Analysis Of Mechanical Property And Optimal Design Of The Multiple-Line Railway Bridge

ABSTRACT:In this paper, mainly study Dui Zhen River1#Extra Large Bridge which located in Xiao Yi city. By consulting Qin shen PDL and others similar bridges relevant materials, summarizing the design theory of bridge structures,Initially selectes6kinds of bridge structures. By analyzing the finite element modeling,this paper include.the main study and the relevant conclusions:1.In this paper, selecting the best superstructure through comparative analysis of the different structure’s mechanical properties.In the static analysis of superstructure through computing six schemes mechanical properties under the various conditions and comparing the results to the standard, by using Grillage analysis studied the Integral bridge deck. It showns that after reference standard T-beam add prestressed, intensity of the main control section can meet the basic requirements of the standard. When considering the system temperature, the overall bridge deck generated excessive tensile stress at the junction of beam end and pier’s top.2.In the static analysis of the substructure, optimal design the section and shape of the three dolphins.By finite element modeling and analyzing the length entity of thin-walled hollow pier,the main pier force is calculated in each seriously load case and displacement of the pier top. The calculated results by the finite element analysis show that:third column piers stiffness is the least, the length of the pier end entity segment influence stress distribution in thin-walled hollow pier, when considering the cooling temperature gradient of the entity transition section, larger tensile stress occurs at the bottom section. We should consider this in the structural design.3. In dynamic analysis, the main work is to discusse the vibration characteristics and seismic characteristics of each program. Finite element calculation results show that structure forces have little effect on the structural vibration, three column piers natural frequency is much lower than the thin-walled hollw pier. When using the response spectrum analyze the structural, considering the various conditions under earthquake response. Identify the most unfavorable load in this control design is frequent earthquake along the span.