Anti-collision pier bearing platform steel jacket box inner support self-adaptive adjusting method adapting to water level change

Abstract

The invention discloses a crash bearer bearing platform steel jacket box inner support self-adaptive adjusting method adapting to water level changes. The method comprises the steps of self-adaptive inner support configuration, sensing module deployment, data monitoring, data transmission and preprocessing, stress analysis and self-adaptive control. Through the design of the self-adaptive inner support, the water level change and the concrete pouring progress are responded in real time, and real-time self-adaptive balance of the dynamic load is achieved; the requirements of concrete pouring continuity and river environment unpredictability for real-time control are met by collecting data in real time, analyzing stress to solve the optimal adjusting quantity and driving the double-acting hydraulic oil cylinder to control stretching and retracting of the self-adaptive inner support, the construction risk is reduced, the operation efficiency is improved, the structural adaptability and safety are enhanced, and the construction cost is reduced. Therefore, intelligent upgrading of construction is promoted.

Description

Technical Field

[0001] This invention belongs to the field of underwater bridge construction technology, and relates to an adaptive adjustment method for the internal support of the steel casing of the anti-collision pier cap to adapt to changes in water level. Background Technology

[0002] In bridge construction projects spanning rivers, underwater construction operations are often impacted by dynamic water levels and flows such as tides and floods. Steel cofferdams, a common underwater construction structure, are widely used in the concrete pouring of separated anti-collision pier caps. They can isolate external water bodies in one go, providing a dry and stable working space for the cap. Steel cofferdam structures typically include sidewalls, ring beams, and internal supports. The internal supports often employ I-beam ring beams and spiral pipe bracing to resist external water pressure and the lateral pressure generated during internal concrete pouring, ensuring the stability and sealing of the cofferdam structure.

[0003] River water levels fluctuate periodically or suddenly due to seasonal, tidal, and meteorological factors, causing continuous changes in water pressure acting on the outer wall of the steel caisson. Simultaneously, the foundation concrete is typically poured in stages, and as the height of the poured concrete increases, the lateral pressure on the inner wall of the steel caisson gradually increases. Existing steel caisson support systems mostly employ a fixed structural design, and their prestress values ​​are preset during installation and cannot be dynamically adjusted, making it difficult to adapt to the dynamic changes in the aforementioned loads.

[0004] When fixed prestressed steel supports face dynamic loads, two extreme risks can easily arise: if the prestress is insufficient, the sidewalls of the steel caisson may deform, leak, or even become unstable due to excessive water pressure or concrete lateral pressure; if the prestress is too high, the excessive constraint force will cause the sidewalls of the steel caisson to become unbalanced, increasing the risk of overturning, while excessive compression of the formwork may cause defects in concrete forming. In addition, the adjustment of traditional steel supports relies on manual inspection and mechanical operation, which not only lags behind load changes in response speed but also has limited control precision. In complex conditions such as typhoon season and high water levels, frequent manual intervention will increase construction risks and reduce work efficiency.

[0005] Furthermore, existing monitoring methods often only record problems after the fact and cannot proactively adjust the support force. Moreover, the unpredictability of the river environment and the continuity of concrete pouring require real-time, adaptive control, which is difficult to achieve in actual construction.

[0006] Therefore, designing an intelligent control mechanism for the steel caisson support system that can sense and adaptively balance water pressure and concrete lateral pressure in real time has become a key requirement for solving the above-mentioned technical pain points and improving the construction safety and economy of the anti-collision pier cap. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention proposes an adaptive adjustment method for the internal support of the steel casing of the anti-collision pier foundation that adapts to changes in water level. This method solves the problem that the existing internal support of the steel casing of the anti-collision pier foundation cannot adapt to dynamic water pressure or concrete lateral pressure. It establishes an intelligent control mechanism that senses and adaptively balances water pressure and concrete lateral pressure in real time, thereby achieving safety and efficiency of the steel casing of the anti-collision pier foundation during construction.

