Study On The Whole Process Of Construction Control Of Concrete-filled Steel Tubular Tied Arch Bridge

The concrete-filled steel tubular arch bridge is widely used in bridge engineering in China.Especially,the middle and lower arch bridge buildings are beautiful in shape and are used in urban bridges.The construction process of concrete-filled steel tubular tie-arch arch bridge is complicated,the arch-rib skeleton hoisting,concrete pouring and boom and tie-bar tension stage are going through many system transformation,and the tie rod needs to be subjected to multiple prestressed tension,so it is necessary to Its construction process to carry out all-round monitoring to ensure the safety of bridge construction and achieve the goal into the bridge state.In this paper,a main span of 82 m under the concrete-filled steel pipe tied arch bridge engineering background,the main construction phase of the bridge to carry out the whole process of construction control,the main research includes the following three aspects.(1)According to the structural characteristics of the concrete-filled steel tubular tandem arch bridge,the overall construction monitoring scheme is put forward,and each pole is evenly arranged with seven displacement measuring points.Fifteen arch ribs are set at all the hanging points on each rib The control points of the bridge,to achieve a full bridge main line monitoring;each tie rod 5 control sections are arranged 14 stress measurement points,each ribs 5 control sections are arranged 10 stress measurement points,8 pairs of temporary boom are installed Stress sensors,cross-long boom in the beam and short boom at the beam in the layout of the two stress points to achieve the main bridge of the main structural stress monitoring.(2)Based on the construction process of the concrete-filled steel tubular tie-arch bridge,the construction stage of the concrete building is divided into 12 construction stages,and the finite element analysis model of MIDAS is established in stages.The finite element analysis and field measurement are used to track and analyze the whole process.The main structural parameters of the construction process site test are used to modify the finite element modeling and improve the theoretical calculation accuracy.The modified finite element modeling and analysis results also guide the construction process monitoring.(3)The three key processes,such as the arching of the arch ribs,the construction of the pole concrete,the lifting of the boom and so on,are carried out.The monitoring results show that the structural stress conforms to the design requirements.The arch ribs and arch foot displacements meet the specifications.The results of field measurement and the finite element simulation theory are in good agreement with each other,which indicates that the bridge construction process is reasonable and the monitoring scheme is effective.The bridge construction control work to ensure that the lifting,arch rib construction,tie beam casting,tie tension,boom tension to meet the design and related specifications,the whole process of construction safety,construction phase and bridge state internal force and linear meet the design requirements,to achieve a bridge design goal status.