Study On Construction Control Of Concrete-filled Steel Tube Tied Arch Bridge Based On BIM

Concrete-filled steel tube(CFST)cable-tied arch bridge is a composite system of beams and arches,which has the advantages of light weight,reasonable stress,strong adaptability and beautiful shape,and has been widely used in engineering.Its construction process is complex,the accurate control of the construction process becomes the key to improve the construction quality,efficiency and safety.With the gradual maturity of Building Information Modelling(BIM),its application scope in the field of bridge engineering continues to expand,and BIM-based construction control has become the focus of current research.Based on the engineering background of Wujindu arch bridge,this paper studies the construction control of BIM based concrete-filled steel tube tied arch bridge.Firstly,a set of information classification and coding system of highway bridge components is studied and developed.On this basis,through parametric modeling,the core component family library including longitudinal beams,arch ribbed steel pipes and wind bracing components was established.The whole bridge BIM model was formed according to the spatial location,and 11 drawing errors were found through design checking.Through parametric modeling of detailed components,an elaborate local BIM model of arch foot was established,and 18 collision problems related to prestressed tendons were found through collision inspection.Through the compilation of Dynamo visual programming,information integration of BIM model was completed,which improved the efficiency of BIM model associated with subsidiary information.Secondly,the BIM-based finite element analysis data conversion method for the whole bridge was studied.Based on Dynamo and Python programming,the MCT command flow conversion of node,element and section of the full bridge BIM model was realized,and the Midas Civil finite element analysis model was generated.The analysis results show that the arch foot is the most unfavorable position of arch rib and tie beam,which should be controlled in the construction process.Through parameter sensitivity analysis in each construction stage,the main control parameters and secondary control parameters of arch rib alignment and steel pipe stress in each construction stage are determined,so as to provide data support for construction control and determine the main control objectives.Thirdly,the data conversion method of local finite element analysis of arch foot based on BIM was studied.The division and transformation of geometric model of arch foot was realized based on Dynamo and Python programming,and the detailed analysis model of Midas FEA was generated.According to the stress analysis of arch foot under the most unfavorable load conditions,it can be seen that most of the areas meet the design requirements,and a small part of the areas have the phenomenon of stress concentration,such as the junction between steel tube above and below the arch rib and concrete arch foot,which must be paid attention to in the construction process.Based on the advantages of BIM parametric modeling,the influence of bearing plate and stiffener on the stress result of arch foot was explored.According to the analysis results,bearing plate and stiffener can significantly reduce the maximum stress of arch rib steel pipe and effectively relieve the stress concentration in the arch foot area.Finally,the classification and coding system of construction monitoring and measuring locations were studied and developed,and a BIM model of construction monitoring and measuring locations was established.Based on Dynamo,a monitoring and measuring location data management system was developed,including three modules of measuring location data management,data analysis and visual warning.Based on the calculation results of Midas Civil and the measured data during construction,the efficient unified management and analysis of data were realized.Aiming at the variation of construction parameters caused by the delay of construction schedule during the epidemic,the real-time feedback correction of actual construction structural parameters and Midas Civil model was realized by programming based on Dynamo and Python,,which improved the accuracy of construction control.