Positioning mechanism of low-strain pile foundation detection hammer

Abstract

The utility model relates to a positioning mechanism of a low-strain pile foundation detection hammer, which comprises a positioning cylinder, a rubber seat and a rubber pad, the detection hammer is inserted into the positioning cylinder, the rubber seat is arranged below the positioning cylinder, the rubber pad is arranged in the rubber seat, an accommodating cavity is formed at the bottom of the rubber seat, and the rubber pad is detachably arranged in the accommodating cavity. According to the positioning mechanism of the low-strain pile foundation detection hammer, the stability of the detection hammer is achieved through the positioning cylinder, errors caused by shaking or deviation of the hammer body in the hammering process can be effectively reduced, and therefore the accuracy and stability of low-strain pile foundation detection are improved; according to the invention, the control of the hammering position and angle is more accurate and easy to repeat, the time consumed by repeatedly adjusting the hammering position is reduced, and meanwhile, the stable hammering effect ensures the quality of signals acquired each time and reduces the number of invalid acquisition times, so that the detection efficiency is remarkably improved.

Description

Technical Field

[0001] This utility model relates to a positioning mechanism for a low-strain pile foundation testing hammer, belonging to the field of engineering pile foundation testing technology. Background Technology

[0002] The core principle of low-strain testing technology lies in stress wave theory. This technology applies a dynamic force (i.e., dynamic load) to the pile top, which can be a transient impact force or a steady-state excitation force, thereby stimulating the dynamic response of the pile-soil system. Using sensors with various functions, we can accurately capture and measure the dynamic response signals generated at the pile top, encompassing multiple dimensions such as displacement, velocity, and acceleration. By performing time-domain analysis or transfer function analysis on these signals, the integrity of the pile structure can be scientifically assessed.

[0003] Currently, the hammer impact method is commonly used for vibration testing in low-strain testing. It is worth noting that the required vibration energy is directly proportional to the pile length; that is, the longer the pile, the greater the required vibration energy. Therefore, in practice, the type of hammer must be selected appropriately based on the pile length. In particular, when the pile length being tested reaches or exceeds 30 meters, a heavier hammer—a cast iron force bar (weighing up to 15 kg)—must be used to ensure sufficient vibration energy.

[0004] According to relevant specifications, when acquiring low-strain signals, 2 to 4 sensor-equipped detection points should be symmetrically arranged around the pile core to ensure the comprehensiveness and accuracy of the data. Each detection point should record no fewer than 3 valid signals, and these signals must be authentic, distortion-free, and free of zero drift. Furthermore, the acquired signals should exhibit good consistency.

[0005] However, when signal acquisition is performed manually using a hammer, the large mass and strong inertia of the hammer make it difficult to precisely control the position and angle of the impact, thus affecting the consistency and stability of the hammering effect. Therefore, each signal acquisition requires multiple repeated hammerings, which is not only time-consuming and labor-intensive but also reduces detection efficiency. Furthermore, cast iron hammerheads tend to generate high-frequency signals, which contain a lot of noise. Because high-frequency signals have short wavelengths, energy loss during transmission is significant, making the acquisition of pile bottom reflection signals particularly difficult. Utility Model Content

[0006] The purpose of this invention is to provide a positioning mechanism for a low-strain pile foundation testing hammer, which can effectively improve the accuracy, stability, adaptability and efficiency of pile foundation testing, while protecting the pile top structure and optimizing signal quality, bringing significant improvements and convenience to the field of pile foundation quality testing.

[0007] To achieve the above objectives, this utility model provides the following technical solution: a positioning mechanism for a low-strain pile foundation testing hammer, comprising a positioning cylinder for inserting the testing hammer, a rubber seat disposed below the positioning cylinder, and a rubber pad disposed within the rubber seat, wherein a receiving cavity is formed at the bottom of the rubber seat, and the rubber pad is detachably disposed within the receiving cavity.

