subsoil

They embedded the pilings deep into the subsoil.

他把桩深深打进地基下的中。

He embedded the pilings deep into the subsoil.

他把桩深深打进地基下的中。

Earthworms burrow deep into the subsoil.

蚯蚓深深地钻进底。

Some movement in the building will occur as it settles into the subsoil.

楼房沉到下层时，楼里就会有动静。

In loessal regions and alluvial valley fills of the western United States, both surface soil and subsoil are commonly friable.

在美国西部黄冲积河谷里，表底一般是容易破碎的。