Hammer type pile foundation horizontal bearing capacity testing device and method

Abstract

The invention relates to a hammer type pile foundation horizontal bearing capacity testing device and method, and aims to provide a simple, accurate and economical solution for testing the ocean pile foundation horizontal bearing capacity. The device is connected with the pile foundation through the hammer ball, horizontal load application is achieved, and the bearing capacity of the pile foundation under different horizontal loads is measured. The device mainly comprises a weight throw, a rigid rod, a driving device, a displacement and tension measuring device and a control system. The weight ball is connected with the pile foundation, the weight ball moves around the pile through the driving device to generate horizontal force, and the movement direction and the load of the weight ball are controlled; the displacement and tension measuring device monitors the horizontal displacement and the horizontal force of the pile foundation in real time, and the control system adjusts the load according to feedback data and records test information. According to the testing method, the horizontal bearing capacity of the pile foundation in the marine environment is simulated by accurately controlling the motion path and the load of the hammer, the stability and the bearing performance of the pile foundation are effectively evaluated, and the testing method is suitable for ocean engineering pile foundation performance detection.

Description

Technical Field

[0001] The invention belongs to the technical field of pile foundation engineering, and relates to a device and method for testing the horizontal bearing capacity of a chain ball type pile foundation. Background Art

[0002] As the global energy transition accelerates, wind power, as a key clean energy source, is experiencing unprecedented development opportunities. The development of offshore wind power will not only help optimize the energy mix and reduce reliance on fossil fuels, but also accelerate the transformation and upgrading of the energy structure, driving global energy development towards green and low-carbon development. Regional economic integration is also driving the construction of major bridges. To address the growth of marine engineering, it is crucial to strengthen research on the horizontal bearing capacity of offshore pile foundations.

[0003] Existing pile foundation horizontal bearing capacity tests primarily rely on jacks. However, in marine engineering, due to the high horizontal bearing capacity required, the contact area between the jack and the pile is small, while the reaction structure bearing the reaction force must provide even greater horizontal bearing capacity. This necessitates increasing design parameters such as the diameter, reinforcement, and length of the reaction beam, increasing the complexity and cost of design and construction. Furthermore, the jack's output force and accuracy are limited in high-pressure and highly corrosive environments, potentially leading to problems such as leaks in oil pipes and joints, and insufficient oil pump pressure, affecting the accuracy of test results. Furthermore, natural factors in the marine environment, such as temperature, humidity, salt spray, currents, tides, and wind and waves, can significantly impact the testing equipment and testing process. For example, salt spray can cause corrosion of metal components, while currents and tides can increase equipment instability and operational difficulty. Therefore, traditional jack-based pile foundation horizontal bearing capacity testing is not suitable for marine and water conditions.

[0004] Marine pile foundations face a variety of complex loading environments during construction and operation. Because pile foundations are subject to external influences such as wave loads, low temperatures, high pressure, and ocean currents, testing the horizontal bearing capacity of pile foundations requires considering complex stress paths, stress states, and loading diversity. Therefore, to address these issues, a test device suitable for marine water environments is needed to accurately and quickly conduct horizontal bearing capacity tests on marine pile foundations. Summary of the Invention

[0005] The purpose of the present invention is to provide a rapid marine pile foundation horizontal bearing capacity testing device and method that is efficient and applicable to marine environments, so as to solve the shortcomings of the current marine pile foundation horizontal bearing capacity testing methods.

