隧道坍方突发性事件风险可拓法综合评估

Comprehensive extension assessment on tunnel collapse risk

为了综合评价隧道坍方风险,在统计分析坍方诱因的基础上,借鉴可拓学原理,建立隧道坍方风险可拓评估流程,构建评价指标体系和评价标准,对定性指标进行量化,并对各指标进行归一化、无量纲化预处理,用简单关联函数计算指标权重,从而避免人为主观因素的影响,并将可拓评估模型应用到武广客运专线浏阳河隧道坍方风险评估中。研究结果表明:坍方主要诱因是降雨、围岩软弱破碎及施工方法不当等;浏阳河隧道的坍方风险为高度,预防坍方应加强施工地质勘测,重视监测信息反馈,提高施工应变和施工处理能力。

On the basis of statistical analysis on inducing factors of tunnel collapse,extension theory was applied to comprehensively evaluate tunnel collapse risk.The process is as follows.Flow chart of extension assessment was firstly established,and some main influencing factors with non-dimension preprocessed,including the classification of tunnel collapse,were used to set up classical and limited matter-elements.A simple dependent function was then used to determine factor weight for avoiding human subjective effect.The extension assessment model was used to evaluate collapse risk in Liuyanghe tunnel.The results show that the main inducing factors of tunnel collapse are weak rock and rainfall,for weak rock has very poor mechanical properties and rainfall will weaken rock mechanics and reduce the effective stress in surrounding rock.Thus it is easy to yield and become more instable.Collapse risk of Liuyanghe tunnel is high and some prevention measures must be taken such as putting emphasis on geology survey and monitoring during construction,and improving treatment capacity of collapse as well.