trough vault

例句：

1. 1. The engineers were working on the construction of a new tunnel vault.
   工程师们正在建设一个新的隧道拱顶。
2. 2.The tunnel vault was constructed to support the weight of the heavy equipment.
   隧道拱顶被建造来支撑重型设备的重压。
3. 3.The tunnel vault is an essential part of the underground transportation system.
   隧道拱顶是地下交通系统的重要组成部分。