Mooring & Berthing Cells - Manholes

[Dewh0002]

This might be more appropriate in a different forum, but I was wondering if anyone has experience with detailing cells for mooring & berthing of vessels. In my experience, these cells are constructed out of flat sections of sheet pile installed in a circle with a concrete cap. In the center of the concrete cap, I've seen manholes installed. What is the purpose of these manholes? The cells I've inspected don't have any utilities in them and don’t have anything else within the cell except fill material? Are they just to inspect the material within the cell for signs of settlement?

 

[LittleWheels]

Generally to check for fill settlement or fill loss. The concrete capping is typically considered to be supported on the fill.

On rare occasions, there might be an earthing point under a pit lid but earthing is commonly directly to the sheet piles.