基于模糊层次综合评判法的隧道坍塌风险评估

An improved risk assessment method in regard to the cross-tunnel landslide geological zones

在隧道工程实施阶段,开展定量施工安全风险评估,对预防和控制风险、降低事故发生概率有重要作用。以某工程施工隧道不良地质条件区域（古滑坡K9＋600~K10＋000和浅埋段K10＋430~K10＋490）为研究对象,采用模糊层次综合评判法,通过建立因素集（包括勘察、设计、施工情况,施工方式及支护结构,地质环境因素,监控测量与地质预报和施工管理5个一阶因素）、评价集、权重集对隧道施工坍塌风险进行模糊判定,经矩阵计算,隧道滑坡区域和浅埋段区域坍塌事故可能性均为Ⅳ级。依据指标体系法及模糊层次综合评判法所得结果分别为Ⅲ级和Ⅳ级,鉴于模糊层次综合评判法较指标体系法涉及评判指标更全面、更有针对性、更符合施工场地客观条件,坍塌事故可能性最终评判结果为Ⅳ级。研究表明：模糊层次综合评判法在不良地质隧道安全风险评估中的应用使估测指标更精确、更有效;评估的技术创新使施工安全风险评估更具针对性,保证了施工的安全。

This paper would like to present an improved risk assessment method as regard to the tunnel crossing landslide geological zone or zones. In the paper,we have taken as research study sample a tunnel project under construction in the area of the poor geological conditions（ ancient landslide（ K9 ＋ 600-K10 ＋ 000）in the shallow buried section（ K10 ＋ 430-K10 ＋ 490）） by establishing the factor sets（ including the five first-order factors,i. e.the condition of survey,the design and construction,the construction method and the supporting structures,and the geological environment factors,in addition to monitoring the measurement and geological prediction,and the construction management）,evaluation sets and the weight sets to make fuzzy decision for the risk assessment indexes of the tunnel collapse in construction through applying the method of comprehensive fuzzy hierarchical evaluation. In the construction stage of the tunnel project,we have made the quantitative risk assessment for the safety construction the most important link in controlling and preventing from the risks concerned so as to reduce the accident probability. And in turn the probability for the tunnel collapse both of the ancient landslide and the shallow buried sections have been set up at grade IV by the matrix calculation. Nevertheless,according to the above application results,the risk probabilities have been identified and determined respectively as grade Ⅲ and grade Ⅳ,in view of which,the risks involved should be more comprehensive,more targeted,more in line with the actually existing conditions of the construction site and the other related factors than merely illustrated in the index system,while taking into account the comprehensive factors,the possibility of the final assessment results should be set up at about grade Ⅳ,which is likely to cause collapse accidents. Thus,the results of our evaluation have shown that the comprehensive evaluation method of the fuzzy hierarchical evaluation model can successfully be used for the safety risk assessment for the poor geological tunnel conditions more reliable and effective. In addition,the technological innovation we have gained can be made the risk assessment of construction safety more targeted to ensure the construction safety in the process of excavation. Thus,it can be expected to have important theoretical and practical value to predict the risk of construction safety and provide a referential basis and technical support for the evaluation of such like projects.