This paper proposes a subset simulation (SS) based approach for space and time-dependent reliability analysis of corroding pipelines. It is assumed that the pipeline can fail either due to leakage and/or burst. We propose two distinct approaches for tackling the problem. In the first approach, we treat the problem as a time-variant system reliability problem. The problem is formulated as a series system where failure at one of the defect locations will result in failure of the pipeline. This approach is particularly suitable when there are only a limited number of corrosion defects. In the second approach, the reliability analysis problem is treated as a ‘space-time variant’ reliability analysis problem. This approach is particularly suitable when exact knowledge about the number of defects is not available. In both the approaches, the time-dependent probability of failure is represented in an auto-regressive form such that the probability of failure at a given time can be computed based on the probability of failure at the previous time and an incremental failure probability. A simple composite limit-state function is proposed for computing the incremental failure probability. SS is used for computing the initial and incremental failure probabilities. To illustrate performance of the proposed approach, four pipeline problems representing different scenarios are considered. For all cases, the proposed approach is found to yield highly accurate results.

本文提出了一种基于子集仿真（SS）的腐蚀管道时空相关可靠性分析方法。假定管道可能由于泄漏和/或爆裂而失败。我们提出了两种解决问题的方法。在第一种方法中，我们将问题视为时变系统可靠性问题。该问题被表述为一个串联系统，其中一个缺陷位置的故障将导致管道故障。当腐蚀缺陷数量有限时，此方法特别适用。在第二种方法中，将可靠性分析问题视为“时空变异”可靠性分析问题。当无法获得有关缺陷数量的确切知识时，此方法特别适用。在这两种方法中 随时间变化的故障概率以自回归形式表示，因此可以基于前一时间的故障概率和递增的故障概率来计算给定时间的故障概率。提出了一种简单的复合极限状态函数来计算增量失效概率。SS用于计算初始和增量故障概率。为了说明所提出方法的性能，考虑了代表不同情况的四个管道问题。对于所有情况，发现所提出的方法都能产生高度准确的结果。