Burnigill Bank is a landslide site with a long history of instability which dates to construction of the East Coast Mainline (ECML)in the 1860s. In 1895, the Engineer for the railway, William Armstrong, reported that “when the line was being made the embankment gave great trouble by continually slipping towards the Browney River…The bank has given trouble from the very beginning and is continually shifting…’
In recent years this movement caused cracking and damage to the road resulting in a lane closure with temporary traffic lights being required for the road to remain in use.
The stabilisation works comprised of contiguous bored pile retaining walls constructed either side of the ECML railway, below overhead power supplies and adjacent to a farm with access required to be maintained during the works. Given the ongoing slope instability, the design involved implementing restrictions on the weight of the piling plant and implementing a carefully controlled temporary works sequence to ensure no net increase in load on the unstable slope.
Key achievements of this project include:
- Efficient, targeted design to reduce the scope and environmental impact.
- Effective communication to stakeholders of this important transport link.
- Completion of the works on an embankment that had slipped significantly and continued to slip significantly as the works progress.
- Understanding of a complex slip to provide a design that could be built safely.
- Developing methodology to pose no risk to the adjacent east coast mainline.
- No reportable accidents in over 1400 hours of working.
- Working with the client to facilitate surfacing of the entire east approach to prevent future road closures.
- Reducing the potential programme by 6 weeks and facilitating opening to road users 3 weeks prior to completion.
- Successfully managing and providing access at all times to residents and landowners for the duration of the works.
- Appointment of 70% of the suppliers from within 30 miles of the project.
- Site visits for Durham County Council’s apprentices to give them insights into the design and construction of a major landslip scheme.
- Site visit from 25 Leeds University again to provide insights into the construction of a major landslip scheme.
- Delivery of three employability sessions held with Year 10 students at Parkside Academy in Willington in November.
- £3,417 donate to Endeavour Woodcraft CIC in Ferryhill.
Three Winning Facts:
- Designing and constructing a new retaining wall on an active landslip.
- 70% of suppliers been based within 30 miles of the site.
- Value Engineering the project scope to reduce the overall programme by 6 weeks and final contact value.
