The Research And Application Of CFST Tied-Arch Bridge Construction Monitoring

The CFST tied-arch bridge has been widely used in modern bridge construction as a relatively new structure.However,along with the increase of bridge span and the improvements of construction technology,there are more and more problems in construction process.Tied-arch bridge is thrust-free acrch bridge,which is externally statically determinated and internally statically indeterminated,its ideal geometry linear and internal force state is not only determined by the desing,but also depends on scientific and feasible construction methods.The key issue in the constructiong of CFST tied-arch bridge is how to set up a feasible construction sequence,how to adjust the elevation of tie beams and arch ribs and the tension forces in hanger rods,to meet the design requirements about the stress state and geometry linear in finished dead state of bridge.However,there are a variety of factors likely to cause the change of stress and linear state of CFST tied-arch bridge,such as tie beam weight,elastic moduli,temperature field,the tension forces of prestressing tendons and hanger rods,the error between the actual value and the theoretical value will cause deviations between the linear and internal force state of bridge structure and the ideal state.To ensure that the appearance linear smoothly and the force state legitimately,the bridge construction process must be monitoring,through the scientific field data collection and effective control means to adjust the above-mentioned factors,ensure that the stress value of bridge is in the allowable range by standard,the linear as close as possible to design expected value.Under the background of a bridge of South North Water Diversion Project in Henan section,this paper researches about the construction monitoring of CFST tied-arch bridge,The main subjects are summarized as follow:(1)Set up the finite element model of CFST tied-arch bridge with design drawing and other related information,adjust the model based on the actual material properties and construction process,to ensure that the model is in line with the actual situation,using this model can simulate the action characteristics and structural behavior in whole construction process.(2)The whole construction process simulation analysis of CFST tied-arch bridge shows that tie beams and arch ribs are in compression state,and the stress values are in the safe range,the results show that the bridge structure security.(3)Based on the results of whole construction process simulation analysis,and combined with the actual situation,formulate CFST tied-arch bridge construction monitoring scheme,use adaptive control method guidance the implementation of the scheme.(4)On a CFST tied-arch bridge whole construction process of implementing monitoring,measure the stress and deformation of the key section of the bridge structure accurately,compared with the theoretical values,put forward effective adjustment measures,ensure the safety during in the bridge construction process,the linear and stress state agrees with the design requirements.