[0008] An adaptive adjustment method for the internal support of the steel casing of a crash barrier pier to adapt to water level changes includes the following steps:

[0009] S1. Configuration of adaptive internal support:

[0010] After the steel casing of the anti-collision pier is in place, the adaptive internal support is installed in the predetermined position. The adaptive internal support includes a steel pipe, a double-acting hydraulic cylinder, an electromagnetic directional valve, and a pressure relay. The steel pipe is a spiral steel pipe with an outer diameter of 325mm and a thickness of 5mm. The double-acting hydraulic cylinder is centrally located along the axial direction of the steel pipe, and its two ends are welded to the inner wall of the steel pipe through annular flanges. A 20mm diameter through hole is opened 100mm from each end of the steel pipe. The oil inlet and return port of the double-acting hydraulic cylinder are led out from the through hole through a high-pressure hose and connected to the hydraulic pump station of the control terminal to form a closed hydraulic circuit. The electromagnetic directional valve and the pressure relay are integrated into the tail of the cylinder of the double-acting hydraulic cylinder. The pressure relay monitors the pressure value of the double-acting hydraulic cylinder in real time. When the deviation between the measured pressure and the target pressure calculated by the control terminal exceeds ±5%, the pressure relay sends a switching signal to the electromagnetic directional valve. After receiving the signal, the electromagnetic directional valve controls the oil supply and return of the double-acting hydraulic cylinder.

[0011] S2. Deployment of the sensing module:

[0012] After the adaptive internal support is installed, the sensing module is deployed; the sensing module includes a laser range sensor, a water flow velocity sensor, and an internal support stress sensor.

[0013] The laser rangefinder is securely mounted on a bracket on the top of the side wall of the steel casing to prevent positional shift caused by water flow impact or vibration. The laser emission direction is perpendicular to the river surface and the surface of the poured concrete, thereby acquiring river water elevation data and poured concrete elevation data in real time.

[0014] The water flow velocity sensor is installed on a buoy near the steel casing and submerged in the river water, with a distance of not less than 300mm from the outer surface of the side wall of the steel casing to avoid turbulence affecting the accuracy of the flow velocity measurement. The sensor probe is facing the direction of water flow to ensure that the direction of flow velocity measurement is consistent with the actual direction of water flow.

[0015] The internal support stress sensor is installed in the middle of the steel pipe of each of the adaptive internal supports and is attached along the axial direction of the steel pipe to ensure that the measurement direction is consistent with the force direction of the internal support, thereby directly monitoring the axial stress of the steel pipe.

[0016] S3, Data Monitoring:

[0017] The monitoring method for acquiring river water elevation data through the laser ranging sensor and river water flow velocity data through the water flow velocity sensor is as follows: real-time acquisition of river water elevation and river water flow velocity data, with data recorded every 30 minutes; when encountering extreme weather such as typhoons or rainstorms that cause drastic changes in water level, the monitoring frequency is increased to once every 3 minutes.

[0018] The monitoring method for acquiring the elevation data of poured concrete through the laser ranging sensor is as follows: data is collected every 3 minutes during the concrete pouring, vibration and solidification stages, and every 30 minutes in other cases.

[0019] The monitoring method for obtaining axial stress data of the steel pipe through the internal support stress sensor is as follows: data is collected once every 1 minute when the control of the double-acting hydraulic cylinder is triggered, and data is collected once every 30 minutes under other circumstances.

[0020] S4. Data transmission and preprocessing:

[0021] The data from each sensor is transmitted wirelessly to the control terminal, where the raw data is then filtered to remove abnormal data with deviations exceeding three times the standard deviation caused by water flow impact and vibration.

