Test device for simulating impact of filler in column hammer impacted and expanded pile hole

Abstract

The invention discloses a test device for simulating the impact of filler in a column hammer punching and expanding pile hole, which comprises a frame, and a column hammer device and a material placing device are arranged on the frame; the column hammer device comprises a plurality of guide columns and a winch, column hammers are arranged in the guide columns, and a cylindrical electromagnet is arranged at the end of a steel wire rope in the winch; the material containing device comprises a rigid sealing container, a flexible film container, a water inlet and outlet device and an electromagnet column hammer clamp combined device. The flexible film container can simulate the wrapping effect of surrounding soil as a flexible boundary in a real environment, and the water inlet and outlet device can simulate soil pressure in different depth environments, so that the test environment of a sample is consistent with an actual engineering environment, and the accuracy of a filler impact test is improved; the electromagnet column hammer clamp combined device clamps the secondary springback column hammer according to the column hammer acceleration collected by the acceleration sensor, so that secondary springback of the column hammer is avoided, interference to test data is reduced, and the accuracy of data collection is improved.

Description

Technical Field

[0001] The invention relates to the technical field of foundation treatment engineering application, in particular to a test device for simulating the impact of a filler in a pile hole by a column hammer. Background Art

[0002] The column hammer impact pile is a technology widely used in the foundation reinforcement treatment of collapsible loess, silt, clay and other soils. This method repeatedly lifts the column hammer to a certain height, allowing it to fall freely to impact the filling material in the foundation channel, so that the filling material in the hole is subjected to super-strong dynamic consolidation and the soil around the pile is horizontally squeezed, thereby achieving the purpose of strengthening the foundation. The existing column hammer impact test can lift the column hammer to a corresponding height, release the column hammer and let it fall freely to impact the sample.

[0003] The existing column hammer test device is difficult to simulate the on-site construction environment under this condition. One reason is that during the pile forming process, the filling material in the hole is mainly affected by two effects. On the one hand, it is the impact of the column hammer, and on the other hand, it is the wrapping effect of the surrounding soil as a flexible boundary. The stress of the surrounding soil will also change during the impact. The traditional column hammer test cannot simulate the wrapping effect of the on-site soil on the filling material, which is different from the actual engineering environment, so it affects the research conclusions.

[0004] For the column hammer impact expansion pile test, the column hammer is heavy and the impact force is large during collision. The column hammer will rebound secondary, which will cause great interference to the test data and affect data collection.

[0005] At present, most impact test devices limit the sliding trajectory of the column hammer through the guide rail. When the column hammer impacts the specimen, it is also restricted by the side guide rail, so that the guide rail always moves in the vertical direction. However, the column hammer impact and expansion pile test we are involved in requires that the column hammer is not restrained around it during impact and the column hammer swings freely.

[0006] In response to the three problems mentioned above, we provide a test device for simulating the impact of fillers in pile holes by column hammer expansion to solve the above problems. Summary of the invention

[0007] In view of the above-mentioned problems in the prior art, the present invention provides a device for simulating the impact of a column hammer on the filler in the pile hole, which solves the problem that the existing column hammer test device cannot simulate the wrapping effect of the on-site soil on the filler and the column hammer will cause secondary rebound, which will cause great interference to the test data and affect data collection.

[0008] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is as follows:

[0009] Provided is a device for simulating the impact test of filler in a pile hole by a column hammer, which comprises a frame, on which a column hammer device and a material placing device located below the column hammer device are arranged;

[0010] The column hammer device includes multiple guide columns and a winch. The multiple guide columns are vertically arranged, column hammers are arranged inside the multiple guide columns, the winch is arranged on the top of the frame, and a cylindrical electromagnet for adsorbing the column hammer is arranged at the end of the wire rope in the winch.

