Electromagnetic ejection type rapid load method pile foundation vertical bearing capacity detection device and method

Abstract

The invention particularly relates to a device and method for detecting the vertical bearing capacity of a pile foundation through an electromagnetic ejection type speed load method, the device comprises an equipment support and a lifting and releasing device on the equipment support, and an electromagnetic ejection device at the top of the equipment support comprises two electromagnetic guide rails extending vertically and an armature arranged on the electromagnetic guide rails in a sliding and sleeving mode; the power generation system is electrically connected with the electromagnetic guide rail and the armature; the bearing platform is connected with the armature and sleeved on the electromagnetic guide rail to vertically move along the electromagnetic guide rail; the detection counterweight is arranged on the bearing platform; the lifting and releasing device is connected with the bearing platform through a plurality of steel cables wound on the guide pulley block; the buffer device is arranged above the pile head of the to-be-detected pile foundation and is used for bearing the impact of the detection counterweight; the signal detection system is arranged on one side of the pile head of the to-be-detected pile foundation; and the control system is in signal connection with the electromagnetic ejection device and the lifting release device. The method has the advantages that the counterweight lifting height or the counterweight mass is reduced under the same counterweight kinetic energy, and the applicability of a quick loading method is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of pile foundation detection, and in particular to a device and method for detecting the vertical bearing capacity of a pile foundation using an electromagnetic ejection rapid loading method. Background Art

[0002] Pile foundation is a commonly used foundation form in high-rise buildings, ports, bridges and other projects. Whether its vertical bearing capacity can meet the design requirements is a key factor in determining the safety of the superstructure. Therefore, pile foundation testing has become an essential part of ensuring construction quality and performance in civil engineering.

[0003] Currently, the vertical bearing capacity of pile foundations is primarily tested using three techniques: static load testing, high-strain testing, and rapid loading. The static load test method applies progressive static loads to the pile top and simultaneously measures pile settlement, directly obtaining a load-settlement curve for assessing the ultimate bearing capacity of a single pile. This method is generally considered the most intuitive and reliable method. However, this method requires a large reaction device and a large number of counterweights, resulting in a long test cycle and high costs. The high-strain testing method applies a transient impact load to the pile top and analyzes the stress wave response of the pile body using stress wave propagation theory. This method can simultaneously evaluate the bearing capacity and integrity of the pile, offering a deep test depth and rich information, but it also significantly disturbs the pile body. The rapid loading method is a new testing technology recently introduced in China. While it shares the basic principles of the static-dynamic method, it avoids explosive impact loading in favor of a controlled release of counterweights for rapid loading, improving test safety and efficiency. However, to achieve sufficient impact energy, the counterweights must be elevated to a high position, making it difficult to implement in space-constrained conditions. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the existing technology and provide an electromagnetic catapult-type rapid loading method pile foundation vertical bearing capacity detection device and method, which is used to reduce the counterweight lifting height or reduce the counterweight mass under the same counterweight kinetic energy, thereby saving material delivery costs and site space, and improving the applicability of the rapid loading method.

[0005] In order to achieve the above purpose, an electromagnetic ejection type rapid loading method pile foundation vertical bearing capacity detection device is designed, comprising: an equipment bracket arranged on the foundation and a lifting and releasing device arranged on the equipment bracket, and also comprising: an electromagnetic ejection device, arranged on the top of the equipment bracket, comprising: two vertically extending electromagnetic guide rails and an armature slidably mounted on the electromagnetic guide rails; a power generation system, electrically connected to the electromagnetic guide rails and the armature, for forming a strong magnetic field between the electromagnetic guide rails when energized, and applying a downward electromagnetic thrust to the armature; a bearing platform, connected to the armature and mounted on the electromagnetic guide rails. The magnetic guide rail moves vertically along the electromagnetic guide rail; the detection counterweight is arranged on the bearing platform; the lifting and releasing device is connected to the bearing platform through a number of steel cables wound on the guide pulley group, which is used to lift the bearing platform and release it in a controllable manner; the buffer device is arranged above the pile head of the pile foundation to be tested, which is used to bear the impact of the detection counterweight; the signal detection system is arranged on one side of the pile head of the pile foundation to be tested, which is used to collect the force-displacement-acceleration time history curve; the control system is connected to the electromagnetic ejection device and the lifting and releasing device signals to synchronously control the application of electromagnetic thrust and the release of the counterweight.

