Cantilever casting construction method for hanging basket of cable-stayed bridge

Abstract

The invention discloses a suspended pouring construction method for a hanging basket of a cable-stayed bridge, belongs to the technical field of bridge construction, and aims to solve the problems of beam section linear deviation caused by deformation of a hanging basket system and bridge tower deviation caused by asynchronous tensioning of stay cables. Performing a staged loading preloading test to obtain elastic deformation data, calculating an anti-arch value based on the data, and dynamically adjusting the elevation of a bottom die platform; a layered pouring process is combined with a real-time deformation monitoring and compensation mechanism, and the accumulated deformation amount is controlled; the longitudinal prestressed steel beams are tensioned in stages, the symmetric tensioning process of the stay cables is synchronously implemented, and bridge tower deviation closed-loop correction is achieved through combination of a displacement sensor and a pressure sensor; in the moving process of the hanging basket, the gravity center offset is monitored, the balance weight is adjusted, and after full-bridge closure, the cable force of the stay cable is optimized in a staged mode to the design state. The method is suitable for large-span cable-stayed bridge girder construction, and high-precision linear control and stable structure forming are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge construction, and in particular relates to a hanging basket suspended pouring construction method for a cable-stayed bridge. Background Art

[0002] During the suspended pouring of cable-stayed bridge main beams, controlling the deformation of the hanging basket system and synchronizing the tensioning of the cable stays are key challenges affecting the completed bridge's alignment and structural safety. In traditional hanging basket construction, prestressing tests often utilize static load simulations, setting the pre-camber based solely on experience. The impact of dynamic construction loads (such as concrete pumping impact and vibration disturbances) on the elastic deformation of the hanging basket is not fully considered. This leads to discrepancies between prestressing data and actual deformation, insufficient precision in adjusting the elevation of newly cast beam sections, and cumulative alignment deviations. Furthermore, during cable tensioning, due to the limited stiffness of the towers and the lack of a real-time feedback mechanism for cable tension adjustment, unilateral cable tension deviations can easily cause tower misalignment. Correction operations after misalignment often rely on manual experience, resulting in lags and potential for exacerbated structural stress imbalances and even localized cracking. Furthermore, after the bridge is fully closed, cable tensioning is often adjusted sequentially, cable by cable. This process fails to consider cable tension coupling and residual stress redistribution, resulting in lengthy and inefficient adjustments and ultimately difficulty in converging the cable tensions to the designed state. The root cause of the above problems is that the dynamic coupling relationship between load, deformation and cable force during construction has not been quantitatively modeled, and deformation compensation and cable force adjustment lack closed-loop control logic. To achieve this goal, it is necessary to solve technical problems such as multi-sensor data fusion, dynamic response prediction and multi-system collaborative control. Traditional processes cannot take into account both construction efficiency and precision requirements. Summary of the Invention

[0003] In the traditional cable-stayed bridge hanging basket suspended casting construction, the deformation of the hanging basket system causes the accumulation of linear deviations of the beam segments, and the bridge tower displacement caused by the asynchronous tensioning of the cable-stayed cables, which affects the accuracy of bridge construction and structural safety.

[0004] The present invention provides a method for suspended pouring of a cable-stayed bridge using a hanging basket, comprising the following steps: A hanging basket system is installed on the bridge tower. The hanging basket system includes a load-bearing truss, a bottom formwork platform, a suspension system, a hydraulic travel mechanism, and a post-anchoring system that connects the cast beam sections via precision-rolled threaded steel bars. A preload test is performed on the hanging basket system with a design load. The preload test adopts a graded loading method. After loading is completed, the pressure is stabilized for a set time to obtain elastic and inelastic deformation data of the hanging basket system. According to the elastic deformation data, a camber value is set at the front end of the bottom formwork platform. The camber value is a set multiple of the elastic deformation amount, and the bottom formwork platform elevation is adjusted by the screw jack of the suspension system so that the elevation deviation between the front end of the newly cast beam segment and the already formed beam segment is controlled within a preset range; The box girder reinforcement skeleton is tied on the adjusted bottom formwork platform, and the longitudinal prestressed corrugated pipe and the inclined cable conduit are embedded. The axis positioning error of the inclined cable conduit is less than the set value; The concrete is constructed using a layered pouring process, with each layer pouring to a set thickness. The interval between two adjacent layers does not exceed the set ratio of the concrete's initial setting time. During the pouring process, deformation sensors placed at key nodes of the load-bearing trusses monitor the deformation of the hanging basket system in real time. When the accumulated deformation exceeds the set ratio of the span, the bottom formwork platform elevation is compensated and adjusted. After the concrete strength reaches the set value of the design strength and the age is greater than the set number of days, the longitudinal prestressed steel tendons are tensioned in stages; After the longitudinal prestressing is completed, the corresponding segment of the cable is installed simultaneously. A symmetrical tensioning process is used to control the difference in cable force on both sides to be less than the set ratio of the design cable force. During the tensioning process, the cable force value is monitored by a pressure sensor, and the deflection value of the bridge tower top is monitored by a displacement sensor. When the deflection value of the bridge tower exceeds the set threshold, the tensioning is suspended and the cable force is adjusted. Release the constraints of the finished rolled rebar of the rear anchoring system, start the hydraulic travel mechanism and move the hanging basket system forward to the next section at the set speed. During the movement, monitor the center of gravity offset in real time. When the offset exceeds the set ratio of the span, stop the movement and adjust the counterweight. After the entire bridge is connected, the cable tension is adjusted in stages to the designed bridge state, and the final cable tension error is controlled within the preset range.

[0005] The traditional preloading test only simulates static loads and does not consider the impact of dynamic loads such as concrete pumping impact on the hanging basket system, resulting in a significant deviation between the preloading data and the actual construction deformation. Preferably, the graded loading preloading test of the present invention includes a static load application stage and a dynamic construction load simulation stage in sequence. In the static load stage, the static load under the concrete pouring state is simulated by uniformly distributed pile load, and the load is maintained for the first set time after reaching the target load; During the dynamic construction load simulation phase, a periodic load matching the concrete pumping impact frequency is applied to the load-bearing truss nodes of the hanging basket system through a hydraulic vibrator. The loading amplitude is a set proportion of the static load, and the load is maintained for a second set time after completion. The static load stage and the dynamic construction load simulation stage are carried out alternately. After each loading stage, the elastic deformation and inelastic deformation data of the hanging basket system are measured, and the loading amplitude of the next stage is corrected based on the accumulated deformation data.

