the anchor bolt 10 have external threads, and the lower end of the anchor bolt threaded connection sleeve 9 has an internal threaded hole that matches the external thread at the upper end of the anchor bolt 10. The lower end of the connecting sleeve 9 is detachably connected to the upper end of the anchor rod 10 via threads; the locking nut 11 is threaded onto the upper end of the anchor rod 10 and abuts against the bottom of the anchor rod threaded connecting sleeve 9; the steel pipe 12 is fitted onto the outside of the anchor rod 10; the tray 13 is fitted onto the lower end of the anchor rod 10 and abuts against the bottom of the steel pipe 12; the anchor rod accessory 14 includes a nut, which is screwed onto the external thread at the lower end of the anchor rod 10 and abuts against the bottom of the tray 13; a pressure sensor is provided on the tray 13, and a displacement sensor is provided at the bottom of the anchor rod 10.

[0046] The drop hammer impact test method using the pre-tightening anchor bolt drop hammer impact test device described in Example 1 includes the following experimental steps:

[0047] S1. Assemble the anchor bolt simulation assembly 4: Screw the locking nut 11 to the upper thread of the anchor bolt 10, and screw the upper thread of the anchor bolt 10 into the internal thread hole at the lower end of the anchor bolt threaded connecting sleeve 9. Tighten the locking nut 11. Pass the anchor bolt 10 through the steel pipe 12, with the end of the steel pipe 12 tightly against the anchor bolt threaded connecting sleeve 9. Install the tray 13 and anchor bolt accessory 14 in sequence at the lower end of the anchor bolt 10. Adjust the positions of the steel pipe 12, anchor bolt 10, tray 13, and anchor bolt accessory 14 so that the tray 13 is tightly against the steel pipe 12, ensuring that the anchor bolt 10, anchor bolt threaded connecting sleeve 9, and tray 13 are on the same central axis. Finally, use a torque wrench to tighten the nut in the anchor bolt accessory 14 until the experimental preload torque or design preload force is reached.

[0048] S2. Connect the anchor bolt simulation assembly 4, after the pre-tightening torque (pre-tightening force) has been applied, to the hanger 3 through the anchor bolt threaded connection sleeve 9;

[0049] S3. Raise hammer 2 to the set height;

[0050] S4. Release hammer 2. Hammer 2 falls freely under the action of gravity and impacts tray 13. The impact force is transmitted to anchor 10 through tray 13 and anchor bolt accessory 14. Anchor 19 is deformed by the force until it breaks. Pressure sensor and displacement sensor acquire real-time impact data and transmit the signal to the external data acquisition instrument and analysis software.

[0051] S5. Lift hammer 2, measure and record experimental data.

[0052] Example 2

[0053] like Figure 3 As shown, based on Example 1, the difference from Example 1 is that a pre-tensioned anchor cable drop hammer impact test device does not use the anchor rod simulation assembly of 4 pieces, but instead uses the anchor cable simulation assembly of 15 pieces;

[0054] The anchor cable simulation assembly 15 includes an anchor cable threaded connection sleeve 16, an anchor cable 17, an anchor 18, a steel pipe 19, a tray 20, and an anchor cable accessory 21. The upper end of the anchor cable threaded connection sleeve 16 has an internal threaded hole that matches the external thread of the lower end of the hanger 3. The upper end of the anchor cable threaded connection sleeve 16 is detachably connected to the lower end of the hanger 3 via threads. The lower end of the anchor cable threaded connection sleeve 16 has a through hole with a diameter larger than that of the anchor cable 17 but smaller than that of the anchor 18. The upper end of anchor cable 17 extends through the through hole into the anchor cable threaded connection sleeve 16, and is locked by anchor 18, thus securing anchor cable 17 within anchor cable threaded connection sleeve 16; steel pipe 29 is sleeved on the outside of anchor cable 17; tray 20 is sleeved on the lower end of anchor cable 17 and abuts against the bottom of steel pipe 29; anchor cable accessory 21 includes anchor 2, which locks the lower end of anchor cable 17 and abuts against the bottom of tray 20; a pressure sensor is provided on tray 20, and a displacement sensor is provided at the bottom of anchor cable 17.

