基于PHA-LEC结合层次分析法的隧道施工风险评估

Risk Assessment of Tunnel Construction Based on PHA-LEC Method and Analytic Hierarchy Process

浅埋偏压隧道开挖时围岩受力特征复杂,施工难度大,施工风险高,科学合理地开展隧道施工风险评估工作可以很好地保障人员和财产安全。以郑万铁路重庆段人和隧道为依托,从隧道施工过程状态考虑风险发生的规律特征,运用预先危险性分析(PHA)结合作业条件危险性分析法(LEC)筛选出危险性最高的因素,并对此因素建立合理的隧道风险评估指标体系。结果表明,隧道原岩应力失衡危险性最高,危险性分值是其他危险因素的几倍之多。针对风险分析结果提出相应防范措施,同时采用层次分析法进一步评价影响原岩应力失衡的重要因素,并加以权重数量化描述,形成定性定量相结合的安全评估方法。

The stress characteristics of surrounding rock are complex,the construction difficulty is great,and the construction risk is high.Scientific and reasonable risk assessment of tunnel construction risk can ensure the safety of personnel and property.Based on Renhe tunnel in the Chongqing section of Zheng-Wan Railway,this paper selects the tunnel section to carry out construction risk assessment,considers the regularity of risk occurrence from the initial state of things,and establishes a reasonable tunnel risk assessment index system.The results show that the risk of stress imbalance in the original rock is the highest,and the risk degree is several times higher than that of other risk factors.In view of the risk analysis results,we put forward the corresponding precautionary measures,and,at the same time,use the analytic hierarchy process to further evaluate the important factors that affect the original rock stress imbalance,and make a quantitative description of its weight,so as to form the safety assessment method combining qualitative and quantitative research.