Surrounding rocks classification plays a determinative role in the design and construction of tunnels. 摘要围岩分类对于隧道设计和施工起着决定性的作用。
On the basis of the past schemes, new classifications of pyroclasts and the petrographic as well as the petrogenetic classification of pyroclastic rocks are proposed in this paper. 中国学者提出的火山碎屑岩分类时间较早，有自己特色，在一定的范围得到了应用。