[0022] S5. Force Analysis:

[0023] The hydrodynamic pressure P exerted by the river water on the side wall of the steel casing d It consists of a hydrostatic pressure component and a dynamic water pressure component, and satisfies the following expression:

[0024] P d =ρ w ·g·H w ·A w / 2+ρ w ·v 2 ·A w / 2

[0025] Where, ρ w The density of water is kg / m³. 3 v is the real-time flow velocity value acquired by the water flow velocity sensor, in m / s; g is the acceleration due to gravity, in m / s². 2 H w The elevation value of the river water acquired by the laser ranging sensor, in meters (m); A wThe projected area of ​​the hydrodynamic pressure exerted by the river water on the side wall of the steel casing is given in m. 2 ;

[0026] Concrete lateral pressure P acting on the side wall of the steel casing c Satisfy the following expression:

[0027] P c =K c ·ρ c ·g·H c ·A c / 2

[0028] Among them, K c Let K be the lateral pressure coefficient of concrete. According to the "Code for Construction of Concrete Structures" (GB 50666-2011), concrete has high fluidity during the initial setting period, and the lateral pressure is close to the hydrostatic pressure. Therefore, K is taken as the lateral pressure coefficient during the initial setting period. c =1.0, while the lateral pressure during the final setting period decreases significantly, therefore the final setting period is taken as K. c =0.4, K for the remaining solidification stages c Obtained by linear interpolation; ρ c The density of concrete is expressed in kg / m³. 3 g is the acceleration due to gravity, m / s² 2 H c The elevation value of the poured concrete obtained by the laser ranging sensor, in meters (m); A c The projected area of ​​the concrete lateral pressure acting on the side wall of the steel casing is given in m. 2 ;

[0029] Based on the force balance condition of the sidewall and the condition that the preload stress of the adaptive internal support should not exceed the material safety margin, the initial preload P of the nth adaptive internal support is... n The additional hydraulic force ΔP that needs to be adjusted for the nth adaptive internal support. n Satisfy the following expression:

[0030]

[0031] Among them, l pn Let m be the lever arm from the nth adaptive inner support to the bottom of the steel casing; l d The lever arm of the resultant force of the hydrodynamic pressure reaching the bottom of the steel casing is m; l c σ is the lever arm of the lateral pressure from the concrete to the bottom of the steel caisson, in meters (m); y A represents the yield strength of the steel pipe, in MPa; y The cross-sectional area of ​​the steel pipe is in meters. 2 ;K y The preload safety factor of the adaptive internal support;

[0032] S6, Adaptive Control:

[0033] The nth root ΔP obtained through step S5 n When the value is positive, the electromagnetic reversing valve drives the double-acting hydraulic cylinder to extend until the real-time feedback force value from the internal support pressure sensor reaches the target value, at which point it locks; the nth ΔP obtained through step S5... n When the value is negative, the electromagnetic reversing valve drives the double-acting hydraulic cylinder to retract, thereby applying a pulling force to balance the resultant force and torque of the external dynamic water pressure and the internal concrete pressure, until the pressure relay locks after the real-time feedback force value reaches the target value.

[0034] Preferably, the adaptive internal support is connected to the ring beam at both ends via ball joints to meet the requirements of flexibility and structural stability for minute angle adjustments; one end of the ball joint is welded to the end of the steel pipe via a flange, and the other end is bolted to the pre-embedded steel plate of the steel casing ring beam via a flange of the same specification; the rotation angle of the ball joint is limited to ±5° by a limiting block to ensure rigid limiting when the angle exceeds the limit, and to avoid excessive rotation causing stress imbalance in the adaptive internal support.

[0035] Preferably, the water flow velocity sensor is covered with a stainless steel protective net, and the laser rangefinder is equipped with a rainproof cover to ensure stable working performance under heavy rain and strong water flow impact.

[0036] Preferably, in step S4, the specific steps for "removing abnormal data whose deviation exceeds three times the standard deviation due to water flow impact and vibration" are as follows:

[0037] S401. Calculate the standard deviation: Calculate the standard deviation of 20 consecutive sets of filtered effective data from the same sensor.

[0038] S402. Remove outlier data: When the deviation of a sampled value from the mean exceeds 3 times the standard deviation, it is judged as outlier data and removed.

[0039] S403, Linear Interpolation: After removing outlier data, based on three sets of valid data before and after, linear interpolation is used to fill the gaps to ensure the continuity of the data sequence.

[0040] S404 Sensor Fault Determination: If three consecutive samples are determined to be abnormal data, a sensor fault alarm will be triggered.

