A614 Thorne Road sits on an embankment around three metres in height. The road/embankment was in need of urgent repair as a result of major flood damage in early 2020. This caused a failure to the embankment which was causing the carriageway to fail as it was slowly eroding.
All works, with the exception of the carriageway surfacing under a road closure, were carried out while the carriageway was still live, operating under three way temporary traffic signals. This was due to this route being used regularly as a diversion route for the closures required on the M62 works on the Ouse Bridge. It was vital that we achieved the advanced closure date for the surfacing closure. It was therefore critical the embankment construction works were safely executed, preventing undermining of the carriageway and further weakening the structure.
The scheme comprised reconstruction and widening of existing embankments using imported Class 6N granular fill following removal of the existing overgrown vegetation and tree stumps to each embankment, installation of new drainage systems including gullies, filter drains, catch pits and pre-cast concrete headwall, fencing, gates and VRS safety barrier, following removal of the existing. Repairs were made to a section of the existing VRS system which was retained that was found to be in reasonable condition.
The embankment reconstruction would be carefully undertaken in short sections, including excavation of the existing embankment to form a stepped detail and install the new, imported fill. Once the granular fill installation to the embankments were complete, topsoil was then applied to the entire area followed by grass seeding and the installation of new hedges and shrubs.
Maintenance tracks were formed using site won material at the bottom of each embankment, retained by the new fencing and accessed via the new gates. This therefore provides easy access for landscaping maintenance of the newly seeded topsoil to the embankments, hedges and shrubs.
Existing kerbs were replaced and new channels were installed to the carriageway, which was then resurfaced under a full road closure at the end of the scheme. Deep planed patch repairs were carried out adjacent the kerbline where the existing structure had failed and cracked due to the condition of the embankments prior to the contract. A fibreglass coated with polymer resin bituminous surfacing reinforcement grid was installed to the planed surface to provide support and stability for the new structure, prior to receiving the binder course and surface course.
Road markings and white reflectorised road studs were then installed to the newly finished surface, including the refresh of existing lining outside the extent of carriageway resurfacing to improve visibility and safety for drivers across this area.
Hundreds of 32 tonne wagons were employed to deliver the new fill material throughout the duration of the scheme. This process was made seamless by the onsite storage areas and temporary haul road formed to the area of works which allowed a constant flow of material to be installed at the highest output and avoiding the formation being exposed to the elements, particularly during seasons.