Stainless Steel Hollow Bar and Mesh Stabilizes Failing Slopes at Severn Estuary
The frequent closure of the vital rail line connecting South Wales and North England, due to slope failures at the Severn Estuary, has been a significant disruption to passenger and freight traffic. In response, DYWIDAG supplied the necessary geotechnical material to stabilize the slope, thereby preventing future accidents and unnecessary closures.
Context
The Newport to Gloucester rail line—connecting South Wales with the West Country, Midlands, and north of England—is vital to passengers and freight traffic. Still, it has a history of slope collapses in the Severn Estuary area. Four downfalls closed the line following heavy rain in the winter of 2021, further showcasing the need for a long-term failure-prevention solution.
Solution
Given the critical and challenging location of the estuary, positioned close to the sea and its exposure to rain and wind, a solution to stabilize the slopes was both critical and challenging. DYWIDAG developed a comprehensive solution involving the installation of soil nails and mesh, adding surface cover, and stabilizing the slopes (37m high at points). Using stainless steel bars and mesh doubled the solution's lifespan from 60 to 120 years, reducing the requirement for future maintenance and inspections. Using a hollow bar option further reduced drilling costs and time spent on site, lessening traffic disruption.
DYWIDAG supplied the contractor QTS with all necessary materials: grade316 R32-360 stainless steel hollow bar with 90mm DYWIDAG EYY drill bits and stainless steel mesh. Experienced abseil teams and rigs installed the soil nails and mesh and completed all drilling using air flush and secondary grouting.
DYWIDAG completed work to secure the slopes on the Severn Estuary on time and within budget.