[0041] Compared with the prior art, the beneficial effects of this invention are as follows: Addressing the problem that existing internal supports of the steel casing of anti-collision pier caps cannot adapt to dynamic water pressure or concrete lateral pressure, this invention proposes an adaptive adjustment method for the internal supports of the steel casing of anti-collision pier caps that adapts to changes in water level. This method includes the configuration of adaptive internal supports, the deployment of sensing modules, data monitoring, data transmission and preprocessing, stress analysis, and adaptive control. The specific beneficial effects are reflected in the following aspects:

[0042] 1) Real-time adaptive balance of dynamic load: Through the coordinated action of double-acting hydraulic cylinder, pressure relay and electromagnetic reversing valve, it can respond to water level changes and concrete pouring progress in real time. When the pressure deviation exceeds ±5%, it will automatically start adjustment to avoid side wall deformation, leakage or overall instability caused by insufficient prestress in traditional fixed supports, or overturning risk and concrete forming defects caused by excessive prestress.

[0043] 2) Improved control precision and response speed: Data is collected in real time through the sensing module, and the optimal adjustment amount is solved through the force analysis equation set. The control terminal automatically completes the force calculation and hydraulic cylinder action command. The double-acting hydraulic cylinder is driven by the electromagnetic reversing valve to achieve automatic extension and retraction. Compared with traditional manual detection and mechanical operation, the control precision is higher and the response speed is more timely. It can quickly match dynamic working conditions such as water level fluctuations and changes in the concrete pouring stage, and meet the needs of real-time control for the continuity of concrete pouring and the unpredictability of the river environment.

[0044] 3) Reduce construction risks and improve work efficiency: It reduces the reliance on manual intervention, especially in complex conditions such as typhoon season and high water levels, and avoids the safety hazards caused by frequent manual inspection and operation; at the same time, the adaptive adjustment mechanism can ensure that the steel caisson structure is always in a stable stress state, reduce work stoppages and rework caused by imbalance of support force, significantly improve construction efficiency, and ensure the continuity and stability of the construction of the anti-collision pier cap.

[0045] 4) Enhanced structural adaptability and safety: The adaptive internal bracing is connected to the ring beam through ball joint nodes, which can finely adjust the bracing angle to adapt to the angle deviation caused by the slight deformation of the steel caisson, thereby improving the overall structural adaptability; parameters such as the preload safety factor and the yield strength of the steel pipe are introduced into the stress analysis, and the upper limit of the internal bracing force is strictly limited through the equation system to ensure that the bracing force is always within the material safety margin. This mechanism avoids the structural risks caused by excessive constraint force and further ensures construction safety.

[0046] 5) Promote the intelligent upgrading of construction: Transform the traditional passive monitoring into active adaptive control, break through the limitation of existing monitoring methods that can only record problems after the fact, realize the real-time balance control of water pressure and concrete lateral pressure, provide technical support for the intelligent and automated development of bridge underwater construction, and improve the safety and economy of anti-collision pier foundation construction. Attached Figure Description

[0047] Figure 1 This is a flowchart of the adaptive adjustment method for the internal support of the steel casing of the anti-collision pier cap to adapt to water level changes, as described in an embodiment of the present invention.

[0048] Figure 2 This is a schematic diagram of the internal support structure of the steel casing of the anti-collision pier foundation according to an embodiment of the present invention;

[0049] Among them, 1-adaptive internal support, 11-steel pipe, 12-double-acting hydraulic cylinder, 13-ball joint node, 2-side wall, 3-ring beam, 41-laser rangefinder sensor, 42-water flow velocity sensor, 43-internal support stress sensor, 51-river water elevation, 52-elevation of poured concrete. Detailed Implementation

[0050] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments given herein are for illustration and explanation only and are not intended to limit the present invention.

