Low-strain pile foundation excitation device

Abstract

The utility model relates to the technical field of foundation pile integrity detection, in particular to a low-strain pile foundation excitation device. The device comprises an impact hammer and a support used for fixing the impact hammer, and the impact hammer is arranged on a power mechanism used for driving the impact hammer to knock a pile foundation. The power mechanism comprises a vibration excitation rod connected to the impact hammer, a supporting cylinder arranged on the vibration excitation rod in a sleeving mode, a top plate fixedly connected to the supporting cylinder, a partition plate arranged on the vibration excitation rod in a sleeving mode, a spring arranged between the partition plate and the top plate and a locking assembly used for limiting the position of the partition plate on the vibration excitation rod, and the vibration excitation rod vertically penetrates through the top plate. According to the device, the specification and the number of the springs can be adjusted according to the pile length and the pile diameter, and the compression degree of the springs can be controlled so that the device can be suitable for pile foundations with different pile lengths and pile diameters; all the components of the device are detachable, and one component can be freely detached and replaced after being damaged, so that the convenience and sustainability of the device are fully embodied.

Description

Technical Field

[0001] The utility model relates to the technical field of pile foundation integrity detection, in particular to a low-strain pile foundation excitation device. Background Art

[0002] When inspecting the quality of pile foundation projects, low-strain testing is often used to test the structural integrity of the pile body. The low-strain method uses low-energy transient or steady-state excitation at the pile top, measures the velocity time history curve or velocity admittance curve at the pile top, and then determines the pile body integrity through wave theory analysis or frequency domain analysis. The pile is assumed to be a one-dimensional elastic continuous rod. Vertical excitation at the pile top generates elastic waves, which propagate downward along the pile body. When the pile body has a significantly different interface (such as the pile bottom, a broken pile, or severe segregation) or a change in cross-sectional area (such as a shrinkage or expansion), the wave impedance changes, generating a reflected wave. The reflected signal is received by a sensor installed at the pile top. Amplification, filtering, and data processing are performed on the received reflected signal to identify reflected information from different parts of the pile body.

[0003] Traditional low-strain testing involves a hammer that freely falls and strikes the pile top, generating stress waves within the pile. The defect type is then identified based on the reflection characteristics of the stress wave at the impedance change location. During on-site testing, multiple measurements are usually required to obtain better test data. However, this manual operation of the hammer often results in inconsistent stress wave amplitudes.

[0004] Chinese patent CN201922058398.5 discloses "A portable pile foundation excitation device," with announcement number CN211816236U. The device includes an impact hammer, an impact hammer bracket, a lifting mechanism, and a fixed block. The impact hammer is fixed to the impact hammer bracket via a lifting mechanism, and the lifting mechanism can control the height of the impact hammer's free fall. The impact hammer bracket consists of a disc and several support rods, each of which has a hanging ring at one end, and the disc is provided with a through hole for allowing the hanging ring to pass through. The fixed block passes through the hanging ring, and the support rod is fixed to the disc via the fixed block. However, this device has some defects: within a certain elevation, the excitation generated by the device's impact hammer may be small, and the device cannot freely replace the hammer, which may not be suitable for longer or larger diameter pile foundations. Utility Model Content

[0005] In order to solve the above problems of the prior art, the utility model provides a low-strain pile foundation excitation device, which can effectively set the excitation force according to the pile length and pile diameter, and is suitable for pile foundations of different specifications within a certain range.

[0006] To achieve the above object, the utility model provides the following technical scheme: a low strain's pile foundation excitation device, including impact hammer, the support for fixing impact hammer, impact hammer sets up in the power mechanism for driving impact hammer to knock pile foundation, power mechanism includes the excitation rod of being connected on impact hammer, the support cylinder of being set on excitation rod, the top plate of being fixedly connected in support cylinder, the baffle of being set on excitation rod, the spring of being arranged between baffle and top plate, the locking assembly for the position of limiting baffle on excitation rod, excitation rod penetrates top plate up and down.

[0007] Adopt the structure design above, through compression spring, the elastic potential energy of spring elastic deformation is converted into the excitation force of impact hammer to pile foundation, can adjust the spring compression degree according to pile length and pile diameter, within a certain range, can be applicable to different specifications of pile foundation.

[0008] Preferably, the support includes an internal threaded cylinder that is threadably received on the support cylinder, a positioning plate that is fixedly connected to the internal threaded cylinder, and a leg that is hingedly connected to the positioning plate.

[0009] With the above structure design, it is convenient to adjust the leg according to the diameter and height of the pile foundation.

[0010] Preferably, an upper surface of the positioning plate is fixedly connected to a level bubble.

[0011] With the above structure design, it can be ensured that the impact hammer can vertically strike the pile foundation to generate the maximum excitation force.

