Workers excavate a trench, inside of which the lining for the tunnel is built. It is then covered over with the earth or other fill that was originally removed.

工人们开挖一条壕沟，在沟内砌好隧道的衬砌，然后用土覆盖，或用最初挖出的土石方回填。

youdao

He crawled into the tunnel and disappeared from sight, completely covered with straw.

他钻进隧道里，整个儿被稻草埋住，不见了。

youdao

In the middle of the room is a tall triangular tunnel that is covered in mirrors.

VOA: special.2009.03.11

Ofelia, wandering through a tunnel, encounters the Pale Man sitting motionless at the head of a banquet table covered with food.

NEWYORKER: Show The Monster