Electromagnetic catapult type rapid loading method pile foundation vertical bearing capacity detection device and method

Abstract

The application is specifically an electromagnetic ejection type speed loading method pile foundation vertical bearing capacity detection device and method, which comprises: an equipment support, a lifting and releasing device on the equipment support, an electromagnetic ejection device on the top of the equipment support, a power generation system, a bearing platform, a detection counterweight, a buffer device and a signal detection system, wherein the electromagnetic ejection device comprises two vertically extending electromagnetic rails and an armature slidingly sleeved on the electromagnetic rails; the power generation system is electrically connected with the electromagnetic rails and the armature; the bearing platform is connected with the armature and is sleeved on the electromagnetic rails to move vertically along the electromagnetic rails; 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 a guide pulley block; the buffer device is arranged above the pile head of the pile foundation to be detected and is used for receiving 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 detected; and the control system is signal connected with the electromagnetic ejection device and the lifting and releasing device. The application has the advantages that the lifting height of the counterweight or the mass of the counterweight is reduced under the same kinetic energy of the counterweight, and the applicability of the speed loading method is improved.

Description

Technical Field

[0001] This invention relates to the field of pile foundation testing technology, specifically to an electromagnetic catapult-type rapid loading method for testing the vertical bearing capacity of pile foundations. Background Technology

[0002] As a common foundation type for high-rise buildings, ports, bridges and other projects, the vertical bearing capacity of pile foundations is a key factor in determining the safety of the superstructure. Therefore, pile foundation testing has become an essential part of civil engineering to ensure construction quality and performance.

[0003] Currently, the vertical bearing capacity of pile foundations is mainly tested using three techniques: static load testing, high-strain testing, and rapid loading. Static load testing, by applying progressive static loads to the pile top while simultaneously measuring pile settlement, directly obtains the load-settlement curve, thereby assessing the ultimate bearing capacity of a single pile. It is widely recognized as the most intuitive and reliable method; however, this method requires large reaction devices and substantial counterweights, resulting in long testing cycles and high costs. High-strain testing applies instantaneous impact loads to the pile top and analyzes the pile's stress wave response using stress wave propagation theory. It can simultaneously evaluate the pile's bearing capacity and integrity, offering deep detection and rich information, but it significantly disturbs the pile. Rapid loading is a novel testing technique proposed in China in recent years. It follows the basic principles of static and dynamic methods but abandons the explosive impact loading method, instead using a controllable release of counterweights to achieve rapid loading, improving test safety and efficiency. However, to obtain sufficient impact energy, the counterweights need to be raised to a high position, making it difficult to implement in space-constrained conditions. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide an electromagnetic catapult-type rapid loading method for detecting the vertical bearing capacity of pile foundations. This method reduces the lifting height or mass of the counterweight under the same counterweight kinetic energy, thereby saving material entry costs and site space, and improving the applicability of the rapid loading method.

[0005] To achieve the above objectives, an electromagnetic catapult-type rapid loading method pile foundation vertical bearing capacity testing device is designed, comprising: an equipment support mounted on the foundation and a lifting and release device mounted on the equipment support; further comprising: an electromagnetic catapult device mounted on top of the equipment support, including: two vertically extending electromagnetic rails and an armature slidably sleeved on the electromagnetic rails; a power generation system electrically connected to the electromagnetic rails and the armature, used to generate a strong magnetic field between the electromagnetic rails when energized, applying a downward electromagnetic thrust to the armature; and a bearing platform connected to the armature and sleeved on the electromagnetic rails. The device moves vertically along the electromagnetic rail; a counterweight is placed on the bearing platform; a lifting and release device is connected to the bearing platform via several steel cables wound around a guide pulley system, used to lift and controllably release the bearing platform; a buffer device is located above the pile head of the pile to be tested, used to absorb the impact of the counterweight; a signal detection system is located on one side of the pile head of the pile to be tested, used to collect force-displacement-acceleration time history curves; the control system is signal-connected to the electromagnetic catapult and the lifting and release device to synchronously control the application of electromagnetic thrust and the release of the counterweight.

