Device and method for precast pile integrity test through soil-core probe penetration

Abstract

A device and a method for precast pile integrity test through soil-core probe penetration are provided. The device includes a pipe pile to be tested, a connection frame is installed on a top surface of the pipe pile to be tested, a hydraulic telescopic rod is fixedly connected to a top of the connection frame, a bottom of the hydraulic telescopic rod is connected to a probe rod via a casing flange plate, and an end of the probe rod away from the casing flange plate is provided with a probe.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation of International Patent Application No. PCT / CN2025 / 143367, filed December 18, 2025 and claims priority of Chinese Patent Application No. 202510222396.2, filed on February 27, 2025. The entire contents of International Patent Application No. PCT / CN2025 / 143367 and Chinese Patent Application No. 202510222396.2 are incorporated herein by reference.TECHNICAL FIELD

[0002] The disclosure belongs to the technical field of pile foundation test, and in particular relates to a device and a method for foundation pile integrity test of precast pile through soil-core probe penetration.BACKGROUND

[0003] Precast pipe pile technology occupies an important position in foundation engineering. The industrialized production and efficient construction of precast pipe piles significantly improve the construction efficiency and project quality of modern buildings. Precast pipe piles are widely used in large structures such as high-rise buildings, bridges, and ports. Compared with other types of piles, the precast pipe pile has advantages such as high strength, excellent mechanical properties, adaptability to complex geological conditions, convenient construction, and outstanding durability, making it an efficient pile foundation solution widely used in modern foundation engineering. To facilitate urban transportation and on-site hoisting, precast pipe piles produced in factories are often transported to the site for assembly. After being transported to the site, the precast pipe piles need to be connected section by section through splicing to reach the designed depth. However, due to the presence of spliced pile joints, commonly used pile integrity test methods such as the low-strain integrity testing and the crosshole sonic logging method face some difficulties and challenges.

[0004] The low-strain integrity testing is a non-destructive testing method used to assess pile integrity. The method mainly judges the integrity and defects of the pile body by analyzing the propagation characteristics of stress waves in the pile body. Due to the advantages such as rapid efficiency, good portability, and low cost, the method is widely used in actual engineering test. However, when detecting precast spliced pile, because there is a significant difference in impedance between the joints of the precast spliced pile and the pile body, stress waves are prone to induce strong reflection interference at the joints, resulting in test results that typically reflect only the integrity within the range of the first section of the pile, severely hindering the identification of the pile toe reflection signal.

[0005] The crosshole sonic logging method is mainly used for large-diameter bored cast-in-place piles. By transmitting and receiving sound waves between pre-embedded sonic tubes and using relative changes in measured acoustic parameters such as the sound time of sound waves propagating in the concrete medium, the integrity of the pile body is detected. Because the interior of pipe piles is hollow, the crosshole sonic logging method may not be applied to the test of precast pipe piles.

[0006] The cone penetration test (CPT) is one of the most classic in-situ geotechnical testing technologies. This technology was invented in 1932 by Dutch engineer Pieter Barentsen and was used for experimental research on pile bearing capacity. After nearly a century of development, CPT equipment has undergone iterative innovations characterized by mechanical, electric measurement, electronic, and digital types. Currently, probes in CPT devices integrate more test channels. Besides being able to measure cone tip resistance and sleeve friction, the probes may also measure other parameters such as pore water pressure, resistivity, and groundwater pH value.

[0007] To overcome the shortcomings of existing test methods and achieve integrity test of precast pipe pile, a device and a method for foundation pile integrity test of precast pile through soil-core probe penetration are proposed.SUMMARY

[0008] An objective of the present disclosure is to provide a device and a method for precast pile integrity test through soil-core probe penetration to solve the problems existing in the prior art.

[0009] To achieve the above objective, the disclosure provides the following solution: the disclosure provides a device for foundation pile integrity test of precast pile through soil-core probe penetration, including a pipe pile to be tested, where a connection frame is installed on a top surface of the pipe pile to be tested, a hydraulic telescopic rod is fixedly connected to a top of the connection frame, a bottom of the hydraulic telescopic rod is connected to a probe rod via a casing flange plate, and an end of the probe rod away from the casing flange plate is provided with a probe.

[0010] In some embodiments, a pipe pile flange plate is fixedly connected to the top surface of the pipe pile to be tested, connection seats are symmetrically provided on a top surface of the pipe pile flange plate, the connection frame includes two vertical rods symmetrically threadedly connected to the connection seats, top surfaces of the two vertical rods are fixedly connected with a horizontal rod, the horizontal rod and the two vertical rods are fixed via right-angle couplers, and the hydraulic telescopic rod is fixedly connected to the horizontal rod.

[0011] In some embodiments, the probe is internally provided with a three-direction geophone.

