Industry News
Saving £500k through a new approach to subsidence repair
Block of fl ats aff ected by subsidence A
block of fl ats with 12 units, owned and managed by Harrow Council, had suff ered from structural movement due to the clay
shrinking beneath the foundations. T is resulted in cracks in the brickwork, internal walls and ceilings meaning it would require underpinning repairs and the tenants would need to relocate. T e standard approach to this issue was
followed: a site investigation to understand the issue, a structural engineer’s recommendation for underpinning works, and a tender process to identify contractors and delivery. T e tender process began in May 2022, with 20 weeks of work to commence in September 2022. However, contractor Geobear approached
Harrow Council to propose an alternative to underpinning – ground improvement using geopolymer injection. T is innovative approach, developed by Geobear in 1980, uses an innovative ground injection technique to minimise structural movement in buildings aff ected by shrinking clay soil. Crucially, it could be delivered in ten days without tenants needing to relocate for up to 20 weeks. T e benefi ts of the Geobear alternative to
underpinning were so great that Simba Manjonjori, Interim Planned Investment Manager at Harrow Council, put a case forward to the senior management. He argued that there needed to be a change to the procurement approach to enable them to capitalise on the benefi ts. T e request was granted and the scheme delivered benefi ts to Harrow Council, the residents, and the local community.
22 | HMMApril/May 2024 |
www.housingmmonline.co.uk HMM04_Geobear_DPS
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BENEFITS OF INNOVATIVE SUBSIDENCE REPAIR T e benefi ts of using Geobear to deliver the subsidence repairs are both quantitative and qualitative.
BENEFITS FOR RESIDENTS • Residents would not need to vacate the property during work. Many tenants in the units were elderly or disabled, and relocating during underpinning works for 20 weeks would have signifi cantly impacted their mental and physical well-being.
• Relocation would mean residents being moved away from friends and family for 20 weeks, disrupting the support many depend on for day-to-day living.
• T e Geobear works are all outside the property and minimally intrusive. T e residents are not impacted and have full access to the entrance and garden areas.
• No excavation/digging means minimal noise pollution to residents in properties.
BENEFITS TO THE COMMUNITY AND ENVIRONMENT • T e Geobear work is minimally intrusive – just two vehicles needing parking. With underpinning, major heavy machinery would have been required to be in the area for 20 weeks going backwards and forwards through tight residential areas with diffi cult access. • Excavation and machinery would ruin the
Drain monitoring during works
Geobear injection unit on site 29/04/2024 08:42
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