[0051] This application discloses, as follows: Figure 1-2 The adaptive adjustment method for the internal support of the steel casing of the anti-collision pier cap, which adapts to changes in water level, includes the following steps:

[0052] S1. Configuration of adaptive internal support:

[0053] After the steel casing of the anti-collision pier is in place, the adaptive inner support 1 is installed to the predetermined position. The adaptive inner support 1 includes a steel pipe 11, a double-acting hydraulic cylinder 12, an electromagnetic directional valve, and a pressure relay. The steel pipe 11 is a spiral steel pipe with an outer diameter of 325mm and a thickness of 5mm. The double-acting hydraulic cylinder 12 is centrally arranged along the axial direction of the steel pipe 11, and its two ends are welded and fixed to the inner wall of the steel pipe 11 through annular flanges. The steel pipe 11 has through holes with a diameter of 20mm at 100mm from each end. The oil inlet and outlet of the double-acting hydraulic cylinder 12 are led out from the through holes through high-pressure hoses and connected to the hydraulic pump station of the control terminal to form a closed hydraulic circuit. The electromagnetic directional valve and the pressure relay are integrated into the tail of the cylinder of the double-acting hydraulic cylinder 12. The pressure relay is implemented... The pressure value of the double-acting hydraulic cylinder is monitored in real time. When the deviation between the measured pressure and the target pressure calculated by the control terminal exceeds ±5%, the pressure relay sends a switching signal to the solenoid directional valve. After receiving the signal, the solenoid directional valve controls the oil supply and return of the double-acting hydraulic cylinder. In specific implementation, the two ends of the adaptive inner support 1 are connected to the ring beam 3 through ball joint nodes 13 to meet the requirements of flexibility and structural stability for small angle adjustment. One end of the ball joint node 13 is welded to the end of the steel pipe 11 through a flange, and the other end is bolted to the pre-embedded steel plate of the steel box ring beam 3 through a flange of the same specification. The rotation angle of the ball joint node 13 is limited to ±5° by a limit block to ensure rigid limit when the angle exceeds the limit, and to avoid excessive rotation causing the adaptive inner support 1 to become unbalanced.

[0054] S2. Deployment of the sensing module:

[0055] After the adaptive inner support 1 is installed, the sensing module is deployed. The sensing module includes a laser rangefinder 41, a water flow velocity sensor 42, and an inner support stress sensor 43. The laser rangefinder 41 is firmly installed on a bracket on the top of the steel casing side wall 2 to prevent positional displacement caused by water flow impact or vibration. The laser emission direction is perpendicular to the river surface and the surface of the poured concrete, thereby acquiring real-time data on the river water elevation 51 and the elevation 52 of the poured concrete. The water flow velocity sensor 42 is installed on a buoy near the steel casing and submerged in the river water, and is positioned relative to the surface of the steel casing side wall 2. The distance between the surfaces is not less than 300mm to avoid turbulence affecting the accuracy of flow velocity measurement. The sensor probe is directly facing the water flow direction to ensure that the flow velocity measurement direction is consistent with the actual water flow direction. The internal support stress sensor 43 is installed in the middle of the steel pipe of each of the adaptive internal supports 1 and is pasted along the axial direction of the steel pipe 11 to ensure that the measurement direction is consistent with the force direction of the internal support, thereby directly monitoring the axial stress of the steel pipe 11. In specific implementation, the water flow velocity sensor is covered with a stainless steel protective net and the laser rangefinder is equipped with a rainproof cover to ensure stable working performance under heavy rain and strong water flow impact.

[0056] S3, Data Monitoring:

[0057] The monitoring method for acquiring river water elevation 51 data through the laser ranging sensor 41 and river water velocity data through the water flow velocity sensor 42 is as follows: real-time acquisition of river water elevation 51 and river water velocity data, with data recorded every 30 minutes; when encountering extreme weather such as typhoons or rainstorms that cause drastic changes in water level, the monitoring frequency is increased to once every 3 minutes.

[0058] The monitoring method for acquiring the elevation 52 of the poured concrete through the laser ranging sensor 41 is as follows: data is collected every 3 minutes during the concrete pouring, vibration and solidification stages, and every 30 minutes in other cases.

[0059] The monitoring method for obtaining axial stress data of the steel pipe through the internal support stress sensor 43 is as follows: data is collected once every 1 minute when the control of the double-acting hydraulic cylinder 12 is triggered, and data is collected once every 30 minutes under other circumstances.

