My initial thought:

A wave forms due to one "blob" of water colliding with a different "blob" of water moving at a different velocity. The kinetic energy is converted to potential energy, and therefore, you get an equal increase in height of the fluid minus the compressibility of the fluid (and we all know how compressible water is).

Depending on the depth of the pipe and the height of the colliding "blobs" of liquid, the force against a body in it could be in any of the 6 directions. (Depending on the size of the body, I'm fairly certain it could also impart meaningful moment.)

Since we assume the floor itself is also incompressible, the pipe probably isn't going to flex downwards as far as beam analysis is concerned.

Therefore, we should check to see if the buoyancy plus "blob collision lift" causes harm to our pipe.