Document Type
Conference Paper
Publication Date
2024
Abstract
Waterproof coal pillar infiltration water makes water conduction channel formed in the coal pillar and may lead to the occurrence of underground water accident. The monitoring of seepage water in waterproof coal pillars is a necessary means to prevent and control the destabilization of waterproof coal pillars. This paper establishes a coupled model of seepage field and resistivity of water-bearing coal column, analyzes the changes of seepage field and pore water pressure of water- bearing coal column, and combines the inversion technique of direct current method to determine the apparent resistivity changes of seepage process. The following main conclusions are obtained in this paper: high-pressure water intrusion in the waterproof coal column aquifer is the essential cause of waterproof coal column seepage, and the inhomogeneous fissure network inside the coal body provides the necessary channel for high-pressure water circulation; staggered pore water areas are more favorable for pore water circulation compared with parallel pores, and the pore network area has a larger range of water pressures; the results of multiple inversions are obvious for the inversion of high-resistivity areas and low-resistivity areas. The low-resistance area of the apparent resistivity field corresponds well with the high water pressure area of the seepage field in space; there exists an obvious demarcation line between the low-resistance and high-resistance areas of the apparent resistivity, and the demarcation line is the demarcation line of the dangerous area of seepage when comparing with the area of the gradient change of the water pressure of the seepage field. The closer the visual resistivity inversion is to the roadway, the better the inversion effect is, and the higher the accuracy of the test results; the seepage water pressure at different depths shows a strong negative correlation with the visual resistivity, and the correlation reaches more than -0.8, and the DC method has a better detection effect for the seepage process of watertight coal pillars. This study provides a theoretical basis for the detection of seepage in waterproof coal pillars by DC electric method.
Publication Details
Qiang Liu, Liming Qiu, Dazhao Song, Zhenlei Li, Yi Zhu and Jintao Dang, Analysis of apparent resistivity change during waterproof coal pillar seepage based on finite element method, Proceedings of the 2024 Resource Operators Conference, University of Wollongong - Mining Engineering, February 2024, 300-309.