General frameworks for reliability differentiation have evolved over time and are mainly developed for buildings. However, recommendations for the safety of existing quay walls are lacking. In this study, target reliability indices for assessing existing quay walls were derived by economic optimisation and by evaluating the requirements concerning human safety. In quay-wall design, some dominant stochastic design variables are largely time-independent, such as soil and material properties. The influence of time-independent variables on the evolution of the probability of failure was taken into consideration, since this affects the present value of future failure costs and the associated target reliability indices. The target reliability indices obtained for existing quay walls depend on the consequences of failure and the remaining lifetime. If the failure modes of a quay wall are governed by time-independent design parameters and the quay wall has already survived the early service period, the residual probability of failure is lower for an existing quay wall compared to a new structure. Hence, this should be considered in the determination of target reliability indices. The method to evaluate quay-wall reliability over time can also be used to assess other civil and geotechnical structures.

可靠性差异化的通用框架随着时间的推移而发展，并且主要针对建筑物而开发。但是，缺乏有关现有码头墙安全性的建议。在这项研究中，通过经济优化和评估有关人员安全的要求得出了评估现有码头墙的目标可靠性指标。在码头墙设计中，一些主要的随机设计变量在很大程度上与时间无关，例如土壤和材料特性。考虑了时间无关变量对失效概率演变的影响，因为这会影响未来失效成本的现值和相关的目标可靠性指标。现有码头墙获得的目标可靠性指标取决于故障的后果和剩余寿命。如果码头墙的破坏模式由与时间无关的设计参数控制，并且码头墙已经在服务的早期阶段幸存下来，则与新结构相比，现有码头墙的剩余失效概率较低。因此，在确定目标可靠性指标时应考虑这一点。随时间推移评估码头墙可靠性的方法还可用于评估其他土木和岩土结构。