Client: Bowey Homes / Dunelm Castle Homes & Durham County Council
Location: Stanley, County Durham
Contract Value: £1.76 million
Contract Period: November 2005 until October 2007
Appointed as Principal Contractor, Lumsden & Carroll undertook this D&B project, which was part of a development to turn derelict land into a private housing site comprising 164 new homes. The project required a high level of collaboration between Bowey Homes (Client), the Highways Authority and our Designer, Durham County Council. Early consultations with the Client and Designer produced a design that incorporated value engineering from the outset. The project comprised the removal of the existing steel plate girder bridge deck, demolition of existing abutments, earthworks, grouting and piling for new abutments, road and footpath re-alignment, construction of a new junction and alterations to existing highways and footpaths. The bridge construction was a tied arch of 60m span over an existing heavily trafficked highway.
The site was located over ancient mine workings, and had difficult access onto site due the location of an existing skew bridge which supported a former railway line. This had been resurfaced to take the Coast to Coast (C2C) cycle/pedestrian network. The busy A6076 road underneath was narrow and an identified accident blackspot. The scope of works comprised the following:
1. Roadworks / Enabling Works
- Main road improvements, realignment and creation of a traffic signal controlled junction to form the new road access onto the development. This was carried out in conjunction with Durham CC and formed part of a Section 278 Agreement
- Diversion of mains services to accommodate the new road alignment, and provision of new services connections onto the site
2. Bridge Works
- Demolition of an existing steel plate girder bridge deck
- Demolition of existing abutments and reshaping of the existing embankments
- Design and construction of a 60m span tied arch bridge for the C2C network
Carrying out a major grouting exercise to minimise risk of settlement to the new bridge
3. On Site Works
- To carry out a major earthworks operation to re-profile the site
- Carrying out a major grouting exercise to minimise risk of settlement to the new housing from the former mine workings
- To deal with large amounts of ash which were the result of reshaping of the railway embankments and also waste materials which has been previously deposited on the former industrial site
- To construct on-site and off-site drainage connections for surface water and foul water, and to divert existing drainage system that crossed the site
- To construct new roads infrastructure ahead of the building works commencing
4. Street Lighting and Street Furniture
- Installation of 40 standard columns
- Signage for new road layout
5. Public Realm
- Landscaping scheme designed and installed including tree installations, shrub planting and grassed areas
Environmental Issues
To optimise earthworks materials usage we assessed the plans for the site
- We reviewed ground levels and altered them to ensure that the earthworks profile was optimised to minimise the need to remove any surplus suitable materials from the site
- The surplus ash which was uncovered would normally be disposed off-site to a licensed tip. This was chemically testedand as it was found to be low in contamination but was unsuitable to be used in and around public open spaces. As a result we investigated options and gained agreement from the end user to utilise the material:
- as a sub-formation material under the access road footprint; and
to make up the core of the reshaped embankments and to cap off with subsoil and planting
