Seismic isolation devices serve as an important measure to reduce hazards or mitigate structure damage subject to earthquakes. It’s of great necessity to select the optimal parameters of isolation devices to achieve a good performance especially for structures near the fault. In this paper, a risk-based approach is proposed to identify the optimal parameters of isolation devices particularly considering the pulse effect. The seismic risk is convolved combining the near-fault seismic hazard and seismic fragility results. Seismic hazard analysis is performed for the selected IM and seismic fragility analysis is conducted using the probabilistic seismic demand anaylsis (PSDA) method for ordinary bridges which are common in transportation networks with a set of far-field ground motions and a set of pulse-like ground motions. The objective parameters include the elastic stiffness (K₁), characteristic strength (Q) and post-yielding stiffness (K₂) to model the seismic behavior of isolation devies subject to ground motions. Especially, the damage criteria of piers and isolation devices are combined to derive the system-level damage of bridges. The results shows that the damage probability of isolated bridges is significantly influenced by the mechanical properties of isolation devices and pulse effect. With the discrete seismic risk points, Kriging interpolation method is used to obtain the object functions which describe the relationship between the near-fault risk and the parameters of isolation devices. With the help of optimization index, the optimal parameters of isolation devices are identified as a function of structural properties and damage states. Additionally, the pulse effect on the optimal parameters of isolation devices is quantified and the relationship between the optimized results and the source-to-site distance is established. The result can provide effective and practical guidance for design and retrofitting of near-field bridges.

隔震装置是减少地震危险或减轻结构损坏的重要措施。非常需要选择隔离装置的最佳参数以实现良好的性能，尤其是对于故障附近的结构。在本文中，提出了一种基于风险的方法来确定隔离设备的最佳参数，特别是考虑到脉冲效应。地震风险结合了近断层地震危险性和地震易损性结果。针对选定的IM进行地震危险性分析，并使用概率地震需求分析（PSDA）方法对在具有一组远场地面运动和一组类似脉冲的交通网络中常见的普通桥梁进行地震易损性分析地面运动。K ₁），特征强度（Q）和屈服后刚度（K ₂）来模拟受地震动影响的隔离装置的地震行为。特别是，将墩墩和隔离装置的损伤准则结合起来，得出桥梁的系统级损伤。结果表明，隔离桥的损伤概率受隔离装置的机械性能和脉冲效应的显着影响。利用离散的地震风险点，克里格采用插值法获得描述近故障风险与隔离装置参数之间关系的目标函数。借助优化指标，可以将隔离装置的最佳参数确定为结构特性和损坏状态的函数。另外，量化了对隔离装置的最佳参数的脉冲效应，并建立了优化结果与源到站点距离之间的关系。结果可为近场桥梁的设计和改造提供有效和实用的指导。