The Seismic Response Of Isolation Bridges Considering Soil-Piles-Structure Dynamic Interaction

Traditional seismic design method of bridges is to ensure the structure to have enough strength and ductility to resist earthquake. With the development of bridge seismic study in the last few decades, researchers have put forward some new seismic technology including isolation technology, active control technology, passive control technology and hybrid control technology. Isolation technology is applied in the bridges in foreign countries widely. And these bridges have showed good performance in the earthquake. Isolation technology is also applied in our country, and the design theory of isolated bridge is researched as well.Appling isolation technology in bridges, buildings and other structures can significantly increase the natural cycle of structure. And it reduces the role of structures by the earthquake. Isolated bridge is simulated, and whose dynamic model is established. Then nonlinear seismic response analysis of isolated bridge is made using time-history analysis method in this paper. The isolation capabilities of isolated bearings are studied through calculation. The main factors such as bearings, piers size and earthquake wave who impact isolation performance are analyzed and discussed. When people research isolated bridges, they usually assume that pier was fixed on solid ground, with little regard to soil-pile-structure dynamic interaction on the isolated bridge structure. Such an assumption on the construction of bridge in the bedrock is reasonable. However, pile foundation who is built in soft soil is used widely. And soil-pile-bridge structure dynamic interaction has changed the dynamic characteristics of isolated bridge. So neglecting this change is not safe. Comparing to bridge whose soil-pile-structure dynamic interaction is not considered, the bridge whose interaction is considered has many different features when we calculate and analyze the earthquake response. So there are many problems need to be more deeply studied in calculation, analysis and theoretical design. When earthquake occurs, soil-pile-structure dynamic interaction is an objective existence. So this paper also researches the dynamic characteristics and earthquake response of isolated bridge whose soil-pile-structure dynamic interaction is considered, and analyzes the difference between the two situations. Finally, this paper summarize the full text, and states some meaningful conclusions. But there are still several problems, therefore, it is necessary to conduct more in-depth research.