[0060] S4. Data transmission and preprocessing:

[0061] Data from each sensor is transmitted wirelessly to the control terminal, where the raw data is then filtered to remove outliers exceeding three standard deviations due to water flow impact and vibration. The specific steps are as follows:

[0062] S401. Calculate the standard deviation: Calculate the standard deviation of 20 consecutive sets of filtered effective data from the same sensor.

[0063] S402. Remove outlier data: When the deviation of a sampled value from the mean exceeds 3 times the standard deviation, it is judged as outlier data and removed.

[0064] S403, Linear Interpolation: After removing outlier data, based on three sets of valid data before and after, linear interpolation is used to fill the gaps to ensure the continuity of the data sequence.

[0065] S404 Sensor Fault Determination: If three consecutive samples are determined to be abnormal data, a sensor fault alarm will be triggered.

[0066] S5. Force Analysis:

[0067] The hydrodynamic pressure P exerted by the river water on the side wall of the steel casing d It consists of a hydrostatic pressure component and a dynamic water pressure component, and satisfies the following expression:

[0068] P d =ρ w ·g·H w ·A w / 2+ρ w·v 2 ·A w / twenty one)

[0069] Where, ρ w Given the density of water, this invention is designed for river construction and assumes freshwater, i.e., ρ is taken as the density. w =1000kg / m 3 v is the real-time flow velocity value acquired by the water velocity sensor. Considering the normal flow velocity of the river and the high flow velocity during flood season, v is typically 0.05 to 10 m / s; g is the acceleration due to gravity, taken as g = 10 m / s². 2 H w H represents the river water elevation value acquired by the laser ranging sensor, corresponding to the water level depth during conventional bridge anti-collision pier construction. w Typically 0 to 15m; A w The projected area of ​​the hydrodynamic pressure exerted by the river water on the sidewall of the steel casing is calculated as the product of the sidewall height and the sidewall length, in meters. 2 ;

[0070] Concrete lateral pressure P acting on the side wall of the steel casing c Satisfy the following expression:

[0071] P c =K c ·ρ c ·g·H c ·A c / twenty two)

[0072] Among them, K c Let K be the lateral pressure coefficient of concrete. According to the "Code for Construction of Concrete Structures" (GB 50666-2011), concrete has high fluidity during the initial setting period, and the lateral pressure is close to the hydrostatic pressure. Therefore, K is taken as the lateral pressure coefficient during the initial setting period. c =1.0, while the lateral pressure during the final setting period decreases significantly, therefore the final setting period is taken as K. c =0.4, K for the remaining solidification stages c Obtained by linear interpolation; ρ c The density of concrete is usually taken as ρ. c 2500 kg / m 3 g is the acceleration due to gravity, taken as g = 10 m / s². 2 H c The elevation value of the poured concrete obtained by the laser ranging sensor, in meters (m); A c The projected area of ​​the concrete lateral pressure acting on the sidewall of the steel casing is calculated as the product of the sidewall height and the sidewall length, in meters. 2 ;

[0073] Based on the force balance condition of the sidewall and the condition that the preload stress of the adaptive internal support should not exceed the material safety margin, the initial preload P of the nth adaptive internal support is... n The additional hydraulic force ΔP that needs to be adjusted for the nth adaptive internal support. n Satisfy the following expression:

[0074]

[0075] Among them, l pn Let m be the lever arm from the nth adaptive inner support to the bottom of the steel casing; l d The lever arm of the resultant force of the hydrodynamic pressure reaching the bottom of the steel casing is m; l c σ is the lever arm of the lateral pressure from the concrete to the bottom of the steel caisson, in meters (m); y To determine the yield strength of the steel pipe, when using Q235B steel pipe, σ y 235 MPa; A y The cross-sectional area of ​​the steel pipe is in meters. 2 ;K y Let K be the preload safety factor for the adaptive internal support. According to the "Standard for Design of Steel Structures" GB 50017-2017, when considering dynamic loads, K is required. y The stress should not be less than 0.6, meaning that the stress in the steel pipe is always lower than 60% of the material's yield strength.