[0006] Preferably, the present invention further includes: a signal detection system comprising at least: a force sensor, a displacement sensor and an acceleration sensor, used to acquire the force-displacement-acceleration time history curve generated when the pile foundation under test is impacted by the counterweight being tested.

[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 / off state of the power generation system.

[0008] Preferably, the present invention further includes: the armature is provided with a vertical through groove that conforms to the shape of the electromagnetic rail, so as to ensure that the armature forms a guide and low sliding friction on the electromagnetic rail.

[0009] Preferably, the present invention further includes: the lifting and releasing device includes an electric hoist or winch, a guide pulley block and a hinge, one end of the hinge is connected to the electric hoist or winch, and the other end is connected to the carrying platform through the guide pulley block, so as to realize the lifting and locking release of the carrying platform.

[0010] Preferably, the present invention further includes: the detection counterweight and the electromagnetic guide rail are coaxially arranged along the same centroidal axis to avoid off-center loading and ensure the axial transmission of vertical impact load.

[0011] Preferably, the present invention further 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 to prolong the impact time and protect the pile head, and the displacement sensor is set on the foundation, on one side of the buffer device.

[0012] This invention also provides a method for detecting the vertical bearing capacity of pile foundations using the electromagnetic catapult-type rapid loading method implemented by the aforementioned device, comprising the following steps: Step a. Installing and leveling the equipment support on the foundation; Step b. Fixing the electromagnetic guide rail to the top of the equipment support, so that the electromagnetic guide rail also serves as a vertical guide rod; Step c. Using an armature set on the bearing platform, the bearing platform is fitted onto the electromagnetic guide rail, and the detection counterweight is fixed to the bearing platform; Step d. Lifting the bearing platform to the design height and locking it using a lifting and releasing device; Step e. Activating the signal detection system to prepare for data acquisition; Step f. Unlocking and closing the control switch through the control system, so that the power generation system supplies power to the electromagnetic guide rail, and under the combined action of the electromagnetic thrust of the armature and the self-weight of the detection counterweight, the bearing platform and the detection counterweight are pushed downward to impact the buffer device; Step g. The signal detection system collects force-displacement-acceleration time history curves in real time during the action of the detection counterweight and the buffer device; Step h. Analyzing the vertical bearing capacity of the pile foundation under test based on the collected time history curves.

[0013] Preferably, the present invention further includes: in step f, the electromagnetic thrust is adjusted by regulating the output current of the power generation system to achieve millisecond-level adjustable pulse loading from 100 milliseconds to 800 milliseconds, so as to match the detection requirements of different design load capacities.

[0014] Compared with the prior art, the advantages of this invention are: 1. High efficiency and economy, significantly saving time and costs: The electromagnetic catapult-type rapid load method applies transient loads in milliseconds (100-800ms) via electromagnetic catapult. Single pile testing takes only 5-10 minutes, far faster than the several days of traditional static load testing and the approximately 30 minutes of high strain methods. Furthermore, it eliminates the need for hundreds of tons of counterweights and complex anchoring systems; the equipment is lighter than traditional rapid load methods, significantly reducing labor, transportation, and site preparation costs, resulting in outstanding economic benefits.

[0015] 2. Safe, flexible, and highly adaptable to different sites: The electromagnetic catapult instantaneous loading method avoids the safety risks of platform instability and collapse caused by long-term loading in traditional static load tests (especially in deep foundation pits or soft soil sites). Its lightweight design makes it extremely easy to apply to sites with narrow spaces, complex terrain (such as slopes, water platforms, and densely populated urban areas) or limited bearing capacity, solving the problem of difficulty in implementing traditional methods in these scenarios.