[0012] A method for foundation pile integrity test of precast pile through soil-core probe penetration is provided, which includes the following steps:

[0013] S1, installing the connection frame, fixing the two vertical rods to the pipe pile flange plate;

[0014] S2, installing the hydraulic telescopic rod, mounting the hydraulic telescopic rod on the horizontal rod, and fixing the horizontal rod to the two vertical rods via the right-angle couplers;

[0015] S3, installing the probe, fixing the probe to one end of the probe rod, and fixing another end of the probe rod to a bottom of the hydraulic telescopic rod through the casing flange plate;

[0016] S4, inserting the probe and the probe rod vertically into the pile core soil, pressing the probe into the soil at a speed of 20 to 25 millimeters per second (mm / s); and continuously recording vertical static parameters of the soil at different depths through the probe; and

[0017] S5, during a process of pressing in the probe rod, for every certain distance pressed, using a test hammer to strike a top of the pipe pile to be tested, collecting a dynamic response signal of the soil at a depth where the probe is located, and repeating measurement steps until the probe is pressed below a length of the pipe pile to be tested.

[0018] The disclosure discloses the following technical effects. The disclosure utilizes the probe to collect fluctuations of the pile core soil caused by pile body vibration and judges the integrity of the precast spliced pile through the collected soil velocity response time-depth signal. Besides equipment such as the cone tip resistance sensor and side friction resistance sensor in the probe, which may collect the basic physical and mechanical properties of the soil plug and the side friction resistance during penetration, the probe is also integrated with a three-direction geophone, enabling the collection of soil response caused by pile body vibration. The hydraulic telescopic rod provides penetration force for the probe, enabling the probe to penetrate into the pile core soil plug at a constant speed. For every certain depth penetrated, a test hammer is used to strike the pile top, the depth at which the vibration response of the pile core soil is first received is the height of the pile core soil plug. When the probe penetrates deep to the pile toe, the characteristic value of the pile toe bearing capacity of the precast pipe pile may also be estimated through the physical and mechanical indicators measured by the cone tip resistance sensor.BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings constituting a part of the present disclosure are used to provide further understanding of the present disclosure. The schematic embodiments and descriptions of the present disclosure are used to explain the present disclosure and do not constitute an improper limitation of the present disclosure. In the drawings:

[0020] FIG. 1 is a schematic structural diagram of a device for foundation pile integrity test of precast pile through soil-core probe penetration according to the present disclosure.

[0021] FIG. 2 is a schematic internal structural diagram of a probe according to the present disclosure.

[0022] FIG. 3 is a front view of the device for foundation pile integrity test of precast pile through soil-core probe penetration according to the present disclosure.

[0023] FIG. 4 is a flowchart of a method for foundation pile integrity test of precast pile through soil-core probe penetration according to the present disclosure.DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] In the following, the technical solutions in the embodiments of the present disclosure will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present disclosure. Apparently, the described embodiments are only a part of the embodiments of the present disclosure, not all the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by one of ordinary skill in the art without creative effort belong to the protection scope of the present disclosure.

[0025] In order to make the above objects, features and advantages of the present disclosure clearer and more understandable, the present disclosure will be further described in detail with the attached drawings and specific embodiments.

[0026] With reference to FIG. 1 to FIG. 3, this embodiment provides a device for foundation pile integrity test of precast pile through soil-core probe penetration, including a pipe pile to be tested 1, where a connection frame is installed on the top surface of the pipe pile to be tested 1, a hydraulic telescopic rod 2 is fixedly connected to the top of the connection frame, the bottom of the hydraulic telescopic rod 2 is connected to a probe rod 4 via a casing flange plate 3, and an end of the probe rod 4 away from the casing flange plate 3 is provided with a probe 5.

[0027] The disclosure utilizes the probe 5 to collect fluctuations of the pile core soil caused by pile body vibration and judges the integrity of the precast spliced pile through the collected soil velocity response time-depth signal. Besides equipment such as the cone tip resistance sensor 12 and side friction resistance sensor 13 in the probe 5, which may collect the basic physical and mechanical properties of the soil plug and the side friction resistance during penetration, the probe 5 is also integrated with a three-direction geophone 11, enabling the collection of soil response caused by pile body vibration. The hydraulic telescopic rod 2 provides penetration force for the probe 5, enabling the probe 5 to penetrate into the pile core soil plug at a constant speed. For every certain depth penetrated, a test hammer is used to strike the pile top; the depth at which the vibration response of the pile core soil is first received is the height of the pile core soil plug. When the probe 5 penetrates deep to the pile toe, the characteristic value of the pile toe bearing capacity of the precast pipe pile may also be estimated through the physical and mechanical indicators measured by the cone tip resistance sensor.

[0028] The disclosure may perform integrity test on spliced piles. While performing integrity test, it may also obtain additional information such as the basic physical and mechanical properties of the soil plug, the side friction resistance during penetration, the height of the soil plug, and the characteristic value of the pile toe bearing capacity. No additional preliminary work such as drilling is required, and the equipment may be recycled and reused after testing.

