I put up the trellis every year. The beans are moved along every year so a permanent trellis wouldn't work.

I use T posts and rebar for permanent trellises.

I also think moving beans around is a good idea, but if you so desired, you could always leave the trellis for a non-leguminous climber. Maybe cukes?

Outdoor cucumbers are marginal here and would certainly never grow big enough to need eight foot bamboos. Runner Beans are part of my minimalistic rotation and the row is only 15 feet long so it takes less than half an hour to put it up every year.

Redsun, bamboos left out over winter will rot pretty soon, so if you do decide on a permanent trellis bamboo isn't the material for it.

Well, I use about 500' of trellis each year, and it gets torn down & re-erected each year. That does take a considerable amount of time on both ends of the season, but it allows me to work organic matter into the soil, and to keep perennial weeds from getting out of control. It gives me plenty of exercise too, but not many would wish to do so, and quite frankly, I wouldn't recommend it... the time is approaching when I may be unable to do it myself.

Even my measly 310 feet of trellis is too much to move...

I rebuild mine each year. A lot of people rotate crops so leaving them permanently isn't feasible. Just depends on what you're planting each year.

My trellises are made of galvanized electrical conduit for the frames and concrete reinforcing wire for the mesh. Stays outside all winter, and does fine, year after year.......unless I want to move it around....which isn't hard.