Steel pipe pile sinking verticality real-time closed-loop control system based on gravity datum

Abstract

This invention discloses a real-time closed-loop control system for the verticality of steel pipe piles based on gravity reference. This invention relates to the field of pile foundation engineering construction technology. Using absolute gravity as a unified reference, it acquires offset data through coaxial measurement of multiple sections of the entire pile body, calculates the pile body's deflection deformation, and achieves hierarchical collaborative closed-loop control that prioritizes correction of the lower and middle sections of the pile body. The advantages of this invention are: by using a coaxial measurement module deployed along the inner wall of the steel pipe pile, combined with a gravity reference establishment module that penetrates the entire length of the steel pipe pile, offset data of multiple sections of the entire pile body relative to a unified gravity reference is acquired. Then, the pile body deflection calculation module calculates the true deflection deformation curve of the entire pile body. This breaks through the industry's common perception that existing technologies assume steel pipe piles are ideal rigid bodies and use the verticality of the pile top to represent the verticality of the entire pile body. It effectively solves the industry pain point that existing technologies cannot identify or intervene in advance in the hidden deflection deformation of the lower and middle sections of the pile body.

Description

Technical Field

[0001] The present invention relates to the technical field of pile foundation engineering construction, specifically a real-time closed-loop control system for the verticality of steel pipe pile sinking based on the gravity reference. Background Technique

[0002] As a pile foundation structure form with high bearing capacity, strong bending resistance, convenient construction, and wide geological adaptability, steel pipe piles have been widely used in various civil engineering construction fields such as port terminals, cross-river and cross-sea bridges, offshore wind power foundations, deep foundation pit support for super high-rise buildings, and foundation treatment of large industrial plants. It is one of the core foundation bearing structures in pile foundation engineering. During the construction process of steel pipe pile sinking, the verticality of the pile body is the core control index that determines the pile-forming quality, vertical and horizontal bearing performance of the pile foundation, construction accuracy of the upper structure, and long-term operation safety. The current domestic pile foundation engineering construction quality acceptance code has strict limiting requirements for the verticality deviation of steel pipe pile sinking. Especially in the construction of large-depth and large-diameter steel pipe piles, the precise control of verticality directly determines the overall construction quality and safety redundancy of the project;

[0003] The existing steel pipe pile sinking verticality control technology mainly collects the pile top attitude data through measuring devices such as inclinometers and total stations, and配合液压纠偏机构进行桩体姿态调整,来实现沉桩施工过程中的桩体垂直度管控,存在一定的缺陷,首先,现有技术普遍默认钢管桩为理想刚性体,仅以桩顶单点偏移数据作为垂直度控制依据,无法识别桩身中下段的隐性挠曲变形,易出现桩顶检测合格但全桩身垂直度超标的质量隐患,其次,现有技术测量与控制基准不统一,无法解耦打桩架姿态偏移与桩身自身变形的耦合误差,导致纠偏指令与桩身实际修正需求不匹配,难以实现精准的实时闭环控制,为此,我们提出基于重力基准的钢管桩沉桩垂直度实时闭环控制系统。 Summary of the Invention

[0004] The purpose of the present invention is to provide a real-time closed-loop control system for the verticality of steel pipe pile sinking based on the gravity reference.

[0005] [[ID=第十九]]

[0006]

[0006] Gravity reference establishment module: used to construct a unique and stable absolute gravity vertical reference line throughout the entire steel pipe pile to provide a unified gravity vertical reference for the pile top reference measurement module and the full pile body coaxial measurement module;

[0007] It should be noted that there is an unclear part in the original text for item which is marked as "配合液压纠偏机构进行桩体姿态调整,来实现沉桩施工过程中的桩体垂直度管控,存在一定的缺陷,首先,现有技术普遍默认钢管桩为理想刚性体,仅以桩顶单点偏移数据作为垂直度控制依据,无法识别桩身中下段的隐性挠曲变形,易出现桩顶检测合格但全桩身垂直度超标的质量隐患,其次,现有技术测量与控制基准不统一,无法解耦打桩架姿态偏移与桩身自身变形的耦合误差,导致纠偏指令与桩身实际修正需求不匹配,难以实现精准的实时闭环控制,为此,我们提出基于重力基准的钢管桩沉桩垂直度实时闭环控制系统。" The part "配合液压纠偏机构进行桩体姿态调整,来实现沉桩施工过程中的桩体垂直度管控" seems to be incomplete in the description. The above translation is based on the existing content as accurately as possible.Pile top benchmark measurement module: Installed at the top of the steel pipe pile, it is used to collect two-dimensional horizontal offset data of the pile top center relative to the vertical benchmark line of absolute gravity in real time. Its signal output end is connected to the first signal input end of the multi-source data synchronous fusion module, and transmits the collected pile top offset data to the multi-source data synchronous fusion module in real time.

[0008] The whole pile coaxial measurement module is equidistantly fixed along the axial direction of the inner wall of the steel pipe pile. It is used to collect two-dimensional horizontal offset data of the center of multiple corresponding sections of the whole pile relative to the vertical baseline of absolute gravity in real time. Its signal output end is connected to the second signal input end of the multi-source data synchronous fusion module, and transmits the collected multi-section offset data of the whole pile to the multi-source data synchronous fusion module in real time.

[0009] Multi-source data synchronization and fusion module: used to perform clock synchronization, redundancy check and weighted fusion processing on the received pile top offset data and the full pile multi-section offset data, and output a smooth and interference-free full pile continuous offset dataset. Its data output end is connected to the signal input end of the pile deflection calculation module, and transmits the full pile continuous offset dataset to the pile deflection calculation module in real time.

[0010] The pile body deflection calculation module is used to calculate the received continuous offset dataset of the entire pile body, decouple the coupling error between the attitude offset of the pile driving frame and the deflection deformation of the steel pipe pile itself, identify the true deflection deformation mode of the entire steel pipe pile body and generate the deflection deformation curve of the entire pile body. Its calculation result output end is connected to the signal input end of the hierarchical collaborative closed-loop control module, and transmits the deflection deformation curve data of the entire pile body to the hierarchical collaborative closed-loop control module in real time.