[0006] The preloading test with a fixed loading amplitude cannot dynamically adjust the load according to the actual deformation response of the hanging basket. The preloading data is not reliable enough to guide subsequent construction. Preferably, the present invention corrects the loading amplitude of the next stage based on the accumulated deformation data, including the following steps: Comparing the sum of the elastic deformation data and the inelastic deformation data after loading in the current stage with a preset deformation threshold; if the cumulative deformation data exceeds the preset deformation threshold, reducing the loading amplitude of the next stage of dynamic construction load simulation; If the accumulated deformation data does not exceed the preset deformation threshold, the loading amplitude is increased in the next stage of dynamic construction load simulation; The corrected loading amplitude is dynamically adjusted through the pressure closed-loop control system of the hydraulic vibrator, and after the loading amplitude is adjusted, the deformation data is repeatedly measured and the accumulated deformation data is updated until the accumulated deformation data is stabilized within a preset deformation threshold range.

[0007] The uneven temporal and spatial distribution of load during layered concrete pouring results in delayed compensation of hanging basket deformation and decreased beam linear control accuracy. Preferably, the layered pouring process of the present invention comprises the following steps: The single-layer concrete is divided into multiple symmetrically distributed pouring areas along the cross section of the box girder. The concrete in each pouring area is poured in the order from the web to the top plate and from the mid-span to the two ends. After the initial area of each layer of concrete is poured, the deformation of the key nodes of the hanging basket system is obtained in real time, and the cumulative deformation of the next area during pouring is predicted based on the deformation change trend; If the predicted cumulative deformation exceeds the preset threshold, the concrete distribution order of the subsequent unpoured areas will be adjusted, with the corresponding areas with smaller deformation being poured first, and the pouring speed of these areas will be reduced. During the pouring of each layer of concrete, when the real-time monitored deformation reaches the preset compensation trigger condition, the synchronous lifting device of the suspension system dynamically compensates the bottom formwork platform elevation. The compensation amount is the inverse adjustment value of the current deformation. After completing the pouring of a single layer of concrete, suspend construction and continuously monitor the deformation recovery status of the hanging basket system. After the deformation recovers to within the allowable deviation range, pour the next layer of concrete.

[0008] In view of the fact that the stress relaxation loss in the previous stage is not compensated in the latter stage of the staged tensioning, and the insufficient density of the grouting in the duct affects the prestressing transmission effect, the staged tensioning of the longitudinal prestressed steel strands of the present invention preferably includes the following steps: After the first stage of tensioning is completed, the tensioning force is maintained and the stress relaxation rate of the prestressed steel tendons is monitored in real time, and the compensating tensioning force for the second stage of tensioning is calculated according to the stress relaxation rate; The compensating tensioning force is the sum of the tensioning force in the first stage and the increment dynamically adjusted based on the stress relaxation rate; After the second stage of tensioning is completed, the pores are grouted using an alternating pulse grouting process, whereby high-pressure pulses are first injected to expel air from the pores, followed by low-pressure steady flow to fill and compact the pores. During the grouting process, the slurry flow state is detected by an acoustic sensor pre-buried in the channel. If slurry flow stagnation or bubble signals are detected, secondary high-pressure pulse grouting is triggered until the density reaches the standard.

[0009] When the cable is tensioned, the tower deviation is triggered by relying on a single threshold to correct the deviation, which leads to delayed or over-correction of the deviation, thus impairing the structural stability. Preferably, the synchronous monitoring of the deviation value of the top of the tower and correcting the deviation of the tower includes the following steps: Displacement sensors and inclination sensors are symmetrically placed on top of the bridge tower to obtain the lateral displacement, longitudinal displacement, and inclination angle data of the bridge tower in real time. The comprehensive displacement value of the bridge tower is calculated by fusing multi-dimensional displacement feature values. Set multi-level deviation thresholds. When the comprehensive deviation value reaches the first level threshold, the dynamic adjustment strategy of the cable force difference of the single-side inclined cable is automatically triggered. When the comprehensive deviation value reaches the second-level threshold, the tensioning operation of all the inclined cables in the current segment is suspended, and the active deviation correction device of the bridge tower is activated. The correction device applies a correction force opposite to the deviation direction to the bridge tower through a hydraulic jacking mechanism. At the same time, based on the correlation analysis between historical deviation data and real-time cable force values, a new inclined cable tensioning sequence is generated; After the correction is completed, the tensioning operation is resumed, and the displacement-cable force response data during the correction process are input into the adaptive control model to dynamically optimize the deviation threshold range and correction strategy of subsequent segments.

[0010] Conventional cable tension adjustment is performed cable by cable in a fixed order, without considering the cable tension coupling effect, resulting in low adjustment efficiency and difficulty in converging residual deviations. Preferably, the staged adjustment of the cable tension to the designed bridge state of the present invention includes the following steps: The cable force adjustment after the full bridge closure is divided into multiple adjustment cycles, and in each adjustment cycle, at least one pair of symmetrical stay cables is selected in a preset order as the main adjustment cables and the auxiliary adjustment cables; While the main adjusting cable is applying the adjustment force, the bridge deck alignment data, the tower top deviation data, and the cable force changes of the adjacent cable segments of the main adjusting cable are collected in real time, and the coordinated adjustment amount of the auxiliary adjusting cable is calculated based on the data; After completing a single-cycle adjustment, the cable force distribution of the entire bridge is traversed to identify areas where cable force deviations are concentrated, and the main cables for the next adjustment cycle are preferentially allocated to these areas. The above adjustment cycle is repeated until the cable tension error falls within the preset range. In the final stage, the full-bridge cable tension synchronous fine-tuning mode is adopted, and balanced adjustment force is applied to all inclined cables through multi-point synchronous tensioning equipment.

[0011] In view of the lack of historical data and load distribution correlation analysis in traditional deformation prediction, the cumulative deformation prediction accuracy is insufficient and it is impossible to actively avoid construction risks. Preferably, the present invention predicts the cumulative deformation of the next area during pouring based on the deformation change trend, including the following steps: Displacement sensors are placed at the mid-span nodes, suspension nodes, and rear anchor nodes of the hanging basket system to collect three-dimensional deformation data of each node in real time; Based on the deformation data of the current pouring area, the deformation rate and deformation direction are extracted, and the deformation rate and direction are input into a preset linear extrapolation model to calculate the predicted value of the cumulative deformation when pouring the next area; When the predicted cumulative deformation value exceeds the preset safety threshold, the pouring order of the concrete in the next area is automatically adjusted, with the corresponding area on the opposite side of the deformation direction being poured first, and the pouring speed is reduced; During the adjusted pouring process, the deformation data is continuously updated and the predicted value of the cumulative deformation is recalculated until the predicted value falls back to the safety threshold.

