Study On The Tsunami Force Of The Superstructures Of The Medium And Small Span Bridges

Tsunami is one of the most devastating natural disasters,with the characteristics of great destructive power and wide range of influence.In twenty-first Century,two major tsunami disasters occurred in the world:one is 2004 India Ocean Tsunami and another is the 2011 Great East Japan Earthquake-tsunami,which caused many people's death,and many houses and bridges were destroyed.Bridge is not only a key part of the transportation system,but also the important lifeline engineering for disaster relief.The latest research results show that there is a high possibility of tsunami in the southeast coastal area of China,so it is pretty necessary to study the anti-tsunami design for bridges.The investigation of the disaster after the tsunami show that the superstructures of the bridge are more easily damaged,and the superstructure should be the focus of the anti-tsunami design.This paper mainly studies the tsunami force characteristics of the superstructures(including hollow slab beam,box beam,T beam section forms)of medium and small span bridges in the coastal area of China.The main research is detailed as following:(1)By comparing the physical experiments results and the theoretical solution of dam break wave,the key parameters including grid generating method,grid size,turbulence model etc.of the numerical flume are verified.(2)The tsunami bore forces on rectangular slab is studied first as the representative of the three kind superstructures,namely hollow slab beam,box beam and T beam superstructures.The mechanism of tsunami force of rectangular slab is explored and studied.Based on which,a new method for estimating the tsunami force on rectangular slabs is presented.(3)Based on the study of the force characteristics of the tsunami force on the three different superstructures,the method and detailed formula of estimating the tsunami force is suggested.Also the influence parameters such as beam width,number of the girder and the trapped air etc.are discussed.(4)Comparison of the tsunami force calculation methods proposed by other researchers and by this study is conducted and results show different calculation methods have different application conditions and the calculation methods presented by this study has higher precision and better efficiency.