If this is indeed supposed to be a pier (so the children can dock their toy boats near their pirate fortress), I believe that the "pier floorings" should be the deck [of the pier]. And that the "stand of the pier flooring" should be the piles or pillars which are used to support the deck of the pier.

For more assistance in untangling the English, I suggest reposting your question(s) in the English to English forum. :-)

A pier is a raised walkway over water, **supported by widely spread piles or pillars**. The lighter structure of a pier allows tides and currents to flow almost unhindered, whereas the more solid foundations of a quay or the closely-spaced piles of a wharf can act as breakwaters, and are consequently more liable to silting. Piers can range in size and complexity from a simple lightweight wooden structure to major structures extended over a mile out to sea. Piers are the same as docks, which would be found in lakes or on rivers, it is the standard terminology used.
http://en.wikipedia.org/wiki/Pier

In American English, a dock is technically synonymous with pier or wharf—any human-made structure in the water intended for people to be on. However, in modern use, pier is generally used to refer to structures originally intended for industrial use, such as seafood processing or shipping, and more recently for cruise ships, and dock is used for most everything else, often with a qualifier, such as ferry dock, swimming dock, ore dock and others. However, pier is also commonly used to refer to wooden or metal structures that extend into the ocean from beaches and are used, for the most part, to accommodate fishing in the ocean without using a boat.
http://en.wikipedia.org/wiki/Dock_(maritime)

How to Install Deck Piers

Deck piers support the beams that create the joist spans for a deck. This is the foundation of the deck and if not properly installed will result in failure of part or the entire deck. Unlike a concrete footing that distributes the weight of the structure over a large area, piers concentrate the load to a small area. Ground stability and soil compaction are very important when you consider using this type of foundation structure. Be sure to determine the bearing capacity of your soil and keep a factor of safety of at least 4.

This article will show you how to install beam piers to support **a deck**.
http://www.wikihow.com/Install-Deck-Piers