[0011] The hierarchical collaborative closed-loop control module is used to generate hierarchical collaborative correction control commands based on the received full pile body flexural deformation curve as the core control target. These commands prioritize correcting the hidden flexural deformation in the middle and lower sections of the pile body and simultaneously adjust the verticality of the pile top. The control command output end is connected to the control input end of the hydraulic execution correction module, transmitting the hierarchical collaborative correction control commands to the hydraulic execution correction module in real time.

[0012] As a further embodiment of the present invention: the gravity reference establishment module includes a universal hinged suspension seat, a high-density plumb bob, a low-elongation reference steel wire, a damping medium container, and a segmented telescopic protective sleeve. The universal hinged suspension seat is fixed to the center position of the top of the pile driving frame. The top end of the low-elongation reference steel wire is connected to the universal hinged suspension seat, and the bottom end is fixed to the high-density plumb bob. The high-density plumb bob is immersed in the viscous damping liquid in the damping medium container. The segmented telescopic protective sleeve is sleeved on the outside of the low-elongation reference steel wire, arranged along the entire length of the reference steel wire, and maintains a non-contact gap with the reference steel wire. The absolute gravity vertical reference line formed by the low-elongation reference steel wire is coaxial with the designed pile driving axis of the steel pipe pile and penetrates the inner cavity of the steel pipe pile without contact throughout the entire process.

[0013] As a further embodiment of the present invention: the pile top reference measurement module includes a pile top measuring disk, a circumferentially distributed laser ranging sensor group, and a two-dimensional PSD position sensor. The pile top measuring disk is coaxially fixed to the top surface of the steel pipe pile. Multiple laser ranging sensors of the laser ranging sensor group are equidistantly arranged along the circumference of the pile top measuring disk. The emitting end of each sensor is oriented towards the direction of the absolute gravity vertical reference line, and is used to measure the radial distance from the edge of the pile top to the reference line. The two-dimensional PSD position sensor is fixed to the center position of the upper end surface of the pile top measuring disk. Its photosensitive surface is parallel to the upper end surface of the pile top measuring disk, and the geometric center of the photosensitive surface coincides with the designed pile driving axis of the steel pipe pile. It is used to directly detect the projection position coordinates of the absolute gravity vertical reference line on the photosensitive surface. The signal output ends of the laser ranging sensor group and the two-dimensional PSD position sensor are both connected to the first signal input end of the multi-source data synchronous fusion module.

[0014] As a further aspect of the present invention: the coaxial measurement module for the entire pile body includes N sets of miniature photoelectric sensing units equidistantly fixed along the axial direction of the inner wall of the steel pipe pile, where N is a positive integer greater than or equal to 3. Each set of miniature photoelectric sensing units includes a central limiting through-hole and circumferentially distributed miniature laser ranging modules. The central limiting through-hole is coaxial with the design axis of the steel pipe pile, and the absolute gravity vertical reference line passes through all the central limiting through-holes without contact. Multiple miniature laser ranging sensors of each set of miniature laser ranging modules are equidistantly arranged circumferentially along the corresponding steel pipe pile cross-section, with their transmitting ends all facing the absolute gravity vertical reference line. The radial distance data from the edge of the corresponding cross-section to the reference line is collected in real time. The two-dimensional offset of the center of the corresponding cross-section relative to the absolute gravity vertical reference line collected by the miniature photoelectric sensing unit is calculated by the following formula:

[0015] ;

[0016] in, The section number of the miniature photoelectric sensing unit. The corresponding steel pipe pile from the pile top to the pile tip One measurement section, This refers to the number of miniature laser rangefinders within a single miniature photoelectric sensing unit. Even numbers ≥ 4 , The first The offset of the center of each measurement section relative to the vertical baseline of absolute gravity in the X and Y two-dimensional horizontal directions. To determine the inner radius of the steel pipe pile at the corresponding measurement section, For the first Within the measurement section, the first The radial distance from the sensor emitter to the absolute gravity vertical baseline, measured by a miniature laser rangefinder. For the first The azimuth angle of the miniature laser rangefinder is set at 0° in the positive X-axis direction and increases clockwise along the circumference of the cross section.

[0017] As a further aspect of the present invention: the multi-source data synchronization and fusion module incorporates a clock synchronization unit, a redundancy verification unit, and a weighted fusion unit. The clock synchronization unit provides a unified acquisition clock signal for the pile top benchmark measurement module and the full pile coaxial measurement module, ensuring that the timestamps of all measurement data are synchronized. The redundancy verification unit performs consistency verification on the pile top offset data at the same time and the offset data collected by the micro photoelectric sensor unit at the corresponding pile top position, eliminating abnormal data that exceed the error threshold. The weighted fusion unit performs weighted fusion on the verified pile top offset data and the full pile multi-section offset data, and performs optimal estimation on the fused dataset through Kalman filtering to filter out vibration noise and random disturbances, outputting a smooth full pile continuous offset dataset.

[0018] As a further aspect of the present invention: the pile deflection calculation module incorporates a pile deflection calculation submodule and a coupling error decoupling submodule. The pile deflection calculation module calculates the deflection deformation curve of the entire steel pipe pile based on the continuous offset dataset of the entire pile body using the beam deflection theory of mechanics of materials. The calculation formula is as follows:

[0019] ;

[0020] in, For steel pipe piles along the axis of the pile body The two-dimensional flexural deformation vector at the location, Corresponding to the top of the pile, Corresponding to the pile tip position, This is the total length of the steel pipe pile. , These are cubic spline interpolation shape functions in the X and Y directions, respectively, used to fit a continuous pile body deflection curve using discrete measurement section offsets. The coupling error decoupling submodule decouples the rigid offset caused by the pile driving frame attitude offset from the flexible deformation of the steel pipe pile itself. The decoupling calculation formula is as follows:

[0021] ;

[0022] in, This refers to the actual flexible flexural deformation curve of the steel pipe pile itself, that is, the deformation of the pile body itself after eliminating the deviation of the pile driving frame posture. The curve representing the overall rigidity displacement of the pile body due to the attitude deviation of the piling frame is a linear function along the pile axis. The overall tilt slope of the pile body caused by the attitude deviation of the piling frame is obtained by fitting the rigid offset of the measured sections at the pile top and pile end. This is the rigid offset constant at the pile top position.

