Double Demolition makes way for major regeneration

These blocks were cleared for Fife Council in advance of a major regeneration of the area which involves the construction of new low rise properties.

The structures were of Bison Wall Frame Panel construction which had been overclad in the late 80ýs due to insulation problems and water ingress. Safedem removed the overcladding utilising mastclimbers in advance of the explosive demolition. Advance works also included asbestos removal, soft strip, preweakening, drilling and installation of blast protection measures in advance of charging the structure with explosives. Each structure had over 8000 tonnes concrete and took just 28kg of explosives per structure to initiate the controlled collapse.

The collapse mechanism and delay sequence had to take into account both overground and underground liabilities. A live substation and two major retaining walls located less than 5 metres from the west elevation of the structures required the buildings to be directed towards the east. Historical information however indicated the drop area to the east of the buildings was riddled with mine workings. The site investigation identified a series of mine workings approximately 10 metres from the east elevations of the structures which had to be avoided.

Safedem Managing Director and Explosives Engineer explained. ýWe were effectively restricted within a long narrow strip where we had to land the structures. Given the proximity of the mine working we also had to reduce the ground vibration to absolute minimal levels.ý

Ground vibration and air overpressure were limited with the use of delay detonators ranging from 3 to 7.5 seconds. ýWe employ independent vibration and blast monitoring experts to monitor vibration and overpressure levels. The results were even better than predictedý stated Sinclair.

The demolition also required the implementation of an exclusion zone (of approx 160metres from the structures being demolished) with the evacuation of over 400 local residents which included the evacuation of a remaining tower block, and a sheltered housing complex. Safedemýs community liaison team carried out the evacuation with military precision completing the logistical challenge significantly ahead of schedule.

Returning to the technical element of the demolition, Sinclair continues, ýAt first these looked like straight forward blocks, the panel construction being the classic pack of cards. However this type of structure has caused serious problems for others in the past. These structures were almost identical to the buildings in Niddrie, Edinburgh which failed to collapse back in 1991 following an explosive demolition attempt.ý

The important factor with such structures is to effectively disrupt the external panels and break the rigidity and boxiness of the building. At Kincardine this was executed to perfection with excellent results.