钻爆法施工隧道塌方风险分析

目的塌方是钻爆法隧道施工中常见事故，为有效预防塌方事故的发生，运用风险分析理论对隧道塌方风险进行研究．方法以收集的103例隧道塌方案例为背景，对塌方风险因素进行辨识和统计分析，并利用事故树分析法计算各风险因素的重要度．风险分析中用事件树方法估计事故可能性；用层次分析法估计事故可能损失，并给出事故损失等级划分标准；综合事故发生可能性和可能损失运用风险矩阵法进行塌方风险综合评价．结果分析表明不良地质是事故发生的主要内在因素，人为因素是重要诱因，通过控制地质勘察、施工工序、施工中地质观察等因素可有效预防事故发生．结论给出了完整的隧道塌方风险分析流程，可为隧道建设中塌方风险评价提供有效途径．

Risk Analysis of Collapse for Tunnels Constructed by Drill and Blast Method

The occurrence of collapse is common in tunnels constructed by drill and blast method. It often brings about serious or even disastrous damage to construction works. Hence this paper was drawn up to review the main aspects related to collapse, to identify and evaluate its risk, and to present a risk analysis procedure for it. Firstly, risk factors are identified on the basis of an extensive collection of collapse cases. To show the main causes and mechanisms of collapse, the statistical analysis and the fault tree analysis are carfled out, and risk factors ranking is given. Secondly, event tree analysis is employed to evaluate the collapse probability. And the analytic hierarchy process is used to evaluate the potential loss of collapse. Risk matrix method is employed in the following risk assessment. Then a flowchart for tunnel collapse risk analysis is presented, which provides an effective way to avoid or minimize the consequences of collapse during tunnel construction.