[0016] 3. Reliable and informative data, closely approximating static load effects: Compared to the high-strain method, which relies on wave equation assumptions and is prone to errors, the fast-load method's longer load application time makes its pile-soil response closer to quasi-static conditions, directly obtaining high-precision quasi-static load-settlement curves (Qs curves). Combined with sensor data, it can also analyze pile internal forces, lateral and end resistance distributions, and soil damping characteristics, providing rich information close to static load tests (with errors typically <10% after correction), providing a reliable basis for bearing capacity assessment and design optimization. Attached Figure Description

[0017] Figure 1 This is a schematic front view of the structure of the present invention; Figure 2 This is a top view of the armature; In the diagram: 1 Equipment support, 2 Guide pulley block, 3 Lifting and release device, 4 Electromagnetic 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 Implementation

[0018] To make the purpose, principle and structure of the present invention clearer, the following description is provided in conjunction with the accompanying drawings and specific embodiments.

[0019] The embodiments described herein are only a part of the invention, not all of it. The description of at least one exemplary embodiment is for illustrative purposes only and should not be construed as any limitation on the invention or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention. Unless otherwise stated, the relative arrangement, representation, and numerical values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. Furthermore, for ease of description, the dimensions of the parts shown in the accompanying drawings are not drawn to scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but should be considered part of this specification where appropriate. Any specific values ​​in all examples shown and discussed herein should be interpreted as exemplary, not restrictive. Therefore, other examples of exemplary embodiments may have different values.

[0020] This invention provides an electromagnetic catapult-type rapid loading method for detecting the vertical bearing capacity of pile foundations and a method thereof.

[0021] This invention proposes a novel method for testing the vertical bearing capacity and integrity of pile foundations, addressing the shortcomings of existing methods. This method adds an electromagnetic catapult to the rapid load method, providing additional kinetic energy to the counterweight and thus applying a greater impact load to the pile foundation without increasing the design lifting height or counterweight mass. The rapid load method is an improved pile foundation vertical bearing capacity testing technology based on the static-dynamic method. By releasing the counterweight block and placing it on the buffer device of the pile foundation under test, a pulse load is applied to the pile foundation, with an interaction time of 100 ms to 300 ms. The bearing capacity and integrity of the pile foundation are analyzed by outputting displacement-time curves, force-time curves, and acceleration-time curves.

[0022] This invention discloses an electromagnetic catapult-type rapid loading method for detecting the vertical bearing capacity of pile foundations and a detection method thereof. The detection device consists of an equipment support 1, an electromagnetic catapult 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 this invention is as follows: the electromagnetic rail 4 and guide pulley block 2 in the electromagnetic catapult device are used to lift the counterweight to the design height. At the start of the test, the control system closes the control switch of the electromagnetic catapult device and releases the locking state of the lifting release device 3. The armature 10 moves downward under its own weight and Ampere force. It is restricted by the bearing platform 5 and thus generates an interaction force with the bearing platform 5. The bearing platform 5 and the detection counterweight 6 are tied together by a hinge. Under the action of gravity and interaction force, it moves downward. When it contacts the buffer device 7 of the pile foundation 11 to be tested, the signal detection system 8 begins to collect force, displacement and acceleration signals. When the detection counterweight 6 rebounds and separates 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 support 1 is a detachable portal steel structure, and the horizontal and vertical beam supports of the equipment support 1 are spliced ​​together with high-strength bolts. The bottom of the equipment support 1 is rigidly connected to the foundation and leveled, and is set on a solid foundation to ensure that the foundation can bear the weight of the equipment support 1 and the designed counterweight. Preferably, anchor bolts can be used to connect to the foundation. The equipment support 1 can be brought to the site in sections and assembled on-site.

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

[0026] The electromagnetic guide rail 4 consists of two vertically arranged, parallel, highly conductive metal rails. The upper end is connected to the top crossbeam of the equipment support 1 by welding or high-strength bolts, while the lower end is suspended and inserted into the guide hole of the bearing platform 5. The electromagnetic guide rail 4 serves both as the magnetic circuit conductor for the electromagnetic catapult and as a vertical guide for the bearing platform 5, achieving "two uses in one".

