A low strain detection device for a pile

Abstract

The utility model belongs to civil engineering detection equipment field especially relates to a low strain detection device of foundation pile. Including detector, sensor probe and exciting hammer, still including center tube, the exciting hammer is sleeved in the center tube, the exciting hammer includes the hammer body that sets up in the cylindrical shape and sets up rubber column at the bottom of hammer body, the top of hammer body is provided with operating rod, operating rod sets up in the center tube, operating rod is sleeved with exciting spring, the utility model provides a low strain detection device of foundation pile, improves the structure of existing exciting hammer through, makes it convenient and center tube cooperation, reaches the purpose that knocks the foundation pile, simultaneously, utilizes the setting of positioning rod, and the position of sensor probe is convenient to determine when detecting the included angle, thereby reduces the position determination time, improves work efficiency.

Description

Technical Field

[0001] This utility model belongs to the field of civil engineering testing equipment, and in particular relates to a low strain testing device for foundation piles. Background Technology

[0002] Low-strain testing of foundation piles is one of the core methods for quality inspection of engineering pile foundations. The core of it is to determine the integrity of the pile body by vibrating the top of the pile with low energy and using the principle of stress wave reflection. It belongs to non-destructive testing technology and is widely used in the construction quality acceptance of various foundation piles such as cast-in-place concrete piles and precast piles.

[0003] During the specific testing, staff use equipment such as small hammers and vibratory hammers to apply low-energy impacts to the top of the pile (without damaging the pile structure), which excites the pile to generate longitudinal stress waves. The stress waves propagate downwards along the pile and are reflected when they encounter pile defects (such as cracks, broken piles, or necking) or the bottom of the pile. The reflected signals are received by sensors at the top of the pile, and the time and frequency domain characteristics of the signals are analyzed by a detector to determine the integrity of the pile (whether there are defects), the location of the defects, and the length of the pile (as an auxiliary judgment).

[0004] Because the testing process requires diagonal or angled detection, when the pile diameter is less than 1.2m, diagonal detection is needed, requiring only two points. When the pile diameter is greater than or equal to 1.2m, angled detection is required, meaning the angle between adjacent detection points must be 120°. This necessitates that staff take measurements and draw the measurement points. Additionally, the detection points must avoid the pile top edge (≥50mm from the pile edge) and the central excitation point (≥200mm from the excitation point). These testing conditions limit the efficiency of pile testing. Utility Model Content

[0005] This invention addresses the technical problem of low testing efficiency caused by numerous existing pile testing conditions by proposing a pile low-strain testing device that is rationally designed, simple in structure, easy to manufacture, and can significantly improve testing efficiency.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows: This utility model provides a low-strain detection device for foundation piles, including a detector, a sensor probe, and a vibration hammer, and also includes a central tube. The vibration hammer is fitted inside the central tube. The vibration hammer includes a cylindrical hammer body and a rubber column at the bottom of the hammer body. An operating rod is provided at the top of the hammer body, extending out of the central tube. An excitation spring is fitted on the operating rod and is located between the central tube and the hammer body. A positioning rod is provided on the side wall of the central tube. The positioning rod is evenly distributed in a ring on the side wall of the central tube. A sliding groove is provided on the positioning rod, and a slider is provided in the sliding groove. The slider is slidably disposed in the sliding groove. A fixed seat is provided at the end of the slider near the central tube. A through hole is provided on the fixed seat, and the sensor probe can be placed in the through hole. A connecting rod is provided at the bottom of the slider, and a baffle is provided at the end of the connecting rod away from the slider. The horizontal distance between the baffle and the through hole is greater than 50mm.

[0007] Preferably, the baffle is an arc-shaped plate.

[0008] Preferably, the included angle between adjacent positioning rods is 120°.

[0009] Preferably, the positioning rod is inserted into the outer wall of the central tube.

[0010] Compared with the prior art, the advantages and positive effects of this utility model are as follows: This utility model provides a low-strain detection device for foundation piles. By improving the structure of the existing vibratory hammer, it is made easier to cooperate with the central tube to achieve the purpose of striking the foundation pile. At the same time, the positioning rod is used to facilitate the determination of the position of the sensor probe when detecting the included angle, thereby reducing the position determination time and improving work efficiency. Attached Figure Description

[0011] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of the low strain detection device for foundation piles provided in Example 1; Figure 2 A top view of the low strain detection device for foundation piles provided in Example 1; Figure 3 This is a schematic diagram of the structure between the central tube in a semi-sectioned state and the excitation hammer provided in Example 1; Figure 4 This is a schematic diagram of the structure between the slider and the detector provided in Example 1; In the above figures, 1 is the detector; 11 is the sensor probe; 2 is the excitation hammer; 21 is the hammer body; 22 is the rubber column; 23 is the operating rod; 24 is the limit post; 3 is the excitation spring; 4 is the central tube; 41 is the slot; 5 is the positioning rod; 51 is the sliding groove; 6 is the slider; 61 is the fixed base; 62 is the connecting rod; and 63 is the baffle. Detailed Implementation

[0013] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0014] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed in the following specification.

[0015] Example 1, such as Figures 1-4 As shown, this embodiment aims to solve the problem of determining the time of the existing sensor probe 11 on the foundation pile. To this end, the foundation pile low strain detection device provided in this embodiment includes a detector 1, a sensor probe 11 and a vibration hammer. The above devices are common devices in existing foundation pile low strain detection devices, so they will not be described in detail in this embodiment.