[0006] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0007] A ball-and-chain pile foundation horizontal bearing capacity testing device, comprising:

[0008] (1) A ball-chain device, comprising a ball and a chain, wherein the ball is connected to the outer ring of the bearing via the chain;

[0009] (2) a rigid rod, inserted into the groove of the bearing seat and fixed, used to support the chain ball and make it move centrifugally with the rigid rod;

[0010] (3) a driving device, comprising an outer ring rotating bearing, a bearing seat, a gear transmission structure and a PWM driving motor, wherein the inner ring of the bearing is fixed to the pile foundation, the bearing seat is fixed to the outer ring of the bearing, and the gear at the bottom of the bearing seat is engaged with the motor gear to control the direction of movement of the chain ball and the size of the load applied by the chain ball device to the pile foundation;

[0011] (4) Displacement measuring device, a horizontal displacement sensor installed near the pile foundation, used to monitor the horizontal displacement of the pile foundation in real time and collect displacement information;

[0012] (5) Tension measuring device, a bidirectional tension sensor installed in the middle section of the chain, used to detect the horizontal load on the pile foundation in real time and collect tension information;

[0013] (6) A control system comprising a wireless transmission module, an Arduino controller, a terminal control device, a FOC motor controller, and a serial communication converter. The wireless transmission module comprises wireless information transmission between the terminal device and the Arduino controller, wireless information transmission between the FOC motor controller and the PWM drive motor, an information acquisition transmitter located on the displacement measuring device and the tension measuring device, a displacement information receiver connected to the terminal device, and a tension information receiver connected to the Arduino controller. The terminal control device may be a mobile phone or a computer, serving as a host computer, setting a target tension and transmitting information to the Arduino controller via wireless transmission. The Arduino controller is connected to the FOC motor controller via the serial communication converter. The Arduino controller controls the FOC motor controller to change the speed of the PWM drive motor to control the load size. The Arduino controller uses a PID closed-loop algorithm to adjust the speed of the PWM drive motor based on the real-time horizontal tension data fed back by the tension measuring device, controls the application of the horizontal load, and records the test data and transmits it to the terminal control device.

[0014] (7) a support platform for placing and fixing the PWM drive motor;

[0015] (8) A fixing buckle is used to fix the position of the ball to prevent the ball from sliding along the rigid rod toward the pile foundation, causing the chain to be uneven, and to prevent the danger of the ball being thrown out due to chain breakage.

[0016] A method for testing the horizontal bearing capacity of a ball-and-chain pile foundation comprises the following steps:

[0017] (1) Equipment installation and system initialization: Install the bearing platform, driving device, rigid rod, chain ball device, tension measuring device, fixing buckle, horizontal displacement measuring device and control system in sequence, set the data collection time interval of displacement sensor and tension sensor to be the same, observe the real-time displacement and tension data before the driving device is started through the terminal control device, wait for it to stabilize, check the data to zero, calibrate the horizontal displacement reference coordinate of the pile foundation, and set the target load spectrum;

[0018] (2) Dynamic loading stage: The PWM drive motor is started by the FOC motor controller to drive the ball chain device to perform centrifugal motion. The device is operated according to the initially set target load. The speed is adjusted in real time by the PID closed-loop control method so that the applied load increases according to the preset gradient.

[0019] (3) Multi-parameter synchronous acquisition: continuously record the time domain load data of the tension sensor and the spatial displacement matrix parameters of the displacement sensor;

[0020] (4) Data processing: During the dynamic loading process, the relative displacement of the displacement measuring device from the pile head is cycled from small to large and then from large to small. According to the measured force and displacement data, the time corresponding to the minimum relative displacement in each set of data is selected. According to the time corresponding to the minimum relative displacement, the force and displacement data at that moment are statistically calculated to generate a load-displacement characteristic curve and obtain the horizontal bearing capacity of the marine pile foundation.

[0021] Furthermore, the gear transmission structure in the driving device includes: an involute gear ring integrally formed with the bottom of the bearing seat and a harmonic reduction gear set connected to the output shaft of the PWM drive motor.

[0022] Existing pile foundation horizontal bearing capacity testing methods mostly use unidirectional or bidirectional cyclic loading, which cannot simulate the multi-directional loading conditions of pile foundations in the ocean. The circumferential loading method set up by this device can simulate the multi-directional loading conditions of pile foundations and is closer to the actual working conditions. At the same time, existing pile foundation horizontal bearing capacity testing methods mostly require the addition of a reaction force device. Instead of a reaction force device, this device uses a base to fix the PWM drive motor, which is simpler than traditional pile foundation horizontal testing solutions.