[0027] The armature 10 is a block structure. Near its central axis, the armature 10 has two vertical slots that mimic the cross-section of the electromagnetic rail 4. The armature 10 is rigidly connected to the support platform 5, preferably by bolts or welding. The vertical slots of the armature 10 slide against the rail, ensuring that the support platform 5 can only move vertically along the rail, limiting horizontal displacement. Furthermore, because the vertical slots of the armature 10 mimic the electromagnetic rail 4, the clearance between the armature 10 and the electromagnetic rail 4 is extremely small, allowing for slight sliding friction. Simultaneously, due to the small clearance, the armature 10 does not generate excessive movement margin, thus preventing excessive contact between one side of the armature 10 within the two vertical slots and the electromagnetic rail 4, which could generate significant friction.

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

[0029] Preferably, to meet the requirements of electromagnetic catapult, the electromagnetic rail 4 can be made of a highly conductive metal material, and the armature 10 can be made of a metal material with a low coefficient of friction and that is not easily welded to the rail material, such as an alloy material. An insulator made of ceramic or other materials can be set between the equipment bracket 1 and the electromagnetic rail 4 to isolate electrical conduction. The power supply connected to the rail is a high-energy-density pulse power supply.

[0030] The power generation system 9 is a controllable DC power supply, with its output terminals connected to the top terminals of the two electromagnetic rails 4 via cables. The armature 10 slides in contact with the rails, forming a closed loop. After the control switch is closed, the power generation system 9 supplies a strong DC current to the rails, creating a strong magnetic field perpendicular to the paper and pointing inwards between the two rails; the energized armature experiences Ampere force, generating a downward instantaneous electromagnetic thrust. This thrust, combined with the self-overlapping effect of the detection counterweight 6, constitutes a dual force. By adjusting the output current of the power generation system 9, an adjustable millisecond-level pulse loading can be generated within 100ms to 800ms.

[0031] The lifting and release device 3 consists of an electric hoist (or winch), guide pulley blocks 2, and hinges. The electric hoist is fixed to the equipment support 1. There are three sets of guide pulley blocks 2: one bottom set is located on the ground, and the other two sets 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 blocks 2 and above the support platform 5, forming a rope winding system. The top guide pulley blocks 2 can be installed 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 locking pin, and the other end passes around the guide pulley blocks 2 and connects to the support platform 5. When the electric hoist retracts the rope, it lifts the support platform 5 and the detection counterweight 6 to the designed height. The shackle and locking pin of the hinge are unlocked by the control system, achieving instantaneous release. Preferably, an electromagnet or mechanical pull-out of the locking pin can be used to unlock the hinge, thus achieving the connection between the electric hoist and the support platform 5 and releasing the lifted support platform 5.

[0032] The detection counterweight 6 consists of several heavy objects with a large mass. The detection counterweight 6 has a pre-drilled through hole in the center to be fitted onto the outer periphery of the electromagnetic guide rail 4. The detection counterweight 6 is coaxially stacked on the bearing platform 5 through the central through hole and is bound to the bearing platform 5 as a whole by hinges. This ensures that the centroidal axis of the detection counterweight 6 coincides with the axis of the guide rail. The centroidal axis is the geometric center axis in relation to the abstract geometric body. It is used to ensure that the detection counterweight 6 will not cause interference with the center of gravity shift of the bearing platform 5, eliminate the bias effect, and avoid excessive collision and friction between the bearing platform 4 and the electromagnetic guide rail 4 when it falls. When released, the detection counterweight 6 is guided by the electromagnetic guide rail 4 to fall accurately onto the signal detection system 8 of the pile foundation 11 to be tested.

[0033] The buffer device 7 is located below the bearing platform. The buffer device 7 is a cylindrical elastic composite material pad. Force sensors and acceleration sensors are pre-embedded within the buffer device 7. The lower surface of the buffer device 7 is in close contact with the pile head. The material of the buffer device 7 can be rubber or other elastic materials. The displacement sensor laser head is fixed to the foundation surface and aligned with the side of the pad. The buffer device 7 utilizes the elastic properties of the material itself to mitigate the impact of the design counterweight, prolong the impact time, and protect the pile head.

