J Žarn’s scientific contributions

After the CO2 has been captured at the source of emission, the CO2 would have to be transported to the storage site using different technologies. In some countries (i.e. USA) real possibilities exist so that available and new oil and water pipe lines could be used for such operations. In practice it means that transportation could be carried out with motor carriers, railway and water carriers. If the present experiences are taken into account and the real situation checked, such transportation systems are mainly used in praxis. For maximum throughput and to facilitate efficient loading and unloading, the physical condition with respect to pressure and temperature for the CO2 should be the liquid or supercritical/dense phases. Temporary storage of CO2 is of importance for finding a comprehensive solution for long-term storage under various environmental circumstances. Underground caverns are one of the possibilities of temporary storage. Geotechnical analysis of stress and strain changes that are present in the rocks around underground caverns filled with CO2 under high pressure provides a realistic assessment of conditions for temporary storage. This paper presents the analysis described above, for different parameters relating to underground storage of CO2.

Swelling pressures of the rock as a result of chemical and physical processes which are present during construction and operation of tunnels and have the influence on loads and deformations of primary and inner concrete lining. Deep geomechanical analysis of swelling indicates that in practice very often conservative way of calculating load capacity of primary as well as inner lining were used with a goal to keep long-term stability of the tunnel. Particular emphasis was placed on the physical and chemical assessment of the time dependent development of deformation. In the present paper the practical case of tunnel construction in specific swelling clay ground »Sivica« is analyzed. Based on 2D and 3D geostatic analyses, a rigid primary lining was chosen as a final design, because the depth of the tunnel is only about 30 m below the surface. The geotechnical parameters of hoist ground »Sivica« are a result of laboratory and »in situ« tests, which were conducted according to technical standards. During a construction and after it the geotechnical measurements were conducted. The measurement results confirm the correct technical decision in the design stage.