Comparative Analysis Of Dynamic Characteristics Of Continuous Rigid Frame Bridge And Extradosed Cable-stayed Bridge

Since the 20 th century,with the continuous innovation of building materials and construction technology,the span of bridges across mountains and valleys have been constantly breaking records.High-pier and long-span continuous rigid frame bridge and extradosed cable-stayed bridge have obvious advantages in span of 200 m~300 m,they are more and more favored by engineers.With the widely application of the bridges in practical engineering,the study of their dynamic characteristics and seismic response analysis has become indispensable.(1)Firstly,the master dissertation briefly introduces the development history of the continuous rigid frame bridge and extradosed cable-stayed bridge,and summarizes the research status of their structure characteristics and dynamic characteristics,so as to clarify the research content of this paper.Then the finite element method and seismic response analysis theory of bridge dynamic characteristics are introduced,and the method and theory adopted in this paper are determined.(2)Taking a Continuous Rigid Frame Bridge and a Cable-stayed Bridge with the same main span of 230 m as engineering background in the paper,and the bridges are established the finite element analysis models.The natural vibration characteristics of the two bridges are calculated and analyzed,which are summarized on the basis of calculation and analysis.The influence of the factors of pile-soil interaction on the dynamic characteristics of the structure is analyzed.At the same time,the influence of cables and towers on the natural vibration characteristics of extradosed cable-stayed bridges is analyzed.(3)Based on the analysis of dynamic characteristics,the response spectra of the two bridges under E1 earthquake are analyzed.The results of seismic response are compared to obtained the general rules of seismic response of the two bridges.(4)The linear time history-analysis of the two bridges is carried out by using the appropriate seismic wave — Taft_v wave,and the calculated results are checked with the response spectrum theory.The structural parts that should be paid attention to in seismic design of the two bridges are obtained,which can provide reference for similar practicalengineering analysis and seismic design.