[0023] As a further aspect of the present invention: the hierarchical collaborative closed-loop control module incorporates a priority sorting unit, a hierarchical PID control unit, and a collaborative linkage unit. The priority sorting unit calculates the deflection amplitude of each measured section based on the actual deflection curve of the entire steel pipe pile, and determines the correction priority of each section in descending order of deformation amplitude. The correction priority of the lower and middle sections of the pile is higher than that of the pile top. The hierarchical PID control unit generates hierarchical collaborative correction control commands based on the correction priority. The calculation formula for the control algorithm is as follows:

[0024] ;

[0025] in, for The constant output of the correction control quantity corresponds to the hydraulic cylinder thrust command of the hydraulic execution correction module. for The control deviation at any given time is initially determined by using the deflection of the highest priority section as the control deviation. Once the deformation of the highest priority section drops below a set threshold, the control deviation is switched to the deformation of the next lower priority section. Finally, the offset of the pile top section is used as the control deviation to complete the closed-loop adjustment. This is a proportionality coefficient, with different values ​​set according to different correction priorities. The higher the priority of the cross-section, the larger the proportionality coefficient. The integral coefficient is used to eliminate the steady-state cumulative error during the correction process. The differential coefficient is used to predict the deformation development trend and suppress correction overshoot. The collaborative linkage unit communicates and links with the piling frame attitude control system during the correction process. When the correction control amount exceeds the set threshold, it sends an attitude compensation command to the piling frame to realize the collaborative adjustment of the guide frame tilt angle.

[0026] As a further aspect of the present invention: the hydraulic actuation correction module is installed between the piling frame guide frame and the steel pipe pile, and is used to apply a lateral correction force of corresponding direction and amplitude to the steel pipe pile according to the received hierarchical collaborative correction control command, so as to complete the real-time closed-loop adjustment of the verticality of the steel pipe pile. The hydraulic actuation correction module includes multiple independently controlled hydraulic cylinders evenly distributed along the circumference of the piling frame guide frame. The front end of each hydraulic cylinder is provided with an arc-shaped jacking plate adapted to the outer wall of the steel pipe pile. The arc-shaped jacking plate is embedded with a wear-resistant pad and forms a surface contact with the outer wall of the steel pipe pile. Each hydraulic cylinder is equipped with a proportional servo valve and a built-in displacement sensor to form an independent closed-loop position and force control loop. According to the received hierarchical collaborative correction control command, the jacking force, jacking speed and jacking stroke of the corresponding hydraulic cylinder are independently adjusted to output differentiated lateral correction forces.

[0027] As a further aspect of the present invention: the real-time closed-loop control system further includes a safety interlock protection module, which is connected to the operating status output terminals of all other modules, collects the operating status data of each module in real time, triggers safety protection actions and outputs alarm signals when an abnormal state is detected, and the safety interlock protection module has a built-in data anomaly monitoring unit, a hydraulic system protection unit and a pile stress protection unit. The data anomaly monitoring unit is used to monitor the measurement data and operating status of each module in real time. When a sensor signal failure or data jump exceeding the threshold is detected, a data anomaly alarm is triggered and the correction action is suspended. The hydraulic system protection unit is used to monitor the working pressure of the hydraulic system in real time. When the pressure exceeds the limit, pressure protection is triggered and the hydraulic output is cut off. The pile stress protection unit is used to calculate the pile stress according to the pile body deflection curve. When the pile body stress exceeds the allowable stress of the material, stress protection is triggered and the correction control amount is reduced to avoid pile damage.

[0028] Compared with the prior art, the beneficial effects of the present invention by adopting the above technical solution are as follows:

[0029] 1. This invention uses a coaxial measurement module along the inner wall of the steel pipe pile to measure the entire pile body, in conjunction with a gravity reference establishment module that penetrates the entire section of the steel pipe pile. This module acquires offset data of multiple sections of the entire pile body relative to a unified gravity reference. Then, the pile body deflection calculation module calculates the true deflection deformation curve of the entire pile body. This invention breaks through the industry's common perception that steel pipe piles are ideal rigid bodies and that the verticality of the pile top represents the verticality of the entire pile body. It effectively solves the industry pain point that existing technologies cannot identify or intervene in the hidden deflection deformation of the middle and lower sections of the pile body in advance. This invention achieves an upgrade from single-point verticality control at the pile top to precise control of the entire axis of the pile body. It can capture the deformation of the entire pile body in real time during the pile driving process, effectively improving the verticality control accuracy of the entire pile body and reducing the hidden quality risks of pile body deformation.

[0030] 2. This invention uses a multi-source data synchronization and fusion module to perform clock synchronization, redundancy verification, and fusion processing on the data collected by the pile top benchmark measurement module and the whole pile coaxial measurement module. Combined with the pile body deflection calculation module, it decouples the coupling error between the pile driving frame posture deviation and the pile's own deflection deformation. Then, a hierarchical collaborative closed-loop control module generates correction control commands that match the priority of pile deformation. This effectively solves the problems of inconsistent measurement benchmarks, mismatch between correction commands and actual pile correction needs due to coupling errors, and delayed correction actions in existing technologies. It achieves hierarchical collaborative closed-loop control centered on the actual deformation of the pile body, which can accurately match correction actions with actual deformation needs during pile driving, improving the effectiveness and adaptability of correction actions. It enables real-time, continuous closed-loop adjustment of verticality throughout the entire pile driving process, ensuring the stability of the construction process and the quality of pile formation. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the system control flow in an embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of system module data transmission in an embodiment of the present invention. Detailed Implementation

[0033] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be noted that the description of these embodiments is for the purpose of helping to understand the present invention, but does not constitute a limitation of the present invention.

[0034] Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0035] Please see the appendix Figure 1 -Appendix Figure 2 This invention relates to a real-time closed-loop control system for the verticality of steel pipe pile driving based on gravity reference. The real-time closed-loop control system includes:

[0036] Gravity reference establishment module: used to construct a unique and stable absolute gravity vertical reference line that runs through the entire steel pipe pile, providing a unified gravity vertical reference for the pile top reference measurement module and the coaxial measurement module of the entire pile body;

[0037] Pile top benchmark measurement module: Installed at the top of the steel pipe pile, it is used to collect two-dimensional horizontal offset data of the pile top center relative to the vertical benchmark line of absolute gravity in real time. Its signal output end is connected to the first signal input end of the multi-source data synchronous fusion module, and transmits the collected pile top offset data to the multi-source data synchronous fusion module in real time.

