Simulation study on response characteristics of water rich fracture zone in metal mine monitored by resistivity method

Abstract

Water inrush accidents in metal mines are prone to occur during the construction and production process of mines, which can cause serious casualties and property losses. The prevention of accidents in metal mines is closely related to geophysics. In order to solve the problem of accurately monitoring water permeability, the resistivity method was proposed to effectively monitor water rich fault zones in metal mines. The typical metal mine and water rich fracture zone model are simulated by ANSYS. The calculated resistance data are processed by inversion image processing and compared with the original model; The inversion image clearly shows the abnormal area of the water fracture zone and the location is relatively accurate, which verifies the reliability of the numerical simulation method and the resistivity theory. At the same time, the response characteristics of water rich fracture zone of metal ore under different water content and different development distance are studied by using numerical simulation method. The results show that the resistivity measured by electrical method decreases with the increase of water content in the water rich fracture zone, and the resolution of low resistivity anomaly is strong. When the measuring node of high-density electrical method is inside the water rich fracture zone, the resistivity change curve tends to be a straight line; When the measuring node of high-density electrical method is not near the water rich fracture zone, the resistivity change line tends to curve. In addition, with the expansion and development of the water rich fracture zone, the electrical resistance at the measuring node decreases; When the water rich fracture zone is about to develop and reach the measuring node, the measured resistance value has an abnormal mutation. This paper reveals the characteristics of resistivity and pervious precursor response through numerical tests, and clarifies that resistivity decline and abnormal mutation are important pervious precursor information, which has important reference significance for the monitoring and prediction of pervious disasters in practical projects.