Research On The Collision Effect Under Seismic Response Between The Long-Span Continuous Rigid Frame Bridge And The Multi-Span Simply Supported Bridge

In the past earthquakes, many bridges are damaged or even accompanied by beam falling due to poundings between adjacent beams caused by seismic action. According to the researches before, the poundings between neighboring segments influence the aseismatic performance of bridges, however, there is a lack of contents about pounding issues in seismic codes. Many efforts have been devoted to the researches on pounding effect of bridges at present, but little research has been done in the area of pounding effect of long span continuous rigid bridges and multi-span simply supported bridges, In view of this issue, an in-depth study is conducted in this thesis, the main contents are as follows:(1) Systematically illustrate the basic theory of pounding effect between the main bridge and approach bridge, mechanism and corresponding influence factors of pounding response and measures for reducing the pounding effect as well;(2) In order to simulate pounding effect subjected to seismic action accurately, parameters selection of pounding unit is analyzed. Firstly, the stiffness of pounding units is set as the beam stiffness to analyze, and then the parameter values are changed in a certain range to obtain the most suitable value of unit stiffness;(3) The effect of number of approach bridges on the displacement, relative displacement, pounding force, displacement of pier crown and bending moment at the bottom of piers are analyzed with and without considering the pile-soil interaction, and the consequences are compared carefully to conclude how the number of approach bridges influence the pounding effect;(4) The period ratio of main bridge to approach bridge varies by changing the natural period of approach bridge, and the regularities about pounding effect are studied under the circumstances.