I'm sure GRM would be perfectly happily to do you a Desk Study, Ground Investigation and arrange a Drill and Grout job if required, but you'd probably need to sit down before you read the Quote
Seriously, I would have thought that on your hard rock there would be very little problem with the the workings. Geoff reckons anything more than 5 times the height of the workings should be OK.
I'm sure GRM would be perfectly happily to do you a Desk Study, Ground Investigation and arrange a Drill and Grout job if required, but you'd probably need to sit down before you read the Quote
Seriously, I would have thought that on your hard rock there would be very little problem with the the workings. Geoff reckons anything more than 5 times the height of the workings should be OK.
Alan
"Sit down before I hear the quote" I know a geologist quite well they are not cheap.
When I got this place it was a cash only job, my solicitor insisted I have a mining search done, I said why would I want to pay a bloke a pile of money to go to the records office to look at the plans and tell me there is a mine here which I knew 'cos I looked at the plans before he did.
Ok the upshot or down shot is that so far as I can ascertain studying the old plans shows we are between two of the lodes, there is a 2,000 ft deep shaft about 90ft from where I am now sitting, the larger of these two loads crops out at the very tip of the top end of the garden, the top end of the garden is north of the house, that particular lode dips north so the stopes on that load are beyond the northern end of our northern boundary.
The other lode is south of the house it is also a north dipper but has not been so extensively worked, but it is possible that that lode dips under the house.
The country rock is what we call Killas down here, I'm no geologist but I think it is a metamorphosed sedimentary type of rock, when I dig in the garden around the house the rock is about a foot or so down I have not come across any made up ground around the house itself if there was I might be worried as it could be fill into an already back filling stope, back filling stopes and adits are the most common collapses down here in cornwall as they tend to run once they start.
Ours and the next door neighbours house are both single story and built on a reinforced concrete raft, so I'm guessing that if anything did happen the bedroom wouldn't sheer off and head into the abyss, but just lean a bit!
Cornwall is riddled with shafts and workings as you are probably aware.
There is made up ground in the garden but it is mining deads (rocks) on bedrock so far as I can ascertain as I have dug most of the garden up when laying land drains etc. It sounds like your lad has an interesting job and one that is full of challenges.
Goeff reckons that short of falling down the shaft you should be OK
Yes, Geoff is one of those lucky people who has a job which he thoroughly enjoys.
Alan
Alan I have just had another look at the old plan, although the depth of adit level is not stated I would guess it's around 30 fathoms down from the shaft collar as I do know where the adit portal is so did a rough reverse calculation, the first of the upper levels is around 40 fathoms below adit level, I have the scale details for the plan and it says all level depths are referenced to adit level, this is normall for the mines down here as nearly all are quoted below adit level as that was the level the water was mainly pumped to.
Yes some of the civil engineering projects these days are mind boggling, I have always been interested in the tunneling projects.