Performance Analysis And Advanced Research About Large-span Steel Truss-type Trestle

In recent years,there is an unprecedented rapid progress on the economy and industrialization of China.The traditional type for transport cannot ensure the continuity of production and the costs is very high.The higher requirements have been prompted to carry machinery and equipment to be widely used in the production of coal,cement and metallurgy.Compared with these concrete structure of the truss,truss-type trestle a has series of advantages with light weight,large span,beautiful appearance,good seismic performance and short construction period.In this paper,a general finite element software ANSYS was used to analyze the steel truss with the truss design of a mine belt trestle as an example.The first,according to the engineering characteristics and load cases,the strength and stability of existing structures was analyzed.The design scheme was checked,including the composition of the overall structure of the trestle,the overall force transmission path,the strength and force characteristics of each component according to the calculation results.Secondly,the parameters analysis for the axial stiffness of the components of the trestle bridge were carried out,including the influence of the axial stiffness change of the upper and lower chord,vertical web and diagonal web.Finally,in the case of increasing the span of the trestle to 100 meters,the stress distribution characteristics of the component were studied and the structure of stay-cable bridge was adopted.It can be concluded as follows based on the analysis result,1)The members of the steel truss bear different mechanical loads respectively and bear different roles.The bending resistance is mainly provided by the upper and lower chords while the shear resistance is mainly provided by the diagonal webs.The vertical webs are to enhance the shear resistance.For the structural of three types of components have little effect on each other in the design,it can be considered separately.2)The chord provides flexural strength and the section stiffness which is inversely proportional to the square of the displacement and inversely proportional to the axis stress.The stiffness of section is inversely proportional to the stress and has little effect on the displacement.Besides,it almost has no effect on the displacement;3)Due to the vertical and longitude support of the cable-tensioned cable,the piers with cables are not enough to improve the lateral stiffness of the trestle,and special measures are needed to improve the transverse stiffness of the trestle structure.4)When the span is very large,the method of increasing the cross section of the component is inefficient.The use of a cable stayed type of the bridge can be a good solution for such problem.