[0038] The whole pile coaxial measurement module is equidistantly fixed along the axial direction of the inner wall of the steel pipe pile. It is used to collect two-dimensional horizontal offset data of the center of multiple corresponding sections of the whole pile relative to the vertical baseline of absolute gravity in real time. Its signal output end is connected to the second signal input end of the multi-source data synchronous fusion module, and transmits the collected multi-section offset data of the whole pile to the multi-source data synchronous fusion module in real time.

[0039] Multi-source data synchronization and fusion module: used to perform clock synchronization, redundancy check and weighted fusion processing on the received pile top offset data and the full pile multi-section offset data, and output a smooth and interference-free full pile continuous offset dataset. Its data output end is connected to the signal input end of the pile deflection calculation module, and transmits the full pile continuous offset dataset to the pile deflection calculation module in real time.

[0040] The pile body deflection calculation module is used to calculate the received continuous offset dataset of the entire pile body, decouple the coupling error between the attitude offset of the pile driving frame and the deflection deformation of the steel pipe pile itself, identify the true deflection deformation mode of the entire steel pipe pile body and generate the deflection deformation curve of the entire pile body. Its calculation result output end is connected to the signal input end of the hierarchical collaborative closed-loop control module, and transmits the deflection deformation curve data of the entire pile body to the hierarchical collaborative closed-loop control module in real time.

[0041] The hierarchical collaborative closed-loop control module is used to generate hierarchical collaborative correction control commands based on the received full pile body flexural deformation curve as the core control target. These commands prioritize correcting the hidden flexural deformation in the middle and lower sections of the pile body and simultaneously adjust the verticality of the pile top. The control command output end is connected to the control input end of the hydraulic execution correction module, transmitting the hierarchical collaborative correction control commands to the hydraulic execution correction module in real time.

[0042] Example 1

[0043] This embodiment describes the application scenario of steel pipe pile driving in port and wharf construction in a coastal area with deep soft soil. The construction utilizes the gravity-based real-time closed-loop control system for steel pipe pile verticality described in this invention. Specific implementation details are as follows:

[0044] Engineering and pile parameters

[0045] In this embodiment, the steel pipe pile is a spiral welded steel pipe, and the design parameters are: pile diameter... The steel pipe has a diameter of 1200mm, a wall thickness of 20mm, an inner radius of R=580mm, a designed pile length of L=60m, a penetration depth of 55m, and a designed verticality deviation of ≤1‰. The geological conditions of the construction site are as follows: the upper 0-20m is fluid plastic silty soft soil, 20-35m is soft plastic silty clay, 35-55m is medium-dense silty sand interlayer, and below 55m is dense gravelly sand bearing layer. A D160 diesel pile hammer is used for pile driving.

[0046] Specific implementation parameters and installation methods for each module of the system

[0047] Gravity reference establishment module

[0048] The universal hinged suspension seat adopts a ball hinge structure and is fixed to the center position of the top of the pile driving frame, coaxial with the designed pile driving axis of the steel pipe pile.

[0049] The low-elongation reference steel wire uses 1.2mm diameter tungsten steel wire with a linear expansion coefficient ≤4.5×10. -6 / ℃, the top end is connected to the universal hinge suspension seat, and the bottom end is fixed to the high-density plumb body;

[0050] The high-density plumb bob is made of tungsten alloy, weighs 15kg, and has a streamlined structure.

[0051] The damping medium container is a 300mm diameter, 500mm high acrylic glass container, fixed to the lower platform of the piling frame. The container is filled with a viscous damping fluid with a kinematic viscosity of 5000 mMn. 2 / s of high-viscosity silicone oil, the high-density lead weight is completely immersed in the silicone oil;

[0052] The segmented telescopic protective sleeve uses three sections of aluminum alloy sleeve, each section being 25m long, with a smooth inner wall and an inner diameter of 20mm. It is fitted entirely outside the low-extension-rate reference steel line, maintaining a non-contact gap with the reference steel line. It expands and contracts with the movement of the pile driving frame. The absolute gravity vertical reference line formed by the low-extension-rate reference steel line is coaxial with the designed pile driving axis of the steel pipe pile, penetrating the inner cavity of the steel pipe pile without contact throughout the entire process.

[0053] Pile top benchmark measurement module

[0054] The pile top measuring plate is a 20mm thick steel disc with a diameter consistent with the outer diameter of the steel pipe pile. It is coaxially fixed to the top surface of the steel pipe pile by bolts.

[0055] The laser ranging sensor group uses four ILD1420 laser ranging sensors, which are equidistantly arranged at 90° intervals around the circumference of the pile top measuring disk. The transmitting end of each sensor is oriented towards the absolute gravity vertical baseline. The measurement accuracy is ±0.1mm and the sampling frequency is 100Hz.

[0056] The two-dimensional PSD position sensor uses a two-dimensional position sensitive device of model PSD-903, which is fixed to the center of the upper end face of the pile top measuring plate. The photosensitive surface size is 20mm×20mm, the photosensitive surface is parallel to the upper end face of the pile top measuring plate, the geometric center of the photosensitive surface coincides with the designed pile driving axis of the steel pipe pile, the position resolution is 2μm, and the sampling frequency is 100Hz.

[0057] The signal output terminals of both the laser ranging sensor group and the two-dimensional PSD position sensor are connected to the first signal input terminal of the multi-source data synchronous fusion module via shielded cables.

[0058] Full pile coaxial measurement module

[0059] A total of N=6 sets of miniature photoelectric sensing units are set up and fixed at equal intervals along the axis of the inner wall of the steel pipe pile. The placement positions are 0m, 12m, 24m, 36m, 48m and 58m below the top of the pile, covering the entire body of the steel pipe pile.

[0060] Each set of miniature photoelectric sensing units includes a central limiting through hole and circumferentially distributed miniature laser ranging modules. The central limiting through hole has a diameter of 15mm and is coaxial with the design axis of the steel pipe pile. The absolute gravity vertical baseline passes through all the central limiting through holes without contact.

