Bridge hanging basket pre-pressing construction method

Abstract

The invention relates to the technical field of bridge construction, in particular to a bridge hanging basket pre-pressing construction method which comprises a construction process and an intelligent monitoring system. The intelligent monitoring system is combined with pre-pressing construction for construction; the construction process comprises the following steps that 1, a pre-pressing model is constructed; step 2, graded loading control is carried out, and four-stage loading is carried out; step 3, deformation cooperative monitoring; 4, intelligent early warning and adjustment are carried out; 5, data visualization feedback is carried out; the counterweight device is modularized; the innovation point is that the modularized counterweight units which can be magnetically connected are adopted, compared with a traditional stacking mode, the installation efficiency is improved by three times, and according to actual measurement data, the installation time of a single module is shorter than or equal to 90 s; meanwhile, it is confirmed that the connection mode is not applied in advance in the pre-pressing field through patent retrieval; according to the scheme, the intelligent monitoring method is embodied in a distributed optical fiber and three-dimensional scanning cooperative monitoring mechanism, and the defect that space deformation cannot be captured through traditional single-point monitoring is overcome.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bridge construction, in particular to a bridge hanging basket preloading construction method. BACKGROUND

[0002] The traditional hanging basket preloading method has three technical pain points:

[0003] 1. The preloading method uses sandbags / water tanks for counterweight, which has problems such as low material transportation efficiency (transportation loss rate of 15%-20%), insufficient counterweight accuracy (error>5%) and the like;

[0004] 2. The hydraulic jack counter pressure method shortens the construction period, but is limited by the rigidity requirement of the counterforce frame, resulting in limited single loading amount (maximum loading amount≤80% of the design load);

[0005] 3. The existing monitoring system uses a single point displacement sensor, which cannot obtain real-time three-dimensional deformation data, resulting in a lag in preloading effect evaluation.

[0006] Therefore, in view of the above problems, the present method solves the problems in a targeted manner:

[0007] (1) Precise dynamic control of preloading load;

[0008] (2) Real-time monitoring of three-dimensional spatial deformation;

[0009] (3) Low reuse rate of preloading device.

[0010] Through the linkage of modular counterweight units and BIM models, the construction efficiency is improved by more than 40%, and the material loss is reduced to less than 5%. SUMMARY

[0011] The technical problems solved are:

[0012] In view of the deficiencies of the prior art, the present application provides a bridge hanging basket preloading construction method, thereby solving the technical problems mentioned in the background art.

[0013] To achieve the above purpose, the present application is realized by the following technical scheme:

[0014] A bridge hanging basket preloading construction method, comprising a construction process and an intelligent monitoring system; the construction is combined with the preloading construction through the intelligent monitoring system;

[0015] Among them, the construction process is as follows:

[0016] Step one: preloading model construction, load distribution cloud map is generated based on BIM model; the installation area of the counterweight module is divided;

[0017] Step two: hierarchical loading control, four levels of loading; each level of load time dynamic adjustment;

[0018] Step three: deformation coordination monitoring, distributed optical fiber monitoring main truss strain distribution; three-dimensional laser scanning to obtain the overall deformation of the hanging basket;

[0019] Step four: intelligent early warning and adjustment, set double threshold alarm mechanism; first level warning trigger loading pause; second level warning start automatic unloading program;

[0020] Step five: data visualization feedback, generate preloading evaluation report; automatically correct subsequent construction parameters.

[0021] In one possible implementation, the four-level loading is divided into four levels, namely 30%, 60%, 90% and 105% design load.

[0022] In one possible implementation, the intelligent monitoring system includes a modularized counterweight device and an intelligent monitoring unit; the modularized counterweight device includes a standardized steel counterweight box, a magnetic connection mechanism and a built-in pressure sensor.

[0023] In one possible implementation, as one possible implementation, the modularized counterweight device requires the following:

[0024] The standardized steel counterweight box can have a size of 1.2m×1.0m×0.8m, and the single weight is selected to be 1.5t±2%;

[0025] The magnetic connection mechanism has a contact surface magnetic field strength of ≥0.5T;

[0026] The built-in pressure sensor has a range of 0-20t and an accuracy of 0.5%FS.

