中文摘要：

建筑施工期结构安全事故频发，使施工期结构安全分析的研究得到广泛重视。现有采用基于概率的分段静态安全分析方法，在对施工期的连续时变描述和计算精度方面存在不足。基于时变结构分析理论的安全分析能更准确地评价施工期结构的安全性能，但在实际应用方面存在着很大的局限性。该文将4D（4-Dimensional，四维）技术引入到建筑施工期时变结构安全分析中，可以为解决时变结构连续动态的全过程分析问题，提供随进度变化的结构模型、完整的数据支持和可视化表现，能简化时变结构的计算过程，提高时变结构建模和安全分析的效率，为时变分析理论的实际应用提供可行的途径和方法。该文论证了将4D技术应用于施工期时变结构安全分析的可行性，提出了4D时变结构安全分析模型和分析方法，开发了基于4D的施工管理和安全分析系统。

英文摘要：

Time-dependent theory has been proven to be more accurate and reliable for safety analysis of structures during construction compared to the traditional static method based on probability. However, applications are restricted in partial periods and partial structures because of the immeasurable artificial intervention. By inducting 4D technology to safety analysis of time-dependent structures during construction, a visualized environment is provided, where the entire analysis data including structure models are accessible according to the construction schedule. Thus, continuously and dynamically time-dependent analysis is achieved. This idea simplifies the process and enhances the efficiency of structure calculation. This paper demonstrates that the organic combination of 4D technology and time-dependent theory is feasible, proposes the 4D safety analysis model of time-dependent structures and the corresponding method for safety analysis, and presents a system for 4D-based construction management and safety analysis.