Came across this whilst in a discussion on another forum (courtesy of Rikj);

www.caverescue.org.uk/IREPPDF/ANAL8998.pdf

Makes interesting reading

Ian

When the figures are stuck together on a table it all looks a bit scary! I'm taking this as a handy guide as 'how not to f*ck up'. Still can't understand how, given our litigious and risk averse society, so many caves and mines aren't filled with aerated concrete? (says he, having spent this evening wielding a shovel whilst furtively glancing in all directions)

ivortheengine wrote:
Too many already are

ivortheengine wrote:
Access to all these sites is due in no small part to the hard work of cavers. Individually, via clubs, regional caving councils and at a national level. It is a lot of work and generally thankless. It is very frustrating when all the work is ruined by the selfish acts of one or two individuals who believe it is their "right" to enter sites.

That said, I am not against gaining access to sites via "other" means, so long as it is kept "in house" so to speak. When somebody plasters something all over the net about gaining access to a particular site ("28 days later" are one of the worst offenders for this) then the owners get to know or are forced to do something.

Googlemail being the excellent provider of relevant links that it is, I've noticed that I'm regularly getting links to 'Benefil' - whose website shows various underground spaces being forever lost to foamy expanding mortar, slowly creeping forth and consuming all like some evil force out of a horror flick. I guess we will se more of this until every UK citizen is required to sign a statement of sound mind and personal responsibility upon reaching adulthood.
Ian's video had me quite alarmed - hard hitting and shows how quickly things can go wrong leaving some tough decisions to make. If the others hadn't reappeared, what then?

I'm not really aware of much underground being lost to foamy concrete.
I know of the stone quarries of Coombe Down (Bath) and also there is plans to fill a redundant railway tunnel in the Avon Gorge (Bristol) to stabalise a main road, but I haven't heard of vast numbers of underground sites being infilled.
It is actually quite expensive to fill voids with concrete and is really only done as a last resort