Background
A section of railway embankment on the London-Brighton Railway line in East Sussex was identified to be a potential cause for track faults after it was discovered that badgers had burrowed setts within it.
In total 35 badger setts were discovered and the client needed a permanent infill solution to prevent the badgers from returning and to stablise the embankment, protecting it against the risk of the voids created by the setts collapsing and causing track faults. The total voiding created by the badgers was 25m3, the client needed a fast-curing infill solution that could be implemented within short possessions.
Customer alternatives
There are not many options open to the client in these circumstances, a cementitious grout was a potential option, but the curing time would have an impact on the programme which featured other works. Access was also a consideration on this site as it was limited by the location and time constraints of possessions.
A cementitious infill would also add weight to the existing embankment which could also pose a risk to the site.
Why Geobear
Geobear was selected to deliver the project due to its fast expansive geopolymer solution taking just minutes to cure. The delivery team could also mobilise on and off-site within 30 minutes if required and complete the work over multiple possessions.
Using a Geobear geopolymer is a tried and tested method used to tackle badger setts on many embankments and bridge abutments. The material is designed to be impenetrable to returning badgers but can be removed mechanically if required in the future.
Unit on RRV
Geobear solution
The Geobear solution uses a specifically selected expansive geopolymer resin to fill the voids left by the badgers.
Step one in the process was to ensure all the badgers were safely removed from the setts. Once this was completed the setts were netted for a minimum of 30 days to ensure the badgers do not return.
The project delivery phase was accomplished in 12 hrs over two weekend possessions. The 8m embankment had 35 badger setts with 500mm diameter holes and ranged from 2m to 5m in length. In order to get to the site Geobear used their purpose-built rail injection unit which houses the equipment and materials. The unit was loaded via telehandler and placed on a road rail vehicle and trailer approximately 1000 metres from the site just south of Hassocks station.
A two-part geopolymer and resin was pumped via hoses from our mobile injection unit to the top of the injection tube. Mixing of the two components takes place and the mixed material is pumped down the hole into the surrounding void. The injection rods are extracted whilst the injections are completed and CCTV was used to ensure the area was filled.
The project was completed within the time frame and the badger sett voids completely filled mitigating any future risk of track fault.
Hose from injection trailer
