SEISMIC ANALYSIS OF THE FATIH SULTAN MEHMET (2ND BOSPORUS) SUSPENSION BRIDGE

Theoretical dynamic characteristics of the Fatih Bridge in terms of natural frequencies and mode shapes of free vibration were obtained using a range of finite element models. Based on this free-vibration data, separate analyses of the asynchronous response of the bridge to earthquake excitation in three orthogonal axes with different speeds of wave propagation, and of stochastic response to vertical excitation were used to estimate levels of dynamic response due to seismic loading. Fatih is the third of three modern European long-span box-girder suspension bridges that have been investigated and the relationship of the different design features and the dynamic responses of this type of bridge is reviewed. The main conclusion is that where seismic response is an important consideration, the effects of asynchronous excitation can be significant and must be considered.