Research On Static And Dynamic Characteristics And Wind-resistant Measures Of Pipeline Suspension Bridges

In our country,with the development of oil and gas pipeline construction,more and more large oil and gas pipeline bridges appear.Oil and gas pipeline suspension bridges,which have advantages of great spanning capacity,strongly adaptive ability to topographic elevation difference,and short construction period,have been widely applied in the pipeline crossing engineering.However,unlike traditional suspension bridges,pipeline suspension bridges have the characteristic of low stiffness,much more strongly nonlinear mechanism,long natural period and intensive dynamic response under dynamic action.Considering its special service performance,stress of pipeline is choosed as the control target.In this thesis,China-Burma oil and gas pipeline projection is use as the research object,finite element software MIDAS Civil is used to eastablish the three-dimensional real bridge model in completion state for nonlinear static analysis,the dynamic characteristics and the seismic response under pipeline-bridge coupling based on time-history analysis method are also studied,moreover,effects of the bearing parameters between pipe and bridge,the eccentricity level of the pipeline,the transmission medium and the pipeline-bridge coupling on static,dynamic performance and seismic response of the bridges are analyzed based on parameterization method,which provides reference and guidance for the research of dynamic characteristic and seismic design of this special bridge type.Finally,wind resistant measures are studied in this paper.The main conclusions are as follows:(1)Through the static analysis of pipeline suspension bridges,it can be concluded that pipeline suspension bridges have strong nonlinear mechanism,and the nonlinear analysis should be carried out in the process of design.(2)Through the research on dynamic characteristics of pipeline suspension bridges,it can be concluded that the natural period of pipeline suspension bridges is relatively long,and contraints on the ground,pipeline-coupling action,transmission medium and eccentric loadings have significant effects on the dynamic characteristic of pipeline suspension bridges.(3)Through the research on seismic behavior of pipeline suspension bridges,it can be concluded that the pipeline-bridge coupling has different effects on force and deformation of different components of pipeline suspension bridge,for example,the longitudinal shearing force of the tower and lateral displacement of the main girder all decrease due to the coupling effect,but the axial force of chords and vertical deflection of the main beam and displacement at the top of tower all increase.(4)Through the research on seismic behavior of pipeline suspension bridges,it can be concluded that using the spatial main cable shape,wind resistant cable system and increasing the cross-sectional area of wind tension rods can improve the lateral bending stiffness of stiffening girder of pipeline suspension bridges...