[0012] Preferably, calculating the coordinated adjustment amount of the auxiliary adjusting cables based on the bridge deck alignment data, the tower top offset data, and the cable force variation of adjacent cable segments of the main adjusting cables comprises the following steps: Displacement sensors are placed at the mid-span and 1 / 4 span positions of the bridge deck to collect real-time bridge deck alignment data, including longitudinal slope deviation and transverse elevation difference; Tilt sensors are symmetrically placed on top of the bridge towers to monitor the tower top deviation angle in real time and calculate the lateral and longitudinal displacements of the tower top based on the tower height. The pressure sensor embedded in the anchor of the adjacent cable segment of the main adjustment cable is used to obtain the cable force change of the adjacent cable segment in real time. The cable force change is the difference between the current cable force value and the reference value before adjustment. Input the bridge deck alignment deviation, tower top displacement, and cable force changes of adjacent cable segments into the preset stress coupling model to calculate the coordinated adjustment of the auxiliary cable adjustment. Applying the coordinated adjustment amount to the auxiliary cable using a synchronous hydraulic jack, and checking the cable force variation of adjacent cable segments in real time during the application process. If the cable force variation still exceeds 2% of the design value, suspending loading and recalculating the coordinated adjustment amount; After completing the coordinated adjustment, maintain the load for 10 minutes, and collect the bridge deck linear data and tower top displacement again. If the linear deviation returns to the preset range and the tower top displacement is less than 3mm, the coordinated adjustment is determined to be effective.

[0013] The present invention has at least the following beneficial effects: 1. The present invention significantly reduces the accumulation of linear deviations in beam segments through graded preloading and compensation of anti-arch values based on deformation data, combined with a dynamic adjustment mechanism for layered pouring. The synchronous tensioning and closed-loop deviation correction process suppresses the deviation of bridge towers, achieves a dynamic balance of load, deformation, and cable force, and improves construction accuracy.

[0014] 2. The present invention simulates the combination of dynamic and static loads to more realistically restore construction conditions, improve the accuracy of preloading data, and effectively guide subsequent elevation adjustment and structural reinforcement.

[0015] 3. The present invention adopts a dynamic correction mechanism of loading amplitude based on deformation threshold to avoid the risk of overload or underload and improve the efficiency of preload test.

[0016] 4. The present invention links regional pouring with deformation prediction to reduce elevation compensation lag time and beam linear error.

[0017] 5. The present invention combines stress relaxation dynamic compensation tensioning with pulse grouting technology to reduce prestress loss and improve pore density.

[0018] 6. The present invention triggers a graded deviation correction strategy through multi-level thresholds to improve the response speed of bridge tower deviation control, and the residual deviation after correction is small.

[0019] 7. The present invention shortens the cable force adjustment cycle and reduces the final cable force error through the coordinated adjustment of the main and auxiliary cables and the dynamic focusing mechanism of the deviation area.

[0020] 8. The linear extrapolation prediction of the present invention is linked with the reverse pouring strategy to reduce the risk of cumulative deformation exceeding the limit and significantly enhance construction safety.

[0021] Other advantages, objectives and features of the present invention will be reflected in part from the following description and will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the hanging basket system of the present invention; Figure 2 The present invention is a flow chart of the method for suspended pouring construction of a cable-stayed bridge using a hanging basket.

[0023] Among them, there are load-bearing trusses 10, bottom formwork platform 20, suspension system 30, hydraulic walking mechanism 40, rear anchoring system 50, formed beam section 60, and bridge tower 70. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below with reference to the embodiments so that those skilled in the art can implement the invention with reference to the description.

[0025] As shown in Figures 1 and 2, an example of the hanging basket cast-in-place construction method for a cable-stayed bridge of the present invention includes: A hanging basket system was installed on the bridge tower. The system consists of a load-bearing truss, a base formwork platform, a suspension system, a hydraulic travel mechanism, and a rear anchorage system. The load-bearing truss was welded from Q345B steel. The base formwork platform was paved with 10mm thick steel plates. The rear anchorage system was connected to the pre-cast anchor plates (400mm × 400mm × 20mm) of the cast beam segments using rolled rebar (32mm diameter, strength grade PSB930). During the preloading test, a total load of 1.2 times the design load was applied using a graded sandbag loading system, with each stage accounting for 20% of the total load. Loading intervals were 30 minutes, and the load was stabilized for 48 hours after completion. Elastic deformation data were collected using displacement sensors (range ±50mm, accuracy 0.01mm) placed at the mid-span node (location A) of the load-bearing truss, the suspension node (location B), and the rear anchorage node (location C). Inelastic deformation data were measured using a laser rangefinder.

[0026] Based on the elastic deformation data from the preloading test, the camber value at the front end of the bottom formwork platform was set to 1.05 times the elastic deformation. The suspension system employed four screw jacks (rated load 50t, stroke 200mm) to adjust the bottom formwork elevation, maintaining the elevation deviation between the front end of the newly cast beam segment and the existing beam segment within ±3mm. Concrete was poured in layers, with a single layer thickness of 40cm and the interval between adjacent layers not exceeding 70% of the concrete's initial setting time (approximately 4 hours). During pouring, deformation was monitored in real time using deformation sensors (range ±30mm, sampling frequency 10Hz) installed at the mid-span node (position A) of the load-bearing truss. If the accumulated deformation exceeded 1 / 400 of the span (i.e., 10mm) (assuming a 40m span), the bottom formwork elevation was adjusted using the screw jacks.

[0027] After the concrete reaches 90% of its design strength (C50) and is older than seven days, the longitudinal prestressed steel tendons (15.2mm diameter, 1860MPa strength) are tensioned in two stages: the first stage is tensioned to 50% of the design value (i.e., 930MPa), and the second stage is tensioned to 100%. The stay cables are tensioned using a symmetrical, synchronous process, with the unilateral cable force difference controlled to within 3% (i.e., 60kN) of the design cable force (e.g., 2000kN). The deflection of the pylon top is monitored by displacement sensors mounted on the pylons (range: ±50mm, accuracy: 0.1mm). If the deflection exceeds 10mm, tensioning is suspended and the opposite cable force is adjusted (increase or decrease by no more than 5%) to correct the deflection.

[0028] The basket's forward movement speed was set at 15 cm / minute. During movement, an inclination sensor (range ±5°, accuracy 0.01°) monitored the center of gravity offset. If the offset exceeded 1 / 500 of the span (40 m), or 8 cm, movement was halted and counterweights (each weighing 1 t) were added. After the bridge was fully connected, the cable tension was adjusted to the design value in three steps, with each adjustment amounting to 30% of the total, with adjustments spaced every 24 hours. The final cable tension error was controlled within ±2%.

[0029] The installation and preloading test of the hanging basket system in this embodiment ensures that the preloading conditions match the actual construction loads through graded loading and deformation data quantification, improves the calculation accuracy of the anti-arch value, and significantly reduces the elevation adjustment error. The adjustment of the bottom formwork platform and concrete construction, through the combination of layered pouring and real-time deformation compensation mechanism, reduce the accumulation of linear deviations of the beam body and stabilize the quality of concrete molding. Prestressed tensioning and inclined cables are controlled synchronously. The displacement of the bridge tower is suppressed through staged tensioning and symmetrical processes, and the force balance of the structure is enhanced. The movement of the hanging basket and the adjustment of the cable force are combined with the dynamic monitoring of the center of gravity offset and the staged cable force adjustment to simultaneously optimize the construction efficiency and the cable force accuracy of the completed bridge.

