no or low carbonation flat beer

So I brewed a barley wine which I bottled after 10 days in the primary and another 26 in the secondary. FG was 1.028 and ABV is 9.6%.

I've waited 5 weeks (and agitated the bottles some) but just opened a bottle and no hiss . . . no bubbles. The beer is delicious otherwise.

There is a bit of sediment at the bottom of the bottles. Should I add a carb tab and maybe a couple grains of dry yeast, recap, wait 3-4 weeks?

Other suggestions?

This under-carbonation is a new one for me.

I brewed a Rogue Old Crustacean Barley Wine about 6 months ago. I opened one at the two month mark and it had very little carbonation. I opened one a few days ago and its much better. I would just give it more time. Of course you did add priming sugar when bottling correct? I pretty sure that barley wines are suppose to have very little carbonation overall.

yup, added 3/4 cups of priming sugar to the 5 gallon batch . . . which usually means plenty of bubbly deliciousness . . .