Abstract：
In order to solve some features of the subway construction schedule such as uncertainty and variability, Monte Carlo simulation using this paper, duration risk optimization of underground enclosure structure and the supporting system construction, so as to achieve the reasonable pretreatment on schedule risk control purposes. The use of Crystal Ball software, the relationship between processes for establishing the model, Monte Carlo simulation analysis, obtained within 404 days of completion probability is greater than 85%, and the sensitivity analysis, found the land requisition and pipeline to move is a key activity duration, increase the time limit for a project buffer on them to ensure the implementation of the overall goal. Through the research, fault-tolerance probability of projects completed was evaluated and modified, the project completed on schedule with realistic guiding significance.