[0023] Furthermore, the bearings in the drive device can be prefabricated according to requirements with a size that matches the radius of the marine pile foundation, or bearings with a variable inner ring radius can be selected, such as expansion sleeve bearings and hydraulic expansion bearings.

[0024] Furthermore, the displacement measuring device includes a horizontal displacement sensor, a laser displacement sensor array arranged in the axial direction of the pile foundation, or an optical total station positioning system set in the radial direction of the pile foundation, for monitoring the horizontal displacement changes of the pile foundation.

[0025] Existing methods for testing the horizontal bearing capacity of pile foundations often require regular manual measurement of pile head displacement, making it difficult to achieve real-time dynamic monitoring of pile foundation horizontal displacement. During monitoring, critical displacement changes may be missed, and abnormalities in the pile foundation may not be detected in a timely manner. This setup utilizes a horizontal displacement sensor and a laser displacement sensor array to collect horizontal displacement data of the pile foundation in real time and transmit this data to a monitoring system in real time. Monitoring personnel can use a computer to view real-time displacement changes of the pile foundation, detect displacement anomalies promptly, and take appropriate measures to ensure the safety of the pile foundation.

[0026] Furthermore, the tension measuring device is arranged in the middle position of the chain to monitor the changes in the horizontal load force on the pile foundation.

[0027] In existing pile foundation horizontal bearing capacity testing methods, the horizontal load on the pile body is often obtained by attaching strain gauges to the pile body for data collection. The collection time interval is long and it is difficult to construct in a marine environment. This setting can measure the magnitude of the horizontal load on the pile body in real time, is easy to install, tests quickly, and facilitates data collection and processing.

[0028] Furthermore, the control system includes: a wireless transmission module, which transmits the tension data collected by the tension measurement device to the Arduino controller in real time, transmits the displacement data collected by the displacement measurement device to the terminal control device in real time, and realizes mutual communication between the FOC motor controller and the PWM drive motor, and realizes mutual communication between the terminal control device and the Arduino controller; the Arduino controller, which receives the tension data measured by the tension test device and the terminal control device instructions, and controls the FOC motor controller to change the speed of the PWM drive motor through the PID algorithm. The PID algorithm corrects the horizontal load size in real time according to the target tension value set by the terminal device. When the force measured by the tension measurement device is different from the set target tension, the Arduino controller accelerates or decelerates the PWM drive motor by controlling the FOC motor controller until the tension measured by the tension measurement device is the same as the target tension; the FOC motor controller is controlled by the Arduino controller to change the speed of the PWM drive motor; the terminal control device serves as a host computer, sets the target tension, and is used to receive the real-time measured displacement and tension data and control the control system in real time; a serial communication converter realizes seamless conversion between different communication protocols to facilitate the acquisition of collected information. In the existing pile foundation horizontal bearing capacity test method, the loading process is a separate linear loading or a separate cyclic loading, and each experiment is relatively simple. This device can perform linear loading by setting different target forces, and can also change the magnitude of the force in real time, changing the loading and unloading process to achieve the goal of cyclic loading, making it more convenient to make different loading plans.

[0029] Furthermore, the load regulation adopts closed-loop feedback control to dynamically adjust the motor speed according to the real-time tension data.

[0030] The existing pile foundation horizontal bearing capacity test method has a slow control speed for applying horizontal load, and there may be a large error between the actual value of horizontal load and the target value. Through closed-loop feedback control, the experimental data obtained by real-time correction of the applied horizontal load size is more accurate.

[0031] Furthermore, the wireless communication module supports at least one of the following protocols: Bluetooth, Wi-Fi, ZigBee or LoRa.

