Study On The Arch Rib Integral Hoisting Construction Control Of Long-span Stell Box Arch Bridge

In recent years,the long-span steel box arch bridge has developed rapidly in our country,which has created many firsts in China and even the world.At the same time,the advanced construction methods have been constantly applied to the long-span steel box arch bridge,but more and more problems have arisen in the construction process.Therefore,in order to ensure the construction quality and safety of the bridge,it is necessary to strengthen the construction control of the construction process.Therefore,the study of construction control is of great practical significance.By studying the overall hoisting construction technology and construction control theory of steel box arch bridge,this paper guides the construction of a large-span steel box arch bridge.The main research contents include the following aspects:(1)Taking a long-span steel box arch bridge as the actual engineering background,the construction control system is established and the structure status is monitored in real time;The finite element simulation analysis model is established to analyze the structure state at the critical stage of the construction process and verify that the structure state meets the requirements of the code and construction.(2)The sensitivity analysis of structural influence parameters proves that the main influence parameters of structural deformation are dead weight and temperature load,and the main influence parameters of structural stress are dead weight,temperature load and wind load;Then,according to the results of sensitivity analysis,the original data are denoised by using Kalman filtering method.Finally,an optimized discrete grey theory(DGM(1,1))prediction model is established based on the results of noise reduction processing,and the predicted results are compared with the measured data.The results show that the maximum error percentage of Kalman filtering method decreases from 9.5%to 4.8%after parameter identification,indicating that this method can effectively reduce noise interference.Compared with the traditional DGM(1,1)model and the Kalman-DGM(1,1)model,the optimized Kalman-DGM(1,1)model has the smallest deviation of-0.176mm from the measured data,indicating that the optimized Kalman-DGM(1,1)model is more accurate.(3)In view of the key technologies of construction control of long-span steel box arch bridge,the equivalent theory,linear fitting and simulation analysis are applied to study and analyze the key technologies of constraint displacement,horizontal constraint cable force and overall lifting dissynchronization,and the ideas and methods to solve the above problems are given.In addition,based on the influence matrix optimization method of cable force the normalization principle,it is improved by considering the influence of temperature effect,and finally a more accurate calculation method of sling length is proposed based on cable force optimization.In conclusion,the established optimized Kalman-DGM(1,1)prediction model can guide the engineering practice well,and the structure state meets the requirements.Research on key technologies can effectively solve the main problems encountered in construction control,and the construction effect achieved by application to engineering practice is good as well.