[0006] Preferably, the present invention further comprises: a signal detection system comprising at least: a force sensor, a displacement sensor and an acceleration sensor for collecting a force-displacement-acceleration time history curve generated when the pile foundation to be tested is struck by a detection counterweight.

[0007] Preferably, the present invention further includes: the control system further includes: a control switch electrically connected to the power generation system, for controlling the on and off of the power generation system.

[0008] Preferably, the present invention further comprises: a vertical through slot conforming to the electromagnetic guide rail is provided on the armature to ensure that the armature forms a guide and low sliding friction on the electromagnetic guide rail.

[0009] Preferably, the present invention also includes: the lifting and releasing device includes an electric hoist or winch, a guide pulley group and a hinge, one end of the hinge is connected to the electric hoist or winch, and the other end is connected to the load-bearing platform through the guide pulley group to achieve lifting and locking release of the load-bearing platform.

[0010] Preferably, the present invention further comprises: the detection counterweight and the electromagnetic guide rail are coaxially arranged along the same centroid axis to avoid eccentric loading and ensure axial transmission of vertical impact loads.

[0011] Preferably, the present invention also includes: the buffer device is a pad made of rubber or elastic composite material, the force sensor and acceleration sensor of the signal detection system are integrated in the pad, which are used to extend the impact time and protect the pile head, and the displacement sensor is arranged on the foundation, on one side of the buffer device.

[0012] The present invention also provides a method for detecting the vertical bearing capacity of a pile foundation using an electromagnetic catapult-type rapid loading method implemented using the device, comprising the following steps: step a. installing and leveling an equipment bracket on the foundation; step b. fixing an electromagnetic guide rail to the top of the equipment bracket so that the electromagnetic guide rail also serves as a vertical guide rod; step c. sleeve the bearing platform on the electromagnetic guide rail through an armature arranged on the bearing platform, and fix the detection counterweight on the bearing platform; step d. lift the bearing platform to a designed height and lock it through a lifting and releasing device; step e. start a signal detection system to prepare for data collection; step f. unlock and close a control switch through a control system so that the power generation system supplies power to the electromagnetic guide rail, and push the bearing platform and the detection counterweight downward to impact the buffer device under the dual action of the electromagnetic thrust of the armature and the deadweight of the detection counterweight; step g. the signal detection system collects a force-displacement-acceleration time history curve in real time during the action of the detection counterweight and the buffer device; step h. analyzes the vertical bearing capacity of the pile foundation to be tested based on the collected time history curve.

[0013] Preferably, the present invention also includes: in step f., the electromagnetic thrust realizes millisecond-level adjustable pulse loading of 100 milliseconds to 800 milliseconds by adjusting the output current of the power generation system to match the detection requirements of different design load-bearing capacities.

[0014] Compared with the prior art, the present invention has the following advantages: 1. Highly efficient and economical, significantly saving time and costs: The electromagnetic catapult rapid loading method applies millisecond-level (100-800ms) transient loads via electromagnetic catapults. Single pile testing takes just 5-10 minutes, significantly faster than traditional static load tests, which take several days, and high-strain methods, which take approximately 30 minutes. Furthermore, it eliminates the need for hundreds of tons of counterweights and complex anchoring systems, making the equipment lighter than traditional rapid loading methods. This significantly reduces labor, transportation, and site preparation costs, resulting in outstanding economic efficiency.

[0015] 2. Safe, flexible, and highly adaptable to site conditions: The instantaneous loading method of electromagnetic catapults avoids the safety risks of platform instability and collapse associated with long-term loading in traditional static load tests (particularly in deep foundation pits or soft soil sites). Its lightweight design minimizes site requirements and allows for easy application in confined spaces, complex terrain (such as slopes, water platforms, and densely populated urban areas), or sites with limited load capacity, resolving the challenges of implementing traditional methods in these scenarios.

[0016] 3. Reliable and informative data, approaching static load results: Compared to the high-strain method, which relies on wave equation assumptions and is prone to errors, the rapid loading method's longer loading duration makes the pile-soil response closer to quasi-static, enabling direct acquisition of highly accurate quasi-static load-settlement curves (Qs curves). Combined with sensor data, it also analyzes pile internal forces, lateral and end resistance distributions, and soil damping properties, providing rich information close to static load testing (with correction errors typically <10%), providing a reliable basis for bearing capacity assessment and design optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic front view of the structure of the present invention; Figure 2 is a top view of the armature; In the figure: 1 equipment bracket, 2 guide pulley group, 3 lifting and releasing device, 4 electromagnetic guide rail, 5 bearing platform, 6 detection counterweight, 7 buffer device, 8 detection system, 9 power generation system, 10 armature, 11 pile foundation to be tested. DETAILED DESCRIPTION

[0018] In order to make the purpose, principle and structure of the present invention more clear, it is further described below with reference to the accompanying drawings and specific embodiments.

