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

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.