4D Microgravimetry in Geoengineering

IG-5 4-D MICROGRAVIMETRY IN GEOENGINEERING 1 JAN MRLINA Geophysical Institute Dept. of Gravimetry Boční II 1401 141 31 Prague 4 Czech Republic Introduction Rock stability origin of fractures rock-bursts and sinkholes unknown voids and caverns in the subsurface as well as mass sliding belong to major problems of engineering geology and environment. In all such cases the mass (rock) undergoes changes of bulk density as fracturing disintegration tension and other similar processes cause rock deformation resulting in the increase of porosity. Consequently bulk density can decrease to a significant extent. As these geomechanical processes often progress from geological “source” up