[0032] Furthermore, the Arduino controller includes a main control board and an expansion board. The expansion board integrates a wireless communication chip for pairing with a wireless communication module. The expansion board can be an ESP8266, ESP32, or NRF24L01 wireless communication expansion board. Compared to existing pile foundation horizontal bearing capacity testing methods, which often rely on wired connections between devices, this is inconvenient for marine pile foundation measurements. Using a wireless communication module facilitates experimental operation and improves data acquisition accuracy.

[0033] On the other hand, the present invention also provides different device equipment schemes, which can change the number of balls and the chain radius to meet different horizontal load-bearing requirements, and can change the positional relationship between the chain balls and the rigid rod, that is, the chain is assembled and separated from the rigid rod or the chain is placed in the groove of the rigid rod.

[0034] Compared with the prior art, the chain ball type pile foundation horizontal bearing capacity testing device of the present invention solves multiple key problems compared with the traditional hydraulic jack testing method.

[0035] 1. Easy to operate and highly adaptable: The ball-and-chain device is easy to operate and highly adaptable, making it particularly suitable for complex marine environments and reducing dependence on hydraulic systems and high-precision equipment.

[0036] 2. Simple structure and high flexibility: The ball-and-chain device has a simple structure and high flexibility, and can quickly respond to different testing needs, especially in sea areas with large tidal changes.

[0037] 3. High precision and reliability: The hammer-type test device excels in precision and reliability. It directly applies physical impact force to the pile foundation, accurately reflecting the deformation and bearing capacity characteristics of the pile foundation under horizontal load.

[0038] 4. High test efficiency and low maintenance cost: The ball-and-chain device has higher test efficiency and lower maintenance cost, reducing the risk of equipment failure and improving safety.

[0039] 5. Overcome the limitations of traditional hydraulic jack testing methods and be able to simulate multi-directional loads and other problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 2. It is a front view of the chain ball type pile foundation horizontal bearing capacity testing device of the present invention;

[0041] Figure 2 2. It is a top view of the chain ball type pile foundation horizontal bearing capacity testing device of the present invention;

[0042] Figure 3 Schematic diagram of the driving device of the ball-and-chain pile foundation horizontal bearing capacity testing device of the present invention;

[0043] Figure 4 It is a dynamic schematic diagram of the position of the hammer device during the test process of the present invention;

[0044] Figure 5 This is a schematic diagram of the position of the chain crossing the rigid hollow rod type equipment in the present invention;

[0045] Figure 6 The load-displacement curve obtained by testing the horizontal bearing capacity test device of the chain ball pile foundation of the present invention;

[0046] Figure 7 Schematic diagram of the test process of the hammer-type pile foundation horizontal bearing capacity test device of the present invention;

[0047] In the figure: 1- sliding bearing, 2- bearing seat, 3- bearing seat bottom gear, 4- pile body, 5- motor gear, 6- PWM drive motor, 7- base, 8- columnar bidirectional tension sensor, 9- rigid rod, 10- chain, 11- sphere, 12- horizontal displacement sensor (high-precision optical total station, laser rangefinder), 13- bearing seat groove, 14- fixing buckle. DETAILED DESCRIPTION

[0048] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0049] In the following embodiments or examples, unless otherwise specified, raw materials or processing techniques are conventional commercially available raw materials or conventional processing techniques in the art.

[0050] Example: To solve the problems of the traditional hydraulic jack method in the horizontal bearing capacity test of marine pile foundation, such as large space occupation, complex equipment, difficult operation, susceptibility to the influence of the marine environment, and difficulty in simulating multi-directional loads of the pile foundation, the present invention provides a chain ball type marine pile foundation horizontal bearing capacity test device and method. The construction flow chart is as follows: Figure 7 As shown, the following steps are included:

[0051] (1) Equipment installation

[0052] Base installation: Install the base in the appropriate position and fix it with screws.

[0053] Drive unit installation: Install the drive unit consisting of the PWM drive motor, gear transmission structure, bearings and bearing seats in an appropriate position to ensure that it can drive the chain ball to move around the rigid rod and can accurately control the movement direction and load size.

