Leca® LWA is an expanded clay aggregate formed by heating and firing natural glacial clay. It is inherently light therefore reducing ground bearing pressure in areas of difficult soil conditions. Here at Belvedere, on the edge of the River Thames, the conditions are ‘made ground’, peat and alluvial grade soils.
Construction of embankments over weak and compressible soil deposits, where loading causes soil consolidation and settlement, is common. By lightening the embankment with use of Leca® LWA, subsoil strengthening and lengthy settlement periods can be dramatically reduced or avoided altogether.
Completion of the ramp embankment by main contractor Costain Limited, for Von Roll Environmental Technology Limited, required delivery of almost 63 loads of 60m³ of Leca® LWA 10-20mm aggregate. The fill was loose-tipped onto a geotextile membrane which separates the fill from the underlying soil to avoid migration of fines.