[0034] The signal detection system 8 consists of a force sensor, an acceleration sensor, a laser displacement sensor, and a data acquisition instrument. The three components synchronously acquire and detect the force, displacement, and acceleration time history curves during the application of the counterweight 6 to the buffer device 7. The control system (such as a computer or PLC control system) is connected to the control switch signals of the lifting and releasing device 3 and the power generation system 9 via cables to achieve synchronous control of "unlocking-powering-loading".

[0035] Example 2: Specific implementation of the workflow: (1) Determine the installation location of equipment support 1 and test the bearing capacity and stability of the foundation at the installation location; (2) Equipment bracket 1, electromagnetic rail 4, detection counterweight 6, load-bearing platform 5 and other accessories arrive on site; (3) Install the equipment bracket 1, lifting and release device 3, electromagnetic catapult device, detection system 8, and control system, and use the balance anchor nuts to level the electromagnetic catapult-type fast load detection device; (4) Debug the control system to ensure that the control system can effectively control the lifting, locking, and releasing of the lifting and releasing device 3, as well as the switching of the electromagnetic catapult device; (5) Assemble the counterweight 6 and set the current in the electromagnetic catapult device according to the design bearing capacity of the pile foundation 11 to be tested, and verify the integrity of the counterweight 6. (6) After verification, the test weight 6 is passed through the electromagnetic rail 4, and the electromagnetic rail 4 is located at the center of the test weight 6. The test weight 6 is then installed into the bearing platform 5, and the test weight 6 and the bearing platform 5 are bound together as a whole by the hinge. (7) Lift the bearing platform 5 to the designed testing height by using the lifting release device 3, and lock the lifting release 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 curve, displacement time history curve and acceleration time history curve; (9) After all the above steps are completed, the locking state of the lifting release device 3 is released through the control system, and the control switch of the electromagnetic catapult is closed at the same time. The counterweight 6 is detected to move under its own weight and electromagnetic force and act on the buffer device 7. The signal detection system 8 starts to collect force, displacement and acceleration data. When the designed counterweight rebounds to the point of separation from the buffer device, the signal detection system 8 stops collecting data and outputs the force time history curve, displacement time history curve and acceleration time history curve during the time period t of the designed counterweight and the buffer device. The collected results are analyzed. If the collected results are not qualified, the lifting release device 3 is used to lift the bearing platform 5 and the detected 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] This invention utilizes an electromagnetic catapult system comprised of an electromagnetic guide rail 4 and an armature 10 to provide controllable electromagnetic thrust within millisecond-level pulses, achieving contactless, oil-free, and maintenance-free rapid loading. The electromagnetic guide rail 4 simultaneously functions as a magnetic circuit conductor and a vertical guide, ensuring axial load transmission, simplifying the structure, and eliminating the potential off-center loading hazard that may result from the separation of the traditional guide rod and loading device.

[0037] Through the above specific embodiments, those skilled in the art can completely reproduce the electromagnetic catapult-type rapid loading method for detecting the vertical bearing capacity of pile foundations described in this invention without introducing any new features.

[0038] The above description is merely a specific embodiment of the invention, but the scope of protection of the invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the technical scope disclosed in the invention, based on the technical solutions and novel concepts of the invention, should be covered within the scope of protection of the invention.

