Challenge
Ground movement behind a rail wingwall caused cracking and loss of support, requiring stabilisation without excavation or disruption to rail operations.
Solution
Geobear delivered precision geopolymer injection behind and beneath the wingwall to fill voids, improve ground strength and reinstate support within restricted rail access windows.
Stabilisation adjacent to live infrastructure
Void filling and ground strengthening
No excavation or structural alteration
The Bookham wingwall forms part of a rail structure supporting track infrastructure. Signs of cracking and localised movement indicated a loss of support in the retained ground behind the wall.
Ground instability can develop due to water ingress, washout of fines or long‑term consolidation, leading to void formation and reduced lateral support. Early intervention was required to prevent further deterioration and protect the integrity of the rail asset.
Working adjacent to live rail infrastructure imposes strict access, safety and programme constraints. Traditional excavation behind the wingwall would have required extensive possessions, heavy plant and increased construction risk.
A stabilisation approach was needed that could address voiding and improve ground stiffness while operating within restricted access windows and without disturbing the structural fabric of the wall.
Geobear developed a targeted geopolymer injection design informed by site investigation data. Small‑diameter injection points were installed through the surface behind the wingwall at predetermined locations.
The two‑component geopolymer was injected at depth, where it expanded to fill voids, bind loose material and increase ground strength. Controlled expansion reinstated support without inducing detrimental movement in the structure.
The compact equipment footprint and rapid curing properties enabled works to be completed efficiently within rail possession constraints, minimising disruption to operations.
The intervention restored ground support behind the wingwall and mitigated the risk of further movement. The structure was stabilised without excavation or significant disturbance to the surrounding rail environment.
Delivery within planned access windows maintained operational continuity and provided a technically robust solution aligned with long‑term asset management objectives.
Get in touch with our expert team today and discover how Geobear can extend the life of your critical infrastructure assets.
