NORWEST HOLST Soil Engineering is well into phase two of ground investigations for Aberdeen's new bypass, the Aberdeen Western Peripheral Route (AWPR).
Information on geology and shallow ground conditions along the 30km route to the west of the city was limited, so extensive investigations were needed.
Phase one provided basic ground information and confirmed the extent of the main investigation. Completed in early May, it comprised 136 cable percussion boreholes, 105 rotary boreholes and 53 trial pits.
Phase two began immediately afterwards.
By mid-June Norwest Holst had put down 119 cable percussion boreholes and 69 rotary boreholes through superficial deposits and into bedrock and dug 111 trial pits.Work is being carried out by eight cable percussion boring rigs, nine rotary drilling rigs and two trial pitting crews.
Several of the exploratory holes are in areas of soft ground, rough terrain and steep sloping ground. The route contains sites of ecological and archaeological importance and areas of potential contamination such as landfill sites and disused railways. Future work will include exploratory holes on existing carriageways, central reservations and verges.
The £2M investigation, funded by the Scottish Executive, Aberdeen City Council and Aberdeenshire Council, was commissioned by the specially formed AWPR Managing Agent responsible for overseeing all aspects of the project on behalf of the funders.
Babtie Group is designing, procuring and supervising the ground investigation.
The AWPR, which will form part of the A90 when it opens in 2010, runs from the A90 in the Charleston area south of Aberdeen, rejoining the A90 near Blackdog to the north of the city. Costing £120M (at 2002 prices), it is hoped the road will relieve congestion and pollution in Aberdeen.