Aseismatic Study On The PC Continuous Rigid-frame Bridge Considered The Pile-soil Interaction

PC continuous rigid-frame bridges had more and more development in domestic highway domain, because of its special convenient-construction,reasonable-mechanism, comfortable-driving and so on. And long-span continuous rigid-frame bridges had already got a widely use in particular. However the dynamic analysis of long-span continuous rigid-frame bridges was quite complex, it was difficult to consider the aseismatic response. Therefore the aseismatic study on long-span continuous rigid-frame bridges were important in theory and practical field.In this thesis, the finite element models were established by ANSYS procedure which was backgrouded on the Taizaogou Bridge. And the seismic response was carried out with the response spectrum and the dynamic time-history analysis method .The main works were listed as follows:(1)Elaborated dynamic analysis theory and method of bridge structure . Main methods are the static, the response spectral and the dynamic time-history analysis;(2)Established the finite models: the pier-bottom solid finite element model I and pile-soil interaction finite element model II;(3) Carried out the analysis of finite models with response spectrum method and dynamic time-history method when the earthquake fortification intensity was 8 degree.The main conclusions as follows:(1)When the finite element model suffered from transverse and vertical excitation made a notable effect to longitudinal moment (My) on the top of the pier and the shear force (Fz) on the support section of main beam. Therefore, it was necessary to consider the vertical seismic during aseismatic analysis and design to the long-span continuous rigid-frame bridge.(2)When the pier-bottom solid finite element model I suffered from longitudinal excitation, the effect level to the displacement, the moment and the shear force on the top of pier were ordered by the Tianjin wave, the EIcentro wave ,the Taft wave.(3)When the pile-soil interaction finite element model II suffered from longitudinal excitation, the effect level to the displacement, the moment and the shear force on the top of pier were ordered by the Tianjin wave, the Taft wave, the Elcentro wave.(4)The actual ground flexibility changed the superstructure dynamic character in the model II, namely extended the structure natural period; the foundation soil also changed the structure system damping due to viscous interaction. The superstructure inertia horizontal force and the overturning moment made the foundation produce sway movement and horizontal movement, thus it had different response with the model I .