基于改进PERT的输水隧洞施工进度风险分析

Construction Schedule Risk Analysis of Diversion Tunnel Based on Improved PERT

文章提出了改进的PERT方法,克服了经典PERT中未考虑逻辑关系不确定性和活动时间仅限于特定形式β概率分布的不足。首先从风险事件的角度出发,将定性分析与定量分析相结合,探讨逻辑关系变化对施工进度的影响;其次,在三时估计值的基础上引入四分位数作为第四个参数,提出了不同β分布形式的确定方法;最后,运用Monte Carlo仿真法对改进的PERT网络进行求解,实现对输水隧洞施工进度风险更加全面的分析,为隧洞施工进度管理提供了科学的依据。

Improved PERT is proposed and can be used to overcome the deficiency that traditional PERT neglects the un -certainty of logic relationship and activity time is limited to specific forms of βdistribution.Specifically, firstly, from the perspective of risk event , combine the method of qualitative analysis and quantitative analysis , and study the impact that the change of logic relationship makes on construction schedule .Secondly , apart from original three time parameters , add the fourth parameter-quartile, and propose the method which can help obtain various forms of βdistribution.Lastly, use Monte Carlo simulation to solve the improved PERT network and realize the comprehensive analysis of diversion tunnel schedule risk , which provides scientific basis for tunnel construction management .