They don't just drill a hole and fill it with concrete. I saw them complete one pile, and then move to another. What a mess! Huge crawler crane moves around carrying a suspended tube, taller than a 3 story building, they place it (slowly lower it) vertically into the pre-drilled hole, which has an enormous hollow cylinder surround in it - sticking out above ground. The crawler crane messes up the ground - sand, splilled left over concrete, moveable concrete feeder pipes everywhere, steel reinforcing cylinders in the way, what a site.
And noisy as hell. You see, the concrete truck backs onto the site, delivers the fresh concrete out the back, drops it into another machine chute - a diesel pump, what a noise, which then pumps the concrete through a flexible pipe up to the top of the 3 story cylinder, which is now inside the hole. But the hole is not empty - it starts already full of a special 'mud fluid' which is in the pre-drilled hole to keep it 'open' - so it doesn't fall in(!). So they start to place the concrete AT THE BOTTOM of the hole, while another (!) pump pumps out the fluid as the concrete slowly rises inside the pile.
I saw one concrete truck finish, empty and leave, and another one arrive and take over.
When the hole is filled - it over-flows at the top. But the top concrete is poor quality, because of the 'mud fluid' (now not there - but now in a reserve big tank, for use again!)
Later, with the crane, they hitch to the top of the cylinder, and slowly drag it out - up that is. Drop it to one side. Now the wet concrete sinks down a bit, the top falls away. The reinforcing rods are now sticking out. They tell me that at the next stage, before pouring the big floor slab, they will jack out some more of the top of the new concrete -they only want the pile to come below the surface.
Oh my goodness.
I don't think this house will fall down,
I will be willing to go inside of it.
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