[0054] Rigid rod fixation: Insert the rigid rod into the groove reserved in the bearing seat and use anchor devices or fixed brackets to ensure its stability. The length of the rigid rod should be selected according to the size of the pile foundation and the load range required for the test.

[0055] Chain connection: Connect the chain to the bearing outer ring via a chain, ensuring the chain is secure and allows for free movement. The chain length should be selected based on the length of the rigid rod and the load range required for the test. The number, size, and material of the chain should be selected based on the load range required for the test.

[0056] Displacement sensor installation: Install a horizontal displacement sensor near the pile foundation. Laser rangefinders or optical total stations can be used to monitor the horizontal displacement of the pile foundation in real time. The sensor is connected to the control system via a wireless module to provide real-time data feedback.

[0057] Tension sensor installation: A column-type bidirectional tension sensor is arranged in the middle position of the chain to monitor the changes in the horizontal load force on the pile foundation.

[0058] Control system connection: The real-time tension data measured by the tension sensor is transmitted to the Arduino controller through the wireless module. The terminal control device is connected to the Arduino controller through wireless communication. The Arduino controller is connected to the FOC motor controller through a serial communication converter. The FOC motor controller is connected to the PWM drive motor through wireless communication.

[0059] (2) Equipment debugging and calibration

[0060] Connect all equipment, debug, and calibrate them. Calibrate the horizontal displacement reference coordinates of the pile foundation, record the initial horizontal position of the pile foundation, and set the initial target tension value for the test through the terminal equipment.

[0061] (3) Device startup test

[0062] Start the drive device: Start the PWM drive motor through the terminal control device, so that the chain ball produces centrifugal motion around the rigid rod, and gradually applies horizontal load to the pile foundation.

[0063] Load Control: Based on a pre-set test plan, a PID closed-loop control algorithm is used. Based on real-time feedback and the terminal device's control plan, the speed and direction of the hammer are controlled, and the magnitude and direction of the horizontal load are varied to achieve multi-path loading. The test plan should include parameters such as load magnitude, direction, and application time, which can be adjusted based on actual conditions.

[0064] (4) Test operation

[0065] Real-time monitoring: Horizontal displacement sensors and tension sensors are used to monitor the horizontal displacement and horizontal tension changes of the pile foundation in real time to ensure that the equipment is within the normal working range and can obtain real-time data.

[0066] Control and adjustment: Based on the monitored horizontal displacement data of the pile foundation, the control system adjusts the movement path of the chain ball, the load size and the application time to accurately control the load changes during the test.

[0067] Data recording: record test data, including load size, pile foundation horizontal displacement, tension value, etc.

[0068] (5) Test stop

[0069] Stop load: When the horizontal displacement of the pile foundation reaches the preset limit value, or the load is applied to the predetermined limit value, or the relationship between the horizontal pile foundation and the horizontal displacement tends to be stable, stop applying the load.

[0070] Stop the power unit: disconnect the power unit and stop the hammer movement.

[0071] (6) Data Analysis

[0072] Draw curves: Based on the test data, draw force and displacement curves to analyze the horizontal bearing capacity characteristics of the pile foundation.

[0073] Performance evaluation: Evaluate the stability and bearing capacity of the pile foundation based on factors such as its size, material, and burial depth.

[0074] In some specific embodiments, the size of the balls in the chain ball, the assembly scheme, the chain radius, and the number of balls can all be adjusted. Depending on the horizontal load required for testing pile foundations of different sizes, balls of different materials and sizes or chains of different radii or different numbers of balls are selected for testing.

[0075] In some specific embodiments, the rigid rod is lightweight and available in two configurations: a solid rigid rod that, when installed, passes through the center of the hollow ball in the chain-and-ball assembly, without the chain contacting the rigid rod; and a hollow rigid rod that, when installed, allows the chain of the chain-and-ball assembly to be stored within the hollow rigid rod and pass through the center of the ball. During testing, the centrifugal force generated by the rigid rod was less than 5% of the centrifugal force generated by the chain-and-ball assembly.

