Burying them in the soil would be far better than burning them.

kimmq is kimmsr

When my bamboos start to be brittle I break them up and use them as row markers or canes for short plants. When they are too brittle for that I put them into the compost heap. They are basically just tough grass and break up quite quickly. Certainly burning them would be a waste and polluting.

Will they work as hugelkultur beds or not?

Yes.

kimmq is kimmsr

You could make char for the garden, but open fire is not the way to do it.

The large 1-2.5 inch bamboo can stay in compost pile or garden soil for 2-3 years without composting.

Bamboo is in the Grass family with bananas & corn, it is a wood that is used to make hardwood floors.

So bamboo is a special class of woody grass.

For hugelkultur bed it would work just fine, in my opinion.

I cut & dry bamboo, then use it as garden stake for two years, then lay it out to rot & some times it take up to three more year to break down.