[0019] The embodiments described herein are only a part of the present invention, not all embodiments. The description of at least one exemplary embodiment is for illustration only and should not be regarded as any limitation on the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Unless otherwise specified, the relative arrangement, expression and numerical values ​​of the components and steps described in these embodiments do not limit the scope of the present invention. At the same time, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to scale. Technologies, methods and equipment known to ordinary technicians in this field may not be discussed in detail, but should be regarded as part of this specification where appropriate. In all examples shown and discussed herein, any specific values ​​should be interpreted as exemplary, not restrictive. Therefore, other examples of exemplary embodiments may have different values.

[0020] The present invention provides a device and method for detecting the vertical bearing capacity of a pile foundation using an electromagnetic ejection rapid loading method.

[0021] In response to the shortcomings of existing pile foundation detection methods, the present invention proposes a new method for detecting the vertical bearing capacity and integrity of pile foundations. This method adds an electromagnetic catapult device to the rapid loading method, which can provide additional kinetic energy to the counterweight, thereby giving the pile foundation a greater impact load without increasing the designed lifting height and counterweight mass. The rapid loading method is an improved pile foundation vertical bearing capacity detection technology based on the static and dynamic method. By releasing the counterweight block and letting it fall on the buffer device of the pile foundation to be tested, a pulse load is applied to the pile foundation, and the action time on the pile foundation can reach 100 ms~300 ms. The bearing capacity and integrity of the pile foundation are analyzed by outputting the displacement-time curve, force-time curve and acceleration-time curve.

[0022] The present invention discloses an electromagnetic ejection rapid loading method pile foundation vertical bearing capacity detection device and detection method, the detection device is composed of an equipment bracket 1, an electromagnetic ejection device, a lifting and releasing device 3, a detection counterweight 6, a buffer device 7, a signal detection system 8 and a control system.

[0023] The working principle of the present invention is to use the electromagnetic guide rail 4 and the guide pulley group 2 in the electromagnetic catapult device to lift the counterweight to the designed height. When the detection starts, the control system is closed and the control switch of the electromagnetic catapult device is used to release the locking state of the lifting release device 3. The armature 10 moves downward under the action of its own weight and Ampere force, and is restricted by the bearing platform 5, thereby generating an interaction force with the bearing platform 5. The bearing platform 5 and the detection counterweight 6 are tied together by a hinge and move downward under the action of gravity and interaction force. When it contacts the buffer device 7 of the pile foundation 11 to be tested, the signal detection system 8 starts to collect force, displacement and acceleration signals. When the detection counterweight 6 rebounds to separate from the buffer device 7, the signal detection system stops collecting and outputs the force time history curve, displacement time history curve and acceleration time history curve within the counterweight action time period t for subsequent analysis of the vertical bearing capacity and integrity of the pile foundation.

[0024] Example 1: like Figure 1 As shown, the entire device is installed directly above the pile foundation 11 to be tested. The equipment bracket 1 is a removable, portal-shaped steel structure, with its horizontal and vertical beam supports connected by high-strength bolts. The bottom of the equipment bracket 1 is rigidly connected to the foundation and leveled. It is then placed on a solid foundation to ensure that the foundation can support the weight of the equipment bracket 1 and the designed counterweight. Preferably, anchor bolts are used to connect the equipment bracket 1 to the foundation. The equipment bracket 1 can be delivered to the site in sections for on-site assembly.

[0025] Two electromagnetic rails 4 are fixed vertically to the center of the top crossbeam of the equipment bracket 1. Preferably, welding or high-strength bolts can be used to connect the equipment bracket 1 and the electromagnetic rails 4. The axis of the electromagnetic rails 4 coincides with the center line of the pile foundation 11 to ensure that the load is transferred along the pile axis.

[0026] The electromagnetic rails 4 consist of two vertical, parallel, highly conductive metal rails. Their upper ends are connected to the top crossbeam of the equipment bracket 1 by welding or high-strength bolts, while their lower ends are suspended and inserted into guide holes in the support platform 5. These rails serve both as the magnetic circuit conductor for the electromagnetic catapult and as vertical guides for the support platform 5, achieving dual purposes.