[0029] In an embodiment, a pipe pile flange plate 7 is fixedly connected to the top surface of the pipe pile to be tested 1, where connection seats 6 are symmetrically provided on the top surface of the pipe pile flange plate 7. The connection frame includes vertical rods 8 symmetrically threadedly connected to the connection seats 6, respectively. Top surfaces of the two vertical rods 8 are fixedly connected with a horizontal rod 9, the horizontal rod 9 and the vertical rods 8 are fixed via right-angle couplers 10, and the hydraulic telescopic rod 2 is fixedly connected to the horizontal rod 9.

[0030] In an embodiment, the probe 5 is internally provided with the three-direction geophone 11, the cone tip resistance sensor 12 and the side friction resistance sensor 13.

[0031] As shown in FIG. 4, a method for foundation pile integrity test of precast pile through soil-core probe penetration is further provided, the method includes the following steps.

[0032] S1, installation of the connection frame: the vertical rods 8 are fixed to the pipe pile flange plate 7.

[0033] S2, installation of the hydraulic telescopic rod 2: the hydraulic telescopic rod 2 is mounted on the horizontal rod 9, and the horizontal rod 9 is fixed to the vertical rods 8 via the right-angle couplers 10. A block (such as the casing flange plate) with a reserved gap (for protecting the wire) is used to press against the end of the probe rod 4 with the wire, and the wire is threaded from inside to outside through the small hole of the casing flange plate. Then the probe rod 4 is pressed into the casing flange plate, ensuring the probe rod 4 is pressed to the bottom and then the probe rod 4 is fixed with screws.

[0034] S3, installation of the probe 5: the probe 5 is fixed to one end of the probe rod 4, and the other end of the probe rod 4 is fixed to the bottom of the hydraulic telescopic rod through the casing flange plate.

[0035] S4, the probe 5 and the probe rod 4 are inserted vertically into the soil in the pile core (i.e., the soil plug), the probe 5 is slowly pressed into the soil at a speed of 20 to 25 millimeters per second (mm / s); and the probe 5 continuously records vertical static parameters of the soil at different depths.

[0036] S5, during the process of pressing in the probe rod 4, for every certain distance pressed, a test hammer is used to strike the top of the pipe pile, the dynamic response signal of the soil at the depth where the probe 5 is located is collected; the measurement steps are repeated until the probe 5 is pressed below the length of the pipe pile to be tested 1.

[0037] In the description of the present disclosure, it should be understood that the terms “longitudinal”, “transverse”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, etc. indicate orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, only for the convenience of describing the present disclosure, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present disclosure.

[0038] The above-mentioned embodiments only describe the preferred mode of the present disclosure, and do not limit the scope of the present disclosure. Under the premise of not departing from the design spirit of the present disclosure, various modifications and improvements made by one of ordinary skill in the art to the technical solution of the present disclosure should fall within the protection scope determined by the claims of the present disclosure.

Claims

1. A device for foundation pile integrity test of precast pile through soil-core probe penetration, comprising: a pipe pile to be tested, wherein a connection frame is installed on a top surface of the pipe pile to be tested, a hydraulic telescopic rod is fixedly connected to a top of the connection frame, a bottom of the hydraulic telescopic rod is connected to a probe rod via a casing flange plate, an end of the probe rod away from the casing flange plate is provided with a probe, and a three-direction geophone, a cone tip resistance sensor, and a side friction resistance sensor are arranged in the probe.

2. The device for foundation pile integrity test of precast pile through soil-core probe penetration according to claim 1, wherein a pipe pile flange plate is fixedly connected to the top surface of the pipe pile to be tested, connection seats are symmetrically provided on a top surface of the pipe pile flange plate, the connection frame comprises two vertical rods symmetrically threadedly connected to the connection seats, top surfaces of the two vertical rods are fixedly connected with a horizontal rod, the horizontal rod and the two vertical rods are fixed via right-angle couplers, and the hydraulic telescopic rod is fixedly connected to the horizontal rod.

3. A method for foundation pile integrity test of precast pile through soil-core probe penetration, based on the device for foundation pile integrity test of precast pile through soil-core probe penetration according to claim 2, comprising following steps:S1, installing the connection frame: fixing the two vertical rods to the pipe pile flange plate;S2, installing the hydraulic telescopic rod: mounting the hydraulic telescopic rod on the horizontal rod, and fixing the horizontal rod to the two vertical rods via the right-angle couplers;S3, installing the probe: fixing the probe to the probe rod, and fixing the probe rod to the casing flange plate;S4, inserting the probe and the probe rod vertically into a soil in a pile core, pressing the probe into the soil at a speed of 20 to 25 millimeters per second, and continuously recording vertical static parameters of the soil at different depths through the probe; andS5, during a process of pressing the probe rod, for every certain distance pressed, using a test hammer to strike a top of the pipe pile to be tested, collecting a dynamic response signal of the soil at a depth with the probe located, and repeating measurement steps until the probe is pressed below a length of the pipe pile to be tested.

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