[0076] S6, Adaptive Control:

[0077] The nth root ΔP obtained through step S5 n When the value is positive, the electromagnetic reversing valve drives the double-acting hydraulic cylinder to extend until the real-time feedback force value from the internal support pressure sensor reaches the target value, at which point it locks; the nth ΔP obtained through step S5... n When the value is negative, the electromagnetic reversing valve drives the double-acting hydraulic cylinder to retract, thereby applying a pulling force to balance the resultant force and torque of the external dynamic water pressure and the internal concrete pressure, until the pressure relay locks after the real-time feedback force value reaches the target value.

[0078] The above describes one or more embodiments of the present invention in a relatively specific and detailed manner, but it should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A method for adaptive adjustment of the internal support of the steel casing of a crash barrier pier to adapt to water level changes, characterized in that, Includes the following steps: S1. Configuration of adaptive internal support: After the steel casing of the anti-collision pier is in place, the adaptive internal support is installed in the predetermined position. The adaptive internal support includes a steel pipe, a double-acting hydraulic cylinder, an electromagnetic directional valve, and a pressure relay. The steel pipe is a spiral steel pipe with an outer diameter of 325mm and a thickness of 5mm. The double-acting hydraulic cylinder is centrally located along the axial direction of the steel pipe, and its two ends are welded to the inner wall of the steel pipe through annular flanges. A 20mm diameter through hole is opened 100mm from each end of the steel pipe. The oil inlet and return port of the double-acting hydraulic cylinder are led out from the through hole through a high-pressure hose and connected to the hydraulic pump station of the control terminal to form a closed hydraulic circuit. The electromagnetic directional valve and the pressure relay are integrated into the tail of the cylinder of the double-acting hydraulic cylinder. The pressure relay monitors the pressure value of the double-acting hydraulic cylinder in real time. When the deviation between the measured pressure and the target pressure calculated by the control terminal exceeds ±5%, the pressure relay sends a switching signal to the electromagnetic directional valve. After receiving the signal, the electromagnetic directional valve controls the oil supply and return of the double-acting hydraulic cylinder. S2. Deployment of the sensing module: After the adaptive inner support is installed, a sensing module is deployed. The sensing module includes a laser ranging sensor, a water flow velocity sensor, and an inner support stress sensor. The laser ranging sensor is firmly installed on a bracket on the top of the side wall of the steel casing, with the laser emission direction perpendicular to the river surface and the surface of the poured concrete, thereby acquiring real-time river water elevation data and poured concrete elevation data. The water flow velocity sensor is installed on a buoy near the steel casing and submerged in the river water, with a distance of not less than 300mm from the outer surface of the side wall of the steel casing to avoid turbulence affecting the accuracy of the flow velocity measurement. The sensor probe is facing the direction of water flow to ensure that the direction of flow velocity measurement is consistent with the actual direction of water flow. The inner support stress sensor is installed in the middle of the steel pipe of each adaptive inner support and is pasted along the axial direction of the steel pipe to ensure that the measurement direction is consistent with the direction of force on the inner support, thereby directly monitoring the axial stress of the steel pipe. S3, Data Monitoring: The monitoring methods for acquiring river water elevation data via the laser ranging sensor and river water velocity data via the water flow velocity sensor are as follows: real-time acquisition of river water elevation and flow velocity data, with data recorded every 30 minutes; when extreme weather events such as typhoons and rainstorms cause drastic changes in water level, the monitoring frequency is increased to once every 3 minutes; the monitoring method for acquiring the elevation data of poured concrete via the laser ranging sensor is as follows: data is collected every 3 minutes during the concrete pouring, vibration, and solidification stages, and every 30 minutes under other conditions; the monitoring method for acquiring the axial stress data of the steel pipe via the internal support stress sensor is as follows: data is collected every 1 minute when the control of the double-acting hydraulic cylinder is triggered, and every 30 minutes under other conditions. S4. Data transmission and preprocessing: The data from each sensor is transmitted wirelessly to the control terminal, where the raw data is then filtered to remove abnormal data with deviations exceeding three times the standard deviation caused by water flow impact and vibration. S5. Force Analysis: The hydrodynamic pressure P exerted by the river water on the side wall of the steel casing d Satisfy the following expression: P d =ρ w ·g·H w ·A w / 2+r w ·v 2 ·A w / 2 Where, ρ w The density of water is kg / m³. 3 v is the real-time flow velocity value acquired by the water flow velocity sensor, in m / s; g is the acceleration due to gravity, in m / s². 2 H w The elevation value of the river water acquired by the laser ranging sensor, in meters (m); A w The projected area of ​​the hydrodynamic pressure exerted by the river water on the side wall of the steel casing is given in m. 2 ; Concrete lateral pressure P acting on the side wall of the steel casing c Satisfy the following expression: P.S c HK c ·ρ c ·g·H c ·A c / 2 Among them, K c ρ is the lateral pressure coefficient of concrete. c The density of concrete, kg / m³ 3 g is the acceleration due to gravity, in m / s². 2 H c The elevation value of the poured concrete obtained by the laser ranging sensor, in meters (m); A c The projected area of ​​the concrete lateral pressure acting on the side wall of the steel casing is given in m. 2 ; The initial preload P of the nth adaptive internal support n The additional hydraulic force ΔP that needs to be adjusted for the nth adaptive internal support. n Satisfy the following expression: Among them, l pn Let m be the lever arm from the nth adaptive inner support to the bottom of the steel casing; l d The lever arm of the resultant force of the hydrodynamic pressure reaching the bottom of the steel casing is m; l c σ is the lever arm of the concrete lateral pressure to the bottom of the steel caisson, in meters (m); y A represents the yield strength of the steel pipe, in MPa; y The cross-sectional area of ​​the steel pipe is in meters. 2 ;K y The preload safety factor of the adaptive internal support; S6, Adaptive Control: The nth root ΔP obtained through step S5 n When the value is positive, the electromagnetic reversing valve drives the double-acting hydraulic cylinder to extend until the real-time feedback force value from the internal support pressure sensor reaches the target value, at which point it locks; the nth ΔP obtained through step S5... n When the value is negative, the electromagnetic reversing valve drives the double-acting hydraulic cylinder to retract, thereby applying a pulling force to balance the resultant force and torque of the external dynamic water pressure and the internal concrete pressure, until the pressure relay locks after the real-time feedback force value reaches the target value.

