Research On The Static Performence Of Concrete Self-Anchored Suspension Bridge

The self-anchored suspension bridge retained the advantage characteristics of thetraditional suspension Bridges, with beautiful appearance、beautiful lines、 good economicperformance and strong adaptability of the topography and geological conditions etc, it makesthe self-anchored suspension bridge take a lead position in bridge scheme selecting. Thispaper sets QinZhou ZiCai Bridge—the two tower across three sapan concrete self-anchoredsuspension bridge as a engineering background, some key technical problems of concrete self-anchored suspension bridge are analyzed and studied. The main contents and results are asfollows:First of all, combined with the development history, the structure characteristics,mechanical characteristics and application situation of the concrete self-anchored suspensionbridge; The study theory, experimental research and design methods of the concrete self-anchored suspension bridge are reviewed in this paper.Secondly, the three calculation theory of suspension bridge: elasticity theory, deflectiontheory, nonlinear finite element theory are discussed in this paper. The nonlinear finiteelement analysis method and the nonlinear influence factors of the concrete self-anchoredsuspension bridge are introduced, Such as the cable sag effect, large displacement effect,initial internal force effect, stents contact nonlinear effect, concrete shrinkage and creep offactors which influence the self-anchored suspension bridge are researched.Third, this paper set a finite element model with Midas/Civil program, using the finiteelement method to calculate the concrete self-anchored suspension bridge structure system。The method of determintion reasonable bridge state of the concrete self-anchored suspensionbridge are researched—the influence matrix method, apply the influence matrix method tothe cable force optimization calculation of suspension Bridges example and Zicai bridge ofQinZhou city, get a relatively ideal bridge state. To the cable support structure with obviousgeometric nonlinear characteristics, through iterative calculation update the influence matrix,the keypoint of influence matrix method of cable force optimization calculation principle is determination of reasonable constraint target.Fourth, respectively introduces main cable no stress cable long calculation methods:parabolic method and subsection catenary method. for parabolic method brief too much, theresult is more accurate. take the saddle correction and anchor cable correction into account,according to section catenary method and parabolic method to calculate the benchmark cablelength of ZiCai bridge. The influence of the factors effects the cable material shares: constantload, girders of the sling stiffness, the boom and stiffness, the cable elastic modulus,construction error on the analysis are researched. The erection of benchmark cable isresearched and analysised, set up the the corresponding relation of cable sag and no stresscable length, tower partial, girders span, cable tower height, temperature.Finally, the further research of the static performance of self-anchored suspension bridgethrough static calculation and parameters analysis. Parameter analysis research the effects tointernal force including the rise-span ratio, side-across ratio, arch degrees girder, bendingrigidity and cable tower height, shrinkage of concrete creep, and the results show that:increase the cable rise-span ratios are and arch degrees of stiffening girder, can improve thestructure stiffness, reduce the internal force produced by live load; Side-across ratio makessignificant effects to the stiffness of the suspension bridge; Bending stiffness of girder isextremely significant influence to the stiffness and internal force distribution of self-anchoredsuspension bridge; It exist the most appropriate cable tower height makes a main cross’bending moment minimum; Therefore, the concrete shrinkage and creep effects should betaken account of when calculating the profile of the main cable when installed.