Claims

1. An electromagnetic catapult-type rapid loading method pile foundation vertical bearing capacity testing device, comprising: The equipment support (1) mounted on the foundation and the lifting and releasing device (3) mounted on the equipment support (1) are characterized in that they further include: The electromagnetic catapult device is installed on the top of the equipment support (1) and includes: two vertically extending electromagnetic rails (4) and an armature (10) slidably sleeved on the electromagnetic rails (4); a power generation system (9) is electrically connected to the electromagnetic rails (4) and the armature (10) and is used to form a strong magnetic field between the electromagnetic rails (4) when energized, and to apply a downward electromagnetic thrust to the armature (10); The support platform (5) is connected to the armature (10) and is mounted on the electromagnetic rail (4) to move vertically along the electromagnetic rail (4); the detection counterweight (6) is set on the support platform (5); The lifting and releasing device (3) is connected to the carrying platform (5) via several steel cables wound around the guide pulley group (2) and is used to lift and controllably release the carrying platform (5); A buffer device (7) is installed above the pile head of the pile foundation (11) to be tested, and is used to withstand the impact of the test counterweight (6); The signal detection system (8) is set on one side of the pile head of the pile foundation (11) to be tested, and is used to collect the force-displacement-acceleration time history curve; The control system is connected to the electromagnetic catapult and the lifting and release device (3) to synchronously control the application of electromagnetic thrust and the release of counterweight; The armature (10) is provided with a vertical through slot that conforms to the electromagnetic rail (4) to ensure that the armature (10) forms a guide and low sliding friction on the electromagnetic rail (4); The detection counterweight (6) and the electromagnetic rail (4) are coaxially arranged along the same centroidal axis to avoid off-center loading and ensure the axial transmission of vertical impact load.

2. The electromagnetic catapult-type rapid loading method for detecting the vertical bearing capacity of pile foundations as described in claim 1, characterized in that, The signal detection system (8) includes at least a force sensor, a displacement sensor and an acceleration sensor, used to collect the force-displacement-acceleration time history curve generated when the pile foundation (11) is impacted by the counterweight (6).

3. The electromagnetic catapult-type rapid loading method pile foundation vertical bearing capacity testing device as described in claim 1, characterized in that, The control system also includes a control switch, which is electrically connected to the power generation system (9) and is used to control the on / off state of the power generation system (9).

4. The electromagnetic catapult-type rapid loading method pile foundation vertical bearing capacity testing device as described in claim 1, characterized in that, The lifting and releasing device (3) includes an electric hoist or winch, a guide pulley block (2) and a hinge. One end of the hinge is connected to the electric hoist or winch, and the other end is connected to the carrying platform (5) through the guide pulley block (2) to realize the lifting and locking release of the carrying platform (5).

5. The electromagnetic catapult-type rapid loading method for detecting the vertical bearing capacity of pile foundations as described in 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 prolong the impact time and protect the pile head. The displacement sensor is set on the foundation and on one side of the buffer device (7).

6. A method for detecting the vertical bearing capacity of pile foundations using the electromagnetic catapult-type rapid loading method implemented with the device described in any one of claims 1-5, characterized in that, Includes the following steps: Step a. Install and level the equipment support on the foundation (1); Step b. Fix the electromagnetic rail (4) to the top of the equipment bracket (1) so that the electromagnetic rail (4) also serves as a vertical guide rod; Step c. Using the armature (10) set on the bearing platform (5), the bearing platform (5) is fitted onto the electromagnetic rail (4), and the detection counterweight (6) is fixed to the bearing platform (5); Step d. Lift the support platform (5) to the designed height and lock it using the lifting release device (3); Step e. Start the signal detection system (8) to prepare for data acquisition; Step f. Unlock and close the control switch through the control system to make the power generation system (9) supply power to the electromagnetic rail (4). Under the dual action of the electromagnetic thrust of the armature (10) and the self-weight of the detection counterweight (6), the bearing platform (5) and the detection counterweight (6) are pushed downward to impact the buffer device (7). Step g. The signal detection system (8) acquires the force-displacement-acceleration time history curve in real time during the action of the 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 curves.

7. The method for detecting the vertical bearing capacity of pile foundations using the electromagnetic catapult-type rapid loading method as described in claim 6, characterized in that, In step f, the electromagnetic thrust is achieved by adjusting the output current of the power generation system (9) to achieve millisecond-level adjustable pulse loading from 100 milliseconds to 800 milliseconds, in order to match the detection requirements of different design load capacities.

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