[0011] The loading device includes a rigid sealed container, a flexible membrane container and a water inlet and outlet device; an upper cover is arranged inside the rigid sealed container, a loading hole is arranged at the center of the upper cover and is located directly below the column hammer, the diameter of the loading hole is larger than the diameter of the column hammer, the flexible membrane container is arranged inside the rigid sealed container through the loading hole, the inside of the flexible membrane container is used for filling samples, a water pressure space is arranged between the rigid sealed container and the flexible membrane container, a flexible membrane cap edge is arranged on the top of the flexible membrane container, and the flexible membrane cap edge passes through the loading hole and is fixed to the upper surface of the upper cover; the water inlet and outlet device is connected with the water pressure space.

[0012] The upper end surface of the upper cover is provided with an electromagnetic column hammer clamp assembly device for preventing the column hammer from rebounding again after impact.

[0013] The basic principle of a device for simulating the impact test of the filling material in the pile hole by using a column hammer is as follows: the sample is loaded into a flexible film container, and the flexible film cap edge is pasted on the upper end surface of the upper cover by a waterproof adhesive, and then the water pressure space is filled with water by a water inlet and outlet device to reach the pressure required for the test and then stopped, simulating the soil stress of the sample in a static state; the cylindrical electromagnet is connected by a winch, and the column hammer is adsorbed after the cylindrical electromagnet is energized, and the column hammer is lifted to the required height for the test, and the column hammer is freely dropped after the cylindrical electromagnet is powered off. The column hammer is restricted to move vertically downward by multiple guide columns, and the column hammer performs free fall motion to impact the sample. The column hammer is heavy, and the impact force is large during collision, so the column hammer will rebound and leave the sample, and then the electromagnet column hammer clamp combination device clamps the column before it falls for the second time to prevent the column hammer from rebounding for the second time.

[0014] Furthermore, the number of the multiple guide columns is 4, the 4 guide columns are evenly spaced in the circumferential direction, a guide rail flush ring is fixed to the lower end of the 4 guide columns, and both ends of the 4 guide columns are fixed to the frame through a platform and a clamp; the distance between the bottom end of the 4 guide columns and the upper cover is greater than the length of the column hammer.

[0015] In the above technical solution, the guide rail flush ring connects the four guide columns into a whole and can move up and down at the same time. When using column hammers of different lengths, loosen the clamp, move the guide column up and down, make the distance from the bottom guide rail flush ring to the upper cover greater than the length of the column hammer, and then fix the clamp. The above setting can facilitate the adjustment of the position of the four guide column rings on the frame to achieve the technical effect of adapting to column hammers of different lengths.

[0016] Furthermore, an acceleration sensor is provided on the column hammer, and the acceleration sensor is electrically connected to the electromagnetic column hammer clamp assembly device. The acceleration sensor can monitor the acceleration of the column hammer during the falling and impact process, and when the acceleration is detected to be reduced to 0, a signal is transmitted to control the electromagnetic column hammer clamp assembly device to clamp the rebounding column hammer.

[0017] Furthermore, a water pressure sensor is provided at the bottom of the rigid sealed container. When the column hammer impacts the sample, it squeezes the flexible membrane container, increasing the water pressure in the water pressure space. When the water pressure sensor detects the increase in water pressure, it transmits a signal to the water inlet and outlet device at the outlet, opens the valve and slowly releases some water to keep the water pressure stable within a certain range, thereby simulating the change in the stress of the surrounding soil during impact.

[0018] Furthermore, a water inlet hole and a water outlet hole communicating with the water pressure space are arranged on the upper cover, and the water inlet end and the water outlet end of the water inlet and outlet device are connected with the water inlet hole and the water outlet hole respectively.

[0019] Furthermore, the rigid sealed container includes a base, the upper end surface of the base is sealed with a transparent waterproof cover, the upper cover is sealed and connected to the top of the transparent waterproof cover, and multiple external reinforcement columns and internal reinforcement columns are arranged between the upper cover and the base; the multiple external reinforcement columns and internal reinforcement columns are respectively located outside and inside the transparent waterproof cover. In the above technical solution, the transparent waterproof cover facilitates observation of the shape changes of the flexible membrane container and the sample inside; and the arrangement of multiple external reinforcement columns and internal reinforcement columns strengthens the structural strength of the entire rigid sealed container, so that it can bear a large load impact.