[0030] Furthermore, in another embodiment, the total load applied during the static loading phase can be set to 1.2 times the design load, using sandbags or water tanks to simulate the weight of the concrete pour. Each sandbag weighs one ton, and the loading area covers the entire bottom formwork platform. The graded loading capacity is 20% of the total load, with a 30-minute interval between each loading stage. After loading is completed, the pressure is stabilized for 48 hours. During this period, the elastic deformation data of the mid-span nodes and suspension nodes of the load-bearing trusses are measured every hour using displacement sensors (range ±50mm, accuracy 0.01mm). Inelastic deformation data are collected using a laser rangefinder (range 50m, accuracy 0.1mm), with the measurement point located at the connection of the rear anchor system.

[0031] Dynamic load simulations employed cyclical loads using hydraulic vibrators (maximum excitation force 100 kN, frequency range 1-10 Hz). The vibrators were installed at the mid-span and suspension nodes of the load-bearing trusses. The loading amplitude was 20% of the static load, and the frequency was set at 2-4 Hz to simulate the impact of concrete pumping. Each dynamic loading session lasted 10 minutes, followed by a two-hour stabilization period. During this period, dynamic response data from the nodes was collected using vibration sensors (range ±5 g, sampling frequency 100 Hz). Dynamic deformation data was uploaded to a data analysis platform via a wireless transmission module and superimposed with the deformation data from the static loading phase.

[0032] Static and dynamic loads were applied alternately three times, with cumulative deformation measured after each alternating cycle. If the cumulative deformation exceeded a preset threshold of 10 mm, the dynamic loading amplitude for the next stage was reduced by 5%. If the threshold was not exceeded, the dynamic loading amplitude was increased by 5%. This corrected loading amplitude was achieved using a closed-loop pressure control system using a hydraulic vibrator, equipped with a built-in PID controller (proportional coefficient 0.8, integration time 1.2 seconds). During the loading process, a one-hour pause was maintained after each alternating cycle to inspect the welds and bolt connections of the hanging basket system, with a particular focus on the connection node (position G) between the load-bearing truss and the bottom formwork platform.

[0033] In this implementation, the static loading phase utilizes graded loading and pressure measurement to accurately quantify the static deformation characteristics of the basket system, providing reliable data for inverse camber calculation. The dynamic construction load simulation phase, through simulated pumping impact loads, reveals dynamic weaknesses in the basket system and guides local reinforcement measures. Alternating loading and amplitude adjustment, along with a dynamic amplitude correction mechanism based on deformation thresholds, ensure that the preload test covers realistic construction conditions, enhancing the effectiveness of basket system stiffness verification.

[0034] Furthermore, in another embodiment, the preset threshold for cumulative deformation data can be set at 10mm. Displacement sensors (range ±50mm, accuracy 0.01mm) are used to collect elastic deformation data from the mid-span and suspension nodes of the load-bearing trusses, combined with a laser rangefinder (range 50m, accuracy 0.1mm) to measure the inelastic deformation data of the rear anchoring system. If the cumulative deformation exceeds the threshold of 10mm, the dynamic loading amplitude in the next stage is reduced by the ratio of the excess to the threshold. For example, if the cumulative deformation is 12mm, the reduction ratio is (12-10) / 10 = 20%, corresponding to a 20% reduction in the amplitude. If the cumulative deformation is 8mm, the amplitude in the next stage is increased by 5% of the current amplitude.

[0035] The hydraulic vibrator's closed-loop pressure control system utilizes a proportional valve (response time ≤50ms) combined with a pressure sensor (range 0-20MPa, accuracy 0.1%FS). The controller outputs a control signal based on the corrected loading amplitude. The system's built-in PID control parameters are set to a proportional coefficient of 0.6, an integral time of 1.5s, and a differential time of 0.2s to ensure a loading amplitude adjustment error of less than 2%. During adjustment, the vibrator is installed at the mid-span node of the load-bearing truss, with the loading direction aligned with the primary force of the gantry system.

[0036] After each load amplitude adjustment, deformation data is remeasured using a displacement sensor, and the cumulative value is updated and entered into the control system's database. If the cumulative deformation data fluctuates within 1 mm for three consecutive times, the deformation is considered stable. During the stability verification phase, loading is suspended to inspect the integrity of the welds and bolted connection nodes of the hanging basket system's load-bearing trusses. Bolt preload is verified using a torque wrench (range 0-300 N·m) to ensure it reaches 90%-110% of the design value.

[0037] The threshold comparison and amplitude adjustment mechanism in this implementation dynamically optimizes the loading strategy by comparing deformation data with thresholds in real time, avoiding overload risks and aligning with real-world operating conditions. The closed-loop control system achieves dynamic adjustment, ensuring rapid response to loading amplitude adjustments through high-precision pressure control, improving the repeatability and consistency of preloading tests. Continuous data monitoring and mechanical connection status checks ensure the structural stability of the hanging basket system during the preloading process, mitigating construction safety risks.

[0038] Furthermore, in another embodiment, a single layer of concrete can be divided into four symmetrical pouring areas (e.g., Area 1, Area 2, Area 3, and Area 4) along the cross-section of the box girder, with the area dividing line located at the intersection of the web centerline and the top slab centerline. The order of pouring concrete within each area is as follows: first, pour the web area (Area 1 and Area 2), advancing from the mid-span toward each end; then pour the top slab area (Area 3 and Area 4), converging from both sides toward the centerline. The single pour height of the web area is 40 cm, and the single pour thickness of the top slab area is 25 cm. The pouring equipment can be a boom pump (delivery capacity 90 m³ / h) combined with an insert vibrator (50 mm diameter, 200 Hz frequency), with the vibration points spaced no more than 30 cm apart.

[0039] Deformation monitoring points for key nodes of the hanging basket system were located at the mid-span nodes, suspension nodes, and rear anchorage nodes of the load-bearing trusses. Displacement sensors (range ±30mm, sampling frequency 10Hz) collected real-time 3D displacement data. After pouring of web section 1 was completed, the deformation rate (unit: mm / min) and orientation angle (relative to the longitudinal axis of the box girder) were calculated based on the displacement data. A preset linear extrapolation model was then used to predict the cumulative deformation of web section 2. If the predicted value exceeded the threshold of 8mm, the pouring order of subsequent top slab sections 3 and 4 was adjusted, prioritizing the section on the opposite side of the deformation direction (e.g., section 3). The pouring speed in this section was reduced to 50% of the original rate.

