OWNER:
Lidl
ENGINEER:
Crossfields/MJM/RSP
GENERAL CONTRACTOR:
Winvic Construction Limited
MAIN FIGURES:
c.1,700 CMCs
Project Details
Winvic Construction Ltd was employed as the principal contractor to construct a UK regional distribution centre for one of Europe’s largest supermarket chains on a geotechnically complex site at Eurocentral, Motherwell. A 60,000m2 steel frame distribution centre was to be constructed on the 210,000m2 site spanning areas of varying ground conditions which included a former backfilled coal quarry up to 15m deep. Ground improvement was required beneath the foundation and ground bearing slab of the structure to limit total and differential settlements to an acceptable level.
Ground Conditions
The quarry area totalled approximately 15,300m2 which had been backfilled with soft reworked clay and landfill material containing, brick, concrete and sandstone boulders down to depths of 15m overlying firm to stiff colliery fill over mudstone with band of sandstone. Within the treatment area there were quarry high walls and a subsurface rock head outside the area of the quarry.
Solution
Menard provided a solution to install a total of 1711no. CMCs to depths of 15.5m beneath the slab and foundations of the structure using 2no. CMC rigs to achieve an anchorage of 0.5m in the stiff colliery fill. The CMCs were installed on varying grids of between 4.5m2 and 9.0m2 dependent on the local depth of soft compressible material. Zone and plate load tests were undertaken upon completion.
In the shallow quarry areas, drilling trials were carried out with the use of the on-board ABAC system to refine the final design and delineate the profile of the quarry which led to a significate cost and programme saving for the client.
The presence of sub-surface rock head immediately outside the quarry has been dealt with by the design and installation of a thicker than usual load distribution mat (2.5m thick) which comprised the upfilling works on site.
The CMC solution allowed the client to construct regular shallow foundations and a ground bearing slab as an alternative to a suspended slab, pile caps and ground beams outlined in the original solution.