[0027] In one possible implementation, the intelligent monitoring unit includes a distributed optical fiber sensor, a three-dimensional laser scanner and a data processing terminal.

[0028] The intelligent monitoring unit requires the following:

[0029] The distributed optical fiber sensor is arranged along the main truss axis of the hanging basket with a spacing of ≤50cm;

[0030] The three-dimensional laser scanner has a scanning frequency of ≥10Hz and an accuracy of ±0.1mm;

[0031] The data processing terminal integrates a finite element real-time comparison algorithm.

[0032] In one possible implementation, the modularized counterweight device architecture includes device system composition, system topology, magnetic quick connection structure and counterweight distribution optimization algorithm.

[0033] In one possible implementation, the construction process of the modular counterweight device architecture includes pre-loading preparation, staged loading, dynamic adjustment and unloading recovery.

[0034] In one possible implementation, the intelligent detection system architecture includes system components, which include data acquisition layer, data transmission layer, data processing layer and decision control layer.

[0035] And core hardware, which includes distributed fiber optic sensors, 3D laser scanners and edge computing terminals.

[0036] In one possible implementation, the monitoring method of the intelligent detection system includes:

[0037] Collaborative perception of inter-deformation

[0038] A fusion solution of optical fiber strain field reconstruction algorithm and 3D point cloud registration technology: including optical fiber strain field reconstruction; laser point cloud registration and multi-source data fusion;

[0039] Dynamic load feedback mechanism

[0040] The control logic establishes a load-deformation dual closed-loop control system: including an inner loop: real-time adjustment of the magnetic attraction of the counterweight module through a pressure sensor;

[0041] Outer loop: Predicting structural stability based on deformation rate.

[0042] In one possible implementation,

[0043] Beneficial effects:

[0044] 1. This solution features a modular counterweight system. Its innovation lies in its modular counterweight units that can be connected magnetically. Compared to traditional stacking methods, this system increases installation efficiency by three times. Actual installation time for a single module is ≤ 90 seconds. Furthermore, a patent search confirmed that this connection method has no prior applications in the preloading field.

[0045] 2. This solution utilizes an intelligent monitoring method that utilizes a coordinated monitoring mechanism of distributed optical fiber and 3D scanning, addressing the limitation of traditional single-point monitoring that cannot capture spatial deformation.

[0046] 3. In this solution, the load dynamic control algorithm adopts an adaptive PID control model, and the transfer function has been verified by field tests to increase the convergence speed by 40%. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention with reference to the accompanying drawings.

[0048] Figure 1 A construction flowchart of the present application;

[0049] Figure 2 A smart monitoring system diagram of the present application;

[0050] Figure 3 A system topology of the present application. DETAILED DESCRIPTION

[0051] The preferred embodiments of the present application will be described in detail with reference to the accompanying drawings. However, the present application can be realized in various different forms and therefore the present application is not limited to the embodiments described below, and in addition, components not connected to the invention will be omitted from the drawings in order to more clearly describe the present application;

[0052] The technical solutions in the embodiments of the present application are to solve the problems in the above background art, and the general idea is as follows:

[0053] Embodiment One:

[0054] Please refer to Figure 1 The present embodiment introduces a bridge hanging basket preloading construction method, including a construction flowchart and a smart monitoring system. The combination of the smart monitoring system and the preloading construction improves the process management;

[0055] Among them, the construction flowchart is as follows:

[0056] Step One: Preloading Model Construction

[0057] 1. Load distribution cloud diagram based on BIM model;

[0058] Technical requirements: load gradient difference ≤ 5%;

[0059] 2. Partition load module installation area

[0060] Technical requirements: partition size error ≤ 3 cm.

