2015 Plummer House Case Study
Transcription
2015 Plummer House Case Study
CASE STUDY Ref: 6281D PLUMMER HOUSE—FORMER CHAPMANS STORE 2015 £500K CLIENT—ROBERTSON CONSTRUCTION 4 MONTHS At the end of Summer 2015, Thompsons of Prudhoe completed another tight and complex City Centre demolition project at the former Grade II listed Chapmans Furniture Store in the centre of Newcastle. They were appointed by Fusion Residential’s Principal Contractor, Robertson Construction Ltd, to carry out the full internal soft strip, selected demolitions, asbestos removal and associated works at Plummer House, Carliol Street in Newcastle upon Tyne, ahead of the site’s redevelopment for student accommodation. The site was divided into 3 zones, each requiring differing levels of demolition work. Zone 1 comprised the elegant Grade II listed front part of the site; the centre part of the store, including a listed dancefloor formed Zone 2, and Zone 3 comprised the rear part of the site that had spanned the underground car park and service entrance at the former store. The site was located within a very busy part of Newcastle upon Tyne City Centre, adjacent to offices, bars, a night club, hotel, NHS walk-in centre and a leading architects practice located in the Grade II Listed Plummer Tower – only 4 metres from the edge of the site. To add to the level of difficulty the site was on a bend in the road and on a slope. The surrounding footpaths and roads had to remain in use throughout the course of the works. The whole site was enclosed by robust wooden hoarding with a controlled access gate. The desired position of a site boundary on any demolition site is calculated at being twice the height of the structure to be demolished. Ideally, Thompsons would have had an exclusion zone to the site boundary of around 48 metres – instead the site constraints only allowed 4 metres. A Traffic Management Plan was put into place before any work could commence to ensure the safe movement and interaction of site vehicles, other City Centre traffic and most particularly pedestrians to, from and around site. The space around the site was so restricted that only a half road closure could be put in place by Robertson Construction, closing the northern side of Carliol Street which bordered the southern site boundary. Thompsons employed MTL Scaffolding Ltd to erect a sheeted scaffolding externally to the full height of the building around 3 of the elevations in order to provide a safe working platform for the works to be conducted and for a suitable ‘buffer’ zone to be in place. Thompsons also specified an internal ‘birdcage’ scaffold to the third floor of the building in Zone 2 to protect the listed dancefloor beneath. Each level of the scaffolding was reduced periodically as the demolition prgressed. CASE STUDY Ref: 6281D PLUMMER HOUSE—FORMER CHAPMANS STORE 2015 £500K CLIENT—ROBERTSON CONSTRUCTION 4 MONTHS Prior to commencement of demolition works Thompsons’ specialist asbestos removal operatives completed the removal of asbestos materials in the building and conducted a full internal soft strip to remove any items remaining within the building, removing all fixtures & fittings and stripping the structure back to its original shell to allow for a safe and unrestricted demolition. This technique also ensured that the resulting demolition debris was as clean as possible so as to maximise its potential for being recycled. Due to the varying Zones, differing extent of demolitions required and extremely tight site constraints, the specialist demolition team at Thompsons determined to carry out the work using a mix of specialist techniques including manual work, robotic and minimachine, high-reach machine and finally traditional machine demolition and clearance. Following a temporary road closure agreed with Newcastle City Council, Thompsons’ in-house “Appointed Person for Lifting Operations” designed and supervised the lifting by crane of 1 Bobcat skid-steer minimachine and 2 Brokk robotic breakers onto the roof of the store to commence preparatory demolition works from the top down. This was agreed to by the Robertson team after Thompsons’ independent specialist structural engineering consultant RW Clarke Ltd had carried out floor-loading calculations to prove their preferred methodology was safe. Zone 2 was brought down on a floor by floor basis by the mini machines equipped with pulverisors and breakers. The debris was carried from each floor by the skid-steer and dropped down the existing lift shaft within the building. This debris was then carried by machine from the lift shaft and loaded onto Thompsons’ trucks in the existing loading bay of the building, reducing noise, vibration and dust nuisance. Following completion of the roof-level and other preparatory works the building was carefully demolished from highest point at about 24m on the south-west corner of Zone 3 using one of Thompsons’ high-reach demolition spec 360o excavator machines. The highreach operator interacted with and was supported by a trained demolition burner, working from a 25m “Cherry-Picker” mast to both damp down dust and assist with safely dismantling the structure’s steel beams immediately bordering the site’s perimeter to avoid any risk of debris falling outside the site’s tight boundary. Once the High-Reach machine had taken down the top two storeys, additional demolition spec excavator CASE STUDY Ref: 6281D PLUMMER HOUSE—FORMER CHAPMANS STORE 2015 £500K CLIENT—ROBERTSON CONSTRUCTION 4 MONTHS machines were used to demolish the low level portions of the building and to sort, process and load the resulting demolition arisings. The site was too small to crush and recycle the debris on site, but of the seven and a half thousand tonnes of material that came off the site, over 98½% was recycled at Thompsons’ nearby Aggregate Recycling Facility in Gateshead, being used on other construction projects in the region. The Grade II listed structure at Zone 1 was left completely intact, having been stripped back within the limits permitted by law. Zone 2 was partially demolished, removing all external render and all floors above the undamaged Grade II listed dancefloor. The whole of the part of the building in Zone 3 was demolished, its concrete floor and foundations removed, the ground excavated and cleared down to several metres below the surface and material supplied by one of Thompsons’ quarries was placed and compacted in layers in readiness to receive the specialist piling contractors and commence the construction phase. The project was completed on time, within its 17 week programme, taking 5580 manhours and with zero accidents. All demolition was carried out in accordance with Thompsons’ accredited ISO9001, ISO14001 and OHSAS18001 management standards and with BS6187:2011 - Code of Practice for Demolition Operations.