Seismic Response Analysis And Isolation Investigation For Elevated Bridges And Station-Bridge Structural Systems Of Light Railways

Structural system in a light railway mainly consists of elevated bridges and station buildings, and most station buildings are built on the elevated bridges, combining as the integrated station-bridge structures. Due to the differences between the seismic standards and design codes for bridges and buildings, the seismic safety of the integrated station-bridge structures cannot be ensured appropriately. Hence, in order to achieve the high-quality construction for light railways, the seismic safety of the integrated station-bridge structures should be roundly analyzed.In this thesis, against the Tianjin Light Railway located at high seismic intensity area, the seismic response analysis and isolation investigation for elevated bridges and an integrated station-bridge structure are performed and the main researches are involved as follows:⑴ Seismic response analysis for the elevated bridge structure. Based on the related specifications in "Code for Seismic Design of Railway Engineering (GBJ111-87)" and "Code for Seismic Design of Highway Engineering(JTJ004-89)", the seismic response analysis for a 8-span simply-supported elevated bridge is carried out using the response spectrum method and the time-history analysis method respectively, and the calculated results based on different methods are compared. ⑵ Seismic response analysis for the integrated station-bridge structure. Based on the related specifications in "Code for Seismic Design of Building (GB50011-2001)" and the codes of GBJ111-87, the seismic response analysis for an integrated station-bridge structure is carried out using the response spectrum method and the time-history analysis method respectively, and the calculated results based on different methods are compared.⑶ Isolation investigation for the integrated station-bridge structure. The isolation for the integrated station-bridge structure, installed the composite SMA (Shape Memory Alloys) smart isolators developed recently at the joints between the station building and the elevated bridge and the joints between the girders and piers, is investigated, and the isolated effect is numerically simulated.Finally, some conclusions are given that the seismic safety, based on the prescribed response spectrum in GB50011-2001 and GBJ111-87, of the integrated station-bridge structure in light railway is lower, and the time-history analysis based on the response spectrum from the specific site evaluation should be employed to ensure the seismic safety of the light railway. In addition, the seismic safety of the light railway could be significantly increased, installing the composite SMA smart isolators.