Optimization Of Cable Force And Construction Control Of Extroversive And Unsymmetrical Steel Arch Bridge

With the rapidly and desirably development of arch bridge construction and aesthetic design,there comes the obstruction and impetus in searching for reasonable construction and design of long-span and novel arch bridge.The recent study shows the inadequate research in derricks optimization of novel arch bridge,while the cable force optimization study is relatively mature in the cable-stayed bridge so far.Guangzhou Jiaomen Bridge is a kind of novel arch bridge,the characters of extroversive and unsymmetrical increasing the difficulties in design and construction control.Taking Jiaomen Bridge as the engineering background and research object,proceeding the work of construction analysis,jig remove optimization and derricks force optimization.All the work in this paper are summed up as followings:(1)Reviewing and summarizing the special-shaped arch bridge construction and development,and then discussing about the novel arch bridge jigs removing methods and derricks force adjustment and optimization of theories and practices.(2)A finite element model is established to analyze the construction stage,and also to determine the structure characteristics and internal stress distribution.The model parameters are updated by the field monitoring data to meet a more reasonable finite model.(3)Plan 8 is chosen to remove the jigs among eight potential plans modeled with FE model,effectively reducing the maximum lateral displacement(DY)of arch rib and the maximum axis force(Fx)of jigs and balancing the maximum DY of arch rib and the maximum Fx of jig when removing temporary supports at high altitude.(4)Procceeding the derricks force optimization based on the quadratic programming optimization algorithm.Due to the principle of minimum bending strain energy method,some factors are considered for arch rib and girder respectively as followings: i)in-plane bending moment;ii)out-plane bending moment;iii)torque.All factors are scrutinized to characterize the influence derived from all derricks,and five key factors among the six factors are chosen as the indicator to attend optimum derricks force by using Matlab software.(5)A new method is proposed to takes axis position and declination control at the same time into consideration.This method is tested on one real bridge,the results show that the method is effective in reducing construction errors.Completing the whole bridge construction monitoring process and derricks adjustment to ensure the reasonable stress state.