Can I upload my open access publications on researchgate.net or academia.edu?
Maybe. But not necessarily. It depends on the exact terms and conditions of the open access paper: there are many different variants (Springer use more than one, as do many other publishers). It also depends on the exact terms and conditions of the site you intend to upload to.

So there is no general answer, beyond this:


Read and understand the licence on the paper.
Read and understand the terms and conditions of the site you want to upload to.
Work out whether they're mutually consistent, and whether you want to accept the T&amp;Cs of the site you want to upload to.