Surrounding rocks classification plays a determinative role in the design and construction of tunnels. 摘要圍岩分類對於隧道設計和施工起著決定性的作用。
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. 中國學者提出的火山碎屑岩分類時間較早，有自己特色，在一定的範圍得到了應用。
