Concrete, even with a lot of rebar in it, is just 2.4 g/cc. A 1 foot diameter pipe will hold the concrete in it so long as the concrete to steel bond has at least 1800 Pa shear strength. That's a quarter psi. Greasy pasta sticks better than that.Assuming they coat the steel pipe interior with grease, it seems really difficult to pull it up off the piling. And even if they did, they'd lose all the side friction between the piling and the undisturbed soil. That side friction is a major component of how pilings work.Something doesn't seem right here.
I've seen a lot of pilings poured for bridges in portsmouth nh. They always leave the steel tubes around the pilings. They just rust away. They may cut some of the tubing above the water line. It makes it look better.
Living in the heart of Boston I watch a LOT of very large scale construction and have watched just about every sort of foundation work - from driven piles to slurry walls to drilled footings. The gear shown in Nomad's pics is pretty small stuff and it looks like they're only vibrating in small circular sleeves. Is there a drill on site for excavating out the soil within the sleeves? Typically the rebar inserts are already preformed into the proper diameter cages and dropped into the excavated hole. Is the rebar in site straight runs or preformed cages?
Quote from: Johnnyhinbos on 08/25/2016 03:32 pmLiving in the heart of Boston I watch a LOT of very large scale construction and have watched just about every sort of foundation work - from driven piles to slurry walls to drilled footings. The gear shown in Nomad's pics is pretty small stuff and it looks like they're only vibrating in small circular sleeves. Is there a drill on site for excavating out the soil within the sleeves? Typically the rebar inserts are already preformed into the proper diameter cages and dropped into the excavated hole. Is the rebar in site straight runs or preformed cages? You can see the drill and rebar cages in the photos.
Is the terrain unsuitable for driving in prefab pilings?
I'm not saying it's unusual, but those piling tops look terribly dirty to me. When they pour the concrete that goes over the top, they'll have to dig out around the top of that poured piling, and then blast it clean. What a pain in the butt. And they'll never completely seal the joint between the two pours.I'm impressed they were able to pull 50' long 1' diameter pipes out of the ground. I would have expected that to take a huge amount of hammering, basically a pile driver running in reverse.