With the standard disclaimer (I'm not a lawyer, this is not legal advice, etc.): in order to put your dissertation under a CC license, you need to have the right to redistribute all material in the dissertation under that license. To that end, you might find it useful to classify each piece of your dissertation according to the following criteria:
- You hold the copyright in the material. This applies to anything you've written yourself as long as the copyright has not been transferred to another party. OK.
You don't hold the copyright in the material...
...but the copyright holder has licensed it to you for redistribution...
- ...and the terms allow you to redistribute it under the CC license. OK. This is the case for any material from papers that are themselves distributed under the CC license you want to use. It may also be the case for papers that are not CC-licensed, depending on the terms of the copyright transfer agreement.
- ...and the terms don't allow you to redistribute it under the CC license...
- ...but your use of the material is defensible as fair use. OK. This is probably the case if you're quoting passages here and there. Maybe reusing a figure.
- ...and your use of the material is not defensible as fair use. STOP. You cannot put your dissertation under the CC license.
...and the copyright holder has not licensed it to you for redistribution...
- ...but your use of the material is defensible as fair use. OK.
- ...and your use of the material is not defensible as fair use. STOP. If anything in this category is in your dissertation, you can't distribute it at all (which makes it fairly useless as a dissertation).
The question in your case is whether the copyright transfer agreement gives you the right to redistribute under a CC license - in other words, does the material you take from your papers fall under 2.1.1 or 2.1.2? That you probably need to consult a lawyer for.
In the part of the agreement you quoted, it sure seems like the only condition they put on your reuse of the material is that you give credit, and if that's really the case, then it's okay (because you will give credit; that's just good academics and also part of the CC license itself). But the piece of the agreement you quoted doesn't actually say you're allowed to redistribute your distribution with the Springer-owned material in it, and even if you are, it doesn't say you're allowed to choose the license. This is the sort of thing a lawyer might pick on, and why I say you need to consult one of your own.