2. The adaptive adjustment method for the internal support of the steel casing of the anti-collision pier cap according to claim 1, characterized in that, The adaptive internal support is connected to the ring beam at both ends via ball joints, satisfying the requirements of flexibility and structural stability for minute angle adjustments. One end of the ball joint is welded to the end of the steel pipe via a flange, and the other end is bolted to the pre-embedded steel plate of the steel box girder via a flange of the same specification. The rotation angle of the ball joint is limited to ±5° by a limiting block to ensure rigid restraint when the angle exceeds the limit, avoiding excessive rotation that could cause the adaptive internal support to become unbalanced.

3. The adaptive adjustment method for the internal support of the steel casing of the anti-collision pier cap according to claim 1, characterized in that, The water flow velocity sensor is covered by a stainless steel protective net, and the laser rangefinder is equipped with a rainproof cover to ensure stable performance under heavy rain and strong water flow impact.

4. The adaptive adjustment method for the internal support of the steel casing of the anti-collision pier cap to adapt to water level changes according to claim 1, characterized in that, In step S4, the specific steps for "removing abnormal data whose deviation exceeds 3 times the standard deviation due to water flow impact and vibration" are as follows: S401. Calculate the standard deviation: Calculate the standard deviation of 20 consecutive sets of filtered effective data from the same sensor. S402. Remove outlier data: When the deviation of a sampled value from the mean exceeds 3 times the standard deviation, it is judged as outlier data and removed. S403, Linear Interpolation: After removing outlier data, based on three sets of valid data before and after, linear interpolation is used to fill the gaps to ensure the continuity of the data sequence. S404 Sensor Fault Determination: If three consecutive samples are determined to be abnormal data, a sensor fault alarm will be triggered.

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