[0040] During the pouring of web area 2, if the real-time monitored deformation reaches the compensation trigger condition (accumulated deformation of 5mm), the base formwork platform elevation is dynamically compensated using the suspension system's four synchronized hydraulic jacks (200mm stroke, 0.1mm accuracy). The compensation amount is the inverse of the current deformation (e.g., a +5mm deformation is compensated with a -5mm compensation). After pouring a single layer of concrete, construction is suspended for six hours, and the deformation recovery status of the hanging basket system is continuously monitored. If the residual deformation exceeds the allowable deviation of ±2mm, the suspension period is extended until the deformation returns to the required level. After recovery verification, the beam segment alignment is rechecked using a total station (angle measurement accuracy of 1″ and distance measurement accuracy of 1mm + 1ppm) to ensure that the elevation deviation is within ±3mm.

[0041] In this implementation, pouring area division and sequence control reduce uneven load distribution through symmetrical zoning and sequence optimization, suppressing unilateral deformation of the gantry. Deformation monitoring and predictive adjustment, based on linear model-based deformation prediction and dynamic adjustment of the pouring sequence, reduce the risk of cumulative deformation exceeding limits. Dynamic compensation and recovery verification, combined with real-time compensation and recovery monitoring, ensure beam linear accuracy and structural stability.

[0042] Furthermore, triaxial displacement sensors (with a range of ±30mm and an accuracy of 0.02mm) can be installed at the midspan nodes, suspension nodes, and rear anchorage nodes of the hanging basket system. These sensors are bolted to the surface of the node connection plates. Data acquisition is set at 10 times per second, with real-time transmission to the data analysis terminal. The sensors at the midspan nodes are aligned with the longitudinal axis of the box girder. Suspension node sensors monitor vertical and lateral displacement, while rear anchorage node sensors monitor longitudinal displacement.

[0043] Based on the deformation data of the current pouring area, the deformation rate (unit: mm / min) and the main deformation direction (angular deviation ±5°) are extracted and input into a preset linear extrapolation model. The model calculates a predicted cumulative deformation value for the next pouring area using the formula: Prediction = Current Deformation + Deformation Rate × Pouring Time (estimated based on a 20-minute pouring time for each area). A preset safety threshold of 8mm is used. If the predicted value exceeds the threshold, the system automatically generates an adjustment instruction: prioritize pouring the area opposite the deformation direction (for example, if the current deformation direction is left, prioritize pouring the area to the right) and reduce the pouring speed in that area to 60% of the original rate.

[0044] During the adjusted pouring process, deformation data is updated and the predicted value is recalculated every time 10% of the concrete volume in the area is completed. If the updated predicted value still exceeds the threshold, the pouring speed is further reduced to 40% of the original rate. After the pour is completed, construction is suspended for 30 minutes, and the beam segment alignment is reviewed using a total station (with an angle measurement accuracy of 1") to ensure that the elevation deviation is within ±3mm. If the deviation exceeds the limit, additional pre-camber compensation in the opposite direction is added during the next pour (the compensation amount is 1.2 times the excess deviation).

[0045] Furthermore, in another embodiment, the first-stage tensioning force can be set to 50% of the design tensioning force. After tensioning is completed, the load is maintained for 30 minutes. The stress relaxation rate is monitored in real time using a stress sensor (range 0-2000 MPa, accuracy 0.5% FS) installed on the prestressed steel strand (diameter 15.2 mm, strength 1860 MPa). If the stress relaxation rate exceeds 0.5 MPa / min, the second-stage compensatory tensioning force is the first-stage tensioning force plus 10 times the relaxation rate (for example, if the relaxation rate is 0.6 MPa / min, the compensation is increased by 6 MPa). If the relaxation rate is less than 0.3 MPa / min, the compensation is 3 MPa. After the second-stage tensioning is completed, the anchor clip is immediately tightened using a torque wrench (range 0-500 N·m) to ensure that the clip preload reaches 95% of the design value.

[0046] The grouting was carried out using a dual-mode grouting machine. The first stage involved a high-pressure pulse pressure of 1.0 MPa at a pulse frequency of 2 Hz for 5 minutes. The second stage involved a low-pressure steady-flow pressure of 0.5 MPa and a flow rate of 0.8 m³ / h. The slurry had a water-cement ratio of 0.28, and a polycarboxylate-based water reducer (0.1%) was added. Acoustic sensors (frequency response range 20 kHz-1 MHz) were embedded in the middle and ends of the slurry to monitor slurry flow signals in real time. If the acoustic signal indicated stagnation or the air bubble ratio exceeded 5%, a second high-pressure pulse grouting injection was triggered, increasing the pressure to 1.2 MPa for 3 minutes.

[0047] 24 hours after grouting, scan the entire length of the tunnel using an impact echometer (center frequency 50kHz) to test for compactness. If local voids (diameter greater than 3mm) are found, drill holes (8mm diameter) at the corresponding locations and inject epoxy resin (viscosity 300cps) at a pressure of 0.3MPa until the backfill is fully filled. After repair, retest with impact echo to ensure a compactness of at least 98%.

[0048] This implementation incorporates stress relaxation monitoring and dynamic compensation. By quantifying the compensation value through real-time relaxation rates, this approach reduces prestress loss and improves effective stress retention in the tendons. High-pressure pulses expel air from the pores, while low-pressure steady-flow fills the pores densely, reducing voids and improving the bond strength between the slurry and the tendons. Combined acoustic wave testing and impact echo verification ensure that pore filling quality meets standards, minimizing the risk of subsequent corrosion.

[0049] Furthermore, in another embodiment, four displacement sensors (range ±50mm, accuracy 0.1mm) and two inclination sensors (range ±5°, accuracy 0.01°) can be installed atop the bridge tower. The sensors are symmetrically located at the four corners and along the centerline of the tower. Transverse displacement, longitudinal displacement, and inclination angle data are transmitted to the data processing unit via a wired transmission module. The combined calculation formula is: Comprehensive displacement = Transverse displacement × 0.6 + Longitudinal displacement × 0.3 + Inclination angle (radians) × Tower height × 0.1. The data processing unit updates the comprehensive displacement value every 5 seconds and displays it on the control interface.

[0050] The first-level misalignment threshold is set at 8mm. When the combined misalignment reaches 8mm, the control system automatically reduces the cable tension difference in the opposite side of the misalignment direction by 20% of the current cable tension difference (for example, if the original cable tension difference is 100kN, it is adjusted to 80kN). The second-level threshold is set at 12mm. Once triggered, tensioning operations are suspended and the hydraulic jacking mechanism is activated to correct the misalignment (jacking force 0-500kN, stroke 200mm). The jacking point is located at the base of the pylon (position U), applying a force opposite to the misalignment direction. At the same time, a new tensioning sequence is generated based on historical misalignment data: the two adjacent pairs of cables on the misaligned side are prioritized, and the single tensioning force is reduced by 10%.

[0051] The displacement-cable force response data collected during the correction process is trained using a machine learning model (a random forest algorithm). Input features include cable force, deflection, ambient temperature (ranging from -20°C to 50°C), and wind speed (ranging from 0 to 15 m / s). The output is an optimized deflection threshold range (for example, adjusted to 7-11 mm) and a corrective force gradient (40 kN of thrust for every 1 mm of deflection). The model is updated every 24 hours, and after the update, the effectiveness of the strategy is verified through simulated loading, with the verification load set at 80% of the design load.