[0061] Each miniature laser ranging module uses M=4 miniature laser ranging sensors, which are equidistantly arranged at 90° intervals along the circumference of the corresponding steel pipe pile section. The sensor model is GP2Y0A21YK0F miniature laser ranging sensor, with a measurement accuracy of ±1mm and a sampling frequency of 50Hz. The transmitting end is oriented towards the absolute gravity vertical baseline, and the radial distance data from the edge of the corresponding section to the baseline is collected in real time.

[0062] Multi-source data synchronization and fusion module

[0063] It uses the STM32H743 embedded processor as its core and has built-in clock synchronization unit, redundancy check unit and weighted fusion unit;

[0064] The clock synchronization unit provides a unified 100Hz acquisition clock signal for the pile top benchmark measurement module and the full pile coaxial measurement module, ensuring that the timestamp synchronization error of all measurement data is ≤1ms;

[0065] The redundancy verification unit performs consistency verification between the pile top offset data at the same time and the offset data collected by the micro photoelectric sensor unit at 0m. The error threshold is set to 2mm, and abnormal data exceeding the threshold are removed.

[0066] The weighted fusion unit performs weighted fusion of the verified pile top offset data and the multi-section offset data of the entire pile body. The weight of the pile top benchmark measurement data is 0.6, and the weight of the coaxial measurement data of the entire pile body is 0.4. The fused dataset is then optimized by Kalman filtering to filter out noise and random disturbances caused by pile driving vibration and output a smooth continuous offset dataset of the entire pile body.

[0067] Pile Deflection Calculation Module

[0068] It adopts the same model of embedded processor, and has a built-in pile body deflection calculation submodule and coupling error decoupling submodule;

[0069] The pile body deflection calculation module obtains the deflection deformation curve of the entire steel pipe pile body by using cubic spline interpolation fitting based on the continuous offset dataset of the entire pile body and the beam deflection theory of mechanics of materials.

[0070] The coupling error decoupling submodule decouples the rigid offset caused by the attitude deviation of the piling frame from the flexible deformation of the steel pipe pile itself through linear fitting, and outputs the true flexible flexural deformation curve of the steel pipe pile itself, with a calculation frequency of 50Hz.

[0071] The hierarchical collaborative closed-loop control module uses a PLC controller as its core and incorporates a priority sorting unit, a hierarchical PID control unit, and a collaborative linkage unit.

[0072] The priority sorting unit calculates the flexural deformation amplitude of 6 measurement sections based on the actual flexural deformation curve of the entire steel pipe pile. The correction priority of each section is determined in descending order of deformation amplitude. The correction priority of the sections at 24m, 36m and 48m in the middle and lower section of the pile is higher than that of the section at 0m at the top of the pile.

[0073] The hierarchical PID control unit generates hierarchical collaborative correction control commands based on the correction priority, with a control cycle of 20ms.

[0074] The collaborative linkage unit communicates and links with the piling frame attitude control system via Modbus bus. The threshold value of the correction control quantity is set to 800kN. When the correction control quantity exceeds the threshold value, the unit sends an attitude compensation command to the piling frame to achieve collaborative adjustment of the guide frame tilt angle.

[0075] Hydraulic actuation correction module

[0076] A total of 4 sets of hydraulic cylinders are set up, evenly distributed at 90° around the circumference of the piling frame guide frame. The rated working pressure of the hydraulic cylinder is 31.5MPa, the rated jacking force is 1000kN, and the stroke is 200mm.

[0077] Each hydraulic cylinder is equipped with an arc-shaped push plate at the front end that is adapted to the outer wall of the steel pipe pile. The arc of the push plate is consistent with the outer diameter of the steel pipe pile, the contact width is 300mm, and a 5mm thick polyurethane wear-resistant pad is embedded inside to form a surface contact with the outer wall of the steel pipe pile.

[0078] Each hydraulic cylinder is equipped with an electro-hydraulic proportional servo valve and a built-in magnetostrictive displacement sensor. The displacement sensor has a measurement accuracy of ±0.1mm, forming an independent closed-loop position and force control circuit. Based on the received hierarchical collaborative correction control commands, it can independently adjust the jacking force, jacking speed and jacking stroke of the corresponding hydraulic cylinder, and output differentiated lateral correction force.

[0079] Safety interlock protection module

[0080] It communicates in real time with the operation status output terminals of the above 7 modules, and has a built-in data anomaly monitoring unit, hydraulic system protection unit and pile stress protection unit;

[0081] The data anomaly monitoring unit monitors the measurement data and operating status of each module in real time. When it detects that the sensor signal has failed or the data jump exceeds 5mm / 20ms, it triggers a data anomaly alarm and suspends the correction action.

[0082] The hydraulic system protection unit monitors the working pressure of the hydraulic system in real time. When the pressure exceeds 35MPa, it triggers pressure protection and cuts off the hydraulic output.

[0083] The pile stress protection unit calculates the pile bending stress based on the pile bending deformation curve. When the pile stress exceeds the allowable stress of Q355 steel by 170MPa, the stress protection is triggered and the correction control amount is gradually reduced to avoid pile damage.

[0084] Specific calculation example

[0085] Taking the data collected at a certain moment during pile driving construction as an example, the core parameters are calculated:

[0086] (1) Calculation of cross-sectional offset: Taking the fourth group of miniature photoelectric sensing units at 36m as an example, the azimuth angle of the four miniature laser rangefinders is calculated. The radial distances were measured at 0°, 90°, 180°, and 270°, respectively. The diameters are 572mm, 575mm, 568mm, and 570mm respectively, and the inner radius of the steel pipe is R=580mm. Substituting these values ​​into the cross-sectional offset calculation formula:

[0087] ;

[0088] ;

[0089] That is, the center of the section at 36m is offset by -2mm in the X direction and -1.25mm in the Y direction.

[0090] (2) Flexural deformation curve fitting: The flexural deformation curve of the entire pile was obtained by using cubic spline interpolation to fit the offset data of 6 measurement sections. The cubic spline interpolation shape function in the X direction Y-direction shape function The continuous full-pile flexural deformation curve is obtained by solving the boundary conditions (free at the pile top and elastic constraint at the pile end) and finally fitting the curve.

[0091] (3) Decoupling of coupling error: By fitting the offset of the section at 0m at the pile top and 58m at the pile end, the rigid offset curve caused by the posture of the pile driving frame is obtained. =0.08 +1.2, where the slope =0.08mm / m, constant =1.2mm, substituting into the decoupling formula yields the true flexible flexural deformation curve of the steel pipe pile. -(0.08 +1.2), to eliminate the influence of pile driving frame attitude deviation.

