In the process of performance-based design of bridges with aseismic bearings, there exist intrinsic trade-off between minimization of the bearing displacement and pier displacement during strong earthquake events. However, difficulty in selecting the optimal parameters of the bearings that satisfy the two objectives arises, in conjunction with considerable computational resource requirements for nonlinear time-history analysis (NTHA). A computationally efficient approach to determine the optimal bearing design parameters by utilizing the stochastic structural response of equivalent linear systems is proposed in this paper. The key idea is to use the assumed optimal parameters obtained from a stochastic model as the approximation of the exact optimal parameters found from a deterministic model. The stochastic model allows rapid exploration of optimal parameter candidates. A computationally intensive deterministic model is used to determine the performance-based optimal design by performing NTHA only for the design parameter candidates obtained by exploiting the stochastic model. Compared with the exhaustive search approach, the required number of NTHA cases in this method can be significantly reduced. As a numerical example, the proposed method is applied to optimal parameter selection of two slide type bearings in a girder bridge, namely the uplifting slide shoe and the functionally discrete bearings. The seismic performance indices of the bridge with the design parameters determined by the proposed procedure are shown to be almost equivalent to the optimal values found by the exhaustive search approach. An extended parameter search algorithm is incorporated with the proposed procedure for refinement of the assessment at the slightly increased cost of computation.

在基于性能的抗震支座桥梁设计过程中，在强震事件中，最小化支座位移和桥墩位移之间存在内在的权衡。然而，选择满足这两个目标的轴承的最佳参数会出现困难，同时非线性时程分析 (NTHA) 需要大量的计算资源。本文提出了一种利用等效线性系统的随机结构响应来确定最佳轴承设计参数的计算有效方法。关键思想是使用从随机模型中获得的假设最优参数作为从确定性模型中找到的精确最优参数的近似值。随机模型允许快速探索最佳参数候选。计算密集型确定性模型用于通过仅对利用随机模型获得的设计参数候选执行 NTHA 来确定基于性能的优化设计。与穷举搜索方法相比，该方法所需的NTHA案例数量可以显着减少。作为一个数值例子，所提出的方法被应用于梁桥中两种滑动式支座的优化参数选择，即提升滑靴和功能离散支座。由所提出的程序确定的设计参数的桥梁的抗震性能指标几乎等同于穷举搜索方法找到的最佳值。