Seismic Response And Seismic Performance Analysis Of Continuous Rigid Frame Bridge With High Pier And Long Span

Compared with the conventional medium and small span rigid frame bridge,the static and dynamic effects of high pier and long span continuous rigid frame bridge are more complicated due to the influence of pier height ratio The southwest area of China is in the geologically active plate with many earthquake disasters,which makes the structural dynamic response problem is prominent.However,the existing seismic design code of Bridges in China still needs to improve the seismic rules for Bridges with high pier and long span.Therefore,it is very necessary to conduct in-depth analysis and research on the seismic response of high-pier and long-span rigid frame Bridges.In this thesis,the research status and seismic response theory of high pier and long span rigid frame bridge at home and abroad are described.Taking Wugong Bridge(80m+150m×2+80m)continuous rigid frame bridge as the research background,the finite element software is used to analyze its seismic response.The main research contents and conclusions are as follows:(1)Based on the finite element method,the pier bottom consolidation model and the pile-soil-structure model were built to analyze the influence of pile-soil interaction on the dynamic characteristics of high pier and long-span continuous rigid frame bridge,and the law of pile-soil interaction leading to the mass transfer of low-order modal parts to high-order modal parts was found.(2)The response spectrum method is adopted to carry out the earthquake response of the structure under a bridge in the field characteristic analysis,it is concluded that the pier height and collar beam number set up to consider the influence law of effect of seismic response of the structure of piles and soil,the author puts forward the reasonable of long-span continuous rigid frame bridge with high-rise piers pier height and collar beam set mode,high piers for the future to provide reference for seismic design of long-span continuous rigid frame bridge.(3)Conducted a cross section of dynamic elastoplastic analysis,obtained the plastic hinge under different ground motion peak position and its plastic law of development Points out that the structure in the bridge to the plastic hinge of relative to cross the bridge to the plastic hinge has better energy dissipation effect,and through the analysis of the plastic deformation of different ground motion peak,summarizes proposes short pier pier base and pier top section for weak seismic section.(4)Based on the large mass method,a multi-point excitation model was established to analyze the effects of longitudinal wave and transverse wave considering the traveling wave effect on the structural response of the bridge.It was found that the longitudinal wave and transverse wave considering the traveling wave effect had different effects on the internal forces of each pier,and both longitudinal wave and transverse wave had greater effects on the internal forces of the lower pier.