[0092] (4) The corrective control values ​​were calculated and prioritized. The cross-sectional deformation amplitude at 36m was the largest, so it was the highest priority and the control deviation was controlled. =2.36mm, under this priority setting , =25kN / (mm s), =12kN Substituting s / mm into the PID control algorithm formula, the initial correction control quantity is calculated. =424.8kN, corresponding to a negative hydraulic cylinder output thrust of 425kN in the X direction, completing the graded correction control.

[0093] Complete system workflow

[0094] (1) Preparations before pile driving: Complete the fabrication of steel pipe piles and the installation and fixing of the coaxial measurement module of the entire pile body, hoist the steel pipe piles into the guide frame of the pile driving frame, complete the installation and benchmark calibration of the gravity benchmark establishment module, ensure that the absolute gravity vertical benchmark line is coaxial with the design pile driving axis of the steel pipe pile, and complete the power-on debugging and communication debugging of each module of the system.

[0095] (2) Initial data acquisition: Start the pile driving hammer to carry out pile driving construction. All modules of the system start synchronously. The pile top benchmark measurement module and the whole pile body coaxial measurement module collect the offset data of the pile top and the whole pile body sections in real time according to the set frequency, and transmit them to the multi-source data synchronous fusion module.

[0096] (3) Data synchronization and fusion processing: The multi-source data synchronization and fusion module performs clock synchronization, redundancy check and weighted fusion on the received multi-source data, filters out vibration noise through Kalman filtering, outputs a smooth full pile continuous offset dataset, and transmits it to the pile deflection calculation module.

[0097] (4) Pile body deflection calculation and error decoupling: The pile body deflection calculation module calculates the entire pile body offset dataset, fits the entire pile body deflection deformation curve, and decouples the coupling error between the pile driving frame attitude offset and the pile body's own deflection deformation, outputs the true flexible deflection deformation curve of the pile body, and transmits it to the hierarchical collaborative closed-loop control module.

[0098] (5) Hierarchical collaborative correction control: The hierarchical collaborative closed-loop control module determines the correction priority of each section according to the pile body deflection curve, generates corresponding correction control commands through hierarchical PID control algorithm, and transmits them to the hydraulic execution correction module. At the same time, it coordinates with the pile driving frame attitude control system according to the magnitude of the correction control amount.

[0099] (6) Closed-loop execution and feedback: The hydraulic execution correction module controls the corresponding hydraulic cylinder to output precise lateral correction force according to the received correction control command, and performs real-time correction adjustment of the steel pipe pile. At the same time, the coaxial measurement module of the whole pile body provides real-time feedback of the pile deformation data after correction, forming a complete real-time closed-loop control.

[0100] (7) Safety interlock protection: During the entire construction process, the safety interlock protection module monitors the operating status of each module of the system in real time. When an abnormal situation occurs, it immediately triggers an alarm and corresponding protection action to ensure construction safety.

[0101] (8) Pile verification: After the steel pipe pile is driven to the design elevation, the system outputs full-process monitoring data of the verticality of the entire pile body, and completes the pile quality verification in conjunction with the hole detection.

[0102] Implementation effect

[0103] In this embodiment, after the pile driving construction was completed using the system of the present invention, the maximum verticality deviation of the entire pile body was 0.78‰ after testing with an ultrasonic borehole detector, which meets the design requirement of ≤1‰. There was no problem of excessive bending deformation of the pile body, the pass rate of pile driving in one go was 100%, the construction time of a single pile was shortened by 18% compared with the conventional process, and there were no problems such as pile damage or equipment failure.

[0104] Example 2

[0105] This embodiment describes an application scenario for the construction of large-diameter steel pipe piles for offshore wind power foundations. It utilizes the gravity-based real-time closed-loop control system for the verticality of steel pipe piles described in this invention. The difference between this embodiment and Embodiment 1 is:

[0106] In this embodiment, the design parameters for the steel pipe pile are: pile diameter The steel pipe has a diameter of 2000mm, a wall thickness of 30mm, an inner radius of R=970mm, a designed pile length of L=80m, an insertion depth of 75m, and a designed verticality deviation of ≤0.8‰. The construction site is located in near-shore waters, with the following geological conditions: the upper 0-30m consists of marine silty soft soil, 30-60m consists of alternating layers of silty clay and silty sand, 60-75m consists of dense medium-coarse sand, and below 75m is a moderately weathered granite bearing layer. Hydraulic pile hammers will be used for vibratory-hammer composite pile driving.

[0107] The system parameters are adjusted as follows: The full-pile coaxial measurement module is equipped with N=8 sets of miniature photoelectric sensor units, equidistantly arranged along the inner wall axis of the steel pipe pile at 10m intervals, covering the entire pile body; each set of miniature photoelectric sensor units uses M=6 miniature laser ranging sensors, equidistantly arranged at 60° intervals along the circumference of the cross-section; the hydraulic actuation correction module is equipped with 6 sets of hydraulic cylinders, evenly distributed at 60° intervals along the circumference of the pile driving frame guide frame, with a rated jacking force of 1500kN and a stroke of 300mm; in the graded PID control unit, the correction priority is highest at the cross-sections at 30m, 40m, 50m, and 60m in the lower section of the pile body, corresponding to the proportional coefficient... Set to 220kN / mm.

[0108] The remaining system structure and working principle of this embodiment are the same as those of Embodiment 1. After final pile testing, the maximum verticality deviation of the entire pile body was 0.65‰, which meets the design requirement of ≤0.8‰. There was no problem of excessive hidden flexural deformation of the pile body. The pass rate of pile formation was 100%, the construction time of a single pile was 148 minutes, and there were no problems such as pile damage or equipment failure. This verifies the applicability and reliability of the present invention in the construction of large-diameter and deep offshore steel pipe piles.

[0109] Comparative Example

[0110] This comparative example uses steel pipe pile driving construction with the same site, pile type, geological conditions, and design requirements as Example 1, and adopts existing conventional verticality control technology. The specific scheme is as follows:

[0111] This comparative model adopts a conventional control scheme of "tilt sensor + total station manual sampling + hydraulic correction". A dual-axis tilt sensor is installed on the top of the steel pipe pile to collect the tilt angle data of the pile top in real time, with a sampling frequency of 50Hz.