[0076]

[0077] F 链球 ≥20F 杆

[0078] Where: F 链球 —The horizontal centrifugal force generated by the centrifugal motion of the hammer;

[0079] M i —The mass of each sphere;

[0080] ω 2 — angular velocity of the hammer during its rotation;

[0081] L 链 —The distance from the ball to the pile, i.e. the length of the chain;

[0082] M 链 — chain quality;

[0083] F 杆 —Horizontal centrifugal force generated by the centrifugal motion of the rod;

[0084] M 杆 —mass of the rigid rod;

[0085] L 杆 —Length of the rigid rod.

[0086] In some specific embodiments, the bearings in the driving device can be prefabricated according to requirements with a size that matches the radius of the marine pile foundation, or bearings with a variable inner ring radius can be selected, such as expansion sleeve bearings and hydraulic expansion bearings.

[0087] In some specific embodiments, the test is stopped when the pile foundation horizontal displacement reaches a limit or the load is applied to a predetermined limit or the relationship between the horizontal pile foundation and the horizontal displacement tends to be stable or meets the corresponding test specifications or standards.

[0088] Example 1:

[0089] For example, at a construction site, the diameter of a marine pile foundation 4 is known, and the requirement is to determine the horizontal load the pile withstands when the pile head reaches a horizontal displacement of 10 cm. This test is performed by selecting an assembly solution with appropriate bearing dimensions and the relationship between the ball and rod. The specific implementation steps are as follows:

[0090] Step 1: According to the measured pile foundation diameter, select the appropriate radius of the bearing 1, the length of the rigid rod 9, the chain 10 and the number of balls 11 for equipment installation, and firmly fix the rigid rod 9 on the bearing groove 13 to ensure its stability; connect the chain ball to the outer ring pull ring of the bearing 1 through the chain 10 to ensure that the chain ball device is firmly connected and can ensure that the ball 11 can move freely on the rigid rod 9, and install the tension sensor 8 between the chains; install the bearing 1, bearing seat 2, gear transmission structure 3 and 5, PWM drive motor 6 and base 7 in the horizontal load drive device to the appropriate position to ensure that it can drive the chain ball to move around the rigid rod 9 and can accurately control the movement direction and load size; install the fixing buckle 14 in front of the ball 11 and at the end of the rigid rod 9, and install the horizontal displacement sensor 12 near the pile foundation to ensure that the horizontal displacement change of the pile foundation can be monitored in real time. The sensor needs to be connected to the control system through a wireless module to feedback data in real time.

[0091] Step 2: Calibrate the horizontal displacement reference coordinates of the pile foundation, record the initial horizontal position of the pile foundation, and set the initial target tension value of the test through the terminal device. Start the drive device to make the ball chain move centrifugally around the rigid rod 9, gradually applying horizontal load to the pile foundation;

[0092] Step 3: Test operation, using the displacement measuring device 12 and the tension sensor 8 to monitor the horizontal displacement of the pile foundation and the change in the horizontal tensile load in real time, ensuring that the equipment is within the normal operating range and that real-time data can be obtained; based on the monitored horizontal displacement data of the pile foundation, the control system adjusts the motion path of the hammer, the load size, and the application time, accurately controlling the load change during the test process until the horizontal displacement of the pile head reaches the predetermined target, at which point the test is stopped;

[0093] Step 4: After the test is completed, stop applying the load, disconnect the PWM drive motor 6 of the power equipment, and confirm that all data has been completely recorded and saved; dismantle the test device, clean up the site, and ensure that the equipment will not affect subsequent projects;

[0094] Step 5: Prepare a test report based on the test results. The report includes the horizontal bearing capacity of the pile foundation, the horizontal displacement of the pile head, and the force-displacement curve relationship. Figure 6 , and finally the horizontal bearing capacity of the marine pile foundation is obtained.

