Title: Efficient seismic reliability and fragility analysis of lifeline networks using subset simulation Show Chinese title

Title: 基于子集模拟的线路网络高效地震可靠性和易损性分析

Abstract: Various simulation-based and analytical methods have been developed to evaluate the seismic fragilities of individual structures. However, a community's seismic safety and resilience are substantially affected by network reliability, determined not only by component fragilities but also by network topology and commodity/information flows. However, seismic reliability analyses of networks often encounter significant challenges due to complex network topologies, interdependencies among ground motions, and low failure probabilities. This paper proposes to overcome these challenges by a variance-reduction method for network fragility analysis using subset simulation. The binary network limit-state function in the subset simulation is reformulated into more informative piecewise continuous functions. The proposed limit-state functions quantify the proximity of each sample to a potential network failure domain, thereby enabling the construction of specialized intermediate failure events, which can be utilized in subset simulation and other sequential Monte Carlo approaches. Moreover, by discovering an implicit connection between intermediate failure events and seismic intensity, we propose a technique to obtain the entire network fragility curve with a single execution of specialized subset simulation. Numerical examples demonstrate that the proposed method can effectively evaluate system-level fragility for large-scale networks. Show Chinese abstract

Abstract: 各种基于仿真的和分析的方法已被开发用于评估单个结构的地震易损性。 然而，社区的地震安全性和恢复力在很大程度上受到网络可靠性的制约，这不仅由部件易损性决定，还由网络拓扑结构和物资/信息流动决定。 然而，由于复杂的网络拓扑结构、地面运动之间的相互依赖性以及低失效概率，网络的地震可靠性分析常常遇到重大挑战。 本文提出通过一种基于子集模拟的网络易损性分析方差减少方法来克服这些挑战。 在子集模拟中的二元网络极限状态函数被重新表述为更具信息量的分段连续函数。 所提出的极限状态函数量化了每个样本接近潜在网络失效域的程度，从而能够构建专门的中间失效事件，这些事件可以用于子集模拟和其他顺序蒙特卡洛方法。 此外，通过发现中间失效事件与地震强度之间的隐含联系，我们提出了一种技术，只需一次专门的子集模拟执行即可获得整个网络易损性曲线。 数值示例表明，所提出的方法可以有效地评估大规模网络的系统级易损性。