[0112] A total station was used to manually check the verticality of the pile top every 5m of sinking, and the offset of the pile top center relative to the design axis was measured.

[0113] The hydraulic correction mechanism uses the same four sets of hydraulic cylinders as in Example 1. Based on the pile top inclination angle data and sampling results, the hydraulic system is manually operated to make correction adjustments.

[0114] After the completion of the comparative construction, the verticality deviation of the pile top was measured by an ultrasonic drilling tester and found to be 1.8‰, which meets the requirement of ≤3‰ in the specification. However, the maximum verticality deviation of the middle and lower section of the pile body at 35m reached 5.2‰, which far exceeds the design requirement of ≤1‰. The pile body showed an "S-shaped" flexural deformation and required secondary correction treatment. The construction time of a single pile was 159 minutes, and the pass rate of the first pile was only 65%.

[0115] Comparison of effects between the examples and the comparative examples

[0116] The construction effects of Examples 1 and 2 are compared with those of the comparative example. The specific data are shown in Table 1 below:

[0117] Table 1

[0118] Maximum verticality deviation of the entire pile 0.78‰ 0.65‰ 5.2‰ Verticality deviation of pile top 0.62‰ 0.58‰ 1.8‰ First-time pile completion rate 100% 100% 65% Single pile construction time 112min 148min 159min Excessive rate of pile body flexural deformation 0% 0% 100% Secondary correction processing rate 0% 0% 100%

[0119] The comparative data shows that, compared with existing conventional technologies, the system described in this invention can effectively identify and correct the hidden flexural deformation in the middle and lower sections of the pile, significantly improve the verticality control accuracy of the entire pile, significantly increase the first-time pile completion rate, and shorten the construction time. It has outstanding technical advantages and significant progress in both land port projects and offshore wind power deep and large-diameter pile construction scenarios.

[0120] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any variations and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the invention, fall within the protection scope defined by the claims of the present invention.

Claims

1. A real-time closed-loop control system for the verticality of steel pipe pile driving based on gravity reference, characterized in that, The real-time closed-loop control system includes: Gravity reference establishment module: used to construct a unique and stable absolute gravity vertical reference line that runs through the entire steel pipe pile, providing a unified gravity vertical reference for the pile top reference measurement module and the coaxial measurement module of the entire pile body; Pile top benchmark measurement module: installed at the top of the steel pipe pile, used to collect two-dimensional horizontal offset data of the pile top center relative to the absolute gravity vertical benchmark line in real time; The whole pile coaxial measurement module is equidistantly fixed along the axial direction of the inner wall of the steel pipe pile and is used to collect two-dimensional horizontal offset data of the center of multiple corresponding sections of the whole pile relative to the vertical reference line of absolute gravity in real time. Multi-source data synchronization and fusion module: used to perform clock synchronization, redundancy check and weighted fusion processing on the received pile top offset data and the full pile multi-section offset data, and output a smooth and interference-free full pile continuous offset dataset. Pile body deflection calculation module: used to calculate the received continuous offset dataset of the entire pile body, decouple the coupling error between the attitude offset of the pile driving frame and the deflection deformation of the steel pipe pile itself, identify the true deflection deformation mode of the entire steel pipe pile body and generate the deflection deformation curve of the entire pile body. The hierarchical collaborative closed-loop control module is used to generate hierarchical collaborative correction control commands that prioritize correcting the hidden flexural deformation of the middle and lower sections of the pile and simultaneously adjust the verticality of the pile top, with the received full pile body flexural deformation curve as the core control target.

2. The real-time closed-loop control system for the verticality of steel pipe pile driving based on gravity reference as described in claim 1, characterized in that: The gravity reference establishment module includes a universal hinged suspension seat, a high-density plumb bob, a low-elongation reference steel wire, a damping medium container, and a segmented telescopic protective sleeve. The universal hinged suspension seat is fixed to the center of the top of the pile driving frame. The top end of the low-elongation reference steel wire is connected to the universal hinged suspension seat, and the bottom end is fixed to the high-density plumb bob. The high-density plumb bob is immersed in the viscous damping liquid in the damping medium container. The segmented telescopic protective sleeve is sleeved on the outside of the low-elongation reference steel wire, arranged along the entire length of the reference steel wire, and maintains a non-contact gap with the reference steel wire. The absolute gravity vertical reference line formed by the low-elongation reference steel wire is coaxial with the designed pile driving axis of the steel pipe pile and penetrates the inner cavity of the steel pipe pile without contact throughout its entire length.

3. The real-time closed-loop control system for the verticality of steel pipe pile driving based on gravity reference as described in claim 2, characterized in that: The pile top reference measurement module includes a pile top measuring disk, a circumferentially distributed laser ranging sensor group, and a two-dimensional PSD position sensor. The pile top measuring disk is coaxially fixed to the top surface of the steel pipe pile. Multiple laser ranging sensors of the laser ranging sensor group are equidistantly arranged along the circumference of the pile top measuring disk, and the emitting end of each sensor is facing the direction of the absolute gravity perpendicular reference line. The two-dimensional PSD position sensor is fixed to the center position of the upper end surface of the pile top measuring disk, and its photosensitive surface is parallel to the upper end surface of the pile top measuring disk. The geometric center of the photosensitive surface coincides with the designed pile driving axis of the steel pipe pile.

