King post fence
Background
The Glenn Douglas railway section, adjacent to a loch with a steep embankment, relied on a King Post retaining wall to hold the ballast in place. Over time, the wooden sleepers forming this wall deteriorated, leading to gaps that caused the ballast to erode down the embankment, jeopardizing track stability.
Problem
The primary issue was the deterioration of the retaining wall, leading to ballast loss and structural instability of the rail line. Rebuilding the wall would have been highly costly and required extensive closures.
Customer Alternatives
A complete rebuild of the retaining wall was considered but deemed impractical due to the high costs, complexity, and potential for extended rail line closures. Building a new wall in front of the existing one was another option, but it still presented significant cost and disruption challenges.
Ballast with injection tubes
Geobear Solution
Geobear proposed a temporary solution using geopolymer injection to bind the ballast. This approach aimed to prevent ballast migration through the deteriorated sleepers, allowing for partial reconstruction of the wall’s base with minimal disruption.
- Injection plan: A strategic injection of geopolymer was implemented to consolidate the ballast. Adjustments were made on-site to improve effectiveness near the king posts.
- Implementation and outcome: The solution was implemented over seven scheduled possessions to minimize rail disruption. The scheme stabilised the ballast and prevented track movement along 72 meters of the line.
Core Benefits
The Geobear solution effectively stabilised the ballast, avoiding a full rebuild and the associated costs and service disruptions. The project also reduced maintenance frequency, resulting in cost savings and a reduced carbon footprint. The Geobear process is verified by carbon footprint to emit upto 70% less carbon than traditional methods in a rail environment.
