OVERVIEW ON RUPTURE PROPAGATION STUDIES OF BURIED GROUND-FISSURES

The number of buried ground fissures is much more than that of exposed ones. The buried ground fissures have brought about great hazards and thus attracted more attentions. Rupture propagation modes of buried ground fissures are affected by many factors including the displacement, inclination and activity rate of ground fissures, the properties, thickness and strata structure of overlying soil, as well as surface-water infiltration, groundwater exploitation, ground motion and time effects. The different combinations of these factors result in the complex mechanical mechanism of rupture propagation over buried ground fissures and make it difficult to reproduce the rupture propagation process. Currently, research methods of the rupture propagation are mainly about in-situ investigation and exploration, model test, mechanical analysis and numerical simulation. The research contents focus on the rupture propagation effect based on the change of single formation condition or inducing factor. Such future priority research subjects include 1)analyzing comprehensive effects and mechanical mechanism of rupture propagation under its formation geological conditions, multi-stage activity, long-term creeping motion and a variety of inducing factors, 2)studying on the rupture propagation process to track the fracture position and its influence width at a different depth, 3)calculating the maximum vertical surface displacement caused by rupture propagation and the minimum safe overburden thickness under certain conditions, and 4)determining unified methods and standards for the effect zone width of ground fissure. All these research subjects can use to interpret the actual fracture phenomena and provide the basis for the comprehensive prevention and control of ground fissures.