A Trial for Seismic Fragility Evaluation of a Large Lattice Dome Supported by Buckling Restrained Braces

A trial to evaluate the seismic fragility of a large dome supported by buckling restrained braces is performed and discussed in comparison with a dome supported by ordinary braces of tension-active capability. In order to evaluate the fragility depending on an adopted bracing system, the damage burdened to the dome structure due to earthquakes is calculated and interpreted as total fragility in terms of assumed seismic intensity varying from small to large earthquakes. The procedure for calculating the total fragility utilizes a simple event tree modelling, where the total fragility is counted considering the damage intensity to structural members, non-structural walls and ceilings. Based on a simple calculation, an example is illustrated to see how the buckling restrained braces are effective or not effective as an anti-seismic reinforcement method.