[0016] To achieve rapid positioning, it would be best to have an existing template for convenient positioning. Ideally, the center of the existing position should be determined, but this would affect the use of the vibration hammer 2. Therefore, in this embodiment, the structure of the vibration hammer 2 is improved. Specifically, it includes a central tube 4, which is cylindrical with a cap at the top. The vibration hammer 2 is housed within the central tube 4. Specifically, the vibration hammer 2 includes a cylindrical hammer body 21 and a rubber column 22 at the bottom of the hammer body 21. An operating rod 23, also cylindrical, is located at the top of the hammer body 21. Thus, the hammer body 21, rubber column 22, and operating rod 23 are coaxially arranged. The operating rod 23 extends out of the central tube 4. In this embodiment, to prevent the vibration hammer 2 from falling, a limiting post 24 is threaded onto the top of the operating rod 23. The diameter of the limiting post 24 is larger than the opening at the top of the central tube 4, thus preventing it from falling.

[0017] An excitation spring 3 is mounted on the operating rod 23. The excitation spring 3 is located between the central tube 4 and the hammer body 21. In this way, during the test, the operator grabs the extended part of the operating rod 23 or the limiting post 24, pulls it up, compresses the excitation spring 3, and releases it. Under the reaction force of the excitation spring 3, the foundation pile is struck.

[0018] To achieve positioning, positioning rods 5 are provided on the side wall of the central tube 4. The positioning rods 5 are evenly distributed in a ring on the side wall of the central tube 4. Since the most troublesome part is determining the three-point detection (after determining one point through two-point detection, it can be directly moved symmetrically), the included angle between adjacent positioning rods 5 is 120°. Considering that the diameter of the foundation pile is more than 1.2m and the entire structure is large, in this embodiment, the end of the positioning rod 5 near the central tube 4 is set in a T-shape, and a slot 41 is provided on the side wall of the central tube 4. The slot 41 on one side is set in an L-shape, so that the positioning rod 5 can be inserted into the outer wall of the central tube 4 for easy carrying.

[0019] In this embodiment, the positioning rod 5 is generally rectangular in shape. A sliding groove 51 is provided on the positioning rod 5, extending through both the upper and lower ends of the positioning rod 5 and the end furthest from the central tube 4. The distance between the sliding groove 51 and the central tube 4 is greater than 200mm, thus ensuring the requirement of distance from the center of the foundation pile. Guide grooves (not shown in the figure) are also provided on both sides of the sliding groove 51. A slider 6 is installed inside the sliding groove 51, and the width of the slider 6 can extend into the guide groove, thus preventing the slider 6 from falling out and allowing it to slide within the sliding groove. The slider 6 is a rectangular block. A fixing seat 61 is provided at the end of the slider 6 near the central tube 4. The fixing seat 61 is also a rectangular block, but its width is smaller than the width of the sliding groove 51, forming a T-shape with the slider 6. A through hole is provided on the fixing seat 61, into which the sensor probe 11 can be placed, ensuring that the sensor probe 11 can contact the top surface of the foundation pile.

[0020] To better determine the position of the sensor probe 11, a connecting rod 62 is provided at the bottom of the slider 6, and a baffle 63 is provided at the end of the connecting rod 62 away from the slider 6. The horizontal distance between the baffle 63 and the through hole is greater than 50mm. In this way, the baffle 63 contacts the side wall of the pile, and the horizontal distance between the baffle 63 and the through hole is greater than 50mm, which meets the requirement that the detection point should avoid the edge of the pile top. In order to better fit the outer wall of the pile, the baffle 63 is an arc-shaped plate.

[0021] After cleaning the foundation pile, assemble the central tube 4 and the top rod, place the central tube 4 at the center of the foundation pile, push the slider 6 to make the baffle 63 fit against the outer wall of the foundation pile, then inject coupling agent into the through hole and insert the sensor probe 11. Repeat this process to complete the measurement. Alternatively, a positioning groove can be set on the side plate of the positioning rod 5, and locking bolts can be installed on the side wall of the slider 6. At the same time, a scale can be set on the side wall of the positioning rod 5. In this way, by fixing the slider 6 of any one of the positioning rods 5 on the scale of the foundation pile radius, the center of the foundation pile can be quickly determined. Then, push the remaining two sliders 6.

[0022] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present utility model without departing from the technical solution of the present utility model shall still fall within the protection scope of the technical solution of the present utility model.

Claims

1. A low-strain testing device for foundation piles, comprising a testing instrument, a sensor probe, and a vibration hammer, characterized in that, It also includes a central tube, within which the excitation hammer is housed. The excitation hammer comprises a cylindrical hammer body and a rubber column at the bottom of the hammer body. An operating rod is located at the top of the hammer body, extending out of the central tube. An excitation spring is mounted on the operating rod and positioned between the central tube and the hammer body. Positioning rods are located on the side wall of the central tube, evenly distributed in a ring on the side wall. Each positioning rod has a sliding groove, within which a slider is slidably positioned. A fixed seat is located at the end of the slider near the central tube, with a through hole for placing the sensor probe. A connecting rod is located at the bottom of the slider, with a baffle at the end of the connecting rod away from the slider. The horizontal distance between the baffle and the through hole is greater than 50 mm.

2. The low-strain detection device for foundation piles according to claim 1, characterized in that, The baffle is an arc-shaped plate.

3. The low-strain detection device for foundation piles according to claim 2, characterized in that, The included angle between adjacent positioning rods is 120°.

4. The low strain detection device for foundation piles according to claim 3, characterized in that, The positioning rod is inserted and installed on the outer wall of the central tube.

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