[0020] Furthermore, the electromagnetic column hammer clamp assembly device includes six electromagnetic clamps uniformly arranged at annular intervals around the outer periphery of the material placement hole, each of which includes an I-shaped guide rail fixedly connected to the upper cover, one end of the I-shaped guide rail is fixedly provided with a double-cylinder cylinder by bolts, and the other end is slidably provided with a movable device by a movable wheel, the output end of the double-cylinder cylinder is fixedly connected to one side wall of the movable device, and an electromagnetic sheet is fixedly connected to the other side wall of the movable device. When the acceleration is detected to drop to 0, a signal is transmitted to the element controlling the double-cylinder cylinder, the double-cylinder cylinder is started, the electromagnetic sheet is energized and slides rapidly along the I-shaped guide rail to clamp the rebounding column hammer. The friction and adsorption force brought by the electromagnetic sheet clamp the column hammer together to prevent it from falling again. At this time, a test is completed and relevant data is recorded.

[0021] The electromagnet sheet has an arc-shaped structure, and the inner side of the arc of the electromagnet sheet is used to contact the circumferential outer wall of the column hammer. The inner side of the arc of the electromagnet sheet is a rough surface, which increases the friction between the electromagnet sheet and the circumferential outer wall of the column hammer.

[0022] Furthermore, the bottom end surface of each electromagnet sheet is provided with a plurality of spherical protrusions in contact with the upper end surface of the upper cover. The spherical protrusions support the lower end surface of the electromagnet sheet, reduce the deformation of the electromagnet sheet, and at the same time reduce the friction between the electromagnet sheet and the upper cover, thereby reducing the impact on the running speed of the electromagnet sheet.

[0023] Furthermore, an acoustic emission sensor is provided on the upper end surface of the upper cover, which can obtain sound data of the impact test to adapt to different test requirements.

[0024] Compared with the prior art, the beneficial effects of the present invention are: 1. The simulated column hammer impact test device for filling materials in pile holes of the present invention is provided with a rigid sealing container, a flexible membrane container and a water inlet and outlet device. The flexible membrane container is filled with samples to play the role of wrapping the soil, which can simulate the wrapping effect of the surrounding soil as a flexible boundary in the real environment. The water inlet and outlet device can inject water into the water pressure space to apply water pressure to the sample in the flexible membrane container, which can simulate the soil pressure under different depth environments, so that the test environment of the sample is consistent with the actual engineering environment, thereby improving the accuracy of the filler impact test, and being able to complete the column hammer impact test under various pressure environments, thereby expanding the scope of use of the simulated column hammer impact test device for filling materials in pile holes.

[0025] 2. The simulated column hammer impact test device of the present invention is provided with an electromagnetic column hammer clamp assembly device. The electromagnetic column hammer clamp assembly device clamps the column hammer of secondary rebound according to the column hammer acceleration collected by the acceleration sensor to avoid secondary rebound of the column hammer, reduce the interference to the test data, and improve the accuracy of data collection.

[0026] 3. The simulated column hammer impact test device for expanding the filling material in the pile hole in the present invention controls the energy carried by the column hammer during impact by changing the falling height of the column hammer. It can also be achieved by using column hammers of different lengths but the same diameter. Both ends of the guide column are fixed to the frame through a platform and a clamp. The distance between the bottom ends of the four guide columns and the upper cover can be adjusted according to the actual needs of the impact test to adapt to column hammers of different lengths. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the three-dimensional structure of a test device simulating the impact of filler in pile hole expansion by column hammer.

[0028] Figure 2 It is a structural schematic diagram of the column hammer device.

[0029] Figure 3 It is a structural schematic diagram of the material placing device.

[0030] Figure 4 It is a schematic diagram of the installation structure of the flexible membrane container and the upper cover.

[0031] Figure 5 It is a schematic diagram of the installation structure of the flexible membrane cap edge in the flexible membrane container.