[0052] This implementation utilizes multi-dimensional deviation monitoring and fusion calculations to improve the accuracy of deviation status assessments by fusing multi-sensor data, avoiding single-dimensional misjudgments. A progressive deviation correction mechanism balances response speed with structural safety, reducing the risk of overcorrection. Data-driven dynamic adjustment of thresholds and strategies adapts to complex environmental changes and enhances long-term construction stability.

[0053] Furthermore, in another embodiment, cable tension adjustment after full bridge closure can be divided into three adjustment cycles, each lasting eight hours. The main cable adjustment is selected based on the symmetrical stay cable pair with the largest cable tension deviation, while the auxiliary cables are selected from two adjacent pairs. The main cable adjustment force is 5% of the design cable tension. During adjustment, pressure sensors (range 0-3000 kN, accuracy 0.2% FS) collect the cable tension changes of adjacent segments of the main cable in real time. If the change exceeds 2% of the design value, the auxiliary cables are coordinated by adjusting the tension to 80% of the change. Coordinated adjustment is performed using four through-hole jacks (200 mm stroke, synchronization accuracy ±1 mm), installed at the auxiliary cable anchorages.

[0054] After a single adjustment cycle is completed, a cable force distribution cloud map is generated using data from 32 cable force monitoring points throughout the bridge. Areas of concentrated deviation are identified when the cable force error for three consecutive pairs of stay cables exceeds ±1.5%. The main cable for the next adjustment cycle is prioritized for this area, with the adjustment force increased to 7% of the design cable force. Data is collected using a wireless force meter (sampling frequency 1Hz). The data processing unit updates the list of deviation areas every 10 minutes and highlights them on the control interface.

[0055] In the final stage, eight synchronized tensioning devices (with a synchronization error of ±0.5%) applied a uniform adjustment force to all stay cables, with a single adjustment amount of 0.3% of the design cable force. During the adjustment process, the adjustment amount was dynamically corrected using elevation data from multiple bridge deck alignment monitoring points (spaced 10m apart). If the elevation change at a particular point exceeded ±2mm, tensioning in that area was suspended and the adjustment amount recalculated. After the adjustment was completed, cable tension uniformity was checked using spectrum analysis with a frequency resolution of 0.01Hz, and the criterion for judging was that the fundamental frequency difference between adjacent cable segments was less than 0.05Hz.

[0056] Furthermore, in another embodiment, while the main adjusting cable applies the adjustment force, the steps of collecting bridge deck alignment data, tower top displacement data, and cable force changes of adjacent cable segments of the main adjusting cable in real time, and calculating the coordinated adjustment amount of the auxiliary adjusting cables are as follows: High-precision displacement sensors (range ±50mm, accuracy 0.1mm) are arranged at the mid-span and 1 / 4 span of the bridge deck to monitor the longitudinal slope deviation (unit: %) and transverse elevation difference (unit: mm) in real time. The data sampling frequency is 5 times per second.

[0057] Install inclination sensors (range ±5°, accuracy 0.01°) at the four corners of the bridge tower top. Combined with the tower height (e.g. 100m), calculate the lateral displacement (formula: lateral displacement = inclination angle × tower height) and longitudinal displacement (directly measured by displacement sensors).

[0058] Pressure sensors (range 0-3000kN, accuracy 0.2%FS) are embedded in the anchors of the adjacent cable sections of the main adjustment cable to collect the cable force value in real time and compare it with the baseline value before adjustment (the average value of the 10 minutes before adjustment) to calculate the cable force change (ΔF = current value - baseline value).

[0059] The bridge deck linear deviation (longitudinal slope deviation threshold ±0.05%, transverse elevation difference threshold ±3mm), tower top displacement (transverse displacement threshold ±10mm, longitudinal displacement threshold ±5mm) and cable force change in adjacent cable segments (ΔF threshold ±2% of design cable force) are input into the preset stress coupling model.

[0060] The bridge deck linear deviation (ΔS, ΔH), tower top displacement (D_x, D_y) and cable force change (ΔF) are normalized into dimensionless values, and the formula is: Among them, Xmax and Xmin are the thresholds of each parameter (such as ΔS_max=0.05%).

[0061] Allocation weights: bridge deck alignment weight 0.4, tower top offset weight 0.3, cable force change weight 0.3.

[0062] Coupling formula: The proportional coefficient K is dynamically adjusted based on historical data (0.6-0.8). If ΔF exceeds the limit three times in a row, K is increased to 0.9. The upper limit of the coordinated adjustment is 5% of the design cable force. If the limit is exceeded, the upper limit is implemented and an alarm is triggered.

[0063] The input data is updated every 5 seconds, and the model outputs the coordinated adjustment amount.

[0064] Four synchronous hydraulic jacks (stroke 200mm, synchronization error ±0.5%) are used to apply coordinated adjustment to the auxiliary adjustment cables. The jacks are installed at the anchoring end of the auxiliary adjustment cables, and the loading rate is 50kN per minute.

[0065] During the loading process, the change in cable force in adjacent cable segments is verified in real time through pressure sensors. If ΔF still exceeds ±2%, loading is suspended and the coordinated adjustment amount is recalculated.

[0066] After loading is complete, maintain the load for 10 minutes, then collect deck alignment data again (the longitudinal slope deviation must be restored to within ±0.03%) and tower top displacement (lateral displacement ≤ 3mm, longitudinal displacement ≤ 2mm). If these values are not met, a secondary coordinated adjustment is triggered, with the adjustment amount being 1.5 times the original value.

[0067] Zero-point calibration of displacement sensors, inclination sensors, and pressure sensors is performed every 24 hours, with calibration errors controlled within 0.1% of the measuring range. If the bridge deck alignment deviation exceeds ±5mm, the tower top displacement exceeds 15mm, or the cable tension changes exceed ±5%, adjustments are immediately stopped and the emergency support system activated.

[0068] This implementation method uses real-time fusion of multi-source data to improve the calculation accuracy of collaborative adjustment amounts and reduce local stress concentration by 40%. During the adjustment process, the peak value of cable force fluctuation is suppressed to within 1.5% of the design value, and the linear disturbance of the bridge deck is reduced by 60%. Example

[0069] This is applied to the main beam construction of a twin-tower cable-stayed bridge with a main span of 400m. The specific implementation steps are as follows: The hanging basket system, including the load-bearing truss, bottom formwork platform, suspension system, and hydraulic travel mechanism, is installed on top of the pier. The rear anchoring system is connected to the pre-buried anchor plates of the cast beam section through fine-rolled threaded steel bars. After the hanging basket is installed, a graded loading preload test is carried out: Static load stage: Sandbags are used to simulate the weight of concrete, and the load is divided into 5 levels to 1.2 times the design load. The interval between each level of loading is 30 minutes. After stabilizing the pressure for 48 hours, the elastic deformation data is measured; Dynamic loading stage: A cyclic load is applied to the load-bearing truss nodes through a hydraulic exciter to simulate the pumping impact effect. The loading amplitude is 20% of the static load, the frequency is 2-4 Hz, and the loading is alternated three times and the cumulative deformation is measured.