[0008] Furthermore, the accommodating cavity is provided with a groove for fixing the edge of the rubber pad.

[0009] Furthermore, the positioning cylinder and the rubber seat are detachably connected.

[0010] Furthermore, the positioning cylinder and the rubber seat are connected by bolts.

[0011] Furthermore, the positioning cylinder includes a base and an extension cylinder, the extension cylinder being superimposed on the base to extend the base in the longitudinal direction.

[0012] Furthermore, the base and the extension cylinder, which are arranged adjacent to each other, are connected and fixed by a clamp structure.

[0013] Furthermore, the clamp structure includes a first groove, a second groove, and a clamp that simultaneously engages with the first groove and the second groove. The first groove is formed on the outer cylinder surface of the base near the upper port side, and the second groove is formed on the outer cylinder surface on the side where the extension cylinder connects with the base.

[0014] Furthermore, an insertion structure is formed between the base and the extension cylinder. The insertion structure includes an insertion groove and an insertion block that engages with the insertion groove. The insertion groove is formed on one of the base and the extension cylinder, and the insertion block is formed on the other of the base and the extension cylinder.

[0015] Furthermore, a reinforcing structure is formed on the sidewall of the accommodating cavity.

[0016] Furthermore, the positioning cylinder includes a housing for accommodating the detection hammer and a cylindrical body disposed on the housing for accommodating the rod of the detection hammer. The inner diameter of the housing is equal to the inner diameter of the cylindrical body, and the housing and the cylindrical body are detachably connected.

[0017] The beneficial effects of this utility model are as follows: By adopting the positioning mechanism of the low-strain pile foundation testing hammer of this application, the stability of the testing hammer is achieved by the positioning cylinder, which can effectively reduce the error caused by the hammer body shaking or deviation during the hammering process, thereby improving the accuracy and stability of low-strain pile foundation testing. It also makes the control of the hammering position and angle more precise and easy to repeat, reducing the time consumed by repeatedly adjusting the hammering position. At the same time, the stable hammering effect ensures the signal quality of each acquisition, reduces the number of invalid acquisitions, and thus significantly improves the testing efficiency. Furthermore, by setting a rubber seat and rubber pad below the positioning cylinder, the stability during hammering is further enhanced, ensuring that each hammering can act on the pile top with the predetermined force and angle, improving data consistency. Moreover, by using the rubber pad as a buffer layer, the impact force generated by the hammering can be effectively absorbed, reducing direct impact damage to the pile top and extending the service life of the pile top and the testing equipment. In addition, the rubber pad can also effectively filter out noise, making the test results easier to analyze and more accurate.

[0018] The above description is only an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, the preferred embodiments of this utility model are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the positioning mechanism according to an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the structure of the extension tube according to an embodiment of the present invention;

[0021] Figure 3 Waveforms detected by positioning mechanisms that do not use this application;

[0022] Figure 4 The waveform detected by the positioning mechanism of this application. Detailed Implementation

[0023] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0024] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "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. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] 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.

[0026] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0027] Please combine Figure 1 A preferred embodiment of this application shows a positioning mechanism (hereinafter referred to as the positioning mechanism) for a low-strain pile foundation testing hammer 100, comprising a positioning cylinder 10 for inserting the testing hammer, a rubber seat 20 disposed below the positioning cylinder 10, and a rubber pad 30 disposed within the rubber seat 20. A receiving cavity 21 is formed at the bottom of the rubber seat 20, and the rubber pad 30 is detachably disposed within the receiving cavity 21. In this embodiment, the positioning cylinder 10 comprises a housing 11 for housing the hammer body 101 of the testing hammer 100 and a cylindrical body 12 disposed on the housing 11 for housing the rod body 102 of the testing hammer 100. The inner diameter of the housing 11 is equal to or approximately equal to the inner diameter of the cylindrical body 12. The housing 11 and the cylindrical body 12 are detachably connected for mounting the testing hammer 100.

