基于可拓学理论的围岩分级方法在变质软岩隧道中的应用

Rock Mass Classification Based on Extenics Theory Applied in Metamorphic Soft Rock Tunnel

对可拓学中物元、可拓集合的概念进行了阐述,并以火车岭隧道为例,结合影响变质软岩区隧道稳定性的岩性、结构面、地下水等主要因素,选取钻孔岩芯质量、隧道埋深、地下水流量、饱和单轴抗压强度、结构面间距作为评价指标,同时选择3个典型岩段,建立相应的待评物元模型;对各评价指标及各围岩级别的关联度指标进行了计算,据此对3个岩段进行分级的结果表明,绿泥钠长石英片岩岩段为Ⅲ级,与原设计相符;绢云母石英片岩岩段为Ⅱ级,比原设计低一级;白云钠长石英片岩岩段为Ⅳ级,比原设计高一级。该分级方法与RMR法、Q法及公路隧道规范分级方法的对比结果表明,传统方法与现场条件存在较大误差,证明基于可拓学理论的围岩分级方法能较好地满足该围岩条件的要求,同时分析了传统围岩分级方法在该地质条件下应用的缺陷。

The paper first presents the concept of object-element and extenics set in Extenics theory. Then it takes Huocheling Tunnel, a metamorphic soft rock tunnel, as example to illustrate the application of such theory. The evaluating indicators, such as RQD, tunnel burying depth, ground flow, saturation uniaxial compression strength, structure spacing, are selected according to the stability factors, for example lithological character, structure surface and ground water. Also chosen are 3 typical section planes. Then the corresponding object-element models are established. Moreover, the paper discusses the calculation of the dependent degree values of all evaluating indicators and rock mass grades, and the classification of 3 section planes. It indicates that the chlorite-albite schist section is a III grade and fits the original design, while the sericite-schist section, II grade, is lower than the design and the muscovite- quartz section, IV grade, is higher than the design. Finally, it compares this method with RMR method, Q method and Tunnel Standard Graduation method, which were inapplicable with the field condition, and declares the applicability of this method in this stratum. Additionally, it analyzes the limitation of the traditional methods in this geological condition.