Abstract

For practical decisions on common recurring maintenance actions, the information from routine inspections form a decision basis for the bridge manager. It is often difficult to assess whether this information is sufficient for deciding on a repair action, or if more information is needed. For many bridges the information for supporting decisions may be limited, although those bridges cause large yearly maintenance costs for the society. The purpose of the study presented in this paper is to show how two different models for decision making based on Bayesian decision theory, a point-in-time decision model and a sequential updating decision model, can be used to improve the decision-making process for common maintenance decisions. The models use information from routine inspections and incorporates time dependent aspects such as material degradation and time value of money to improve the decision-making process. The focus is on presenting the methodology with a case study of a concrete bridge in Sweden where the edge beams may have to be replaced. Three assessment approaches are considered: (i) no assessment, (ii) desktop evaluation and (iii) measurements. The main finding is that sequential updating decision making will provide a higher benefit than a point-in-time decision, and thus give higher Value of Information. This value becomes even higher when the measurements are selected for the assessment. The results also show that the edge beams should be replaced. The general approach presented can be applicable to many decision scenarios related to maintenance of deteriorating structures.

摘要

对于常见的经常性维护行动的实际决策，来自例行检查的信息构成了桥梁管理者的决策基础。通常很难评估这些信息是否足以决定维修行动，或者是否需要更多信息。对于许多桥梁来说，支持决策的信息可能是有限的，尽管这些桥梁每年都会为社会带来巨大的维护成本。本文提出的研究目的是展示如何使用基于贝叶斯决策理论的两种不同的决策模型，即时间点决策模型和顺序更新决策模型来改进决策过程用于常见的维护决策。这些模型使用来自例行检查的信息，并结合时间相关方面，例如材料退化和金钱的时间价值，以改进决策过程。重点是通过瑞典一座混凝土桥的案例研究来介绍该方法，其中可能需要更换边梁。考虑了三种评估方法：（i）不评估，（ii）桌面评估和（iii）测量。主要发现是顺序更新决策将提供比时间点决策更高的收益，从而提供更高的信息价值。This value becomes even higher when the measurements are selected for the assessment. 结果还表明应更换边梁。