[0028] By employing the positioning mechanism of this application, the positioning cylinder 10 achieves stability of the testing hammer 100, effectively reducing errors caused by hammer swaying or deviation during hammering, thereby improving the accuracy and stability of low-strain pile foundation testing. It also makes the control of hammering position and angle more precise and repeatable, reducing the time spent on repeatedly adjusting the hammering position. Simultaneously, the stable hammering effect ensures the signal quality of each acquisition, reducing invalid acquisitions and significantly improving testing efficiency. Furthermore, by setting a rubber seat 20 and a rubber pad 30 below the positioning cylinder 10, the stability during hammering is further enhanced, ensuring that each hammering strike acts on the pile top with the predetermined force and angle, improving data consistency. Moreover, the rubber pad 30, acting as a buffer layer, effectively absorbs the impact force generated by the hammering, reducing direct impact damage to the pile top and extending the service life of the pile top and testing equipment. In addition, the rubber pad 30 effectively filters out noise, making the test results easier to analyze and more accurate.

[0029] In this embodiment, the rubber pad 30 can be cut from discarded bicycle or electric bicycle tires, achieving the purpose of waste utilization. In other embodiments, the rubber pad 30 can also be a custom-made part, and the rubber pad 30 can be a multi-layer structure, such as using rubber layers of different hardness and density to achieve a better shock absorption effect. A reinforcing structure, such as reinforcing ribs, is formed on the sidewall of the accommodating cavity 21, thereby improving the strength of the reinforcing seat.

[0030] In this embodiment, the rubber pad 30 is detachably disposed within the receiving cavity 21 to facilitate replacement of the rubber pad 30. Specifically, the receiving cavity 21 is provided with a groove 22 for fixing the edge of the rubber pad 30, which reduces the difficulty of manual placement and makes it more labor-saving.

[0031] The positioning cylinder 10 and the rubber seat 20 are detachably connected. Specifically, the positioning cylinder 10 and the rubber seat 20 are connected by bolts (not shown). Specifically, the positioning cylinder 10 has side wings (not shown), and corresponding bolt holes (not shown) are formed on the side wings and the rubber seat, into which the bolts are inserted. By making the positioning cylinder 10 and the rubber seat 20 detachably connected, it is convenient to adjust the positioning cylinder 10 and the rubber seat 20 to suit pile foundations of different sizes and shapes.

[0032] To accommodate detection hammers 100 of different lengths, in one embodiment, the positioning cylinder 10 includes a base 13 (in this embodiment, the base 13 includes...). Figure 1The base 13 consists of a box body 11 and a cylinder body 12, and an extension cylinder 14, which is stacked on top of the base 13 to extend the base 13 in the longitudinal direction. The positioning cylinder 10 is configured as two parts: the base 13 and the extension cylinder 14, which also facilitates handling. For easier connection, in an alternative embodiment, the base 13 and the extension cylinder 14, which are arranged vertically adjacent to each other, are connected and fixed by a clamp structure. Specifically, the clamp structure includes a first groove 15, a second groove 16, and a clamp (not shown) that simultaneously engages with the first groove 15 and the second groove 16. The first groove 15 is formed on the outer cylinder surface of the base 13 near the upper port, and the second groove 16 is formed on the outer cylinder surface of the extension cylinder 14 on the side where it connects with the base 13. In this embodiment, in order to facilitate the docking between the base 13 and the extension cylinder 14 and improve the assembly efficiency between the two, an insertion structure is formed between the base 13 and the extension cylinder 14. The insertion structure includes an insertion groove 17 and an insertion block 18 that is inserted into the insertion groove 17. The insertion groove 17 is formed on one of the base 13 and the extension cylinder 14, and the insertion block 18 is formed on the other of the base 13 and the extension cylinder 14.

