Study On Seismic Mitigation And Isolation Measures And Dynamic Analysis Of Self-anchored Suspension Bridge Of Single-tower And Spatial Cable

Taking a certain self-anchored suspension bridge of single-tower and spatialcable as a engineering background, using FEM software Midas/civil to build the spacefinite element model,researching the dynamic characteristics seismic behavior and themeasure of mitigating and isolating seismic of self-anchored suspension bridge ofsingle-tower and spatial cable.The main works and results are as follows：(1) using the method of multiple Ritz to carry out the mode analysis of thecertain self-anchored suspension bridge of consideration of pile-soil-structureinteraction(pile-soil spring model) and irrespective of pile-soil-structureinteraction(fixed model),and obtain the natural vibration of structure and oscillationmode. Analysis shows that considering pile-soil interaction-structure, the flexibility ofthe structure increasesed,and the natural vibration of structure is increased by23%.itmeans that its important to conside pile soil-structure interaction in dynamiccalculation.(2) using the response spectrum method and time-history analysis method toanalyse the seismic response of the certain self-anchored suspension bridge ofsingle-tower and spatial cable.The internal force, the displacement, and the stress ofgirder and tower are calculated subjected to longitudinal excitation, lateral excitation,vertical excitation and two kinds of seismic combinational modes which arelongitudinal vibration plus vertical vibration and transverse plus vertical seismicexcitation, and results were compared between the two method, the effects caused byvertical seismic component and The large longitudinal displacement was discussed.(3) using nonlinear time-history method to calculate the seismic response ofpile-soil spring model and fixed model,the results show that the fixed model’sstiffness is large than the pile-soil spring model. Namely the internal force is lager,butthe displacement is less. Considering the pile-soil-structure interaction is more closeto the actual situation,its necessary to consider the impact of pile-soil-structureinteraction.(4) The seismic mitigation and absorption of viscous damper is introduced in the paper.In addition, fixing the viscous damper on the certain self-anchored suspensionbridge of single-tower and spatial cable,it analysis the sensitivity of main designparameters of viscous damper-Damping Coefficient C and Speed Index ξ,and verifythe effect of the viscous dampers to the damping effect.(5) The seismic mitigation and absorption of LRB is introduced in the paper. Inaddition，it discuss the impaction of bridge structure with diffrent member and type ofLRB,also it verify the effect of the LRB to the damping effect,and compared withviscous dampers.