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Bridge maintenance and management methods should consider various stages of design, construction and maintenance management. Therefore, during the entire life cycle of bridge, the appropriate number of inspections, repairs and reinforcements are the main factors affecting the optimization of bridge costs. As for the evaluation method, domestic steel arch bridges and other special types of bridges mostly use D.E.R.U visual inspection methods for bridge inspection and maintenance. However, domestic special types of bridges such as Lizejian Bridge and Liwu Bridge are mainly supported by steel box girder and steel cables. The internal condition of the box girder, the condition of the anchor end of the steel cable, and the cable force are particularly important. Therefore, it is important to analyze the bridge cable force and its long-term structural change trend through the bridge automatic monitoring system to ensure the safety of the bridge and maximize the benefits. It’s really an important subject at this moment.
To this end, this research aims at the construction of a steel cable monitoring system for the Lizejian Bridge on the 7th Line and the Liwu Bridge on the 9th Line. The main contents include the analysis of the bridge structure, the visual inspection results of the anchor ends, the results of IBIS(Image By Interferometric Survey) scanning, and According to the relevant inspection results, the monitoring configuration is proposed, and the bridge structure vibration monitoring operation is carried out for the two bridges, and the natural frequency and vibration characteristics of the bridge are obtained.
The main content includes analyzing the bridge structure, measuring the cable strength, planning and setting up monitoring instruments such as accelerometers, thermometers, and discussing the trend of cable force and frequency changes, and then assessing the structural safety of the bridge and reducing the probability of future bridge hazards. . In addition, this research uses long-range microwave radar scanning and micro-variable sensing radar scanning to perform cable displacement analysis to calibrate the numerical model of structural analysis to compare information such as cable monitoring results, cable strength measurement results, etc. This research adds the main girder acceleration gauge evaluates the vibration frequency of the main structure of the bridge, so as to fully grasp the structural safety of Lizejian Bridge and Liwu Bridge.
The monitoring results data show that the bridge's numerical model can be established based on the structure size and material parameters recorded in the original as-built drawing of the bridge, and then through modal analysis and monitoring data analysis, the main monitoring frequency of the bridge can be effectively compared. In this way, the change of the sling cable force can be calculated in real time from the monitoring data. Finally, through the real-time bridge safety monitoring system, personal computers or smart phones, etc., remotely log in to the monitoring platform to obtain real-time bridge conditions before, during and after typhoons and heavy rain events, providing bridge management units with a basis for assessing bridge safety, which is effective Improve management efficiency and safety of inspection and survey operations to ensure the safety of passersby is the ultimate goal.
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