15th November 2005, 12:28 PM
All that you say is the way it is supposed to work. Leaving aside the piling question for the moment, which I see as incredibly destructive; at issue is the in-situ preservation of archaeology after I leave the site.
Building designs seem to change frequently and with little respect for the impact on the archaeology. If it changes while the WB is going on there is a chance that something can be done. (the curator can be notified) More often it happens once the WB has been ostensibly completed, once the planning permission has gone through.
I recently went by a site where I'd done an eval followed by preservation in-situ mitigation and a WB. The building was about three times the original design and extended into an area where the archaeological deposits were much closer to the surface. Was I notified that the new build threatened in-situ preservation? No. Was the curator? I don't know. Was the planning condition broken?
As for piling, it is seldom limited to the destruction of deposits in the pile positions. (Usually specified as no more than 5% where I work) As you say water tables are affected, but also a wide area around screw piles is churned up, thus affecting possibly (at a guess) 10 times the area depending on geology. I also know that if the pile hits masonry or even preserved timbers, that the obstruction needs to be removed by machine. This too creates a much wider zone of destruction around the pile. Sometimes this can be recorded if the WB is still on. Where I now work piling is not usually covered by the WB so the true extent of the damage is not known.
That's why I think it's a con.
Building designs seem to change frequently and with little respect for the impact on the archaeology. If it changes while the WB is going on there is a chance that something can be done. (the curator can be notified) More often it happens once the WB has been ostensibly completed, once the planning permission has gone through.
I recently went by a site where I'd done an eval followed by preservation in-situ mitigation and a WB. The building was about three times the original design and extended into an area where the archaeological deposits were much closer to the surface. Was I notified that the new build threatened in-situ preservation? No. Was the curator? I don't know. Was the planning condition broken?
As for piling, it is seldom limited to the destruction of deposits in the pile positions. (Usually specified as no more than 5% where I work) As you say water tables are affected, but also a wide area around screw piles is churned up, thus affecting possibly (at a guess) 10 times the area depending on geology. I also know that if the pile hits masonry or even preserved timbers, that the obstruction needs to be removed by machine. This too creates a much wider zone of destruction around the pile. Sometimes this can be recorded if the WB is still on. Where I now work piling is not usually covered by the WB so the true extent of the damage is not known.
That's why I think it's a con.