USA government debt ceiling

[Zenaan Harkness]

USA gov froze its government debt in March this year since they hit
the 'statutory maximum' of $18,113,000,080,959.35 (yep, and the 35c).
USGov is now in an extraordinary measures situation to be looked at
again October 30, 2015.
http://www.cnsnews.com/news/article/terence-p-jeffrey/150-days-treasury-says-debt-has-been-frozen-18112975000000

This has happened a few times before,
https://en.wikipedia.org/wiki/United_States_debt_ceiling

but I wonder if there are some real limits being reached, where
they'll be unable to practically raise the USGov debt ceiling? Anyone
have further info on this?