4. The real-time closed-loop control system for the verticality of steel pipe pile driving based on gravity reference as described in claim 3, characterized in that: The coaxial measurement module for the entire pile includes N sets of miniature photoelectric sensing units equidistantly fixed along the axial direction of the inner wall of the steel pipe pile, where N is a positive integer greater than or equal to 3. Each set of miniature photoelectric sensing units includes a central limiting through-hole and circumferentially distributed miniature laser ranging modules. The central limiting through-hole is coaxial with the design axis of the steel pipe pile. The absolute gravity vertical reference line passes through all the central limiting through-holes without contact. Multiple miniature laser ranging sensors of each set of miniature laser ranging modules are equidistantly arranged circumferentially along the corresponding steel pipe pile cross-section, with their transmitting ends all facing the absolute gravity vertical reference line. They collect radial distance data from the edge of the corresponding cross-section to the reference line in real time. The two-dimensional offset of the center of the corresponding cross-section relative to the absolute gravity vertical reference line collected by the miniature photoelectric sensing unit is calculated using the following formula: ； in, This refers to the cross-sectional number of the miniature photoelectric sensing unit. The corresponding steel pipe pile from the pile top to the pile tip One measurement section, This refers to the number of miniature laser rangefinders within a single miniature photoelectric sensing unit. Even numbers ≥ 4 , The first The offset of the center of each measurement section relative to the vertical baseline of absolute gravity in the X and Y two-dimensional horizontal directions. To determine the inner radius of the steel pipe pile at the corresponding measurement section, For the first Within the measurement section, the first The radial distance from the sensor emitter to the absolute gravity vertical baseline, measured by a miniature laser rangefinder. For the first The azimuth angle of the miniature laser rangefinder is set at 0° in the positive X-axis direction and increases clockwise along the circumference of the cross section.

5. The real-time closed-loop control system for the verticality of steel pipe pile driving based on gravity reference as described in claim 4, characterized in that: The multi-source data synchronization and fusion module incorporates a clock synchronization unit, a redundancy verification unit, and a weighted fusion unit. The clock synchronization unit provides a unified acquisition clock signal for the pile top benchmark measurement module and the full pile coaxial measurement module. The redundancy verification unit performs consistency verification on the pile top offset data at the same time and the offset data collected by the miniature photoelectric sensor unit at the corresponding pile top position, eliminating abnormal data that exceeds the error threshold. The weighted fusion unit performs weighted fusion on the verified pile top offset data and the full pile multi-section offset data, and performs optimal estimation on the fused dataset through Kalman filtering to filter out vibration noise and random disturbances, outputting a smooth full pile continuous offset dataset.

6. The real-time closed-loop control system for the verticality of steel pipe pile driving based on gravity reference as described in claim 5, characterized in that: The pile deflection calculation module includes a pile deflection calculation submodule and a coupling error decoupling submodule. The pile deflection calculation submodule calculates the deflection deformation curve of the entire steel pipe pile based on the continuous offset dataset of the entire pile body and the beam deflection theory of mechanics of materials. The calculation formula is as follows: ； in, For steel pipe piles along the pile axis direction The two-dimensional flexural deformation vector at the location, Corresponding to the top of the pile, Corresponding to the pile tip position, This is the total length of the steel pipe pile. , The cubic spline interpolation shape functions are respectively used in the X and Y directions. The coupling error decoupling submodule decouples the rigid offset caused by the pile driving frame attitude deviation from the flexible deformation of the steel pipe pile itself. The decoupling calculation formula is as follows: ； in, This refers to the actual flexible flexural deformation curve of the steel pipe pile itself, that is, the deformation of the pile body itself after eliminating the deviation of the pile driving frame posture. The curve representing the overall rigidity displacement of the pile body due to the attitude deviation of the piling frame is a linear function along the pile axis. The overall tilt slope of the pile body caused by the attitude deviation of the piling frame is obtained by fitting the rigid offset of the measured sections at the pile top and pile end. This is the rigid offset constant at the pile top position.

7. The real-time closed-loop control system for the verticality of steel pipe pile driving based on gravity reference as described in claim 6, characterized in that: The hierarchical collaborative closed-loop control module incorporates a priority sorting unit, a hierarchical PID control unit, and a collaborative linkage unit. The priority sorting unit calculates the deflection amplitude of each measured section based on the actual deflection curve of the entire steel pipe pile, and determines the correction priority of each section in descending order of deformation amplitude. The correction priority of the lower and middle sections of the pile is higher than that of the pile top. The hierarchical PID control unit generates hierarchical collaborative correction control commands based on the correction priority. The calculation formula for the control algorithm is as follows: ； in, for The constant output of the correction control quantity corresponds to the hydraulic cylinder thrust command of the hydraulic execution correction module. for For the control deviation at any given time, the deflection deformation of the highest priority section is used as the control deviation first. Once the deformation of the highest priority section drops below a set threshold, the control deviation is switched to the deformation of the next lower priority section. This is a proportionality coefficient, with different values ​​set according to different correction priorities. The higher the priority of the cross-section, the larger the proportionality coefficient. The integral coefficient is... The coefficient is a differential coefficient. During the correction process, the collaborative linkage unit communicates and links with the piling frame attitude control system. When the correction control quantity exceeds the set threshold, it sends an attitude compensation command to the piling frame.

8. The real-time closed-loop control system for the verticality of steel pipe pile driving based on gravity reference as described in claim 7, characterized in that: The hydraulic actuation correction module is installed between the piling frame guide frame and the steel pipe pile. It is used to apply a lateral correction force of corresponding direction and amplitude to the steel pipe pile according to the received hierarchical collaborative correction control command. The hydraulic actuation correction module includes multiple independently controlled hydraulic cylinders evenly distributed along the circumference of the piling frame guide frame. The front end of each hydraulic cylinder is equipped with an arc-shaped push plate adapted to the outer wall of the steel pipe pile. The arc-shaped push plate is embedded with a wear-resistant pad and forms a surface contact with the outer wall of the steel pipe pile. Each hydraulic cylinder is equipped with a proportional servo valve and a built-in displacement sensor.

9. The real-time closed-loop control system for the verticality of steel pipe pile driving based on gravity reference as described in claim 8, characterized in that: The real-time closed-loop control system also includes a safety interlock protection module, which collects the operating status data of each module in real time. When an abnormal state is detected, it triggers a safety protection action and outputs an alarm signal. The safety interlock protection module has a built-in data anomaly monitoring unit, a hydraulic system protection unit, and a pile stress protection unit. The data anomaly monitoring unit is used to monitor the measurement data and operating status of each module in real time. When a sensor signal failure or data jump exceeding the threshold is detected, a data anomaly alarm is triggered and the correction action is suspended. The hydraulic system protection unit is used to monitor the working pressure of the hydraulic system in real time. When the pressure exceeds the limit, pressure protection is triggered and the hydraulic output is cut off. The pile stress protection unit is used to calculate the pile stress based on the pile body deflection curve. When the pile stress exceeds the allowable stress of the material, stress protection is triggered and the correction control amount is reduced to avoid pile damage.

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