长大深埋隧道未开挖段岩爆灾害风险评估

Research on risk assessment of rockburst disaster in unexcavated section of long and deep-lying tunnel

为综合评估长大深埋隧道岩爆灾害风险,基于大量岩爆研究文献及待评估隧道的工程条件建立岩爆风险评估指标体系,包括单轴抗压强度、地应力、岩体完整性系数3个指标,并将岩爆风险划分为低、中、高和极高4个等级;根据围岩等级将待评估的五老峰隧道未开挖部分划分为4个区段,根据指标体系搜集各区段指标值,并将指标区间划分值与实际指标值归一化;基于重要性排序法和可拓综合评判确定未开挖区段的岩爆风险等级。研究结果表明:该隧道区段1,3和4的岩爆风险为中度,后续施工中应予以监测;区段2的岩爆风险为高度,在后续施工中必须采取风险控制措施降低风险并加强监测。

To assess the risk of rockburst disaster in the long and deep-lying tunnels comprehensively,based on the extensive literature of rockburst research and the engineering conditions of the tunnel to be evaluated,an index system of rockburst risk assessment was established,which included three indexes of uniaxial compressive strength,in-situ stress and integrity coefficient of rock mass.The rockburst risk was divided into four grades of low risk,medium risk,high risk and extremely high risk.According to the grade of surrounding rock,the unexcavated part of Wulaofeng tunnel to be evaluated was divided into four sections,and the index values of each section were collected according to the index system,then the interval demarcation values and actual values of the indexes were normalized.The rockburst risk levels of the unexcavated sections were determined by the importance ranking method and the extension comprehensive evaluation.The results showed that the rockburst risk levels of tunnel section 1,section 3 and section 4 were the medium risk,which should be monitored during the subsequent construction.However,the rockburst risk level of section 2 was high risk,and the risk control measures must be taken to reduce the rockburst risk during the subsequent construction,with strengthening the monitoring.