[0027] The armature 10 is a block-shaped structure. The armature 10 is vertically provided with two vertical through-slots that are shaped like the cross-section of the electromagnetic guide rail 4 near the center axis. The armature 10 is rigidly connected to the load-bearing platform 5, and preferably can be connected by bolts or welding. The vertical through-slots of the armature 10 slide in conjunction with the guide rails to ensure that the load-bearing platform 5 can only move vertically along the guide rails, limiting horizontal displacement. And because the vertical through-slots of the armature 10 are shaped like the electromagnetic guide rail 4, the fitting clearance between the armature 10 and the electromagnetic guide rail 4 is extremely small, which can achieve sliding friction under slight contact. At the same time, due to the small fitting clearance, the armature 10 will not produce unnecessary movement margin, and therefore there will be no situation where one side of the two vertical through-slots of the armature 10 contacts the electromagnetic guide rail 4 too much to generate a large friction force.

[0028] Since slight friction is always maintained between the armature 10 and the electromagnetic guide rail 4, the armature 10 can form a closed loop with the two guide rails of the electromagnetic guide rail 4. The two parallel technical guide rails constitute a track. The armature 10 is made of solid metal material. The large current pulse (megaampere level) induces a strong magnetic field between the two guide rails. The Ampere force pushes the armature 10 along the extension direction of the guide rail, causing instantaneous acceleration of the armature 10.

[0029] Preferably, in order to meet the requirements of electromagnetic catapult, the electromagnetic guide rail 4 can be made of a highly conductive metal material, and the armature 10 can be made of a metal material that has a low friction coefficient with the guide rail material and is not easy to weld, such as an alloy material. An insulator made of ceramic or other materials can be arranged between the equipment bracket 1 and the electromagnetic guide rail 4 for electrical isolation, and the power supply connected to the guide rail uses a high-energy-density pulse power supply.

[0030] The power generation system 9 is a controllable DC power supply, with its output connected via cables to the top terminals of the two electromagnetic rails 4. The armature 10 slides in contact with the rails, forming a closed circuit. When the control switch is closed, the power generation system 9 feeds a strong DC current into the rails, creating a strong magnetic field perpendicular to the paper and pointing inward between them. The energized armature, acting under the Ampere force, generates a momentary downward electromagnetic thrust. This thrust, combined with the superposition of the detection counterweight 6, creates a dual force. By adjusting the output current of the power generation system 9, adjustable millisecond-level pulse loading can be generated within 100 to 800 ms.

[0031] The lifting and release device 3 consists of an electric hoist (or winch), a guide pulley block 2, and a hinge. The electric hoist is fixed to the equipment support 1. There are three guide pulley blocks 2: one bottom guide pulley block 2 is located on the ground, and the other two are located on the crossbeam of the equipment support 1. The two top guide pulley blocks 2 on the crossbeam are located above the ground guide pulley block 2 and above the load platform 5, respectively, forming a rope winding system. The top guide pulley blocks 2 can be mounted on the equipment support 1 by welding or bolting. One end of the cable is connected to the electric hoist hook via a hinge with a shackle and a locking pin. The other end passes through the guide pulley block 2 and connects to the load platform 5. When the electric hoist retracts the cable, it raises the load platform 5 and the test weight 6 to the designed height. The hinge shackle and locking pin are unlocked by the control system, achieving instant release. Preferably, the hinge unlocking can be achieved by using an electromagnet or mechanically pulling out the locking pin, thereby connecting the electric hoist to the load platform 5 and releasing the lifted load platform 5.

[0032] The detection counterweight 6 is a number of heavy objects with a large mass. A through hole is reserved in the center of the detection counterweight 6 so that it can be mounted on the outer periphery of the electromagnetic guide rail 4. The detection counterweight 6 is coaxially stacked on the bearing platform 5 through the center through hole, and is bound to the bearing platform 5 into a whole through a hinge to ensure that the centroid axis of the detection counterweight 6 coincides with the axis of the guide rail. The centroid axis is the geometric center axis for abstract geometric bodies, which is used to ensure that the detection counterweight 6 does not cause interference with the center of gravity offset of the bearing platform 5, eliminate the bias effect, and avoid the center of gravity offset of the bearing platform 4 when falling and excessive collision and friction with the electromagnetic guide rail 4. When released, the detection counterweight 6 is guided by the electromagnetic guide rail 4 and accurately falls onto the signal detection system 8 of the pile foundation 11 to be tested.

