Analysis On Construction Control Of Long Span Road-rail Cable-stayed Bridge

Cable-stay bridge is a kind of complex hyperstatic structure with large span and slender proportion.The internal force and linear state of the bridge are closely related to the construction process.In the process of construction,it is necessary to monitor the internal force and line shape of each construction stage to reduce and eliminate the influence of construction error in order to ensure the structure internal force and alignment within the controllable range.In this paper,the construction control analysis of this type of cable-stayed bridge is carried out based on the engineering background of a long span road-rail cable-stayed bridge.The research work and main achievements of this paper are as follows:(1)Summarized he theory of construction control of cable-stayed bridge and the theory of cable force optimization on the basic of reading lots of papers about the construction control of cable-stayed bridges.Learned the method to determine the reasonable cable force of the bridge and the cable force of the construction as well as the scope of application.(2)Comprehend the the general situation of the project in detail and simulate the structural members,loads,boundary conditions properly.Divide the construction stage according to the actual construction sequence and build a three-dimensional model of the cable-stayed bridge.(3)Analyse the model of the bridge and calculate the reasonable cable force under completion state with Unknown load coefficient method based on the influence matrix method.Determine the reasonable bridge state and regard the reasonable bridge state as the target state to optimize the cable force and analyse the model.(4)Determine the cable tension scheme according to the design document and the cable force optimization theory.The tension control of two cable-stayed cables is determined by the positive iteration method and the internal force and line type of the main components of the cable-stayed bridge during the two tensioning process are also analyzed.(5)Compare the results verify the feasibility of the cable tension scheme provided in this paper.