Regularities of development of gravitational processes and their prediction: Fid-Bau Portal

Regularities of development of gravitational processes and their prediction

Lomtadze, V. D.

Summary Gravitational displacement of rock masses is responsible for disturbance of slopes and escarpments. It is produced by gravity, hydro-dynamic pressure, seismic and other forces. The analysis of the causes of gravitation phenomena enables us to conclude that in the long run they can be produced by an increase of absolute or of relative values of shearing forces. An increase of absolute values of shearing forces conducive to rock mass displacement down the slope or escarpment, may be due to changes in slope gradient, the increase of rock weight with moistening, hydrodynamic and partly hydrostatic forces, stress concentration in the zone of the slope or escarpment, loading, seismic or other external influences. A relative increase of shearing forces may be due to a decrease in rock strength induced by the change in physical state with moistening, swelling, loosening, weathering, disturbing the natural structure, changing the stress state or other factors. Each type of gravitational phenomenon is characterized by a particular mechanism of displacement and movement of the rock mass. The paper deals with mechanisms of gravitational processes and the types of gravitational phenomena corresponding to them. The dynamics of gravitational process development include three stages: the preliminary stage, generally characterized by the gradual decrease of rock mass stability; the actual generation of the phenomenon, generally characterized by quick or sharp loss of rock mass stability; and the stage of stabilization or restoration of rock mass stability. The analysis described enables a prognosis of the development of the gravitational process and an estimate of the degree of its threat.