Aseismatic Performance Analysis Of Long Span Continuous Rigid Frame Bridge With Double Thin-wall High Piers

In the recent years, with the fast development of Science & Technology and transportation enterprise, continuous rigid frame bridge is commonly built in China, owning to their advantages on economy and construction. Such bridge usually adopt the structural system of large span and double thin-wall high piers, which modeling is gentle and seismic response also is complex, so their aseismatic performance need to be further researched.Based on the engineering background of Luo River Super-large Bridge, this thesis focuses on the seismic response and aseismatic performance of long span continuous rigid frame bridge with double thin-wall high Piers. The main work is summarized as follows:1,The text explores the structural characteristics and aseismatic research status and existing problems of long span continuous rigid frame bridge with double thin-wall high piers, and the bridge seismic response analysis method are explored. Then, by applying the finite element method, adopting large-scale finite element software, the spatial calculation model of Luo River Super-large Bridge is established, including two calculation models, and the model 1 uses the spatial beam element to establish the spatial truss model of the main beams and piers, and based on the model 1, the model 2 makes an expansion of the three-dimensional entity model of the caps, the piles and soil consider the pile-soil-structure interaction.2,This thesis discusses the bridge vibration characteristics calculation theory and design theory of response spectrum, and analyses the dynamic performance of the Luo River Super-large Bridge and gets it's natural vibration frequency and vibration mode. On this basis, the response spectrum theory is used to make seismic response analysis and obtain the internal force and displacement of the seismic response, and the thesis contrastive analyses the different seismic response characteristics of the high pier and dwarf pier, as well as the side span and mid-span; and disquisitive summarizes the characteristics of seismic response of the bridge.3,Based on the calculation model 1 and model 2 of the Luo River Super-large Bridge, the bridge seismic equation of motion is established at the consistent excitation. Using dynamic time-history analysis method, the thesis makes the seismic response analysis, and discusses on the seismic response characteristics of this bridge at the consistent excitation. On this basis, the paper focuses on the analysis of different influence of the the pile-soil-structure interaction on the seismic response internal force and displacement of high pier and dwarf pier, as well as the side span and mid-span, and disquisitive summarizes the influence rules of the pile-soil-structure interaction on seismic behavior of the bridge; and makes some design suggestions.4,This thesis discusses the bridge dynamic equilibrium equation at the multi-support excitation and the input method of earthquake motion considering traveling-wave effect. Using dynamic time-history analysis method, the paper analyses the seismic response characteristics of the calculation model 1 of the Luo River Super-large Bridge considering traveling-wave effect. Then, this results are contrasted with the results at the consistent excitation, and the paper disquisitive summarizes the influence rules of the traveling-wave effect on seismic behavior of the bridge; and makes some design suggestions.