[0061] Step Two: Graded Loading Control

[0062] 1. Four-stage loading

[0063] Loading is divided into four levels, which are 30%, 60%, 90%, and 105% design load;

[0064] 2. Dynamic adjustment of holding time at each level

[0065] According to the strain rate Δε / Δt ≤ 0.01% / min to determine the stable state;

[0066] Step Three: Deformation Coordination Monitoring

[0067] 1. Distributed optical fiber monitoring main truss strain distribution

[0068] Sampling interval ≤ 1s;

[0069] 2. Three-dimensional laser scanning obtains the overall deformation of the hanging basket

[0070] Generate a three-dimensional point cloud contrast model;

[0071] Step four: intelligent early warning and adjustment

[0072] 1. Set a double-threshold alarm mechanism;

[0073] 2. First-level warning (deformation > 10% of theoretical value) triggers load pause;

[0074] 3. Second-level warning (deformation > 15% of theoretical value) starts the automatic unloading program;

[0075] Step five: data visualization feedback

[0076] 1. Generate a preloading evaluation report

[0077] The report mainly includes 12 key indicators such as load-displacement curve, stress cloud map, etc.

[0078] 2. Automatically correct subsequent construction parameters

[0079] Elastic modulus adjustment coefficient K = measured value / theoretical value.

[0080] Example two:

[0081] This example is an improvement based on example one:

[0082] Please refer to Figure 2 The intelligent monitoring system includes a modular counterweight device and an intelligent monitoring unit.

[0083] The modular counterweight device includes a standardized steel counterweight box, a magnetic connection mechanism, and a built-in pressure sensor.

[0084] As an implementable way, the technical requirements of the modular counterweight device are as follows:

[0085] 1. Standardized steel counterweight box, size can be 1.2m x 1.0m x 0.8m, single weight selection 1.5t ± 2%;

[0086] 2. Magnetic connection mechanism, contact surface magnetic field strength ≥ 0.5T;

[0087] 3. Built-in pressure sensor, range 0-20t, accuracy 0.5% FS;

[0088] The intelligent monitoring unit includes a distributed optical fiber sensor, a three-dimensional laser scanner, and a data processing terminal. As an implementable way, the technical requirements of the intelligent monitoring unit are as follows:

[0089] 1. Distributed optical fiber sensor, arranged along the main truss axis of the hanging basket, with a spacing of ≤50 cm;

[0090] 2. Three-dimensional laser scanner, with a scanning frequency of ≥10 Hz and an accuracy of ±0.1 mm;

[0091] 3. Data processing terminal, integrated with a real-time finite element comparison algorithm.

[0092] Example Three:

[0093] This example is an improvement based on Example One:

[0094] Taking a certain continuous beam bridge with a main span of 150 m as an example:

[0095] Step One: Load Calculation:

[0096] 1. Design load F = construction load (120 t) + formwork weight (80 t) = 200 t;

[0097] 2. Overload preloading value is 105% F = 210 t;

[0098] Step Two: Counterweight Module Arrangement:

[0099] 1. Single-sided hanging basket uses 140 standard modules (140 x 1.5 t = 210 t);

[0100] 2. Installation time: 140 x 1.5 min = 210 min, traditional method requires 6-8 hours;

[0101] Step Three: Monitoring Data Comparison:

[0102] Monitoring items Traditional method error Traditional method error Load application accuracy ±5％ ±1.2％ Displacement monitoring ±2mm ±0.3mm

[0103] Example Four:

[0104] This example is an improvement based on Example Two:

[0105] I. Modular Counterweight Device Technical Architecture Includes:

[0106] 1. Device System Composition and Core Parameters

[0107]

[0108] 2. System Topology Structure (Reference Figure 3 )

[0109] 3. Magnetic Attraction Type Quick Connection Structure

[0110] Contains the main adsorption layer (generate basic adsorption force) and compensation layer (eliminate the uneven contact surface resulting in magnetic force loss) and safety locking mechanism, power off mechanical lock automatic trigger;

[0111] Control logic: python

[0112] Magnetic force dynamic adjustment algorithm code:

[0113] def adjust_magnetic_force(current_load,target_load):

[0114] error=target_load-current_load

[0115] pid_output=PID_controller(error)#PID parameters Kp=1.2, Ki=0.1, Kd=0.05

[0116] set_voltage(24V*pid_output)

[0117] if safety_lock_engaged():

[0118] emergency_release()

[0119] 4. Counterweight distribution optimization algorithm

[0120] Load matching model: based on BIM model to generate three-dimensional load distribution thermal map, through the greedy algorithm to realize the optimal module layout:

[0121]

[0122] Load distribution uniformity is improved to more than 95%, while traditional method is only 70%-80%.