[0032] Figure 6 It is a structural schematic diagram of the electromagnetic column hammer clamp combination device.

[0033] Figure 7 It is a schematic diagram of the structure of a single electromagnetic clamp.

[0034] Among them, 1. frame; 2. column hammer device; 3. material placement device; 4. guide column; 5. winch; 6. column hammer; 7. wire rope; 8. cylindrical electromagnet; 9. rigid sealed container; 10. flexible membrane container; 11. water inlet and outlet device; 12. upper cover; 13. material placement hole; 14. flexible membrane cap edge; 15. electromagnet column hammer clamp assembly device; 16. guide rail flush ring; 17. platform; 18. acceleration sensor; 20. water inlet hole; 21. water outlet hole; 22. base; 23. transparent waterproof cover; 24. outer reinforcement column; 25. inner reinforcement column; 26. electromagnet clamp; 27. I-shaped guide rail; 28. bolt; 29. ​​double-cylinder cylinder; 30. movable wheel; 31. movable device; 32. electromagnet sheet; 33. spherical protrusion; 34. acoustic emission sensor. DETAILED DESCRIPTION

[0035] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0036] like Figure 1 to Figure 5 As shown, the present invention provides a device for simulating the impact test of filler in a pile hole by a column hammer. The device comprises a frame 1 on which a column hammer device 2 and a material placing device 3 located below the column hammer device 2 are arranged.

[0037] The column hammer device 2 includes multiple guide columns 4 and a winch 5. The multiple guide columns 4 are vertically arranged, and column hammers 6 are arranged inside the multiple guide columns 4. The winch 5 is arranged at the top of the frame 1, and a cylindrical electromagnet 8 for adsorbing the column hammer 6 is arranged at the end of the wire rope 7 in the winch 5.

[0038] The loading device 3 includes a rigid sealed container 9, a flexible membrane container 10 and a water inlet and outlet device 11; an upper cover 12 is arranged inside the rigid sealed container 9, a loading hole 13 is arranged at the center position of the upper cover 12 and is located directly below the column hammer 6, the diameter of the loading hole 13 is larger than the diameter of the column hammer 6, the flexible membrane container 10 is arranged inside the rigid sealed container 9 through the loading hole 13, the inside of the flexible membrane container is used to load the sample, a water pressure space is arranged between the rigid sealed container 9 and the flexible membrane container 10, a flexible membrane cap edge 14 is arranged on the top of the flexible membrane container 10, and the flexible membrane cap edge 14 passes through the loading hole 13 and is fixed to the upper surface of the upper cover 12; the water inlet and outlet device 11 is connected to the water pressure space.

[0039] The upper end surface of the upper cover 12 is provided with an electromagnetic column hammer clamp assembly 15 for preventing the column hammer 6 from rebounding after impact.

[0040] The test process of the device for simulating the impact test of the filling material in the pile hole by using a column hammer to expand the pile hole in the present invention is as follows: the sample is loaded into the flexible film container 10, and the flexible film cap edge 14 is pasted on the upper end surface of the upper cover 12 by a waterproof adhesive, and then the water pressure space is filled with water by the water inlet and outlet device 11 to reach the pressure required for the test and then stopped, simulating the soil stress of the sample in a static state; the cylindrical electromagnet 8 is connected by the hoist 5, and the column hammer 6 is adsorbed after the cylindrical electromagnet 8 is energized, and the column hammer 6 is lifted to the required height for the test, and the column hammer 6 is freely dropped after the cylindrical electromagnet 8 is powered off. The column hammer 6 is restricted to move vertically downward by multiple guide columns 4, and the column hammer 6 performs free fall motion to impact the sample. When the column hammer 6 impacts the sample, since it will not contact the guide column 4 and the material placing device 3, there is no restraint around it, so that it can swing freely at the impact moment, simulating the actual working condition. At the same time, the column hammer 6 is heavy and has a large impact force during collision, so the column hammer 6 will rebound and leave the sample. Then the electromagnetic column hammer clamp assembly 15 clamps the column before it falls for the second time to prevent the column hammer 6 from rebounding for the second time.

