Analysis For Construction Mechanical Behavior Of Asymmetric Single Tower Cable-stayed Bridge

Asymmetric single tower cable-stayed bridge is a main type of cable-stayed bridge.It is widely used in bridge construction.Because of the asymmetry of asymmetric cable-stayed bridge,the construction process is different from the traditional twin towers cable-stayed bridge and symmetry single tower cable-stayed bridge.The analysis on the mechanical behavior of the construction process includes construction parameters,construction technology and design factors.The analysis of construction parameters is realized by establishing the model of beam element for sensitivity analysis.The weight and stiffness of the girder,the stiffness of the tower,the cable elastic modulus,cable force,prestressing force and the weight and stiffness of hanging basket will be as analytical parameters.The sensitivity of the displacement of tower top,the displacement of the girder,the cable force and the stress of girder are analyzed in the bridge stage by changing the construction parameters within a certain range.Finally,the weight of the grider and the cable force is more sensitive for bridge state by analysis.The auxiliary pier of the engineering background appears pulling force in the construction process.Increasing the permanent load,removing support bracket step by step and permanent load application and removing support bracket step by step are brought for solving this problem.Finally,the construction plan that permanent load application and removing support bracket step by step is the best plan by comparing auxiliary pier force,beam stress,support bracket stress and bridge state.The design factors include the arrangement of prestressing tendon in anchorage zone of main tower.The anchorage zone where is forced hugely will be analyzed by solid element.Safety and rationality of tower anchorage zone in construction stage and operating stage will be proved.Characteristics and regularity of stress distribution will be obtained.In addition,arrangement of prestressed reinforcement has two types generally,including straight beam plus U beam and line crossing beam.Distribution of stress in main tower of two types will be obtained by model analysis.Finally,the conclusion can be used for guiding designers' selection in two types.