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Accelerated bridge construction (ABC) technology has been widely used due to its many advantages. However, the lack of well-developed and engineering proven connection details have limited the use of prefabricated substructures in seismic zones. The socket connection is one of many different ways of connecting precast substructure, which is characterized by convenient transportation and simple construction. This paper introduces the socket connections of precast bridge columns and reviews it from those aspects including theoretical research, experimental research and research on the application of advanced materials. The socket connection belongs to the emulative monolithic connections, which has good strength and ductility. But there exists a disadvantage of large residual displacement after the earthquake for socket connection. At present, there are many researches on the design of socket connection, but there are few studies on the repair of piers after the earthquake. Therefore, it is necessary to study a quick and economic repair method in the future to exert the functionality of bridge structures following earthquake event.

The energy response equations of the seismically isolated bridge system are established based On the energy equilibrium theory. Bilinear analysis model of the energy response of the seismically isolated bridge is constructed by series connecting the bridge piers and the Lead rubber bearings. According to the applicable Code of Seismic Design for Railway Engineering, forty strong ground motion records are appropriately selected as the seismic input and the nonlinear time history analyses for the seismic energy responses of the bilinear SDOF seismically isolated bridge systems with different natural periods are carried out. The influences of peak ground accelerations, principal dynamic parameters of isolated bridge system on input energy and their distributions are studied.

The Nanjing Dashengguan Yangtze River Bridge is a 108 + 192 + 336 + 336 + 192 + 108 m six-span continuous trussed-arch bridge on the Beijing-Shanghai High-speed Railway. As a feature of the long span structure, the response of the main bridge considering the traveling earthquake wave effect should be calculated. Thus, a finite element method (FEM) model is established. The natural frequencies and mode shapes are acquired by the eigen-parameter analysis. By inputting the El Centro earthquake accelerations to the bridge system in association with the Ex+0.3Ey+0.3Ez and 0.3Ex+Ey+0.3Ez components according to the Europe Code, the dynamic responses of the bridge, including the displacement and accelerations of the main nodes of the structure as well as the seismic forces of the key members, are calculated by the structural analysis program. Based on these responses, the main laws of the seismic responses of the bridge are summarized, and the safety of the structure is evaluated. The displacement and the internal force response of the main bridge excited by the El Centro earthquake, with the traveling speed of 300, 500, 1,000 and 2,000 m/s, respectively, are compared with the final results obtained by the spectrum analysis and the common time history analysis.