[0041] The simulated column hammer impact test device for the filling material in the pile hole of the present invention is provided with a rigid sealing container 9, a flexible membrane container 10 and a water inlet and outlet device 11. The flexible membrane container 10 is filled with a sample to play the role of wrapping the soil, which can simulate the wrapping effect of the surrounding soil as a flexible boundary in the real environment. The water inlet and outlet device 11 can inject water into the water pressure space to apply water pressure to the sample in the flexible membrane container 10, which can simulate the soil pressure under different depth environments, so that the test environment of the sample is consistent with the actual engineering environment, improve the accuracy of the filling material impact test, and complete the column hammer impact test under various pressure environments, expanding the scope of use of the simulated column hammer impact test device for the filling material in the pile hole. The electromagnetic column hammer clamp assembly device 15 clamps the column hammer 6 that rebounds twice according to the acceleration of the column hammer 6 collected by the acceleration sensor 18, so as to avoid the column hammer 6 from rebounding twice, reduce the interference to the test data, and improve the accuracy of data collection.

[0042] Preferably, but not limited to, since the simulated column hammer impact test device for pile hole filling in the present invention involves the use of electromagnets, all guide columns 4 are made of stainless steel or other materials that are not attracted to magnets to reduce interference with the electromagnets during use.

[0043] Specifically, Figure 2 As shown, the number of the multiple guide columns 4 is 4, the 4 guide columns 4 are evenly spaced in the circumferential direction, a guide rail flush ring 16 is fixed to the lower end of the 4 guide columns 4, and both ends of the 4 guide columns 4 are fixed to the frame 1 through a platform 17 and a clamp; the distance between the bottom end of the 4 guide columns 4 and the upper cover 12 is greater than the length of the column hammer 6.

[0044] In the above technical solution, the guide rail flush ring 16 connects the four guide columns 4 as a whole and can move up and down at the same time. When using column hammers 6 of different lengths, loosen the clamp, move the guide columns 4 up and down, and fix the clamp after the distance from the bottom guide rail flush ring 16 to the upper cover 12 is greater than the length of the column hammer 6. The above arrangement can facilitate the adjustment of the position of the four guide columns 4 rings on the frame 1 to achieve the technical effect of adapting to column hammers 6 of different lengths.

[0045] Specifically, the column hammer 6 is provided with an acceleration sensor 18, and the acceleration sensor 18 is electrically connected to the electromagnetic column hammer clamp assembly 15. The acceleration sensor 18 can monitor the acceleration of the column hammer 6 during the falling and impact process. When the acceleration is detected to be reduced to 0, a signal is transmitted to the control electromagnetic column hammer clamp assembly 15 to clamp the rebounding column hammer 6. It should be noted that when the column hammer 6 impacts the sample and rebounds, the acceleration monitored by the acceleration sensor 18 on the upper surface of the column hammer 6 should be reduced from gravity acceleration to 0, then reduced to the maximum negative value, and then increased to gravity acceleration, at which time the column hammer 6 leaves the sample. Therefore, the signal is transmitted when the acceleration is reduced to 0, which is ahead of the end time of the first impact, and can make up for the reaction time of the electromagnetic column hammer clamp assembly 15, and more accurately clamp the column hammer 6 before it falls for the second time.

[0046] Specifically, Figure 3 As shown, the upper cover 12 is provided with a water inlet hole 20 and a water outlet hole 21 communicating with the water pressure space, and the water inlet end and the water outlet end of the water inlet and outlet device 11 are connected to the water inlet hole 20 and the water outlet hole 21 respectively.

[0047] Preferably, a water pressure sensor is provided at the bottom of the rigid sealed container 9. When the column hammer 6 impacts the sample, it squeezes the flexible membrane container 10, increasing the water pressure in the water pressure space. When the water pressure sensor detects the increase in water pressure, it transmits a signal to the water inlet and outlet device 11 at the outlet, opens the valve and slowly releases part of the water to keep the water pressure stable within a certain range, thereby simulating the change in the stress of the surrounding soil during impact.