[0055] The drop hammer impact test method using the pre-tensioned anchor cable drop hammer impact test device described in Example 2 includes the following experimental steps:

[0056] S1. Assemble the anchor cable simulation assembly 15: Install the matching anchor 18 at one end of the anchor cable 17, tighten the clamps of the anchor 18, and fix the anchor cable 17 and the anchor 18; pass the lower end of the anchor cable 17 through the through hole of the anchor cable threaded connection sleeve 16, and insert the end of the anchor cable 17 with the anchor 18 into the anchor cable threaded connection sleeve 16; insert the anchor cable 17 into the steel pipe 19, with the end of the steel pipe 19 tightly against the anchor cable threaded connection sleeve 16; install the tray 20 and the anchor cable accessory 21 in sequence at the lower end of the anchor cable 17, adjust the positions of the steel pipe 19, the anchor cable 17, the tray 20, and the anchor cable accessory 21, so that the tray 20 is tightly against the steel pipe 19, and ensure that the anchor cable 17, the anchor cable threaded connection sleeve 16, and the tray 20 are on the same central axis; finally, use a tensioning jack to lock the anchor 2 in the anchor cable accessory 21 until the experimental design preload is reached;

[0057] S2. The anchor cable simulation assembly 15, after the pre-tightening torque (pre-tightening force) has been applied, is connected to the hanger 3 through the anchor cable threaded connection sleeve 16.

[0058] S3. Raise hammer 2 to the set height;

[0059] S4. Release hammer 2. Hammer 2 falls freely under the action of gravity and impacts tray 20. The impact force is transmitted to anchor cable 17 through tray 20 and anchor cable accessory 21. Anchor cable 17 deforms under the force until it breaks. Pressure sensor and displacement sensor acquire real-time impact data and transmit the signal to the external data acquisition instrument and analysis software.

[0060] S5. Lift hammer 2, measure and record experimental data.

[0061] Example 3

[0062] like Figure 4 As shown, based on embodiments 1 and 2, the difference from embodiments 1 and 2 is that it also includes a counterweight block 22; the hammer body 2 is a cuboid structure with counterweight cavities 23 symmetrically opened on both sides, and a horizontally arranged mounting screw 24 is fixed in the counterweight cavity 23. A tightening limit block 25 is threaded on the mounting screw 24; the counterweight block 22 is screwed onto the mounting screw 24 by a threaded connection, and the tightening limit block 25 holds the counterweight block 22 in place; the weight of the hammer body 2 can be changed by adding or removing the counterweight block 22.

[0063] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A pre-tensioned anchor rod, cable drop hammer impact testing device, characterized in that: It includes a main frame, a lifting device installed on the main frame, a hammer body detachably connected to the lifting device, a rod with its upper end connected to the main frame and its lower end passing through the hammer body, an anchor bolt simulation assembly and an anchor cable simulation assembly with their upper ends detachably connected to the lower end of the rod. The hammer body is provided with a through hole for the lifting rod to pass through, and the diameter of the through hole is larger than the diameter of the lifting rod; The simulated anchor bolt assembly includes an anchor bolt threaded connection sleeve, an anchor bolt, a lock nut, a steel pipe, a tray, and anchor bolt accessories. The upper and lower ends of the anchor bolt threaded connection sleeve are detachably connected to the lower end of the lifting rod and the upper end of the anchor bolt via threads, respectively. The lock nut is threaded onto the upper end of the anchor bolt and abuts against the bottom of the anchor bolt threaded connection sleeve. The steel pipe is fitted onto the outside of the anchor bolt. The tray is fitted onto the lower end of the anchor bolt and abuts against the bottom of the steel pipe. The anchor bolt accessories are detachably installed on the lower end of the anchor bolt and abut against the bottom of the tray. A pressure sensor is provided on the tray, and a displacement sensor is provided at the bottom of the anchor bolt. The anchor cable simulation assembly includes an anchor cable threaded connection sleeve, an anchor cable, an anchor, a second steel pipe, a second tray, and anchor cable accessories. The upper end of the anchor cable threaded connection sleeve is detachably connected to the lower end of the auger via threads. The upper end of the anchor cable is inserted into the anchor cable threaded connection sleeve and fixed by the anchor. The second steel pipe is sleeved on the outside of the anchor cable. The second tray is sleeved on the lower end of the anchor cable and abuts against the bottom of the second steel pipe. The anchor cable accessories are detachably installed on the lower end of the anchor cable and abut against the bottom of the second tray. A pressure sensor is provided on the second tray, and a displacement sensor is provided at the bottom of the anchor cable.

