We looked at the sample, and signed the lease prior to the previous tenant
moving out, just like everybody else does.

Then they have other units? Let them know the noise bothers you quite a bit
and that it looks like the repairs may not meet the building code. Ask that
they let you move to another unit. If it's not too late, be polite, but
firm, in that the noise is well beyond the reasonable amount one might
expect from a normal situation. Meet them halfway, if they don't have a
unit available immediately then give them some time. If they're not willing
to consider the idea then you have to decide how much you want out of the
lease. You may well have to spend a bit of time/money in court to get out of
it.