Study On Dynamic Characteristics And Strengthening Methods Of Long-span Steel Truss Bridge

Bridge as a transport hub, is an important part of lifeline project, plays an important role in people's daily life. Especially the bridge occupies key communication line, once subjected to earthquake damage, will brings great difficulties to post-earthquake relief and reconstruction works. Therefore, it is instructive to seismic design and reinforcement design of bridge that on researches the nonlinear dynamic characteristics and holds the weak region and possible damage form of bridge. Based on above thought, the following works will be carried out this thesis.1. The correlation theories or analysis methods are summarized. Make sure about the status quo of development for non-linear dynamic analysis of bridge and existent problems, and design idea of vibration isolation and controlling damping, as well as dynamic response analysis methods of bridge structure.2. The nonlinear dynamic performance of long-span steel truss bridge is researched. For using TDAP III nonlinear structural dynamic analysis software for establishment three-dimensional finite element model, combining the anti-seismic reinforcement project of Japanese long-span steel truss on Highway Bridge called Katasinagawa Bridge, the nonlinear dynamic response and the largest value of internal forces or deformations are researched by the time-history analysis method. The results show that the seismic capacity of Katasinagawa Bridge can not satisfy the seismic code requirement, and reinforcement is necessary.3. The seismic reinforcement methods of Long-span steel truss bridge are researched. According to the results of nonlinear time-history analysis, from economy and applicability to study various methods of reinforcement what has been applied to bridge. Identification of piers using carbon fiber sheet, replacement of bearings, buckling restrained brace and so on to reinforcement of Katasinagawa Bridge, and then carries on non-linear time history analysis of Katasinagawa Bridge that under earthquake. Reinforced results of analysis show that seismic response of the Katasinagawa Bridge significantly reduced and the seismic performance is improved, can meet the existing code requirements of bridge.