[0033] The positioning mechanism is used as an example, taking only the base 13 as an example:

[0034] Step 1: Install the box body 11 on the rubber seat 20, then place the hammer body 101 of the detection hammer 100 inside the box body 11, then put the cylinder body 12 on the rod body 102 of the detection hammer 100, fix the cylinder body 12 on the box body 11, and finally install the rubber pad 30 inside the receiving cavity 21.

[0035] Step 2: Position the positioning mechanism at the center of the pile to be measured, and install the sensor at a distance of 2 / 3 radius from the center of the pile.

[0036] Step 3: Lift the test hammer 100, and the test hammer 100 strikes downward along the positioning cylinder 10 and vibrates, generating a vibration signal while the dynamic measuring instrument collects the signal.

[0037] Tests have shown that, compared to existing technologies, the detection time for each pile has been reduced by 3-5 minutes, improving detection efficiency. Furthermore, the positioning mechanism effectively filters out interference, resulting in clearer reflected signals from the pile bottom and shortening analysis time for personnel. Figure 3 and Figure 4 The model was collected from the same 50.5m bored pile. Figure 3 The waveforms detected by the positioning mechanism that did not use this application are shown. Figure 4 This is a waveform diagram detected using the positioning mechanism described in this application. Figure 3 It is known that shallow oscillations generate a lot of clutter signals, which can easily lead to misjudgment by analysts, and the bottom pile reflection signals are not clear. Figure 4It can be seen that the shallow signal is clear and distinct, without any noise interference, and the reflection at the bottom of the pile is clearly visible.

[0038] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0039] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A positioning mechanism for a low-strain pile foundation testing hammer, characterized in that, It includes a positioning cylinder for inserting a detection hammer, a rubber seat disposed below the positioning cylinder, and a rubber pad disposed within the rubber seat. The bottom of the rubber seat has a receiving cavity, and the rubber pad is detachably disposed within the receiving cavity.

2. The positioning mechanism of the low-strain pile foundation testing hammer as described in claim 1, characterized in that, The cavity is provided with a groove for fixing the edge of the rubber pad.

3. The positioning mechanism of the low-strain pile foundation testing hammer as described in claim 1, characterized in that, The positioning cylinder and the rubber seat are detachably connected.

4. The positioning mechanism of the low-strain pile foundation testing hammer as described in claim 1, characterized in that, The positioning cylinder and the rubber seat are connected by bolts.

5. The positioning mechanism of the low-strain pile foundation testing hammer as described in claim 1, characterized in that, The positioning cylinder includes a base and an extension cylinder, the extension cylinder being superimposed on the base so that the base extends in the longitudinal direction.

6. The positioning mechanism of the low-strain pile foundation testing hammer as described in claim 5, characterized in that, The base and the extension cylinder, which are arranged adjacent to each other, are connected and fixed by a clamp structure.

7. The positioning mechanism of the low-strain pile foundation testing hammer as described in claim 6, characterized in that, The clamp structure includes a first groove, a second groove, and a clamp that simultaneously engages with the first groove and the second groove. The first groove is formed on the outer cylinder surface of the base near the upper port side, and the second groove is formed on the outer cylinder surface of the extension cylinder on the side where it connects with the base.

8. The positioning mechanism of the low-strain pile foundation testing hammer as described in claim 7, characterized in that, An insertion structure is formed between the base and the extension cylinder. The insertion structure includes an insertion groove and an insertion block that engages with the insertion groove. The insertion groove is formed on one of the base and the extension cylinder, and the insertion block is formed on the other of the base and the extension cylinder.

9. The positioning mechanism of the low-strain pile foundation testing hammer as described in claim 1, characterized in that, A reinforcing structure is formed on the sidewall of the accommodating cavity.

10. The positioning mechanism of the low-strain pile foundation testing hammer as described in claim 1, characterized in that, The positioning cylinder includes a housing for holding the detection hammer and a cylindrical body disposed on the housing for holding the detection hammer. The inner diameter of the housing is equal to the inner diameter of the cylindrical body, and the housing and the cylindrical body are detachably connected.

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