Usually you prebore a little. You drive the first casing as far as you can go at first. Sometimes if the ground allows it and the soil friction is small enough, it can go all the way to only a metre of the casing sticking out above ground which is what you want. In this case you bore out the hole up to the bottom of the casing but go no further. You can then put on the second casing. Sometimes though the casing can't go all the way to the depth you want because of the ground. So you drive the casing as far as possible while forward spinning and back spinning the rotary and casing driver to help it go down. Once it can't really go down any more, you bore out to the bottom of the casing with the auger. You then drive it some more, bore out to the bottom until it reaches the depth you want. And the process repeats. At some point if the soil is weak you might put bentonite in the hole to further prevent potential ground collapse and to lubricate the drilling tool (change to digging bucket from auger when drilling in bentonite fluid)
Drill rig operator here. Best explanation I have ever seen of the drilling process and the order of casing advancement to boring. Excellent video 👍
I have no idea what is happening. Are you driving the casing first then cleaning it out?
Usually you prebore a little. You drive the first casing as far as you can go at first. Sometimes if the ground allows it and the soil friction is small enough, it can go all the way to only a metre of the casing sticking out above ground which is what you want. In this case you bore out the hole up to the bottom of the casing but go no further. You can then put on the second casing.
Sometimes though the casing can't go all the way to the depth you want because of the ground. So you drive the casing as far as possible while forward spinning and back spinning the rotary and casing driver to help it go down. Once it can't really go down any more, you bore out to the bottom of the casing with the auger. You then drive it some more, bore out to the bottom until it reaches the depth you want.
And the process repeats.
At some point if the soil is weak you might put bentonite in the hole to further prevent potential ground collapse and to lubricate the drilling tool (change to digging bucket from auger when drilling in bentonite fluid)