Settlement control using TENAX GEORAFT System, Preston Waste Transfer Station, Lancashire, UK

PRODUCTS:

TENAX GEORAFT Foundation System Using 75,000m2 of TENAX Geogrids TENAX TT geogrids TENAX LBO geogrids

Location: Preston Waste Transfer Station, Lancashire, UK

Contractor: Eric Wright Civil Engineering Ltd

GeoRaft Consultant: P & S Consulting Engineers Ltd (PaSCoE)

TENAX Distributor: Geosynthetics UK

Project description

Part of the Lancashire Municipal Waste Management Strategy is to reduce the requirement for household waste to be taken to landfill.

Lancashire Waste Network comprises the treatment of household waste from 15 local authorities at 4 Central Waste Treatment facilities supported by 11 Waste Transfer Stations.

When complete, the Preston Waste Transfer Station (WTS) will process 60,000 tonnes/yr of mixed waste with future expansion to include a 26,000 tonnes/yr composting plant.

In order to protect the WTS from a 1 in 200 year flood from the adjacent River Ribble the level of the site was raised by up to 3m.

The increased loading from the 3m high platform would cause immediate, consolidation and creep settlement.

The solution was a combination of pre-fabricated vertical drains and surcharging, allowing settlements to take place within a short period.

Differential settlement was controlled by the 500mm high, 22,000m2 TENAX GEORAFT System foundation in accordance with BS8006 using a combination of bi-oriented and mono-oriented geogrids (TENAX LBO and TENAX TT).