一、围岩分类的重要发展 “围岩”是指对坑道施工稳定性有影响的周围岩体,但在传统地质学上常把某一岩体周围发生蚀变的变质岩体称为“围岩”。因此,工程上围岩分类只能称为岩体工程分类,避免误解为坑道周围岩体的“围岩”蚀变分类。 I. Important Development of Surrounding Rock Classification “Surrounding rock” refers to the surrounding rock mass that has an impact on the construction stability of the tunnel. However, in the traditional geology, the metamorphic rock mass that has been altered around a rock mass is often called “ rock”. Therefore, the classification of surrounding rock in engineering can only be referred to as rock engineering classification, to avoid misunderstanding as the “wall rock” alteration classification of rock mass around the tunnel.