Study On Optimal Layout Of Sensors In Life Cycle Of Continuous Rigid Frame Bridge

The concept of full life and health monitoring has been gradually popular.Large span bridge structures require construction monitoring,bridge load test and health monitoring.But in reality,for various reasons,these three parts are often run independently of each other,which leads to the waste of the sensor hardware and the continuity and integrity of the monitoring data being destroyed.In view of the continuous rigid frame bridge,this paper studies its whole life monitoring mode of the construction technology of the sensor measurement points and the various stages of the sensor can work together,to avoid waste.First,aiming at the problem of monitoring information incomplete and poor continuity,the author puts forward the concept of whole life model correction,to amend the model throughout the stages of bridge detection:the test data of the construction monitoring and the test data of the field material test block can be used for the model correction.The bridge load test is an ideal test to confirm the finite element model of the initial state of the bridge.The full life model correction can provide a finite element model that can reflect the true state of the bridge structure for the construction of the sensor.Secondly,in period of the bridge construction the sensor is mainly strain sensor.In order to make the strain sensor from the construction and operation of the bridge being a perfect combination,in this paper,several improvements are put forward for the optimization of the strain sensor of continuous rigid frame bridge.Firstly,in order to make the model reflect the spatial distribution of strain,the shell element model is proposed to replace the traditional beam element.Second,in this paper,the strain modal assurance criterion(SMAC)is used as the optimization criterion of strain sensor.Third,in order to make the sensor from the construction period and the operation period can work together,the auther puts forward the concept of matching fitness in the genetic algorithm,and uses the matching fitness as the optimization degree of the two stages.Fourth,the optimal placement of sensor shell element model,in order to make the measuring points for organization and management,using the method of beam element measurement points,method of key sections of sensor layout is proposed for the shell element model.At last,based on the bridge project,the improved genetic algorithm is used to accomplish the optimal layout of the measuring points.