Abstract：To assess the seismic performance of asymmetric multi-tower structure of resisting shear-torsion coupling failure under stochastic excitation, a new method of multidimensional performance limit states to analyze the structural fragility is developed based on the probability density evolution method (PDEM). The indexes of inter-story drift angle and inter-story torsion angle are adopted considering the threshold randomness and the correlation between indexes, and the exceedance probability is calculated so that the fragility curves under two dimensional performance limit states are fitted. The fireworks algorithm with the discretization and equal variable improvements is applied to optimize the arrangement of buckling restrained brace (BRB) and finally to achieve the stochastic nonlinear vibration control of multi-tower structure. The results indicated that the proposed fragility method can provide comprehensive and reliable evaluation indicator for seismic performance of multi-tower structure, and the optimization design of damper arrangement based on the improved fireworks algorithm can effectively improve the seismic performance of structure of resisting shear-torsion coupling failure.
