usb 3 expantion

i want to make an expansion for the USB 3.0 to connect more devices with the usb 3.0, but the connection will be direct on the board

Are you building a custom carrier board, or is your goal to expand the existing board? A sample case on how this would be used would offer insight into design requirements and goals.

yes i want to build a board connected directly by soldering it on the KIT TX1
to make me able to connect more devices using USB 3.0

Maybe some of the info from this thread will be relevant?
Other approaches typically include onboard USB3 hub, or additional interfaces provided over PCIe or via mini-PCIe/M.2 mezzanine

If you need it on the devkit, perhaps a PCIe USB card.