Study On Construction Safety Of Steel Arch Bracket For Casting Construction Of Arch Rib In Reinforced Concrete Box Arch Bridge

In order to study the safety of steel arch bracket in reinforced concrete box arch bridge's construction process,based on actual engineering-Sanjiazhai bridge,theoretical analysis,numerical simulation and field test methods were adopted.Main results and conclusions are as follows:(1)According to the structural characteristics of Sanjizhai bridge and actual geographical conditions of Sanjizhai bridge,steel arch structure and temporary structure in the construction of reinforced concrete box arch bridge which were suitable for Sanjiazhai bridge were designed.The steel arch structure and temporary structure was verified by construction.Strength,rigidity and stability of the steel arch structure and the temporary structure can meet construction requirements of reinforced concrete box arch bridge.(2)Pre-compression test and finite element numerical analysis were carried out for the designed steel arch structure.The results of finite element numerical analysis show that strength,rigidity and stability of the steel arch structure under preloading load meet the specification requirements,and the pre-compression test results indicates that stress and deformation of the steel arch structure meet the requirements of specification;(3)For the pouring construction of reinforced concrete box arch bridge,the arching ring sub-section pouring scheme which was suitable for Sanjiazhai Bridge was proposed.Monitoring results show that the pouring construction scheme works well;(4)Linear control method and linear control content of reinforced concrete box arch bridge were studied,construction results show that bridge shape of Sanjiazhai Bridge meets the requirements of design and construction specifications,it has a high precision.Proposed linear control method and linear control content is practical;(5)A method for reviewing the designed arch axis was proposed.The results of review indicate that calculation coordinates and designed coordinates of the right arch box's bottom floor are within 4 mm,calculation coordinates and designed coordinates of the right arch box's top floor are within 9 mm.calculation coordinates and designed coordinates of the left arch box's bottom floor are within 0 mm,calculation coordinates and designed coordinates of the left arch box's bottom floor are within 5 mm.