GIS-based multicriteria evaluation of foundation conditions

This article deals with an evaluation of the engineering geological and hydrogeological conditions in Vajnory with relation to landuse planning. Vajnory is one of the city parts of Bratislava, the capital city of Slovakia, with huge building activity. Parametric maps were constructed using a multi-criterial approach and the result is a set of engineering geological and hydrogeological maps of geofactors which present a level of suitability for building foundations using map algebra tools in a GIS environment. Four geofactors which influenced the suitability for building foundations were selected — workability of soil, bearing capacity, groundwater level and aggressivity of groundwater. These factors were analysed for three different depth levels. The suitability map for building purposes at a depth of two meters under the surface showed foundation conditions for simple buildings with the basement below freezing level or for buildings with one underground level. The suitability map for a depth of five meters under the surface presents foundation conditions for buildings with two underground levels. The last evaluated level was for a depth of eight meters under the surface and analyses the foundation conditions for buildings with three underground levels.