Geotechnical

The technology of soils improvement to enhance the foundation capability on marginal development sites takes several forms but in general terms involves an increase in the basic shear strength of the soils strata. This includes:

• vibrated stone columns to stiffen the weak matrix
• surcharge and band drain systems to accelerate consolidation
• modification of weak soils for pavements or slab foundations.

In other circumstances the soils are reinforced by the addition of soil nails, geogrids and geotextiles, each of which rely on the transfer of the tensile stresses from the soils into the reinforcement medium.

The control of water within the soils strata or against the exposed surface is often necessary in the temporary or permanent works to avoid softening, sliding or collapse with cut off systems or targeted dewatering schemes being the standard approach.

Blackwell Geotechnical Division has experience and in-house resources for many of these methods.