§ Lord Aveburyasked Her Majesty's Government:
What is the extent of the damage to the top of Silbury Hill; what emergency works are necessary to prevent any further subsidence of material into the shaft, which has remained open since it was rediscovered in May 2000; and what advice they have been given on a permanent solution that will maintain the original profile of the summit. [HL1326]
§ Lord McIntosh of HaringeyA shaft approximately 10m deep and 1.8m by 1.8m wide opened up in May last year on the top of Silbury Hill. A scaffolding cover with secured metal sheeting was immediately erected to provide protection to the shaft and the surrounding area. This was intended to be a temporary measure while a method of backfilling the shaft was devised. In December, the shaft further collapsed and changed shape. There is now a hole 3.8m deep and 7.2m by 5.5m wide. Structural engineers consider that no backfilling can take place at the top of the hill as this may cause even further damage. It is likely that the mineshaft and any other voids within the hill will have to be grouted from the base of the hill upwards. A seismic survey will be undertaken in the near future to map the voids within the hill, so that a detailed repair specification can be drawn up.
54WA