基本释义:

上导洞开挖

网络释义

1)top heading excavation,上导洞开挖

2)excavation of pilot tunnel,导洞开挖

3)Three guide holes,三导洞开挖

4)Multi-pilot-cavity excavation,多导洞开挖

5)heading and bench excavation,导洞与台阶开挖

6)tunnel-door digging,洞门开挖