Research On Optimal Sensor Placement And Condition Assessment Of Health Monitoring System For Large Span Continuous Rigid Frame Bridge

Large bridges, which cost a lot in general, play a huge role for transportationnetwork both in China and abroad, and its importance is obvious. In recent years,continuous rigid frame bridges are more widely used in the country. But with theincreasing of ages in services, there is a growing number of continuous rigid framebridges that have suffered varying degrees of damage and partial destruction, whichseriously affected the normal use and safety. In the current situation，researches onhealth monitoring system of rigid frame bridges are still relatively less. Therefore,health monitoring and condition assessment for the bridge structure through anappropriate way to ensure the safe operation of the bridge structure has become animportant research direction of many scholars. Therefore, bridge health monitoringsystem has a very important practical significance.In the engineering background of Guan Shi he bridge, continuous rigid framebridge health monitoring system is studied and analyzed in this paper, including thefollowing aspects:（1）By using the finite element software, modeling analysis of the bridge isconducted. By static analysis and considering loading conditions, the response of thebridge structure is analyzed, which helps grasp the static characteristics. Meanwhile,modal analysis of the bridge is also conducted and its modal data is obtained,including vibration frequency, mode of vibration and the specific modal data of eachstage, which helps providing foundation for assignment of the sensors.（2）Theories and methods of optimal placement for acceleration transducersare elaborated. By using the improved Effective Independence method, the dynamiccharacteristics monitoring system is established. In view of the results of the finiteelement analysis, the key sections of the main beam are ascertained, which helpsestablishing the stress, temperature and deflection monitoring systems.（3）The present study situation of bridge health assessment is introduced, aswell as its theories and methods are elaborated. On the condition assessment studyof Guan Shi he bridge, the AHP (Analytic Hierarchy Process)is introduced. The main steps of the assessment are given and the AHP model is obtained. At the sametime, the calculation method of several major underlying indexes is given.