Engineering-Geological Properties of Carbonate Rocks in Relation to Weathering Intensity

Abstract.

For most of the purposes engineering-geological explorations are done on the surface. Afterwards the surface data get correlated with other exploration results in order to produce rock mass quality model. The modelling of subsurface and deeper zones in karst areas in Croatia is usually a difficult task because of a complex geology. The evaluation of rock mass quality in those zones is even more demanding mainly because of the specific weathering processes of carbonate rocks. Since karstification significantly changes engineering-geological properties of carbonate rocks, it is of vital importance to determine the degree of weathering in surface and subsurface zones. Engineering-geological properties of carbonate rocks in the surface zone, subsurface and deeper zones are compared and discussed in the paper. Facts and examples are taken from recent highway projects in Croatia. From those data it has been recognized, that depending on the basic block size, two basic weathering models can be established. Each of the models has its specific engineering-geological properties.