Meitan kexue jishu (Jan 2023)

Full-time and space early-warning method for floor water inrush in working face based on microseismic monitoring

  • XU Yanchun,
  • HUANG Lei

DOI
https://doi.org/10.13199/j.cnki.cst.2022-1286
Journal volume & issue
Vol. 51, no. 1
pp. 369 – 382

Abstract

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To explore the difference of microseismic characteristics in different periods and spaces of the working face and then realize the early warning of water damage, a full-time and space early-warning method for floor water inrush based on microseismic monitoring was proposed based on typical case analysis. The so-called “full-time and space” refers to the 3 time periods of the whole time cycle of the working face, including pre-mining period, advanced-mining period, and mining period, and the 7 evaluation zones of the whole space of the working face. In the first period, based on the engineering information of boreholes and microseismic response characteristics, the expression method of water inrush risk was formed, and the primary abnormal zones were determined, thus realizing the long-term prediction of water inrush risk in the pre-mining period. In the second period, the fixed working face was set up and the microseismic events were repositioned. Based on the nuclear density analysis of the frequency and energy of microseismic events at the “fixed working face”, the water inrush characteristics of the leading influence zone, the lagging influence zone and the lateral influence zone were determined, realizing the water inrush risk early-warning in the advanced mining period. In the third period, the 2D-CE method was introduced to normalize the microseismic events on the plane, the early-warning aquifer was defined, and the roof damage zone, the floor damage zone, and the floor mining damage zone were determined in combination with the frequency of microseismic events and the energy nuclear density analysis, realizing the water inrush risk prediction in the mining period. At the same time, according to the mining verification results, the prediction method in the early phase was modified to serve the water inrush early warning in the subsequent working face, making the prediction results of floor water inrush more accurate in Jiaozuo and Hanxing mining areas.

Keywords