As part of the construction of the Severn Energy Recovery Centre (SERC) for SITA, the existing rail network required upgrading. The existing rail link to the north of the site was built on an embankment, which was approximately 2.0m high. The works required the widening of the existing rail embankment to take the additional rail track required for the SERC.
The site is underlain by up to 1.5m of made ground, over 7-9 m of very soft highly compressible silty clays which overlie medium dense sands and gravels.
The solution required the installation of vertical drains through the made ground and very soft, silty clays, prior to the placement of the embankment. The works were carried out between the exiting rail track and an overhead power line. The vertical drains allowed the accelerated consolidation of the weak soils following placement of the fill and prior to construction of the track.