Study on anomaly characteristics of in-advance DC electric detection of water-accumulated roadway in abandoned coal mines

In order to accurately detect water-accumulating roadway in abandoned of coal mines to avoid disastrous water accident, this paper is based on the principle and previous detection results of DC electric in-advance detection. The statistical method is used to study the anomalous characteristics of the apparent resistivity of the previously detection of goaf water.The results show that it is impossible to distinguish whether the water-accumulating roadway in abandoned of coal mines is orthogonal or oblique to the detection direction, due to the volumetric exploration effect of the electric method. The common anomaly feature is a single lower-point low-resistance anomaly with a relatively small width range (about 3～5 m). When the anomaly is greater than one-fold mean square error, it generally corresponds to the situation that the roadway is full of water (can be used as an early warning starting condition). In the roadway not fully filled with water,the outliers are relatively small, generally larger than half-fold mean square error. The water-conducting fractures often exhibit a low-resistance anomaly characterized by more than one-fold mean square error, but its anomaly range is often wider with different forms. In practice, this technology is used to track the heading face advanced detection of buried goaf water which has successfully prevented multiple accidents.