Michael Faraday Avenue
Overview
A new section of road was constructed to connect the northern and southern arms of the existing road, Michael Faraday Avenue. The missing link was never constructed due to the challenges around the existing topography and other site constraints. Notably these included an existing flood storage plain, steep valley and key wildlife corridor.
This project entailed the creation of an embankment and the installation of twin-bore large diameter steel culverts over the existing Stanney Brook, part of the EA Main River. These measures ensured the road’s continuity whilst safeguarding the natural environment and wildlife in the area. Additional works involved extending the pre-existing section of Michael Faraday Avenue. This extension facilitated the installation of new services to accommodate future development requirements.
Construction of two multi-plate galvanised steel culverts, which were then covered with a road, footpath, and verge, seamlessly integrating them into the existing carriageway. The site is a loop road which was constructed circa 20 years ago, however, the loop remained incomplete due to the necessity of building culverts beneath the road surface. Each of the two culverts were approximately 11 x 7.5 x 34m long. The footpaths to the previously constructed road were never surfaced, which formed part of our works. Other works included infrastructure including the construction of a road, drainage, street lighting and associated utilities infrastructure works.
Key Challenges
- Working from height for the erection of the steel culverts
- Working within a flood zone valley, wildlife corridor and existing watercourse – the works required temporary diversion of the existing watercourse to enable a dry working area. As dewatering was not an option, a drainage trench and flume arrangement was utilised
- Winter working – The original tender programme moved from an April to an August start which pushed the works into a period of winter working. The earthworks were therefore scheduled to take place in autumn/early winter, which meant the increased risk of poor weather. This could have led to a loss of productivity and additional material costs
- The methodology for the backfilling was prescriptive and required regular onsite upstream and downstream testing. We undertook geotechnical monitoring and ensured compliance with the specification when undertaking all earthworks and backfilling around the structures, including monitoring for deflection
- The site required an element of ecological attendance – during the preconstruction stage, the pond needed to be cleared of reptiles and fenced off, nesting bird checks were carried out prior to vegetation clearance and a Non Native Invasive Species (NNIS) survey carried out. During construction – our Construction Environmental Management Plan (CEMP) covered the NNIS method statement and we provided supervision of mitigation/enhancement works for the creation of the new pond areas
- Risk on ground conditions – The original design showed the use of the site won clay for use in the backfilling. We recognised that this approach resulted in an unacceptable risk to the project due to our inherent understanding of geotechnical risk. We worked with the client to maximise the re-use of this material whilst recognising that significant granular import would be needed to maintain compliance with the specification. This allowed the client to ensure they had sufficient budget for the works at the outset
- The site and construction method meant that the culverts, reinforcement and backfilling needed to occur in unison which needed close coordination and control of all backfilling operations
- The original tender included for a named supplier of the culvert materials but their lead times could have resulted in the project not commencing in 2021. EWCE offered an alternative supplier to the client, which was accepted and ensured the overall project programme could be achieved
- Works by others – BT, gas and power services were due to be brought into the site. The client was managing these works and BT ultimately did not get brought onto the site, however there was an issue with the ducting depth of the Electricity North West ducts. This had been resolved and the ducts were laid as per the specification drawings
Added Value
- £916,527 spent within a 30 mile radius of the project (30 miles was the framework definition of local)
- 5 hours delivering STEM sessions in local schools/colleges
- 21 hours delivering advice and guidance to GM SME’s – procurement, social value, supply chain
- £600 materials donated to a Rochdale based charity