[0048] The rigid sealed container 9 includes a base 22, the upper end surface of the base 22 is sealed with a transparent waterproof cover 23, the upper cover 12 is sealed and connected to the top of the transparent waterproof cover 23, and a plurality of outer reinforcing columns 24 and inner reinforcing columns 25 are arranged between the upper cover 12 and the base 22; the plurality of outer reinforcing columns 24 and inner reinforcing columns 25 are respectively located outside and inside the transparent waterproof cover 23. In the above technical solution, the transparent waterproof cover 23 facilitates observation of the shape changes of the flexible film container 10 and the sample inside; and the arrangement of the plurality of outer reinforcing columns 24 and inner reinforcing columns 25 strengthens the structural strength of the entire rigid sealed container 9, so that it can bear a large load impact.

[0049] like Figure 3 , Figure 6 and Figure 7As shown, as a specific setting mode of the electromagnetic column hammer 6 clamp assembly device 15, the electromagnetic column hammer 6 clamp assembly device 15 includes six electromagnetic clamps 26 uniformly arranged around the outer periphery of the material placement hole 13, each of which includes an I-shaped guide rail 27 fixedly connected to the upper cover 12, one end of the I-shaped guide rail 27 is fixedly provided with a double-cylinder cylinder 29 by a bolt 28, and the other end is slidably provided with a movable device 31 by a movable wheel 30, the output end of the double-cylinder cylinder 29 is fixedly connected to one side wall of the movable device 31, and an electromagnetic iron sheet 32 ​​is fixedly connected to the other side wall of the movable device 31. When the acceleration sensor 18 detects that the acceleration drops to 0, a signal is transmitted to the element controlling the double-cylinder cylinder 29, the double-cylinder cylinder 29 is started, and the electromagnetic iron sheet 32 ​​is energized and slides rapidly along the I-shaped guide rail to clamp the rebounding column hammer 6. The friction and adsorption force brought by the electromagnetic iron sheet 32 ​​clamp the column hammer 6 together to prevent it from falling again. At this time, a test is completed and relevant data is recorded.

[0050] The electromagnet sheet 32 ​​has an arc-shaped structure, and the inner side of the arc of the electromagnet sheet 32 ​​is used to contact the circumferential outer wall of the column hammer 6. The inner side of the arc of the electromagnet sheet 32 ​​is a rough surface, which increases the friction between the electromagnet sheet 32 ​​and the circumferential outer wall of the column hammer 6.

[0051] Preferably, the bottom end surface of each electromagnet sheet 32 ​​is provided with a plurality of spherical protrusions 33 in contact with the upper end surface of the upper cover 12. The spherical protrusions 33 support the lower end surface of the electromagnet sheet 32 ​​to reduce deformation of the electromagnet sheet 32, and at the same time can reduce the friction between the electromagnet sheet 32 ​​and the upper cover 12, thereby reducing the impact on the running speed of the electromagnet sheet 32.

[0052] An acoustic emission sensor 34 is disposed on the upper end surface of the upper cover 12 to obtain sound data of the impact test to adapt to different test requirements.

[0053] In summary, the device for simulating the impact test of the filling material in the pile hole by the column hammer in the present invention can simulate the soil stress in different soils or different soil depths, and conduct impact tests on multi-particle or single-particle samples. It can make the column hammer 6 free from constraints when impacting the sample, and can also accurately clamp the column hammer 6 before it falls for the second time to prevent secondary rebound, thus solving the problem that the existing column hammer test device cannot simulate the wrapping effect of the on-site soil on the filling material and the column hammer will rebound twice, which will cause great interference to the test data and affect the data collection.

