Bridge cantilever hanging basket construction is the core technology of long-span continuous beam and rigid bridge construction. The hanging basket has been suspended at high altitude for a long time in an operating environment, and can withstand concrete pouring loads, temperature difference deformation, and wind disturbance. It is prone to major hidden dangers such as excessive load, unbalanced front and rear ends, deformation of the main truss, anchoring failure, and tilt and slip. Traditional hanging basket construction relies on manual timing measurements and on-site naked-eye inspections. The monitoring interval is long and the human error is large. It is difficult to capture the structural force mutation in real time. Once the control is out of control, it will cause the hanging basket to overturn, the beam body will crack, and the high-altitude fall and other vicious construction safety accidents.
Smart hanging basket monitoring system, Composed of a smart monitoring pole, a smart monitor, and a cloud-based control platform, to create a set of all-weather digital monitoring solutions for the monitoring needs of hanging basket construction. The stress, inclination, load, displacement, and wind speed data of the hanging basket are collected in real time through various sensor terminals to realize automatic early warning of risks. In the preparatory stage of the project, bridge construction units and safety management personnel often search for hanging basket construction monitoring, hanging basket construction monitoring plan, smart monitoring pole, smart monitor and other content. Combining the search needs of the whole network, this article comprehensively explains the system composition, monitoring content, program design, and on-site landing value, and provides a reference for intelligent safety control of bridge engineering projects.
1. The composition of the smart hanging basket monitoring system: the core configuration of the smart monitoring pole and the smart monitor
Complete set of micro-special
Smart hanging basket monitoring systemIt is divided into three parts: front-end perception hardware, local control terminal, and remote cloud platform. Smart monitoring poles and smart monitors are the core front-end equipment in the field.
- Smart monitoring rod
As the integrated installation carrier of the sensor, the inclination sensor, wind speed sensor, and high-definition camera device are uniformly arranged, and they are firmly installed in the main truss and front and rear fulcrum positions of the hanging basket. The integrated pole structure is convenient for quick assembly on site, and the protection level is adapted to the outdoor high-altitude sun and rain environment, avoiding the messy arrangement of scattered cables, and simplifying the disassembly and assembly of hanging baskets. Transition operation.
- Smart monitor (local acquisition terminal)
That is, the on-site control cabinet centrally receives all sensor signals and calculates the force balance state of the hanging basket in real time. The local screen displays various monitoring values in real time, and the sound and light alarms are triggered immediately when the early warning threshold is reached. At the same time, it has data storage and breakpoint re-transmission functions. When the network is interrupted, the monitoring data is saved locally, and it is automatically synchronized to the cloud after the network is restored.
- Multi-type sensor module
It includes a stress sensor, a displacement sensor, a load sensor, an inclination sensor, and a wind speed sensor to monitor the truss stress, the settlement offset of the hanging basket, the lifting point load, the overall tilt, and the size of the high-altitude wind.
- Remote cloud monitoring platform
All monitoring data is wirelessly transmitted to the cloud platform through 4G/5G. Project managers can view multiple sets of real-time operation data, historical change curves, and alarm records of hanging baskets at any time through computers and mobile phones, and support remote export of monitoring reports.
2. The main monitoring content of the smart hanging basket monitoring system (core indicators of hanging basket construction monitoring)
Complete hanging basket construction monitoring relies on the smart hanging basket monitoring system to realize digital collection, focusing on monitoring the following key indicators, which is also the core basis for the preparation of hanging basket construction monitoring plan.
1. Monitoring of the load balance of the hanging basket
Real-time monitoring of the front and rear lifting points and the load of the bottom basket, comparing the weight of the poured concrete, identifying the working conditions of one-sided overload and uneven load, and preventing the unbalanced force from causing the hanging basket to flip.
2. Truss stress monitoring
Continuously collect the stress changes of the anchoring position of the main stringer and beam of the hanging basket, track the growth trend of the structural force during the pouring and walking stages, and give early warning of the risk of fatigue and stress overrun of the components.
3. Monitoring of displacement and settlement of hanging baskets
High-precision monitoring of the vertical settlement and horizontal offset values of the front end of the hanging basket, synchronous tracking of the linear shape changes of the beam body, to provide accurate data support for the control of the linear shape of the bridge, to ensure that the linear shape of the bridge meets the design standards.
4. Overall inclination attitude monitoring
The inclination sensor is used to capture the tilt angle of the hanging basket in real time. When the hanging basket tilts abnormally, the system will give early warning to prevent the risk of slippage and overturning.
5. Environmental wind speed monitoring
The high-altitude hanging basket is obviously affected by the wind. The system collects the on-site wind speed in real time, and pushes an early warning when the wind speed exceeds the safety limit to remind the site to stop concrete pouring and hanging basket walking operations.
