Strengthening Embankments – Stoke Mandeville
Client: Network Rail
Date/Duration: Completed on time, on budget
Aspin’s piling and foundations solutions are widely used across the UK in the rail, civils and highways sectors, a bespoke service for all sizes and types of projects including full design and installation which frequently uses the company’s own plant and equipment.
In Stoke Mandeville, Buckinghamshire, Aspin’s solutions have been employed by Network Rail to stabilise an embankment that was causing track quality problems. The problem was compounded as the site had also suffered significant loss of cess, thought to occur due to poor drainage along the toe of the embankment.
Stabilisation works included measures to address the drainage issues and minimise the need for future maintenance as well as providing landscaping and secure site access.
Located on the busy commuter route from Aylesbury to London, the railway embankment had for many years exhibited signs of deep seated rotational failure. It’s the cause of one of the major types of landslides, with a curved slip surface that can result in a deep landslide. Track quality was
affected by the instability of the earthworks and this needed to be addressed.
Aspin’s works addressed the embankment re-grade over 160 metres and the significant loss of cess, attributed to poor drainage along the toe of the embankment. Vegetation was removed from the embankment to facilitate the works. A two metre deep shear key was formed at the base of the embankment, constructed of 1,500 tonnes of Type 1 fill capped with 1,000 tonnes of Class 6C engineering stone to form a starter/free draining layer. A new filter drain was also added.
Works on the embankment included the construction of 3 no. 3.0 metre wide benches using around 6,000 tonnes of Class 1A engineered fill to maintain a safe, four metre wide safe cess. On completion the earthwork was top soiled
The shear key installation works were completed on time on budget and included the use of Aspin’s plant and equipment which helped to streamline programming and avoid costly delays. The construction works were completed within 10 weeks.
The finished result included the installation of rabbit netting and top soiling to allow for the future regeneration of flora and fauna. Security was also addressed in the programme with the replacement of third party and Network Rail boundary fencing and the addition of new access gates for the site.
As part of the works, Aspin collaborated closely with the local landowner to minimise adverse impact on the surrounding arable land. A temporary road access was installed for the works, and the fields were fully re-instated to arable land on completion. Sustainability was integral to the whole
programme including waste from the groundworks which was segregated and recycled.
- Foundations & Piling
- Ground Investigation
- Drainage & Colverts
- Groundworks & Earthworks