Abstract: In rainy seasons, the water-saturated overlying materials caved in sublevel caving mining may be liquefied under blasting-caused dynamic load and rush into the stope to form an underground mud-stone flow, bringing a great danger to underground safety mining. By applying a dynamic non-linear coupled solid-liquid constitutive equation, the paper studies the liquefaction mechanism of saturated soil under the function of dynamic load and analyzes the relation between blasting dynamic load and underground mud flow. An OPENSEES infinite element numerical simulation is made for the underground mud flow events occurring many times in Chengchao Iron Mine. The result shows that dynamic load caused by blasting has direct impact on mud-stone flow. The final computing result conforms to that of numerical simulation, thus providing a basis for realizing a safety production of mine in rainy seasons.

Key words: Soil liquefaction, Liquefaction mechanism, Coupled solid-liquid model, OPENSEES