[0070] According to the elastic deformation data, the anti-arch value (1.05 times the elastic deformation) is set at the front end of the bottom mold platform, and the elevation deviation is adjusted to within ±3mm.

[0071] The single layer of concrete is poured in 4 symmetrical areas: Web area: advance from the mid-span to both ends, single layer thickness 40cm, vibration interval ≤30cm; Top plate area: converges from both sides to the center line, with a thickness of 25cm.

[0072] During the pouring process, displacement sensors were used to monitor the three-dimensional deformation of the mid-span and suspension nodes in real time. If the predicted cumulative deformation exceeded 8mm, pouring would prioritize the area in the opposite direction of the deformation and reduce the pouring speed by 50%. After pouring each layer, a six-hour pause was performed, and construction would resume only after the monitored deformation returned to within ±2mm.

[0073] After the concrete strength reaches 90% of the design value and the concrete age reaches 7 days, the longitudinal prestressing tendons are tensioned in two stages: In the first stage, tensioning is performed to 50% of the design force, and the stress relaxation rate is monitored. In the second stage, compensation is performed to 100%; The grouting of the duct adopts high-pressure pulse (1.0MPa) to exhaust the gas, low-pressure steady flow (0.5MPa) to fill densely, and acoustic wave sensor to detect the density of the slurry.

[0074] When the inclined cables are tensioned, the cable force difference is symmetrically controlled to be ≤3%. When the bridge tower deviation exceeds 10mm, the tensioning is suspended, and the hydraulic jacking and correction device applies reverse force and adjusts the tensioning sequence.

[0075] The hanging basket moves forward at a speed of 15cm / min, and the center of gravity offset is monitored in real time. If the offset exceeds the limit, it will stop and adjust the counterweight. Adjust the cable force in stages: adjust the cable force to the design value in three times, with an interval of 24 hours between each time, and the final error is ≤±2%; During the closure section construction, install a temporary H-shaped steel locking structure during low temperature periods, and use circulating water cooling to control the temperature difference between the inside and outside to ≤15°C.

[0076] After the construction is completed, a total station is used to detect the linear shape of the beam (elevation deviation ±3mm), an impact echo meter is used to detect the density of the channel (≥98%), and a spectrum analyzer is used to check the uniformity of the cable tension (fundamental frequency difference ≤0.05Hz).

[0077] This embodiment achieves high-precision and high-safety construction of large-span cable-stayed bridges by integrating active deformation control, dynamic load simulation and closed-loop adjustment of the force system. It is suitable for bridge construction in complex terrain. The cumulative elevation deviation of the beam section is ≤±5mm, and the joint accuracy is ±3mm; the residual amount of the bridge tower after correction is ≤2mm, and the cable force error converges to ±1.5%; the construction period of a single segment is shortened to 7 days, and the movement stability of the hanging basket is improved.

[0078] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiment. They can be applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily realized.

Claims

1. A hanging basket suspended pouring construction method for a cable-stayed bridge, characterized in that The following steps are involved: Installing a hanging basket system on the bridge tower, including a load-bearing truss, a bottom formwork platform, a suspension system, a hydraulic travel mechanism, and a rear anchoring system, wherein the rear anchoring system is connected to the cast beam section via anchoring components; Carry out graded loading pre-compression test on the hanging basket system, set the pressure to maintain stability for a set time after loading is completed, and measure the elastic deformation and inelastic deformation data of the hanging basket system; The anti-arch value of the bottom formwork platform is calculated based on the elastic deformation data, and the elevation of the bottom formwork platform is adjusted through the suspension system to control the elevation deviation between the front end of the newly cast beam section and the formed beam section within the preset range; Tie the box girder reinforcement skeleton on the bottom formwork platform and pre-embed the longitudinal prestressed pipes and inclined cable guide tubes to control the axis positioning accuracy of the inclined cable guide tubes; The concrete is constructed using a layered pouring process, the deformation of the hanging basket system is monitored in real time, and the elevation of the bottom formwork platform is adjusted according to dynamic compensation of the deformation; After the concrete reaches the preset strength, the longitudinal prestressed steel tendons are tensioned in stages, and the ducts are grouting after tensioning is completed; Install the corresponding segment of the cable and use a symmetrical tensioning process. Simultaneously monitor the cable force and the deflection of the tower top. When the tower deflection exceeds the threshold, suspend tensioning and make corrections. Release the constraints of the rear anchoring system and move the hanging basket system to the next section construction location. During the movement, monitor the center of gravity offset and control the offset range; After the entire bridge is connected, the cable tension is adjusted in stages to the designed bridge state, and the final cable tension error is controlled within the preset range.

2. The method for suspended pouring of a cable-stayed bridge using a hanging basket according to claim 1 is characterized in that: The graded loading preloading test includes a static load application stage and a dynamic construction load simulation stage in sequence; In the static load stage, the static load under the concrete pouring state is simulated by uniformly distributed pile load, and the load is maintained for the first set time after reaching the target load; During the dynamic construction load simulation phase, a periodic load matching the concrete pumping impact frequency is applied to the load-bearing truss nodes of the hanging basket system through a hydraulic vibrator. The loading amplitude is a set proportion of the static load, and the load is maintained for a second set time after completion. The static load stage and the dynamic construction load simulation stage are carried out alternately. After each loading stage, the elastic deformation and inelastic deformation data of the hanging basket system are measured, and the loading amplitude of the next stage is corrected based on the accumulated deformation data.

3. The method for suspended pouring of a cable-stayed bridge using a hanging basket according to claim 2 is characterized in that: The method of correcting the loading amplitude of the next stage based on the accumulated deformation data comprises the following steps: The sum of the elastic deformation data and the inelastic deformation data after loading in the current stage is compared with a preset deformation threshold. If the cumulative deformation data exceeds the preset deformation threshold, the loading amplitude of the next stage of dynamic construction load simulation is reduced. The reduction ratio is the ratio of the portion of the cumulative deformation data exceeding the threshold to the preset deformation threshold. If the accumulated deformation data does not exceed the preset deformation threshold, the loading amplitude is increased in the next stage of dynamic construction load simulation, and the increase amplitude is a set proportion of the loading amplitude in the current stage; The corrected loading amplitude is dynamically adjusted through the pressure closed-loop control system of the hydraulic vibrator, and after the loading amplitude is adjusted, the deformation data is repeatedly measured and the accumulated deformation data is updated until the accumulated deformation data is stabilized within a preset deformation threshold range.

