Sub-grade Improvement
2015
Fleet, Hampshire
Thames Water
MGJV
Maccaferri Ltd
Water Treatment Pumping Station
During Construction
During Construction
The Liebherr crane supported by the reinforced MacGrid WG piling mat
Piling rig crane supported by the reinforced MacGrid WG piling mat
Problem
Thames Water has invested £7.2M on a scheme to reduce the risk of flooding at Grove Farm in the Fleet area, Hampshire. This important scheme will help protect properties in the area from future flooding. A new pumping station will be installed to improve the existing network that is no longer able to cope with the excess water flow from heavy rain.
Solution
Galliford Try—Morrison Construction (MGJV) is the main contractor and is dealing with all the works related: from the drainage connection to the pumping station to the building construction and services.
The new pumping station will be built onto a piling foundation. Due to the characteristics of the soil, with CBR = 1.50 % a reinforced mat has been designed to create a suitable support for the heavy 140 tonnes Liebherr crane and for the sheet piles and piling rig machine. A solution with 2 layers of MacGrid WG 5S within a well-graded granular compacted material has been chosen by the client to support the heavy cranes during the works.
This type of MacGrid consists of woven geogrids, made from high molecular weight, high tenacity polyester multifilament yarns. The yarns are woven under tension in the machine direction and finished with a polymeric coating.
The WG is a cost-effective solution and provides long-term control of deformation and rutting with soft subgrades or high axle loads.