Monitoring And Evaluation System Of Long-span Concrete Beam Bridge's Life Performance Ebolution

The concept of structural health monitoring was proposed in foreign countries since the 1980 s at the first time,marking the beginning of people's attention to the operational safety of transportation infrastructure.Subsequently,the health monitoring system was gradually applied to traffic infrastructure such as roads,bridges and tunnels,which played an important role in the evaluation,improvement and supervision of construction quality.This thesis has carried out the research project of “Research on the monitoring and evaluation system of the full-life performance evolution of longspan truss bridges”.Taking the Jinmeng Yellow River Bridge as the research object,combined with the development of bridge health monitoring system,multi-parameter simulative calculation and analysis of sensors,optimal placement of sensors.A series of research contents including program development,on-site commissioning and installation have obtained research results with important application value.Firstly,based on the finite element analysis method,through the analysis of MIDAS2017 simulation software,the stress,temperature gradient,support settlement and dynamic characteristics of Jinmeng Yellow River Bridge are calculated,and the influence of the maximum parameters on the bridge is demonstrated.The monitoring threshold of the bridge.Secondly,according to the parameters of the simulation,five types of sensors for the bridge are selected and determined,and the working principle and data transmission process of various sensors are introduced in detail.Based on the characteristics of Jinmeng Yellow River Bridge,the layout scheme of each sensor is designed,including the six-point layout of the strained section,the inner and outer layout of the lower edge of the box girder with temperature and humidity,the upstream and downstream layout of the static level and the two axes of the accelerometer.Monitor the layout.Finally,this thesis takes STM32 MCU as the main control chip and FPGA as the acquisition chip,that designs the bridge health monitoring system.The system uses the method of “host summary,slave acquisition” to collect the health data of each bridge at a fixed time point;The system is divided into three parts,including the power board,the collected board and the central processing board,and the host system is a single circuit board.The bridge health monitoring system developed has achieved good results in the installation and testing of the actual bridge,and completed the collection of preset data.