Seismic Performance And Design Methods For Controlled Rocking Bridge Piers

The earthquake response of highway and railway’s bridge construction that is an important part of modern infrastructure system is meaningful to the social and economic development. The seismic performance of bridge structures depend on the bridge piers.. The traditional bridge piers don’t collapse when the earthquakes happen, but the inelastic deformation damages appear at the bottom of the piers.After the earthquake, it needs to spend much money to rebuilt or repair. So, searching a better bridge structure is becoming a hot spot.The controlled rocking bridge piers can reduce damage when the earthquake happen. These piers possess the advantages of both the seismic design for the bridge’s ductility and isolation design method’s advantages. It has great prospects for development.The structural components and their mechanical performance, the basic mechanical property, stability and energy dissipation capacity, the basic theory of computation and the design method that based on the effectiveness or displacement are studied. The structural components, moment capacity, energy-dissipating capacity and design method are researched by theoretical analysis, formula derivation and numerical simulation. The main results are as follows.(1) The components, including piers, prestressed components and energy dissipaters, and their performance of controlled rocking bridge piers are described.(2) The resistance to bending, lateral force resisting ability, energy-dissipating are discussed by theoretical analysis and formula derivation. Than the components’ performance is analyzed by quantitatiive method.The pier part plays an important role in resistance to bending and lateral fores. The prestressed reinforcements can reinforce the structure’s resilience, and keep the elastic state forever. The energy dissipater can consume the energy input by an earthquake.(3) The finite element model of controlled rocking bridge piers is established based on Sap2000. The results of controlled rocking bridge piers by pushover method are compared with those by formula derivation. The finite element model and the formula can be validated. Analysis results show that the controlled rocking bridge piers have better post-earthquake performance under the incremental dynamic analysis.According to the traditional piers’ design method that are based on the equivalent lateral force or residual displacement, the controlled rocking bridge piers’ design methods are proposed. What is more, theequivalent lateral force design method and the method of displacement-based seismic design, are introduced with a case study.