[0123] II. Construction process

[0124] 1. Modular counterweight construction steps

[0125]

[0126]

[0127] 2. Compared with traditional method

[0128] Comparison items Sandbag loading method Hydraulic counterforce method This modular system Single construction period 72 hours 48 hours 36 hours (50% reduction) Material loss rate 15%-20% (sandbag breakage) 8%-10% (hydraulic oil leakage) ≤3% (only mechanical wear) Positioning accuracy ±10cm ±5cm ±1cm (laser guidance) Environmental impact Dust pollution Oil pollution risk Zero pollution (clean construction)

[0129] Example: take a cable-stayed bridge project as an example;

[0130] 1. Engineering parameters

[0131] (1) Hanging basket span: 32 m;

[0132] (2) Design pre-compression load: 180 t;

[0133] (3) Overload requirement: 110% (198 t);

[0134] 2. Modular weight implementation

[0135] (1) Number of modules: 132 (132 x 1.5 t = 198 t);

[0136] (2) Installation time:

[0137] Construction stage Traditional method This system Ground assembly 6 hours 2 hours ** (pre-assembly of 32 groups) Hoisting and positioning 8 hours 3.5 hours ** (including positioning calibration)

[0138] 3. Quantity acceptance data

[0139] (1) Load application error: +1.3% (design value 198 t, actual value 200.6 t);

[0140] (2) Maximum deflection of main truss: 22.1 mm (theoretical value 21.8 mm, deviation +1.4%); (3) Module recovery rate: 99.2% (131 / 132 modules intact).

[0141] Example Five:

[0142] This example is based on the improvement of Example Two:

[0143] I. The technical architecture of the intelligent detection system includes the following:

[0144] 1. System composition

[0145]

[0146] 2. Core hardware technical indicators

[0147]

[0148] II. Monitoring method

[0149] 1. Spatial deformation cooperative sensing

[0150] Fusion scheme of light fiber strain field reconstruction algorithm and three-dimensional point cloud registration technology:

[0151] (1): Fiber strain field reconstruction;

[0152] (2): Laser point cloud registration;

[0153] (3): Multi-source data fusion;

[0154] Realize millimeter-level three-dimensional deformation monitoring (actual measurement error ≤0.3mm), improve the measurement accuracy of traditional total station by 80%.

[0155] 2. Dynamic load feedback mechanism

[0156] The control logic establishes a load-deformation double closed-loop control system:

[0157] (1) Inner loop: real-time adjustment of the magnetic attraction force of the counterweight module through the pressure sensor (response time ≤50ms);

[0158] (2) Outer loop: predict the stability of the structure based on the deformation rate (prediction model R 2 ≥0.95).

[0159] III. Differences compared with existing technology

[0160]

[0161]

[0162] IV. Specific implementation case:

[0163] A certain cross-sea bridge main span 220m continuous beam construction, hanging basket self weight 85t, design preloading 120t.

[0164] Implementation process:

[0165] 1. Sensor layout

[0166] (1) Along the main truss of the hanging basket, arrange 4 optical fiber sensing lines (total length 320m);

[0167] (2) Install 16 pressure sensing units at key nodes (node position error ≤5mm).

[0168] 2. Reference data collection

[0169] (1) Perform 3 total station calibrations under no-load condition (error compensation value is written into the system database).

[0170] 3. Dynamic monitoring implementation

[0171]

[0172] 4. Data analysis output

[0173] (1) Generate three-dimensional deformation cloud map and theoretical model comparison report;

[0174] (2) Output structure stiffness correction coefficient K=0.97 (original design value 1.0).

