I am working as a seismic design engineer and designing bracing for some vertical pipes.
I was wondering whether the floor slab provides any form of restraint for the vertical pipes or if they need to be restrained specifically.
If the pipe is attached to the floor then yes the floor is supporting the pipe, but you also need to consider SAM when the floor moves.
Does the attachment to the floor provide enough support? That depends on the size of the pipe, what's in it and span between floors. You may able to use the rules in B31E. Also have a look at PN19.