Arndale Centre, Leeds

Our brief

Lithos were commissioned to carry out a site investigation at the Arndale Shopping Centre in Headingley, Leeds.  The results of which would help determine whether an access road to the 1st floor offices and carpark could be lowered to accommodate HGVs.  The investigation needed to ascertain ground conditions within the footprint of the access road, including the thickness of hardstanding, shallow ground conditions, the presence of any significant obstructions and underground utilities.

What we did

Fieldwork, carried out by a specialist subcontractor, was managed and supervised by Lithos.  Trial pitting was carried out at 10 locations along the access road.  These were advanced by a combination of concrete cutting, hand-digging and use of a mechanical excavator.  Digging within the vicinity of underground electricity and gas services was undertaken in accordance with safe digging techniques as outlined in HSG47.   Plate load tests were also carried out on natural ground where encountered within the trial pits to enable derivation of CBR values for highway design.

The outcome

It was concluded that the natural ground was suitable for highway construction, although significant constraints associated with a gas main and electricity services required consideration.  In addition, a new customer elevator was proposed by the Client (including a sump to house lift equipment) within the supermarket.  Lithos were asked to investigate ground conditions at this location.  A single window sample borehole was also advanced within the footprint of the proposed lift shaft in the supermarket, in which a well was installed to allow monitoring of groundwater levels.