Research On Construction Control And Monitoring Technology Of Concrete Filled Steel Tube Tied Arch Bridge

As an arch bridge system without thrust or thrust,the steel tube concrete tied arch bridge has the advantages of light weight,high strength,light installation weight and self erection system.It can greatly adapt to the span change of bridge and simplify the construction process.For the next bearing type concrete filled steel tubular arch bridge,because of the external static structure,it breaks through the characteristics that the traditional arch bridge has higher requirements for the pier and the foundation and the poor adaptability to the foundation deformation,thus greatly improving the adaptability under the general terrain conditions,but its structural structure,the stress characteristics,the calculation analysis and the construction precision control.The complexity of the other aspects is urgently needed to be studied in depth.Based on the actual project of the Wushan bridge in Zhangjiagang,the main contents and methods of the construction control and monitoring of the concrete filled steel tube tied arch bridge,the monitoring process,the monitoring simulation calculation and the monitoring conclusion are fully discussed.At the same time,Midas Civil finite element model is established to simulate the whole bridge construction process.The following work is done and the corresponding conclusions are drawn.1.The development and existing problems of the concrete filled steel tube tied arch bridge,and the present situation and development trend of the construction monitoring of the concrete filled steel tube tied arch are expounded.2.Based on the actual project Wushan bridge,the Midas Civil finite element model is established and the construction simulation analysis is carried out.The results show that the key of the construction monitoring of the tied arch bridge is the cable force of the hanger and the stress and displacement at the middle and L/4 locations.3.The sensitivity analysis of the four parameters of the bridge,namely,the construction cable force,the concrete bulk weight,the concrete elastic modulus and the temperature,is used to analyze the influence of each parameter on the cable force,displacement and internal force in the bridge stage.The results show that the construction cable force and the concrete bulk density have great influence on the cable force and the beam displacement of the suspension rod,which is important sensitive.The concrete elastic modulus has no influence on the cable force and displacement of the hanger,it is a secondary sensitive parameter,and the temperature load has no influence on the force of the hanger,and the overall temperature rise has great influence on the displacement of the beam and the arch ribs.On the other hand,the temperature gradient of the cross section has a great influence on the stress of the beam.4.According to the results of the actual bridge construction parameters and parameter sensitivity analysis,the important parameters are modified,the whole bridge construction process is monitored on the basis of the calculation model,and the monitoring data and the theoretical calculation data are compared.The results show that the beam and arch rib of the bridge in the process of construction and the bridge of Wushan bridge are controlled.The elevation error of the system points meets the monitoring requirements,and the cable force deviation of the hanger is within the allowable value of the specification.