2. The pre-tensioned anchor rod, cable drop hammer impact testing device according to claim 1, characterized in that: The main frame includes a base, a top plate, vertical support beams connecting the four corners of the base and the top plate, and two symmetrically arranged guide columns vertically between the base and the top plate; the hammer body is sleeved on the guide columns and can slide along the guide columns.

3. The pre-tensioned anchor rod, cable drop hammer impact testing device according to claim 2, characterized in that: The upper surface of the base is provided with a buffer device.

4. The pre-tensioned anchor rod, cable drop hammer impact testing device according to claim 1, characterized in that: The lifting device includes a lifting motor installed on the top of the main frame, a lifting chain connected to the output end of the lifting motor at its upper end, and a gripping and releasing hammer device connected to the lower end of the lifting chain; there are two lifting motors, symmetrically arranged; there are two lifting chains, each connected to one of the two lifting motors respectively; the gripping and releasing hammer device can be disengaged from the hammer body through an automatic unhooking device.

5. The pre-tensioned anchor rod, cable drop hammer impact testing device according to claim 1, characterized in that: It also includes a counterweight, which is detachably assembled onto the hammer body.

6. The pre-stressed anchor rod, cable drop hammer impact testing device according to claim 5, characterized in that: The hammer body is a cuboid structure with symmetrical counterweight cavities on both sides. A horizontally arranged mounting screw is fixed in the counterweight cavity, and a tightening limit block is threaded onto the mounting screw. The counterweight block is screwed onto the mounting screw by a threaded connection, and the tightening limit block holds the counterweight block in place.

7. The drop hammer impact test device for pre-tightened anchor bolts and cables according to claim 1, characterized in that: The lower end of the boom is provided with an external thread, and the upper end of the anchor bolt threaded connection sleeve is provided with an internal thread hole that is adapted to the external thread of the lower end of the boom; both the upper and lower ends of the anchor bolt are provided with external threads, and the lower end of the anchor bolt threaded connection sleeve is provided with an internal thread hole that is adapted to the external thread of the upper end of the anchor bolt; the anchor bolt accessory includes a nut, which is screwed onto the external thread at the lower end of the anchor bolt and abuts against the bottom of the tray.

8. The drop hammer impact test device for pre-tensioned anchor bolts and anchor cables according to claim 1, characterized in that: The lower end of the boom is provided with an external thread, and the upper end of the anchor cable threaded connection sleeve is provided with an internal thread hole that is compatible with the external thread of the lower end of the boom; the lower end of the anchor cable threaded connection sleeve is provided with a through hole, the diameter of which is larger than the diameter of the anchor cable and smaller than the diameter of the anchor, the upper end of the anchor cable passes through the through hole and extends into the anchor cable threaded connection sleeve, and is locked by the anchor and secured in the anchor cable threaded connection sleeve; the anchor cable accessory includes an anchor second, which locks the lower end of the anchor cable and abuts against the bottom of the tray second.

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