6. Video visual monitoring
It is equipped with a high-definition camera to take real-time pictures of the construction of the hanging basket work surface, remotely view the workers' standardized operations, and assist management personnel in remote inspections.
3. Hanging basket construction monitoring plan｜ Smart hanging basket monitoring system implementation process
A standard floor-to-ceiling hanging basket construction monitoring plan is divided into five major processes: preliminary survey, equipment installation, calibration and commissioning, monitoring of the whole construction process, and project completion archiving.
- Preliminary site survey and site planning
Combining the drawings of the hanging basket and the bridge construction plan, determine the layout points of smart monitoring poles and various sensors, avoid areas prone to collision such as concrete pouring and template disassembly, and plan the direction of the cable.
- On-site installation and layout of equipment
Fix the smart monitoring pole at the preset position of the hanging basket truss, install the stress, displacement, and wind speed sensors in turn, and do a good job of waterproof protection for the wiring; lift the smart monitor and complete the grounding and fixing. The hanging basket is a movable component, and the installation of all equipment needs to take into account the convenience of disassembly and assembly of the hanging basket and the forward transition.
- No-load initial calibration
The initial reference data is collected under the no-load state of the hanging basket, the early warning thresholds at all levels are set, and the sensor calibration is completed; overload and tilt conditions are simulated to test whether the sound and light alarm and cloud push functions of the smart monitor are normal.
- Real-time monitoring of the whole construction process
The concrete pouring stage, the pre-removal stage of the hanging basket, and the whole process of steel bar lashing are maintained by the system for continuous online monitoring. When data abnormalities occur, the system will push early warning information at a hierarchical level, and on-site personnel will take timely measures such as counterweight and suspension of pouring.
- Data summary and archiving of completion data
After the construction of the bridge section is completed, the system automatically generates a full-cycle monitoring report, and all stress, settlement, and load curves are uniformly exported as important technical data for completion acceptance and structural verification.
4. Comparison between traditional manual monitoring and smart hanging basket monitoring system
In the past, most of the construction monitoring of bridge hanging baskets relied on manual levels and stress gauges for regular measurement, and the shortcomings were very prominent. The manual monitoring interval is long, and it is impossible to capture the instantaneous force mutation during concrete pouring; the risk of high-altitude measurement operations is high, and personnel climbing the hanging basket are prone to falling; there are subjective errors in manual readings, and the data is difficult to continuously trace.
After adopting the smart hanging basket monitoring system, it relies on smart monitoring rods and smart monitors to achieve 24-hour uninterrupted automatic collection. The data is updated in seconds, and the whole process is continuously monitored; there is no need for frequent ascents and measurements by personnel to reduce the risk of high-altitude operations; all data is automatically stored and cannot be tampered with, truly reflecting the force state of the hanging basket and the beam body, and simultaneously meeting the information control requirements of owners, supervisors, and quality supervision departments.
5. Deploy the comprehensive application value of the smart hanging basket monitoring system
From the perspective of construction safety, the hanging basket is a temporary load-bearing structure at high altitude, and any imbalance in force can easily cause major accidents. The smart hanging basket monitoring system can grasp the load, deformation, and tilt status of the hanging basket in real time, give early warning of hidden dangers, and put the risk control in the forefront to effectively prevent the overturning of the hanging basket and ensure the safety of construction personnel.
From the perspective of engineering quality, the settlement of the hanging basket and the linear shape of the beam body are continuously monitored. Technical personnel adjust the construction control parameters based on accurate monitoring data to accurately control the linear shape of the bridge to avoid cracks and linear deviations in the beam body that exceed the standard, and improve the quality of bridge construction.
From the perspective of project management, managers can remotely grasp the construction monitoring status of multiple work surface hanging baskets without leaving home, reducing on-site inspection pressure; a complete monitoring ledger is automatically generated, which can easily cope with inspections by supervision and quality supervision stations. The complete system is also an essential information facility for the standardized construction of smart construction sites and bridges.
6. Summary
The smart hanging basket monitoring system relies on hardware such as smart monitoring poles and smart monitors to build a complete digital system of hanging basket construction monitoring, which is an essential safety monitoring method for cantilever construction of long-span bridges. Before the start of the project, a complete hanging basket construction monitoring plan should be prepared, and the sensor layout location should be reasonably planned.
Compared with the traditional manual measurement mode, online automated monitoring has the advantages of strong continuity, accurate data, and lower safety risks. It can not only prevent major safety hazards from overturning the hanging basket in real time, but also accurately control the linear shape of bridge construction, so as to help bridge projects achieve safe production and high-quality construction, and meet the construction standards of modern smart construction sites.
