Challenge
Void formation and reduced ground support beneath a live rail platform required strengthening without excavation or disruption to passenger services.
Solution
Geobear delivered precision geopolymer injection to fill voids and increase bearing capacity beneath the platform within restricted rail possession windows.
Works delivered within rail constraints
Void filling and ground strengthening
No excavation of platform structure
Bristol Temple Meads is a major operational rail hub with high passenger volumes and limited access for intrusive construction works. Ground instability and voiding had developed beneath sections of the platform structure, reducing support and increasing the risk of settlement.
Maintaining structural integrity was critical to ensure continued safe operation of the station and avoid escalation into more significant structural intervention.
Traditional excavation beneath a rail platform would have required significant possession time, structural dismantling and complex temporary works. The station’s operational environment limited access, working hours and plant size.
A strengthening solution was required that could be delivered safely within constrained rail access windows while avoiding disruption to passenger services and protecting existing infrastructure.
Geobear developed a site‑specific geopolymer injection design based on ground investigation findings. Small‑diameter injection points were installed through the platform surface at predetermined locations to target identified voids and weak zones.
The two‑component geopolymer was injected at depth, where it expanded to fill voids, bind loose material and increase stiffness of the underlying soils. Injection volumes and pressures were carefully controlled to ensure stabilisation without inducing detrimental movement to the platform structure.
The compact equipment footprint and rapid curing characteristics of the geopolymer enabled works to be completed efficiently within planned rail possessions.
Ground support beneath the platform was reinstated, mitigating the risk of further settlement and maintaining structural performance.
The intervention was delivered within agreed access constraints and without excavation, allowing continued safe operation of the station while providing a technically robust long‑term strengthening solution.
Get in touch with our expert team today and discover how Geobear can extend the life of your critical infrastructure assets.
