Yongxiu Frame Tied Arch Bridge Static And Dynamic Force Characteristics And Just Finished The Local Stress Analysis

Spanning the Xiushui river, the Yongxiu super large bridge located at Nanchang-Jiujiang intercity railroad with a design speed of 200km/h in Yongxiu county, the main bridge (whose total span is 31.75+128+31.75m) of which is a rigid-framed tied arch bridge, with the arch and piers consolidated, beam and piers separated, load mainly endured by the arch, beam only used for bearing load between joints and providing bridge floor system. The main girder of the bridge is a three-span prestressed concrete continuous beam, while the main arch is a steel-box structure with the main span of 128m. The concrete arch foot is consolidated with the concrete piers and steel box arch, and the load between joints of the beam is transferred by suspender to axial force of the arch. The vertical component force of the axial forces in arch foot is transferred by pier to foundation, while the horizontal component is balanced by tied bar.The bridge has the characteristics of long span and complexity in structure as well as in construction techniques. In order to conform tightly to the requirement of the construction of this project, combining with the final design and the construction blue print, the present thesis analyzes the dynamic characteristic, static characteristics and local stress of rigid joint of the bridge during the construction and operation stages, finishing the following tasks:1. analyzing the structure characteristics of the Yongxiu rigid-framed tied arch bridge, by using the command-flow programme APDL language developed by the author and with the aid of ANSYS, the thesis sets up the spatial analysis model of the Yongxiu rigid-framed tied arch bridge.2. Based on the characteristics of the construction method, the thesis studys the algorithms of the tensile force of rod and reasonable finished dead state systematically: Firstly, the thesis analyzes the tensile force of rod and reasonable finished dead state of Yongxiu rigid-framed tied arch bridge by using different methods, such as rigid supported continuous beam method, balance of force method, rigid suspender method, minimum bending energy method. Secondly, the thesis compares the advantages and disadvantages of all the methods. Lastly, the thesis builds the fractional-step algorithm and optimization method to determine the reasonable finished dead state and verifys and optimizes the designed tensile force of rod.3. Neglecting the construction process, the thesis makes a static analysis on the model of the Yongxiu rigid-framed tied arch bridge, and makes reasonable judgement on the structural performance according to the present design code of railway bridges.4. By means of the techniques of "birth and death element" and "load step", The thesis realizes the simulation during construction of Yongxiu rigid-framed ried arch bridge, analyzes the force and deformation of the whole construction process, and puts forward corresponding suggestions based on the specific problems.5. Considering the complexity of stress in the rigid connection between the arch and pier, the thesis establishes the partial finite element model, analyzes the stress result, evaluates the design rationality of this area and explores the force-delivering rule of the steel-concrete rigid joint between the arch and pier.6. The present thesis is to analyze the self-vibration characteristics of structure and to obtain the first ten natural frequencies and modes as well as to makes further exploration on some factors of structure self-vibration characteristics, such as changes of number and position of transverse, the stiffness of piers and pile-soil effect.