The Research On Construction Control Of Concretefilled Steel Tubular Tied Arch Bridge

The engineering background of this paper is newly built large bridge.According to the construction monitoring theory and method of CFST arch bridge,combined with the actual situation in the field,establish an effective construction monitoring system.Conduct data collection,analysis and adjustment are carried out on the stress and deformation of the superstructure of large bridge during the construction phase.Ensure that the line beam and arch ribs,internal force and boom tension meet the specifications and design requirements after the bridge is completed.The main contents of this paper are as follows:(1)Summary the general situation and current research status of the concrete-filled steel tube tied arch bridge.Decrease the content of the construction monitoring,research status quo,existing problems,precautions and construction monitoring organization and implementation.(2)Using Midas civil to establish a full-bridge spatial finite original model.Through the operation analysis of large bridge,obtain the theoretical results of each construction stage,including the reaction force of the support,the internal force and displacement of the structure,the pre-camber of the tie beam and arch rib and the tension force of the boom.Provide a theoretical basis for engineering construction and monitoring.(3)Compare and analyze the monitoring data of the key cross-section measuring points of the structure with the calculated values of the finite orginal model,and grasp the changes of stress and displacement of the tie-beam,the arch rib and the boom during the main construction phases.During the construction process and after the completion,make sure the 1-88 meter CFST tied arch bridge of large bridge as follows: the stress and deformation of the arch rib and the tie beam conform to the design requirements,and the tension of the boom coincides with the designed value.(4)Study the influence of friction loss and shrinkage creep on the monitoring results of large bridge.Through the field friction test to get the friction coefficient ?,the value of the pipe deviation coefficient k,anchorage and bell mouth friction loss,which are main factors of Friction loss.Use Midas / civil finite original software to compare and analyze influence of friction loss on the monitoring results in the design and test.Through the establishment of two models that consider the time-dependent characteristics of materials to analyze and compare the influence of shrinkage and creep on the stress and deformation of the tie-beam and the main arch.