Emergency works and culvert design – Ferryhill culvert

Challenge

The collapse of a 1500mm culvert beneath a twin track railway line impacted rail operations and necessitated costly over pumping to control water levels. We were commissioned to identify options to remediate the failed culvert or, if necessary, to design a new culvert and associated structures. Ground conditions at the site were poor and the overlying embankment was known to be unstable.

Solution

Remediation of the damaged culvert proved impracticable, so it was infilled and stabilised with foam concrete. A multidisciplinary team of geotechnical , structural and hydraulic designed a new 1220mm OD steel culvert to meet constraints including a design life of 100 years and instruction that the installation to take place without disrupting rail operations or impacting embankment stability. Ground conditions at the site were poor with soft, compressible alluvial and peat deposits so the structure had to resist future settlement of the embankment.

The new pipe was successfully installed using a three stage guided auger bore technique. The dimensions of the launch pit necessitated welding of 6m segments of steel pipe to form the 48m long culvert. The line remained open during works and settlement was within the predicted limits. We provided geotechnical support on-site during construction to record arisings during auger boring operations and to monitor the stability of the embankment during works.

Benefit

Working closely with our client,  we developed an effective, constructible solution to this challenging site. Everyone worked closely throughout the construction phase ensuring that exacting tolerances for movement at track level were achieved.

Want to know more?

Email James Howard to find out more about this project and the work our Geotechnical team do.



Leave a Reply