Odell Embankment Remediation & Culvert Reline
A rail embankment settlement issue caused by factors including burrowing rabbits has been resolved thanks to a design from VEDA.
Prior to VEDA’s involvement, infrastructure monitoring trains used to inspect track alignment had highlighted a ‘rough ride’ across the 10-metre high railway embankment near Souldrop, Bedfordshire.
Having identified evidence of movement in the slope during an initial site walkover, VEDA organised topographical, geotechnical and ecological investigations to assess the geometry and properties of the embankment’s construction material.
VEDA Engineer Jack Edwards investigated the site to determine the safest angle for the proposed slope and liaised with end client Network Rail (NR) on a suitable restoration method.
The natural presence of water at the site due to a culvert under the embankment and the toe’s drainage ditch had weakened the slope. Age-related wear and tear and honeycombing caused by burrowing rabbits had also impacted the Victorian embankment. To counter the embankment failure, VEDA’s design stipulated the construction of a 1A material granular berm at the bottom of the slope.
The solution weights the bottom of the slope such that the sheer force in the slip plane is counteracted by the dead weight of the berm material. It is a popular approach because it requires no physical structure or maintenance. It did, however, oblige NR to purchase a strip of land.
VEDA also recommended extending and relining the culvert using a UV-CIP (cured-in-place) plastic liner, giving it a life expectancy of 100 years. VEDA also specified the installation of a new pre-cast concrete headwall for the culvert along with the extension of the culvert itself from 55m to 60m.
Following installation of the berm, the embankment was finished with top soil and rabbit netting to mitigate against further burrowing.
The timeframe for the design and construction was eight weeks.
Project Name: Odell Embankment Remediation & Culvert Reline
Type of Project: Civil & Structural Engineering
Client: Dyer & Butler
Date completed: March 2017
- Civil Engineering