Abstract: Due to the particularity, diversity and complexity of the working conditions of chemical plants, the unreasonable value of action (load) attribute and the combination for action effects across time and space often occur. It is particularly important to determine the design conditions of transient design situation and accurately apply GB 50068-2018 Unified Standard for Reliability Design of Building Structures. Taking chemical engineering structure as the research object and GB 50068 as the criterion, this paper discusses the attributes of each working condition in the transient design situation of structures in chemical plant and the methods for determining the standard value, puts forward the combination for action effects, and summarizes the structural analysis approach and design methods for the transient design situation of chemical engineering structures.

Key words: transient design situation, limit state design, combination for action effects, limit, partial coefficient