花岗岩风化壳分带与岩体基本质量分级关系探讨

 风化壳分带和岩体质量分级对浅埋隧道设计和施工很重要，需对这两套系统定性和定量指标做平行判别。中国东部花岗岩分布区，强风化带(IV)和全风化带(V)、岩体质量III和IV级界限划分上常存在较大分歧。据此，对此问题开展探讨，并通过大亚湾隧道工程实例予以说明。研究表明，浅埋条件下风化壳分带同岩体质量级别空间上有交叉现象，前者是宏观的，后者是细观的，前者控制后者；风化带IV，V和III，IV级岩体涉及到岩土过渡、岩体节理密度、裂隙水和孔隙水等多个指标和因素的复杂变化；岩体质量级别比风化壳带号大致高1.5。

DISCUSSION ON RELATIONSHIP BETWEEN WEATHERING CRUST ZONATION AND BASIC QUALITY CLASSIFICATION OF ROCK MASS

Both weathering crust zonation and quality classification of rock mass are important for shallow-buried tunnels. Qualitative differentiation and quantitative index should be distinguished for each of the two systems in underground engineering. In granite area with relatively good geological conditions，middle and low in-situ stress and groundwater in East China，the relationship between weathering crust zonation and basic quality classification of rock mass，which has some common ground and spatial crossover in shallow-buried tunnels，is found. Taking the Daya Bay tunnel for an example，the relationship of the two systems and relative indices is discussed. As a result，it is found that the weathering crust zonation is macroscopic，and the quality classification is mesoscopic，and the latter is controlled by the former. Generally，the grade of rock mass quality is about 1.5 times higher than that of the weathering crust zonation of granites in shallow-buried tunnels in East China.