Research On The Integration Of Construction Monitoring And Health Monitoring Of CFST Arch Bridges

As one of the current research hotspots in the field of civil engineering,whole life monitoring can realize the safety guarantee of the entire life cycle of the bridge structure.At present,there is no real life-life monitoring system.Most of the bridge construction monitoring,completion acceptance and health monitoring are handled by three different units,and there is no overlap between them.As a result,the three-stage monitoring systems are not well integrated.In a fragmented state.How to effectively connect the monitoring points and monitoring data at different stages of the bridge is the research focus of the whole life monitoring model.This article takes the G320 line Huayudong Bridge as the background,through studying the monitoring parameters of construction monitoring,completion acceptance and health monitoring,starting from the two routes of the monitored hardware and software information,to build the integrated monitoring mode of the Huayudong Bridge,and then Use this mode to evaluate the safety of the bridge,to carry out early warning classification and the setting of early warning threshold.This article first analyzes the main monitoring parameters and contents of the main components such as the arch ribs,main beams,suspenders,and arches of the Huayudong Bridge during the construction period-the operation period,including linearity,displacement,stress,and cable force,combined with the structural characteristics,force characteristics and on-site operation feasibility of the concrete-filled steel tube arch bridge to select the position of monitoring;In terms of sensor selection,the sensor at the monitoring point is selected according to whether the sensor’s technical parameters meet the accuracy requirements,equipment sustainability and economy.The three-stage integrated monitoring is finally summarized and reflected in health monitoring.It is necessary to study the sensor subsystem,data acquisition and transmission system,and field cable layout and connection trend of health monitoring,so as to open up and build on the hardware based on the whole life.The cyclically designed Huayudong Bridge integrated monitoring system will be finally displayed and applied on the intelligent platform.Secondly,building a finite element model of the Midas Civil Huayudong Bridge during the construction phase,and use the measured data information of construction monitoring to correct the static parameters of the finite element model during the construction phase.According to the specifications and actual engineering experience,the elastic modulus of steel tube arch rib E₁,the bulk density of steel tube arch ribγ₁,the elastic modulus of concrete E₂and the concrete bulk densityγ₂are initially selected as the parameters to be corrected.after sensitivity analysis,three parameters of elastic modulus E1 of steel tube arch ribs,bulk density of steel tube arch ribsγ₁ and concrete bulk densityγ₂ are selected as the parameters to be corrected;After establishing the objective optimization function for displacement correction,16 test combinations were designed using the uniform design method with high test efficiency.After 16 test calculations,the parameters to be corrected in the construction phase finite element model were corrected for the first time;Based on the basis and data of the first revision,use the response surface principle to construct the response surface equation of the objective function,after Matlab’s 500,000-degree equation calculation,the value of the parameter to be corrected corresponding to the optimal solution of the objective function is finally obtained,The corresponding finite element model of the Huayudong Bridge under this static parameter is closer to the actual state of the bridge,thus realizing the continuation of the software information of the Huayudong Bridge integrated monitoring system.After the initial construction of the Huayudong Bridge integrated monitoring system based on the dual continuation of hardware and software information,the load test calculation was carried out using the revised finite element model.After the load test is completed on site,the theoretical design value of the initial model,the theoretical calculation value after the model modification and the actual measurement value are compared and analyzed to verify the correction effect.Calculate the bearing capacity of the arch ribs and suspenders of the Huayudong Bridge under three different bearing capacity ultimate load combinations,and calculate the ultimate bearing capacity index of each member,and compare and analyze the calculation results with the initial finite element model.In terms of the early warning setting of the bridge structure,the Huayudong Bridge warning classification is established according to the serviceability limit state criterion,the bearing capacity limit state criterion and the specification requirements,Four load combinations are considered in the serviceability limit state,Three load combinations are considered in the ultimate state of bearing capacity,according to the corresponding calculation results,the most unfavorable value is selected as the warning value of arch ribs,booms and beams.