[0033] Located beneath the load-bearing platform, buffer 7 is a cylindrical elastic composite pad with a pre-embedded force sensor and acceleration sensor. Its lower surface is in close contact with the pile head. The buffer 7 can be made of rubber or other elastic materials. The displacement sensor's laser head is fixed to the foundation surface and aligned with the side of the pad. The buffer 7 utilizes the inherent elastic properties of the material to mitigate the impact of the designed counterweight, prolonging the impact and protecting the pile head.

[0034] Signal detection system 8 consists of a force sensor, an acceleration sensor, a laser displacement sensor, and a data acquisition device. These three sensors synchronously collect and detect the time history of force, displacement, and acceleration of counterweight 6 while it acts on buffer device 7. A control system (such as a computer or PLC) is connected to the control switch signals of lift release device 3 and power generation system 9 via cables, achieving synchronous "unlock-energize-load" control.

[0035] Example 2: Specific implementation of the workflow: (1) Determine the installation location of the equipment bracket 1 and test the bearing capacity and stability of the foundation at the installation location; (2) Equipment bracket 1, electromagnetic guide rail 4, detection counterweight 6, carrying platform 5 and other accessories are brought to the site; (3) Install the equipment bracket 1, lifting and releasing device 3, electromagnetic ejection device, detection system 8, control system, and use the balancing anchor nut to level the electromagnetic ejection type rapid load method detection device; (4) Debug the control system to ensure that the control system can properly control the lifting, locking, and release of the lifting and releasing device 3 and the switch of the electromagnetic catapult device; (5) Assemble the test weight 6 and set the current in the electromagnetic ejection device according to the designed bearing capacity of the pile foundation 11 to be tested, and verify the integrity of the test weight 6; (6) After verification, pass the detection weight 6 through the electromagnetic guide rail 4, and ensure that the electromagnetic guide rail 4 is located at the center of the detection weight 6, install the detection weight 6 into the carrying platform 5, and bind the detection weight 6 and the carrying platform 5 into a whole through the hinge; (7) Lift the carrying platform 5 to the designed inspection height through the lifting and releasing device 3, and lock the lifting and releasing device 3; (8) Debug the signal detection system to ensure that the signal detection system can normally collect force, displacement, and acceleration data, and output force time history curves, displacement time history curves, and acceleration time history curves; (9) After all the above steps are completed, the locking state of the lifting and releasing device 3 is released by the control system, and the control switch of the electromagnetic catapult device is closed at the same time. The detection counterweight 6 moves under the action of its own weight and electromagnetic force and acts on the buffer device 7. The signal detection system 8 starts to collect force, displacement, and acceleration data. When the design counterweight rebounds and separates from the buffer device, the signal detection system 8 stops collecting and outputs the force time history curve, displacement time history curve, and acceleration time history curve of the design counterweight and the buffer device during the time period t. The collected results are analyzed. If the collected results are unqualified, the lifting and releasing device 3 is used to lift the carrying platform 5 and the detection counterweight 6 back to the designed detection height and release them again until the collected results are qualified. (10) Analyze the integrity and bearing capacity of the pile foundation to be tested based on the collected force time history curve, displacement time history curve and acceleration time history curve, and form a test report.

[0036] The electromagnetic catapult system, comprised of an electromagnetic guide rail 4 and an armature 10, provides controllable electromagnetic thrust within millisecond pulses, enabling contactless, oil-free, and maintenance-free rapid loading. The electromagnetic guide rail 4 simultaneously serves as a magnetic circuit conductor and a vertical guide, ensuring axial load transfer, simplifying the structure, and eliminating the potential for unbalanced loading associated with conventional guide rods separated from the loading mechanism.

[0037] Through the above specific implementation methods, those skilled in the art can fully reproduce the electromagnetic ejection rapid loading method pile foundation vertical bearing capacity detection device and method described in the present invention without introducing any new features.

[0038] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent replacement or change made by any technician familiar with the technical field within the technical scope disclosed by the present invention based on the technical solution and novel concept of the present invention should be covered by the scope of protection of the present invention.