4. The method for suspended pouring of a cable-stayed bridge using a hanging basket according to claim 1 is characterized in that: The layered pouring process for concrete construction comprises the following steps: The single-layer concrete is divided into multiple symmetrically distributed pouring areas along the cross section of the box girder. The concrete in each pouring area is poured in the order from the web to the top plate and from the mid-span to the two ends. After the initial area of each layer of concrete is poured, the deformation of the key nodes of the hanging basket system is obtained in real time, and the cumulative deformation of the next area during pouring is predicted based on the deformation change trend; If the predicted cumulative deformation exceeds the preset threshold, the concrete distribution order of the subsequent unpoured areas will be adjusted, with the corresponding areas with smaller deformation being poured first, and the pouring speed of these areas will be reduced. During the pouring of each layer of concrete, when the real-time monitored deformation reaches the preset compensation trigger condition, the synchronous lifting device of the suspension system dynamically compensates the bottom formwork platform elevation. The compensation amount is the inverse adjustment value of the current deformation. After completing the pouring of a single layer of concrete, suspend construction and continuously monitor the deformation recovery status of the hanging basket system. After the deformation recovers to within the allowable deviation range, pour the next layer of concrete.

5. The method for suspended pouring of a cable-stayed bridge using a hanging basket according to claim 4 is characterized in that: The method of predicting the cumulative deformation amount during pouring of the next area according to the deformation amount change trend includes the following steps: Displacement sensors are placed at the mid-span nodes, suspension nodes, and rear anchor nodes of the hanging basket system to collect three-dimensional deformation data of each node in real time; Based on the deformation data of the current casting area, the deformation rate and deformation direction are extracted, and the deformation rate and direction are input into a preset linear extrapolation model to calculate the predicted value of the cumulative deformation when casting the next area.

6. The method for suspended pouring of a cable-stayed bridge using a hanging basket according to claim 1 is characterized in that: The staged tensioning of longitudinal prestressed steel tendons comprises the following steps: After the first stage of tensioning is completed, the tensioning force is maintained and the stress relaxation rate of the prestressed steel tendons is monitored in real time, and the compensating tensioning force for the second stage of tensioning is calculated according to the stress relaxation rate; The compensating tensioning force is the sum of the tensioning force in the first stage and an increment dynamically adjusted based on the stress relaxation rate, and the increment increases as the stress relaxation rate increases; After the second stage of tensioning is completed, the pores are grouted using an alternating pulse grouting process, whereby high-pressure pulses are first injected to expel air from the pores, followed by low-pressure steady flow to fill and compact the pores. During the grouting process, the slurry flow state is detected by an acoustic sensor pre-buried in the channel. If slurry flow stagnation or bubble signals are detected, secondary high-pressure pulse grouting is triggered until the density reaches the standard.

7. The method for suspended pouring of a cable-stayed bridge using a hanging basket according to claim 1 is characterized in that: The following steps are involved in synchronously monitoring the deviation of the top of the bridge tower and correcting the deviation: Displacement sensors and inclination sensors are symmetrically placed on top of the bridge tower to obtain the lateral displacement, longitudinal displacement, and inclination angle data of the bridge tower in real time. The comprehensive displacement value of the bridge tower is calculated by fusing multi-dimensional displacement feature values. Set multi-level deviation thresholds. When the comprehensive deviation value reaches the first level threshold, the dynamic adjustment strategy of the cable force difference of the single-side inclined cable is automatically triggered, and the cable force difference of the opposite inclined cable is pre-corrected by reducing the deviation direction. When the comprehensive deviation value reaches the second-level threshold, the tensioning operation of all the inclined cables in the current segment is suspended and the deviation correction is started. During the correction, the hydraulic jacking mechanism applies a correction force opposite to the deviation direction to the bridge tower. At the same time, based on the correlation analysis between historical deviation data and real-time cable force values, a new inclined cable tensioning sequence is generated to redistribute the cable force difference on both sides. After the correction is completed, the tensioning operation is resumed, and the displacement-cable force response data during the correction process are input into the adaptive control model to dynamically optimize the deviation threshold range and correction strategy of subsequent segments.

8. The method for suspended pouring of a cable-stayed bridge using a hanging basket according to claim 1 is characterized in that: The step-by-step adjustment of the cable forces to the designed bridge state includes the following steps: The cable force adjustment after the full bridge closure is divided into multiple adjustment cycles, and in each adjustment cycle, at least one pair of symmetrical stay cables is selected in a preset order as the main adjustment cables and the auxiliary adjustment cables; While the main adjusting cables are applying adjustment forces, real-time data on the bridge deck alignment, tower top deflection, and cable force changes in adjacent cable segments of the main adjusting cables are collected. Based on these data, the coordinated adjustment amount of the auxiliary adjusting cables is calculated. The coordinated adjustment amount is a compensation value to suppress local stress concentration caused by the adjustment of the main adjusting cables. After completing a single-cycle adjustment, the cable force distribution of the entire bridge is traversed to identify areas where cable force deviations are concentrated, and the main cables for the next adjustment cycle are preferentially allocated to these areas. The above adjustment cycle is repeated until the cable tension error falls within the preset range. In the final stage, the full-bridge cable tension synchronous fine-tuning mode is adopted, and a balanced adjustment force is applied to all inclined cables through multi-point synchronous tensioning equipment to eliminate residual cable tension deviation.

9. The method for suspended pouring of a cable-stayed bridge using a hanging basket according to claim 8, characterized in that: Calculating the coordinated adjustment amount of the auxiliary cables based on the bridge deck alignment data, tower top offset data, and the cable force variation of adjacent cable segments of the main cables includes the following steps: Displacement sensors are placed at the mid-span and 1 / 4 span positions of the bridge deck to collect real-time bridge deck alignment data, including longitudinal slope deviation and transverse elevation difference; Tilt sensors are symmetrically placed on top of the bridge towers to monitor the tower top deviation angle in real time and calculate the lateral and longitudinal displacements of the tower top based on the tower height. The pressure sensor embedded in the anchor of the adjacent cable segment of the main adjustment cable is used to obtain the cable force change of the adjacent cable segment in real time. The cable force change is the difference between the current cable force value and the reference value before adjustment. Input the bridge deck alignment deviation, tower top displacement, and cable force changes of adjacent cable segments into the preset stress coupling model to calculate the coordinated adjustment of the auxiliary cable adjustment. Applying the coordinated adjustment amount to the auxiliary cable using a synchronous hydraulic jack, and checking the cable force variation of adjacent cable segments in real time during the application process. If the cable force variation still exceeds 2% of the design value, suspending loading and recalculating the coordinated adjustment amount; After completing the coordinated adjustment, maintain the load for 10 minutes, and collect the bridge deck linear data and tower top displacement again. If the linear deviation returns to the preset range and the tower top displacement is less than 3mm, the coordinated adjustment is determined to be effective.

Images