Client: Taylor Wimpey North East
Location: Newcastle upon Tyne
Contract Value: £2.6 million
Contract Period: June 2010 – February 2011
The Newcastle Great Park development covers a total of 1,200 acres. Around half of this is being protected and landscaped into meadowland, hills and vales with eight miles of walkways on the park and bridleways including road crossings for bridle users, and the remainder of the development being divided into commercial and domestic buildings, with Greenside Phase 3 (Cell G) being one of the domestic site for construction.
Newcastle Great Park Cell G Development is located 5.5km north west of Newcastle City Centre, it is approximately 15.9 hectares (39 acres) of previously agricultural land. The A1 trunk road (Newcastle Western Bypass) runs in a north easterly direction adjacent to the eastern boundary of the site. The northern and western boundaries are formed by the Ouse Burn and the southern boundary by Kingston Park Road.
The Scope of the works for Cell G includes – earthworks, road, footpath and parking infrastructure, adaptable sewer networks, utilities service installation and domestic housing construction.
Housing development
Cell G includes, 63 detached houses which include 15 different house types of 4 to 5 bedroom, varying between 2 and 3 storey’s with either double garages or car ports. Property prices valued from £310,000 to £575,000.
Ground Conditions and Foundations
Ground conditions across Cell G were found to be generally firm to stiff sandy and gravelly clays, underlain by loose to medium dense and dense sands/gravels. With the exception of one area in the south-easterly corner of the site, where soft clay and loose sands were identified.
Conventional strip concrete foundations were used on the stiff clay and medium dense sand where the ground bearing capacity was at least 100kN/m2. Due to the high sand/gravel content one layer of B283 reinforcement mesh was incorporated as a precaution against settlement.
Pile foundations were used in the south-easterly corner of the site due to soft clays and loose sands/gravels. Only 5 out of 117 required pile foundations with pile depths ranging between 6.0m and 8.0m.
Ground floors
Ground bearing (GB) floors were considered suitable for areas of stiff clays and medium dense sand/gravel. GB floor slabs were constructed using 150mm of hardcore stone below 75mm Kingspan insulation, Damp proof membrane (DPM), 50mm sand and 150mm thick C35 fibre concrete slab. GB floor slabs were suitable for plots which required no engineered ground levels.
In comparison, were areas of soft clay/loose sands were present or in areas that had 600mm or greater “made-up” ground below finished floor level (FFL) a Suspended slabs (SS) was required for floor construction.
Drainage
Storm and foul drainage both private and domestic were required for the development with storm water outfalls into landscape wetlands and connections to existing live foul drainage systems. Outfalls and Concrete manhole chambers were required to meet Northumbria Waters (NWL) adoption standard. Approximately 5,500m of pipework was installed, with pipe diameters varying between 100 to 600mm Ø and depths up to 5.0m.
Groundwater was commonly confined to the granular deposits underlying the surface of clay at depths of on average of 2.0m. The result of this was that once the clay was penetrated groundwater quickly rose within the excavations found installation. Dewatering systems were required for a number of drainage lines to reduce the effect of running sand.
Highways and traffic management
Highway development for Cell G is categorised by under two road construction types, these being: adoptable road carriageway with footpath/cycleway and “home zone” road construction. The carriage width throughout the site varied from 4.8m to 7.5m wide depending on the type of road, “home zone” areas were required to be wider as no pathways were created adjacent to the carriageway as with adoptable road layouts but the road and path were all classed as one.
In addition to these construction types block paved rumble strips were formed with regular block sets and channel blocks.
Services
As this was a Green field site and previous used for agricultural purposes prior to the housing development all utilities were required to be installed. This included electric mains both high and low voltage cables, substation, gas, water, BT and street lighting including lighting columns. In all over 7000m of service cable and mains were required.
Environmental
Recycled material was used where ever possible for road, footpath and drive construction. Waste materials were kept to a minimum resulting in reducing the need for skips. With the Ouse burn being situated to the north of the site the impact on wildlife and natural habitats was paramount. For these reasons drip trays and spill kits were used on necessary plant and equipment. Also a concrete wash out point was situated within the site compound so contamination to the ground, watercourses and drains were reduced in not stopped.