Claims

1. An electromagnetic ejection rapid loading method pile foundation vertical bearing capacity detection device, comprising: An equipment bracket (1) arranged on a foundation and a lifting and releasing device (3) arranged on the equipment bracket (1) are characterized by further comprising: An electromagnetic ejection device is arranged on the top of an equipment bracket (1), comprising: two vertically extending electromagnetic guide rails (4) and an armature (10) slidably mounted on the electromagnetic guide rails (4); a power generation system (9) electrically connected to the electromagnetic guide rails (4) and the armature (10), and used to form a strong magnetic field between the electromagnetic guide rails (4) when energized, thereby applying a downward electromagnetic thrust to the armature (10); The bearing platform (5) is connected to the armature (10) and is sleeved on the electromagnetic guide rail (4) to move vertically along the electromagnetic guide rail (4); the detection counterweight (6) is arranged on the bearing platform (5); The lifting and releasing device (3) is connected to the load-bearing platform (5) via a plurality of steel cables wound around the guide pulley assembly (2), and is used to lift the load-bearing platform (5) and release it in a controlled manner; A buffer device (7) is provided above the head of the pile foundation (11) to be tested and is used to absorb the impact of the test counterweight (6); A signal detection system (8) is provided on one side of the pile head of the pile foundation (11) to be tested and is used to collect a force-displacement-acceleration time history curve; The control system is connected to the electromagnetic ejection device and the lifting and releasing device (3) by signals to synchronously control the application of electromagnetic thrust and the release of counterweight.

2. The electromagnetic ejection rapid loading method pile foundation vertical bearing capacity detection device according to claim 1, characterized in that: The signal detection system (8) comprises at least: a force sensor, a displacement sensor and an acceleration sensor, which are used to collect a force-displacement-acceleration time history curve generated when the pile foundation (11) to be tested is hit by the detection counterweight (6).

3. The electromagnetic ejection rapid loading method pile foundation vertical bearing capacity detection device according to claim 1, characterized in that: The control system further comprises: a control switch electrically connected to the power generation system (9) and used for controlling the on and off of the power generation system (9).

4. The electromagnetic ejection rapid loading method pile foundation vertical bearing capacity detection device according to claim 1, characterized in that: The armature (10) is provided with a vertical through groove that is shaped like the electromagnetic guide rail (4) to ensure that the armature (10) forms a guide and low sliding friction on the electromagnetic guide rail (4).

5. The electromagnetic ejection type rapid loading method pile foundation vertical bearing capacity detection device according to claim 1, characterized in that: The lifting and releasing device (3) comprises an electric hoist or a winch, a guide pulley block (2) and a hinge, one end of the hinge being connected to the electric hoist or the winch, and the other end being connected to the carrying platform (5) via the guide pulley block (2) to achieve lifting and locking release of the carrying platform (5).

6. The electromagnetic ejection rapid loading method pile foundation vertical bearing capacity detection device according to claim 1, characterized in that: The detection counterweight (6) and the electromagnetic guide rail (4) are coaxially arranged along the same centroid axis to avoid eccentric loading and ensure axial transmission of vertical impact loads.

7. The electromagnetic ejection rapid loading method pile foundation vertical bearing capacity detection device according to claim 2, characterized in that: The buffer device (7) is a pad made of rubber or elastic composite material. The force sensor and acceleration sensor of the signal detection system (8) are integrated in the pad to extend the impact time and protect the pile head. The displacement sensor is arranged on the foundation, on one side of the buffer device (7).

8. A method for detecting the vertical bearing capacity of a pile foundation using an electromagnetic ejection rapid loading method implemented by the device according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step a. Install and level the equipment bracket (1) on the foundation; Step b. fixing the electromagnetic guide rail (4) to the top of the equipment bracket (1), so that the electromagnetic guide rail (4) also serves as a vertical guide rod; Step c. The armature (10) is provided on the carrying platform (5), the carrying platform (5) is sleeved on the electromagnetic guide rail (4), and the detection weight (6) is fixed to the carrying platform (5); Step d. lifting the carrying platform (5) to the designed height and locking it by lifting the release device (3); Step e. Starting the signal detection system (8) to prepare for data collection; Step f. unlocking and closing the control switch through the control system, so that the power generation system (9) supplies power to the electromagnetic guide rail (4), and the load-bearing platform (5) and the detection counterweight (6) are pushed downward to impact the buffer device (7) under the dual action of the electromagnetic thrust of the armature (10) and the deadweight of the detection counterweight (6); Step g. The signal detection system (8) collects the force-displacement-acceleration time history curve in real time during the action of the detection counterweight (6) and the buffer device (7); Step h. Analyze the vertical bearing capacity of the pile foundation (11) to be tested based on the collected time history curve.

9. The method for detecting the vertical bearing capacity of a pile foundation using an electromagnetic ejection rapid loading method according to claim 8, wherein: In step f., the electromagnetic thrust is adjusted to achieve millisecond-level adjustable pulse loading of 100 milliseconds to 800 milliseconds by adjusting the output current of the power generation system (9) to match the detection requirements of different design load-bearing capacities.

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