Some geotechnical characteristics of soft soil deposits along the Terryland River Valley, Galway

Abstract

The ground conditions in the Terryland River Valley area present considerable site development challenges to geotechnical engineers. The soft soil formation consists of peat overlying very soft, highly compressible calcareous silt overlying slow draining organic silts and inorganic clays. These soil deposits are typical of those encountered in Limestone Basin regions throughout Ireland. NUI Galway has been involved in investigating these soils since the 1980s. The investigations at Terryland involved Cone Penetration Testing (CPT), shear vane and piston sampling plus laboratory testing. This paper summarises some previously unpublished data and places the results in the context of various published soil data from sites elsewhere in Ireland. The laboratory testing confirms that the design parameters for the soft soils in the Terryland River Valley are more onerous than for many other soft soil sites in Ireland.