[0012] Preferably, a protective cover is disposed below the support cylinder, the protective cover is threadably connected below the support cylinder, and the excitation rod penetrates the protective cover.

[0013] With the above structure design, the protective cover and the top plate together limit the excitation rod to ensure that the excitation rod can move vertically downward, while protecting the internal structure of the support cylinder.

[0014] Preferably, a lifting handle is disposed on an upper end of the excitation rod, a threaded rod is fixedly connected to the lifting handle, and a threaded hole that matches the threaded rod is formed on the upper end of the excitation rod.

[0015] With the above structure design, when the excitation rod is disassembled, the lifting handle can be disassembled without causing obstruction, and the damaged lifting handle can be replaced.

[0016] Preferably, a plurality of baffles are provided, and springs are disposed between the baffles and the top plate and between adjacent baffles.

[0017] With the above structure design, the plurality of springs act together to generate a greater excitation force.

[0018] Preferably, the locking assembly includes a locking ring sleeved on the excitation rod, a locking screw threaded through the locking ring, the locking screw passes through the excitation rod, and the excitation rod is provided with a plurality of through holes matching the locking screws.

[0019] By adopting the above structural design, the specifications and quantity of the springs can be adjusted according to the pile length and pile diameter, so as to be applicable to pile foundations with different pile lengths and pile diameters.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] 1) This device can adjust the specifications and quantity of the springs according to the pile length and pile diameter, and can also control the degree of compression of the springs to be suitable for pile foundations of different pile lengths and pile diameters.

[0022] 2) All components of the device are detachable. If a component is damaged, it can be freely removed and replaced. As the project continues to develop, if a greater excitation force is required, the spring with a higher impact coefficient can be replaced, which fully reflects the convenience and sustainability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural diagram of the utility model;

[0024] Figure 2 This is a schematic diagram of the structure of the power mechanism of the utility model;

[0025] Figure 3 For this utility model Figure 2 A in the middle is an enlarged structural diagram;

[0026] Figure 4 This is a schematic diagram of the structure of the impact hammer of the utility model; DETAILED DESCRIPTION

[0027] See also Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 The utility model provides a technical solution: a low-strain pile foundation excitation device, including an impact hammer 1 and a bracket 2 for fixing the impact hammer 1. The impact hammer 1 is arranged in a power mechanism for driving the impact hammer to strike the pile foundation. The power mechanism includes an excitation rod 11 connected to the impact hammer 1, a support tube 12 sleeved on the excitation rod 11, a top plate 13 fixedly connected to the support tube 12, a partition 14 sleeved on the excitation rod 11, a spring 15 arranged between the partition 14 and the top plate 13, and a locking component for limiting the position of the partition 14 on the excitation rod 11. The spring 15 is sleeved on the excitation rod 11, and the excitation rod 11 passes through the top plate 13 up and down.

[0028] The impact hammer 1 is provided with a mounting hole with an internal thread, and the lower end of the exciting rod 11 is provided with an external thread. The impact hammer 1 can be screwed to the lower end of the exciting rod 11. If a larger exciting force is required or to cope with other types of pile foundations, the impact hammer 1 can be replaced.

[0029] The bracket 2 comprises an internally threaded barrel 21 threadedly mounted on the support barrel 12, a positioning plate 22 fixedly connected to the internally threaded barrel 21, and a leg 23 hingedly connected to the positioning plate 22. A collar 26 is fixedly connected to the leg 23, through which a rope 25 is threaded. To facilitate insertion of the leg into the ground and enhance the stability of the bracket 2, the lower end of the leg 23 is conical. A vial 24 is fixedly connected to the upper surface of the positioning plate 22.

[0030] When the bracket 2 is in use, the legs 23 are first opened, and the positioning plate 22 is adjusted to a horizontal state according to the level bubble 24. The legs 23 are inserted into the ground outside the pile foundation, and then the staff passes the rope 25 through the ring 26 and fixes the end of the rope 25 to prevent the legs 23 from continuing to open.

[0031] A protective cover 16 is provided below the support tube 12 . The protective cover 16 is connected to the bottom of the support tube 12 via threads, and the exciting rod 11 passes through the protective cover 16 .

[0032] A lifting handle 3 is provided at the upper end of the exciting rod 11 , to which a threaded rod 31 is fixedly connected. A threaded hole matching the threaded rod 31 is provided at the upper end of the exciting rod 11 .

[0033] A plurality of partitions 14 are provided, and springs 15 are provided between the partitions 14 and the top plate 13 and between adjacent partitions 14 .

[0034] The locking assembly includes a locking ring 41 sleeved on the excitation rod 11, and a locking screw 42 threaded through the locking ring 41. The locking screw 42 passes through the excitation rod 11. The excitation rod 11 is provided with multiple through holes matching the locking screw 42. The locking screw 42 is in a bolt style.

