Mathematical Prediction on Effect of Tailing Discharge of Open-Pit on Stability of Underground Mined Out Area

doi:10.12068/j.issn.1005-3026.2017.04.028

Abstract

Abstract: To reveal the impact of the height of the tailing dry stacked gangue (H) on the span of double gob area (D) and the roof thickness (h)， the simulation software FLAC^3D was used to simulate the excavation process of the double gob area of different spans during the tailing-backfilling process. The stress， plastic zones and the displacement of monitoring points of double gob area were analyzed by combining with the hyperbolic fitting equations， traditional failure criterion and the thickness reduction methods. When D is kept constant， tensile and compressive stress and the plastic zone area increase with the increase of H， and the displacement of all monitoring points increase significantly when the span is larger than 20m. When H is kept constant， the displacement and the plastic zone area increase with the increase of D， and it can be quantitatively predicted that when the span is up to 26m， the critical damage height of tailing dry stacked gangue is 182.44 and 189.85m， respectively. When D and H are changed， the plastic zones of the double gob area take on a butterfly-shape， and the plastic zone area of the upper gob is greater than that of the lower part. A cutting-through failure will occur when the span exceeds 20m and the tailing height exceeds 150m.

Key words: tailing discharge into open-pit, double gob area, boundary pillar, numerical simulation, mathematical prediction

CLC Number:

TD325

SHI Xiu-zhi， CHEN Jia-yao， ZHOU Jian， QIU Xian-yang. Mathematical Prediction on Effect of Tailing Discharge of Open-Pit on Stability of Underground Mined Out Area[J]. Journal of Northeastern University Natural Science, 2017, 38(4): 591-597.

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