The Surrounding Rock Quality Classification Of The Underground Building Main Workshop In The Hydropower

The main underground powerhouse caverns of the hydropower project are all arrangement in granite bodies at right bank of the Yellow River. As for the whole aspects, the quality of rock mass is good. But in the workshop area, the rock mass has grown a large number of structural planes because of the influence of many phase of tectonic disturbances and surface transformation. It not only deteriorates the quality of rock mass, reduces the intensity of rock mass, but also affects to the partial stress field distribution of the project area. So it has the extremely disadvantageous influence to underground hole's excavation and the adjacent formation stability. Therefore, we must conduct the rock mass quality graduation research to the main hole room of underground workshop.This article introduced the concrete uses and the evaluation criteria of the geological mechanics classification(RMR), the BQ classification and the taxonomic approach proposed in hydropower engineering geology reconnaissance standard (below said "hydropower system classification", is called the HC classification) Carrying on the classification to the adjacent formation of underground workshop, with these 3 taxonomic approach, reference to the project, carrying on the contrast and the relevant analysis to the result, it has obtained reasonable and scientific appraisal classification result of the adjacent formation. Based on this measure results, it has drew the dam area rock mass quality graduation chart and demonstrated accurately the underground workshop's rock mass quality character, it has confirmed the serviceability and the unity of these three taxonomic approaches in this kind of rock mass graduation. In the foundation of the full investigation and the grasping of materials, it proposes the inadequacy of the rock mass engineering geology classification in the actual project's application, raised specific targets and the actual operation method, summed up the development direction of rock quality classification in future.