[0095] The above description of the embodiments is intended to facilitate understanding and use of the invention by those skilled in the art. It will be apparent that those skilled in the art can readily make various modifications to these embodiments and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the present invention is not limited to the above-described embodiments. Improvements and modifications made by those skilled in the art based on the explanations of the present invention without departing from the scope of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A ball-and-chain pile foundation horizontal bearing capacity testing device, characterized in that: Includes the following structures: A ball-chain device, comprising a ball and a chain, wherein the ball is connected to the outer ring of the bearing via the chain; A rigid rod is inserted into the groove of the bearing seat and fixed, and is used to support the chain ball and make it move centrifugally with the rigid rod; a driving device includes an outer ring rotating bearing, a bearing seat, a gear transmission structure and a PWM drive motor, wherein the inner ring of the bearing is fixed to the pile foundation, the bearing seat is fixed to the outer ring of the bearing, and the gear at the bottom of the bearing seat is engaged with the motor gear to control the direction of movement of the chain ball and the load applied by the chain ball device to the pile foundation; The displacement measuring device is installed near the pile foundation to monitor the horizontal displacement of the pile foundation in real time and collect displacement information; The tension measuring device is installed in the middle of the chain to detect the horizontal load on the pile foundation in real time and collect tension information; the control system, The control system includes a wireless transmission module, an Arduino controller, a terminal control device, a FOC motor controller, and a serial communication converter. The wireless transmission module includes wireless information transmission between the terminal device and the Arduino controller, wireless information transmission between the FOC motor controller and the PWM drive motor, an information acquisition transmitter located on a displacement measuring device and a tension measuring device, and a displacement information receiver connected to the terminal device and a tension information receiver connected to the Arduino controller. The terminal control device is a mobile phone or a computer, which serves as a host computer, sets the target tension and transmits the information to the Arduino controller via wireless transmission. The Arduino controller is connected to the FOC motor controller via a serial communication converter. The Arduino controller controls the FOC motor controller to change the PWM drive motor speed to control the load size. The Arduino controller uses a PID closed-loop algorithm to adjust the PWM drive motor speed based on real-time horizontal tension data fed back by the tension measuring device to control the applied horizontal load, thereby achieving the purpose of load regulation and recording the test data for transmission to the terminal control device. The support is used to place and fix the PWM drive motor. The fixing buckle is used to fix the position of the ball to prevent the ball from sliding along the rigid rod toward the pile foundation, causing the chain to be uneven, and to prevent the danger of the ball being thrown out due to chain breakage.

2. A hammer-type pile foundation horizontal bearing capacity testing device according to claim 1, characterized in that: The ball in the hammer device adopts a graded counterweight structure, comprising: an outer titanium alloy shell; and an inner cavity filled with a lead-zinc composite counterweight.

3. A hammer-type pile foundation horizontal bearing capacity testing device according to claim 2, characterized in that: The rigid rod is lightweight and comes in two structural types: a solid rigid rod that, when installed, passes through the center of the hollow ball in the chain ball device, without the chain and the rigid rod contacting each other; and a hollow rigid rod that, when installed, allows the chain of the chain ball device to be stored within the hollow rigid rod and pass through the center of the ball. During testing, the centrifugal force generated by the rigid rod was less than 5% of the centrifugal force generated by the chain ball device. F 链球 ≥20F 杆 Where: F 链球 —The horizontal centrifugal force generated by the centrifugal motion of the hammer; M i —The mass of each sphere; ω 2 — angular velocity of the hammer during its rotation; L 链 —The distance from the ball to the pile, i.e. the length of the chain; M 链 — chain quality; F 杆 —Horizontal centrifugal force generated by the centrifugal motion of the rod; M 杆 —mass of the rigid rod; L 杆 —Length of the rigid rod.

