Risk Analysis And Assessment During Construction Of Metro Shield Section Tunnel

The metro shield sector tunneling has the characteristic of high invesment,large scale,complex construction procedure,involving many factors serious consequence and heavy effect.Thereby, it is necessary to implement risk identification, analysis and assessment for the construction of metro shield section tunnel early.The resulsts can be reference for project decision.The parper dissect various parts of construction analysis for subway shield sector tunnel including: risk identification, risk estimation, risk index system and risk assessment. The main contents and achievments of the paper summarized as follows:Discuss the identification method of the risk identification for subway shield sector tunnel based on the project Work Breakdown Structure (WBS) and Risk Breakdown Structure (RBS).Estabish construction risk assessment index system using the Analytic Hierarchy progress method(AHP),and confirm relative index weight of each level with 1-9 scales method.According as the characteristic of fuzzy in risk estimation of subway shield sector tunnel, and the risk factor is quantified by fuzzy theory. The paper put forward experience distributing method base on estimation from expert, solving the quantification issue in risk estimation.Base on R=P×C Model, which considers the collective effect of risk factor occurrence probability and loss serious degree, ascertain the risk level range,accordingly get the risk level of each essential factor.Utilizing fuzzy synthetic evaluation method,get the risk level of each index and holistic risk.Take Guilin Road Station~ Yishan Road Station sector of Shanghai subway R4 line as an example, make risk analysis using textual risk model.