穿越近海破碎带隧道工程风险模糊评价和应用

Risk Fuzzy Assessment for Offshore Tunnels Crossing Fault Zones and Its Application

针对矿山法隧道穿越近海破碎带的工程风险评估,通过事故调研,选取围岩失稳和突水风险的四小类影响因素和对应的9个工程风险评价指标,并确定各评价指标的分级标准,形成工程风险的四层次评价体系;采用模糊可变集合工程方法,对实际穿越点的评价指标实测值进行隶属度分析,并通过关联函数法动态赋权,加权求和确定穿越点的工程风险隶属度和特征值,建立矿山法隧道穿越近海破碎带工程风险的四层次模糊评价方法。在工程应用中,结合地质雷达等超前地质预报数据,对青岛地铁某近海区间隧道两次穿越次生构造破碎带进行工程风险评估,结果与实际施工情况一致。

In regard of the risk assessment for offshore tunnels crossing fault zones,four subfactors with nine indicators as well as the critical standards are confirmed to establish a four-level evaluation system for risk assessment of instability and water inrush. The membership degrees of measured values obtained from practical crossing sites are analyzed based on the variable fuzzy set assessment method,and weights of indicators are distributed through the dependent function. Afterwards,the comprehensive membership degree and eigenvalue of the project risk during crossing the fault zones are obtained by the weighted sum method. Thus,a fuzzy risk assessment method with fourlevel synthetic evaluation for offshore tunnel crossing fault zones is established in this paper. A case is studied based on an offshore metro tunnel project in Qingdao,China. In the light of advanced geological prediction,the risk of two crossing sites are analyzed through the method obtained in this paper,and the evaluation results agree well with the actual situation.