Question

The lower portion of a manhole is is known as

Answer 1

hey mate here is your answer..
The lowest component is called the base section.

hope it will help you my dear friend plz mark it as brainliest one.

Answer 2

Answer:

The lower portion of a manhole is usually known as the working chamber.

Explanation:

The lower portion of the manhole is designated or known as the working chamber. It gives a proper working space for inspection and cleaning the operations of the working sewer. Its minimum or short size for a rectangular-shaped manhole is usually 1.2 m x 0.9 m and for a circle-shaped manhole, the minimum diameter is usually about 1.2 - 1.4 m. The height of this chamber needs to generally be not less than 1.7- 1.8m.