Is it possible to use several JR Passes in a row?

Yes, it is possible, but you must be able to collect all the exchange vouchers within 3 months before the desired starting date in Japan.

You can choose this solution, for example if you travel in Japan for a month and need two 7-days JR pass, one on the first week of your stay, and the other on the last week.

Naturally it is also possible to combine regional JR Passes as well.