Conceptual Design And Static And Dynamic Analysis Of Double-Line Steel Box Continuoun Girder Railway Bridge

A continuous box-girder bridge with a long span is very popular in highway bridge construction work; although the same stytle isn't existed in railway bridge, we still believe that it has a bright future as the development of steel construction.The thesis firstly reviews the domestic and international development and summaries the structural characteristics of continuous steel box beam. Based on the plan of the Jialing River Bridge, the conceptual design of a continuous box-girder bridge with 180 meters-mainspan is proposed. A combined finite element model involving beam element for the bridge is developed by using Midas/civil, which is a general commercial finite element software. Stress and deformations of the beam and piers are analyzed incrementally following the construction stages. Based on the result of the finite element model, we examine the static load cases' behavior including live train load, wind load, temperature variations, braking force and the horizontal sway force of the train and combinations of these loads at operational stage. Dynamic analysis are carried out, free vibration modes and frequencies of the bridge are included in the term of subspace iteration method. Using response spectrum method and time history method, we study the seismic design of the bridge and compare the results. Analysising the elastic state of equilibrium in different states, we can include the safety of the bridge. Afterward, a finite element model involving brick and plate element for the bridge is developed by using Algor, a general commercial finite element software. Detail stress analysis on top slab, base slab, web, longitudinal beam and other parts are included in dead load and live load cases.Therefore, the static and dynamic performance of the bridge with a continuous steel box beam is comprehensively understood, and the analyzing method of bridge is conceived.