Abstract:
The prevention and control of the disaster of water-sand mixture inrush caused by mining is becoming one of important bottlenecks, which restricts mining safety. The state-of-the-art and trend of water-sand mixture inrush from seam roof were reviewed, including the catastrophic mechanism, movement law and risk evaluation. The engineering geological models of disaster formation are divided into four categories, including water-sand mixture inrush by direct or indirect exposure of unconsolidated aquifers, by seepage failure due to water-conducting fractured zone connecting, by man-made borehole drilling through unconsolidated aquifers, and by softened overburden with deterioration of water and inrush under the combined action of water pressure and mining pressure. In view of the seepage failure of water-sand mixture inrush, combined with the model test and theoretical derivation results, the basic movement law of the water-sand mixture flow through the orifice, single fracture, fracture network and caving zone was obtained, which lays the foundation for the establishment of a unified equation of the movement of water-sand mixture flow. An expression of critical hydraulic gradient from top to bottom seepage was derived, and the concept and calculation method of safe water head against water-sand mixture inrush were proposed. A qualitative and quantitative evaluation method for water-sand mixture was established, and a dynamically quantitative evaluation method for water-sand mixture inrush was realized. The successful application of active prevention and control measures was introduced by grouting to transform the properties of unconsolidated aquifers and backfill mining, in order to reduce overburden failure and prevent water-sand mixture inrush failure. Finally, the scientific problems of the mechanism of water-sand mixture inrush from seam roof and key technical issues, which should be solved in the next step of prevention and control, were proposed. The main scientific issues include that establishment of a digital twin model of the geological geology of water-sand mixture inrush from seam roof, revealing the formation mechanism of the water-sand mixture inrush pathway, the interaction between the water-sand mixture and the surrounding rocks, constructing the motion equation reflecting the whole process of water-sand mixture inrush, obtaining the grout propagation and solidification characteristics in the advanced area of preventing water-sand mixture inrush, etc. Research and development of key technologies include monitoring and early warning technology, actual environment modeling technology, and equipment for high-efficiency grouting. Β© 2022 οΌο½_x008f_ｕｒο½_x008e_ο½ο½_x008c_ ο½_x008f_ｆ οΌ¥ο½ο½’ο½”ο½ οΌ³ο½ƒο½‰ο½…ο½_x008e_ｃｅｓο½ο½_x008e_ｄ οΌ¥ο½_x008e_ｖｉｒο½_x008f_ο½_x008e_ο½_x008d_ο½…ο½_x008e_ο½”. All rights reserved.
