基于AHP-TOPSIS的深长引水隧洞穿越破碎地层塌方风险评价

Risk Assessment of Collapse in Fractured Strata for Deep and Long Water Diversion Tunnels Based on AHP-TOPSIS

深长引水隧洞穿越破碎地层时极易诱发塌方风险,地层塌方风险评价的科学准确评级对于降低施工风险和成本具有重要意义。如何简单、快速、准确地对地层塌方风险进行评价一直是一个有挑战性的研究内容,也是现场施工的迫切需求。深长引水隧洞穿越破碎地层塌方风险受多种因素的影响。从地质角度和施工角度选取隧洞开挖跨度,隧洞埋深,岩体完整性、地下水发育程度,结构面状态和施工管理水平6个指标,建立了深长隧洞塌方风险评价体系。基于AHP-TOPSIS的基本原理,建立了深长引水隧洞穿越破碎地层塌方风险评价模型。通过AHP确定其权重系数,使用TOPSIS理论确定破碎地层塌方风险等级。该模型成功对磨盘山隧洞进行评级,取得了良好的评价效果。结果显示:71+899~999段落的评价结果为V级风险,现场风险极大,开挖过程中在71+995发生小型塌方。

When the deep and long water diversion tunnel passes through fractured strata,it is highly likely to trigger the risk of collapse.The scientific and accurate rating of geological collapse risk assessment is of great significance for reducing construction risks and costs.How to evaluate the risk of geological collapse simply,quickly,and accurately has always been a challenging research topic and an urgent need for on-site construction.The risk of collapse of a deep and long water diversion tunnel passing through fractured strata is influenced by various factors.A risk assessment system for deep and long tunnel collapse was established by selecting six indicators from geological and construction perspectives,including tunnel excavation span,tunnel burial depth,rock integrity,groundwater development level,structural plane status,and construction management level.Based on the basic principles of AHP-TOPSIS,this paper establishes a risk assessment model for the collapse of deep and long water diversion tunnels crossing fractured strata.It determines the weight coefficients through AHP and uses TOPSIS theory to determine the risk level of collapse in fractured strata.The model successfully rated Mopanshan Tunnel and achieved good evaluation results.The results show that the evaluation of paragraphs 71+899~999 is a V-level risk,with extremely high on-site risk.During the excavation process,a small collapse occurred at 71+995.