4. A hammer-type pile foundation horizontal bearing capacity testing device according to claim 1, characterized in that: The gear transmission structure in the drive device includes: an involute gear ring integrally formed with the bottom of the bearing seat and a harmonic reduction gear set connected to the output shaft of the PWM drive motor; the PWM drive motor receives the PWM signal output by the PID to adjust the motor speed to control the load.

5. The hammer-type pile foundation horizontal bearing capacity testing device according to claim 1, characterized in that: The displacement measuring device includes a horizontal displacement sensor, a laser displacement sensor array arranged in the axial direction of the pile foundation, or an optical total station positioning system set in the radial direction of the pile foundation, which is used to monitor the horizontal displacement changes of the pile foundation.

6. The hammer-type pile foundation horizontal bearing capacity testing device according to claim 1, characterized in that: The tension measuring device includes a bidirectional tension sensor, which is arranged in the middle of the chain and is used to monitor the change of the horizontal load force on the pile foundation.

7. The hammer-type pile foundation horizontal bearing capacity testing device according to claim 1, characterized in that: The control system includes: a wireless transmission module, which transmits the tension data collected by the tension measurement device to the Arduino controller in real time, and transmits the displacement data collected by the displacement measurement device to the terminal control device in real time, thereby realizing mutual communication between the FOC motor controller and the PWM drive motor, and realizing mutual communication between the terminal control device and the Arduino controller; the Arduino controller, which receives the tension data measured by the tension test device and the terminal control device instructions, and controls the FOC motor controller to change the speed of the PWM drive motor through a PID algorithm; the FOC motor controller, which is controlled by the Arduino controller to change the speed of the PWM drive motor; the terminal control device serves as a host computer, sets the target tension, and is used to receive the real-time measured displacement and tension data and to control the control system in real time; and a serial communication converter, which realizes seamless conversion between different communication protocols to facilitate the acquisition of collected information.

8. The hammer-type pile foundation horizontal bearing capacity testing device according to claim 1, characterized in that: The ball chain device controls the load applied to the pile foundation using closed-loop feedback control, dynamically adjusting the motor speed based on real-time tension data.

9. The hammer-type pile foundation horizontal bearing capacity testing device according to claim 1, characterized in that: The wireless module supports at least one of the following protocols: Bluetooth, Wi-Fi, ZigBee or LoRa; The Arduino controller includes a main control board and an expansion board. The expansion board integrates a wireless communication chip for pairing with a wireless communication module. The expansion board is an ESP8266, ESP32 or NRF24L01 wireless communication expansion board.

10. A method for testing the horizontal bearing capacity of a hammer-type pile foundation, characterized in that: Using the hammer-type pile foundation horizontal bearing capacity testing device according to any one of claims 1 to 9, the method comprises the following steps: (1) Equipment installation and system initialization: Install the bearing platform, driving device, rigid rod, chain ball device, tension measuring device, fixing buckle, horizontal displacement measuring device and control system in sequence, set the data collection time interval of displacement sensor and tension sensor to be the same, observe the real-time displacement and tension data before the driving device is started through the terminal control device, wait for it to stabilize, check the data to zero, calibrate the horizontal displacement reference coordinate of the pile foundation, and set the target load spectrum; (2) Dynamic loading stage: The PWM drive motor is started by the FOC motor controller to drive the ball chain device to perform centrifugal motion. The device is operated according to the initially set target load. The speed is adjusted in real time by the PID closed-loop control method so that the applied load increases according to the preset gradient. (3) Multi-parameter synchronous acquisition: continuously record the time domain load data of the tension sensor and the spatial displacement matrix parameters of the displacement sensor; (4) Data processing: During the dynamic loading process, the relative displacement of the displacement measuring device from the pile head is cycled from small to large and then from large to small. According to the measured force and displacement data, the time corresponding to the minimum relative displacement in each set of data is selected. According to the time corresponding to the minimum relative displacement, the force and displacement data at that moment are statistically calculated to generate a load-displacement characteristic curve and obtain the horizontal bearing capacity of the marine pile foundation.

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