Efficient Subsidence Remediation: Geobear’s Solution for Social Housing

Subsidence is a common concern for housing associations, especially when housing demand outpaces supply. Traditionally, addressing subsidence-related structural problems has meant disruptive and time-consuming processes like underpinning or piling. These methods often lead to tenant displacement, high accommodation costs, administrative challenges, and tenant inconvenience.

Housing Association Subsidence Challenge

This association faced structural issues affecting a block of flats due to subsidence. Subsidence is the gradual sinking or settling of the ground beneath a building, causing it to become uneven. In this case, weakened soils beneath a shallow foundation caused the south side of the building to sink, with visible cracks in the brickwork as evidence.

Traditional vs. Modern Approaches

Considering an unrelated structural issue had already led to the building’s vacancy, the client initially contemplated traditional micro-piling. However, this would have meant leaving the property vacant for several months during the extensive repair process. That’s when Geobear’s geopolymer stabilisation solution emerged as an alternative.

Geobear’s geopolymer injection method, invented in the 1980s, has earned them a reputation as pioneers in building stabilisation. Licensed for use on over 200,000 sites worldwide, they act as the primary contractor across the UK, Europe, Asia, and North America.

Geobear’s approach involved injecting a multi-component geopolymer resin at various depths below the building’s foundations. This stabilised the structure, providing results comparable to traditional methods but with minimal disruption and typically in just a few days.

The Step-by-Step Process:

• Service Exposure: When services are near injection points, Geobear carefully exposes them to ensure safe drilling without affecting property services.
• Pre DCP Testing: Soil strength is assessed before and after the project.
• Drilling and Injection Tubes: Steel injection tubes, 14mm in diameter, are drilled through existing foundations according to the design plan.
• Geopolymer Injection: Geobear’s technical team attaches an injection hose and injects the geopolymer material.
• Monitoring and Verification: Laser levels on the building’s exterior walls measure vertical pressure or lift, indicating foundation stability.
• Post DCP Testing: Soil strength is re-evaluated post-stabilisation.

Geobear’s on-site technical unit contains the necessary materials, generators, and pumps, allowing for effective injection even when the unit is located up to 100 metres from the property, making it suitable for challenging access situations.

The project serves as a practical example of the efficiency of Geobear’s geopolymer stabilisation solution. Following Geobear’s intervention, other contractors quickly executed internal repairs, resulting in the accommodation being ready for occupancy six weeks ahead of schedule.

Working with Geobear, the housing association has illustrated that seeking alternatives and collaborative working can provide a swift and effective alternative to traditional subsidence remedies. It shows how efficient foundation stabilisation can reduce the alternative accommodation and administrative requirements, and also improve tenant satisfaction.