基于粗糙集与AHP的深埋隧道软岩大变形研究

Research on the Large Deformation of Soft Rock in Deep Tunnel Based on Rough Set and AHP

研究目的:软岩大变形是铁路深埋隧道修建过程中遇到的主要工程地质问题。本文根据兰渝铁路的施工数据,分析控制软岩大变形级别的主要影响因素,确定其主客观权重,建立软岩大变形预测模型并对其进行计算验证。研究结论:(1)岩性、岩体完整程度、层厚、地应力状态、岩层走向与隧道关系、地下水、岩层倾角7个指标为影响软岩大变形的主要因素;(2)粗糙集和层次分析法(AHP)主客观分析中,岩体完整程度、岩层层厚、地应力状态的权重均显著更高,而岩层走向与隧道夹角、地下水、岩层倾角、岩性等相对影响较小;(3)计算结果显示,本次建立的AHP结构模型在兰渝铁路哈达铺隧道中匹配度极高;(4)本文研究可为类似铁路地质选线、风险评估和工程设计提供支撑,同时给隧道围岩大变形的分级和预测提供新的思路。

Research purposes: Large deformation of soft rock is the main engineering geological problem encountered in the construction of deep buried railway tunnels. Based on the construction data of Lanzhou-Chongqing railway, this paper analyzes the main influencing factors controlling the large deformation level of soft rock, determines its subjective and objective weight, establishes the prediction model of large deformation of soft rock and carries out calculation verification.Research conclusions:(1) Lithology, rock integrity, layer thickness, ground stress state, relationship between rock strata strike and tunnel, groundwater and rock strata dip angle are the main factors affecting large deformation of soft rock.(2) In the subjective and objective analysis methods of rough set and Analytic Hierarchy Process(AHP), the weights of rock integrity degree, layer thickness and ground stress state are significantly higher, while the other factors are relatively minor.(3) The calculation results show that the AHP structural model has a high matching degree in Hadapu tunnel of Lanzhou-Chongqing railway.(4) The research result can provide support for similar railway geological line selection, risk assessment and engineering design, and provide a new idea for classification and prediction of large deformation of tunnel surrounding rock.