Research On Key Technologies Of Cantilever Construction Control For Curved Continuous Beams

With the construction of expressway and urban traffic network,curved continuous beam have widely used in urban viaducts and interchanges.They can not only reduce the length of the connection lines between bridges and roads,but also greatly adapt to the restrictions of terrain on bridge sites and improve the overall function of road system.However,the alignment and internal force distribution of curved continuous girder bridge are closely related to the construction process.There are many influence factors.It is necessary to analyze the bridge according to different influencing factors in order to better guide the construction of curved bridge.This paper relies on the actual curved bridge,which adopts cantilever pouring construction technology.Its span arrangement is(51+88+51+37 m)and the radius is 1322 m.Under the condition that the section?material?reinforcement of the main girder and the span remain unchanged,the influence of the curve radius on the force and deformation of the bridge is analyzed by changing the curve radius,and the construction control results of the bridge are analyzed.The main contents are as follows:(1)Combining with the literature on curved bridges at home and abroad,this paper discusses the research status and development trends of the theory and construction control of curved bridges at home and abroad.At the same time,it briefly discusses the existing problems of curved bridges and the differences between curved bridges and straight bridges in various aspects.(2)The theoretical analysis and corresponding calculation methods of curved bridges are discussed,including the equilibrium differential equation of curved beams ? plane deformation equation and theoretical internal force of curved beams under prestressing.The mechanical characteristics of curved bridges are studied in depth by combining relevant literature.(3)By changing the center angle of curved bridge,the influence of the change on the stress and deformation of curved bridge is analyzed.The finite element analysis model with radius of 750 m,500 m,400 m and 250 m is established while the span?cross section?material and reinforcement of the bridge remain unchanged.The parameters are compared and analyzed.The influence of the change of the center angle on the stress and deformation of curved bridge is considered.The reasonable radius of cantilever construction is discussed.At the same time,the influence of temperature load on curved bridge is analyzed.Based on this bridge,some suggestions on construction control are put forward after comprehensive correlation analysis.(4)Sensitivity analysis of bridge design parameters to determine the design parameters which have a greater impact on bridge construction structure behavior,At the same time,combined with the sensitivity analysis results of design parameters,It can effectively improve the construction control accuracy of curved bridges and better guide the actual bridge construction.(5)The technical scheme and monitoring results of curved bridge with radius of 1322 m are sorted out and analyzed,including the analysis of linear monitoring results and stress monitoring results.