[0035] In order to facilitate control of the length of the pulling of the vibration rod 11 , scale lines are provided on the outer surface of the vibration rod 11 .

[0036] Working principle: When assembling this device, the staff first assembles the power mechanism, and the staff first puts the locking ring 41, partition 14, and spring 15 on the exciting rod 11 in turn. The number of partitions 14 and springs 15 and the elastic coefficient of the spring 15 are selected according to the pile foundation. Then the staff rotates the locking screw 42, passes the locking screw 42 through the exciting rod 11, and then fixes the locking ring 41 on the exciting rod 11. Then the staff inserts the exciting rod 11 into the support tube 12, the upper end of the spring 15 rests on the top plate 13, and the partition 14 rests on the locking ring 41. Then the staff screws the protective cover 16 to the lower end of the support tube 12. Then the staff screws the lifting handle 3 to the upper end of the exciting rod 11, and the impact hammer 1 is screwed to the lower end of the exciting rod 11. Then the staff screws the support tube 12 to the internal threaded tube 21; next, the staff fixes the bracket 2, first opens the leg 23, and adjusts the positioning plate 22 to a horizontal state according to the level bubble 24. Insert the support leg 23 into the ground outside the pile foundation, then the staff passes the rope 25 through the ring 26 and fixes the end of the rope 25 to prevent the support leg 23 from continuing to open; next, the staff rotates the support tube 12 so that the impact hammer 1 can rest on the top surface of the pile foundation, and then the staff lifts the lifting handle 3 and compresses the spring 15, so that the impact hammer 1 generates an exciting force on the pile foundation.

[0037] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in this specification for the understanding and reading of those familiar with this technology. They are not used to limit the conditions for the implementation of this utility model and therefore have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed in this utility model without affecting the efficacy and purpose of the utility model. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description and are not used to limit the scope of the implementation of this utility model. Changes or adjustments in their relative relationships should also be considered as the scope of the implementation of this utility model without substantially changing the technical content.

[0038] The present invention has been described above with reference to preferred embodiments. However, the scope of protection of the present invention is not limited thereto. All technical solutions falling within the scope of the claims are within the scope of protection of the present invention. Various improvements may be made to the present invention, and components may be replaced with equivalents without departing from the scope of the present invention. In particular, the various technical features described in the various embodiments may be combined in any manner, as long as there are no structural conflicts.

Claims

1. A low-strain pile foundation excitation device, comprising an impact hammer (1) and a bracket (2) for fixing the impact hammer (1), characterized in that: The impact hammer (1) is arranged on a power mechanism for driving the impact hammer to strike a pile foundation, the power mechanism comprising a vibration rod (11) connected to the impact hammer (1), a support tube (12) sleeved on the vibration rod (11), a top plate (13) fixedly connected to the support tube (12), a partition (14) sleeved on the vibration rod (11), a spring (15) arranged between the partition (14) and the top plate (13), and a locking assembly for limiting the position of the partition (14) on the vibration rod (11), wherein the vibration rod (11) passes through the top plate (13) from top to bottom.

2. A low-strain pile foundation excitation device according to claim 1, characterized in that: The bracket (2) comprises an internal threaded cylinder (21) threadedly sleeved on a support cylinder (12), a positioning plate (22) fixedly connected to the internal threaded cylinder (21), and a support leg (23) hinged to the positioning plate (22).

3. The low-strain pile foundation excitation device according to claim 2, characterized in that: The upper surface of the positioning plate (22) is fixedly connected to a level bubble (24).

4. The low-strain pile foundation excitation device according to claim 1, characterized in that: A protective cover (16) is provided below the support tube (12), the protective cover (16) is connected to the bottom of the support tube (12) through threads, and the exciting rod (11) passes through the protective cover (16).

5. The low-strain pile foundation excitation device according to claim 1, characterized in that: A lifting handle (3) is provided at the upper end of the exciting rod (11), a threaded rod (31) is fixedly connected to the lifting handle (3), and a threaded hole matching the threaded rod (31) is provided at the upper end of the exciting rod (11).

6. The low-strain pile foundation excitation device according to claim 1, characterized in that: A plurality of partitions (14) are provided, and springs (15) are provided between the partitions (14) and the top plate (13) and between adjacent partitions (14).

7. A low-strain pile foundation excitation device according to any one of claims 1 to 6, characterized in that: The locking assembly comprises a locking ring (41) sleeved on the excitation rod (11), a locking screw (42) threadedly passed through the locking ring (41), the locking screw (42) passing through the excitation rod (11), and a plurality of through holes matching the locking screw (42) are provided on the excitation rod (11).

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