Claims

1. A device for simulating the impact test of filling materials in pile holes by using a column hammer, characterized in that: It comprises a frame, on which a column hammer device and a material placing device located below the column hammer device are arranged; The column hammer device includes a plurality of guide columns and a winch, wherein the plurality of guide columns are vertically arranged, column hammers are arranged inside the plurality of guide columns, the winch is arranged at the top of the frame, and a cylindrical electromagnet for adsorbing the column hammer is arranged at the end of the steel wire rope in the winch; The material placement device comprises a rigid sealed container, a flexible film container and a water inlet and outlet device; an upper cover is arranged inside the rigid sealed container, a material placement hole is arranged at the center of the upper cover and is located directly below the column hammer, the diameter of the material placement hole is larger than the diameter of the column hammer, the flexible film container is arranged inside the rigid sealed container through the material placement hole, the flexible film container is used to fill the sample, a water pressure space is arranged between the rigid sealed container and the flexible film container, a flexible film cap edge is arranged on the top of the flexible film container, and the flexible film cap edge passes through the material placement hole and is fixed to the upper surface of the upper cover; the water inlet and outlet device is connected with the water pressure space; The upper end surface of the upper cover is provided with an electromagnetic column hammer clamp assembly device for preventing the column hammer from rebounding again after impact.

2. The device for testing the impact of fillers in pile holes by simulating column hammer expansion according to claim 1 is characterized in that: The number of the plurality of guide columns is 4, the 4 guide columns are evenly spaced in the circumferential direction, a guide rail flush ring is fixed to the lower end of the 4 guide columns, both ends of the 4 guide columns are fixed to the frame through a platform and a clamp; the distance between the bottom ends of the 4 guide columns and the upper cover is greater than the length of the column hammer.

3. The device for testing the impact of fillers in pile holes by simulating column hammer expansion according to claim 1 is characterized in that: The column hammer is provided with an acceleration sensor, and the acceleration sensor is electrically connected to the electromagnet column hammer clamp assembly device.

4. The device for testing the impact of fillers in pile holes by simulating column hammer expansion according to claim 2 is characterized in that: A water pressure sensor is arranged at the bottom of the rigid sealed container.

5. The device for testing the impact of fillers in pile holes by simulating column hammer expansion according to claim 1 is characterized in that: The upper cover is provided with a water inlet hole and a water outlet hole which are in communication with the water pressure space, and the water inlet end and the water outlet end of the water inlet and outlet device are connected with the water inlet hole and the water outlet hole respectively.

6. The device for testing the impact of fillers in pile holes by simulating column hammer expansion according to claim 1 is characterized in that: The rigid sealed container includes a base, the upper end surface of the base is sealed with a transparent waterproof cover, the upper cover is sealed and connected to the top of the transparent waterproof cover, and a plurality of outer reinforcing columns and inner reinforcing columns are arranged between the upper cover and the base; the plurality of outer reinforcing columns and inner reinforcing columns are respectively located outside and inside the transparent waterproof cover.

7. The device for testing the impact of fillers in pile holes by simulating column hammer expansion according to claim 3 is characterized in that: The electromagnetic column hammer clamp assembly device includes a plurality of electromagnetic clamps uniformly arranged at annular intervals around the outer periphery of the material placing hole, each of which includes an I-shaped guide rail fixedly connected to the upper cover, one end of the I-shaped guide rail is fixedly provided with a double-cylinder cylinder by bolts, and the other end is slidably provided with a movable device by a movable wheel, the output end of the double-cylinder cylinder is fixedly connected to one side wall of the movable device, and an electromagnetic sheet is fixedly connected to the other side wall of the movable device, the electromagnetic sheet is in an arc-shaped structure, and the inner side surface of the arc of the electromagnetic sheet is used to contact the circumferential outer wall of the column hammer, and the inner side surface of the arc of the electromagnetic sheet is a rough surface.

8. The device for testing the impact of fillers in pile holes by simulating column hammer expansion according to claim 7 is characterized in that: The bottom end surface of each electromagnet sheet is provided with a plurality of spherical protrusions which are in contact with the upper end surface of the upper cover.

9. The device for testing the impact of fillers in pile holes by simulating column hammer expansion according to claim 1 is characterized in that: An acoustic emission sensor is arranged on the upper end surface of the upper cover.

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