[0175] It should be noted that the above-mentioned embodiments are merely used to clearly illustrate the technical solutions of the present application, and should not be construed as limitations to the present application. Based on the above-mentioned embodiments, those skilled in the art can make other variations or modifications without departing from the spirit of the present application. The present application is not required to enumerate all of the embodiments, and the variations or modifications made without departing from the spirit of the present application should fall within the scope of the present application.

Claims

1. A bridge hanging basket preloading construction method, characterized in that: Including construction process and intelligent monitoring system; construction is combined with intelligent monitoring system and preloading construction; The construction process is as follows: Step 1: Build the preloading model and generate a load distribution cloud map based on the BIM model; divide the installation area of ​​the weight distribution module; Step 2: Gradual loading control, divided into four levels of loading; dynamic adjustment of the holding time of each level; Step 3: Collaborative deformation monitoring: distributed optical fiber monitoring of the main truss strain distribution; 3D laser scanning to obtain the overall deformation of the hanging basket; Step 4: Intelligent early warning and adjustment, set up a dual-threshold alarm mechanism; the first-level warning triggers the loading pause; the second-level warning starts the automatic uninstallation program; Step 5: Visualize data feedback and generate a preloading assessment report; automatically correct subsequent construction parameters.

2. A bridge hanging basket preloading construction method according to claim 1, characterized in that: The four-level loading is performed at four levels, namely 30%, 60%, 90% and 105% of the design load.

3. A bridge hanging basket preloading construction method according to claim 2, characterized in that: The intelligent monitoring system includes a modular counterweight device and an intelligent monitoring unit; the modular counterweight device includes a standardized steel counterweight box, a magnetic connection mechanism and a built-in pressure sensor.

4. A bridge hanging basket preloading construction method according to claim 3, characterized in that: As an implementable method, the modular counterweight device requires the following: Standardized steel counterweight box, the size can be 1.2m×1.0m×0.8m, the single unit weight is 1.5t±2%; Magnetic connection mechanism, contact surface magnetic field strength ≥0.5T; Built-in pressure sensor, measuring range 0-20t, accuracy 0.5% FS.

5. The bridge hanging basket preloading construction method according to claim 3, characterized in that: The intelligent monitoring unit includes a distributed optical fiber sensor, a three-dimensional laser scanner and a data processing terminal; The requirements for the intelligent monitoring unit are as follows: Distributed fiber optic sensors are arranged along the axis of the main truss of the hanging basket with a spacing of ≤50cm; 3D laser scanner, scanning frequency ≥10Hz, accuracy ±0.1mm; Data processing terminal, integrated finite element real-time comparison algorithm.

6. The bridge hanging basket preloading construction method according to claim 3, characterized in that: The modular counterweight device architecture includes device system composition, system topology, magnetic quick connection structure, and counterweight distribution optimization algorithm.

7. The bridge hanging basket preloading construction method according to claim 6, characterized in that: The construction process of the modular counterweight device architecture includes pre-loading preparation, staged loading, dynamic adjustment and unloading recovery.

8. The bridge hanging basket preloading construction method according to claim 3, characterized in that: The intelligent detection system architecture includes system components, which include data acquisition layer, data transmission layer, data processing layer and decision control layer. And core hardware, which includes distributed fiber optic sensors, 3D laser scanners and edge computing terminals.

9. The bridge hanging basket preloading construction method according to claim 8, characterized in that: The monitoring method of the intelligent detection system includes: Collaborative perception of inter-deformation A fusion solution of optical fiber strain field reconstruction algorithm and 3D point cloud registration technology: including optical fiber strain field reconstruction; laser point cloud registration and multi-source data fusion; Dynamic load feedback mechanism The control logic establishes a load-deformation dual closed-loop control system: including an inner loop: real-time adjustment of the magnetic attraction of the counterweight module through a pressure sensor; Outer loop: Predicting structural stability based on deformation rate.

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