Ground improvement solutions at the plot 14 of the Northern Lisbon logistic platform

The present work addresses the ground improvement solutions adopted for the soft soils as foundation of the future industrial warehouse, to be built at the plot 14 of the Northern Lisbon Logistic Platform, at Castanheira do Ribatejo, Vila Franca de Xira, Portugal, comprising an area of 49 813 m². A description of the existing conditions is made, particularly of the geological-geotechnical scenario, highlighting the existence of an alluvial layer, with clayed soft soils, with low characteristics of strength and stiffness as well as very low average permeability. The solution adopted consists in the execution of preload embankments associated with (i) stone columns, executed at the area of the warehouse indoor pavements, and (ii) vertical prefabricated geodrains, at the area of the outdoor pavements, in the places designed for car parking and circulation of light and heavy vehicles. This article describes the criteria and methods used at the design of the preload fills, seeking to reduce the hydrodynamic consolidation schedule. The Monitoring and Survey Plan and respective results are also presented.