Mechanical Properties Adaptability Analysis Of Heavy Haul Railway Steel Truss Bridge

Our country is vast in territory, large capacity,long distance transportation of materials. Rapid economic development has also put forward new requirements for railway transportation, on the existing railway line running heavy haul train is a feasible method for low cost, but it is bound to have an adverse effect on the safety, the fatigue life of existing railway bridges. Therefore, we need to stress performance analysis of overloaded bridges.In this paper, with the major issue China Railway General Company of science and technology research and development plan of "The Beijing Guangzhou line is a key technology of large axle load of heavy haul transportation adaptation steel bridge"(2013G010-A) based on. Taking the Xinhe Changdong Yellow River Bridge(4×108m) continuous steel truss girder bridge as the research object. Respectively, using the finite element software Midas and ANSYS to establish the finite element model, rod bearing performance and fatigue life of the steel truss bridges under the heavy haul train. The main research contents and conclusions are as follows:(1)According to the design drawings, determine the section size of bar, boundary conditions and node connection pattern of the continuous steel trussed girder on the Changdong Yellow River Bridge. To establish the finite element model of Midas and carries on the check.(2)The steel truss girder bridge under the action of heavy haul train overall stress adaptation are analyzed. Through the static performance analysis using Midas software. The results show that the vertical deflection effect of heavy haul train loads and lateral deflection in the swing force, under the action of wind are meet the current specification requirements. And in the live loads are compared, the vertical deflection safety margindecreased 22%, lateral deflection safety margin basically unchanged. Dynamic response analysis was performed using ANSYS software. The results show that the mid span deflection, transverse and vertical dynamicamplitude, vertical acceleration and movable bearing angle caused heavy haul train effect respectively in the live loads increased by 26.0%, 32.0%, 42.9% and 26.8%.(3) The steel truss girder bridge under the action of heavy haul trains the member stress adaptation are analyzed, the results showed that in the medium under the action of live load member stress, stress amplitude, stability can meet the requirement. The bottom chord and support oblique rod in the middle of the span stress amplitude do not meet the requirements. The cross at the top chord, support under the lower chord, flat rod, inclined rod part rod stability does not meet the requirements.(4)The fatigue life of the steel truss girder bridge under the action of heavy haul train typical rod are analyzed. According to the obtained in the dynamic analysis of typical members of the stress time history, with the rain flow method to count the stress amplitude, get the cumulative damage degree. Then according to the linear cumulative damage theory of each typical membersin the role of heavy haul trains and ordinary trains the fatigue life is analyzed. In general, the bridge in the role of C96 heavy haul train under typical rod fatigue life than the ordinary train load average is about 80% shorter.