Mechanism of Water-Conducting Fractured Zone in Jiaojia Gold Mine With Deep Mining Based on Constitutive Model

Abstract

The deep resources of the gold mines have great potential to be the leading area of the national gold industry. However, with the increase of mining depth in Jiaojia gold mine of Shandong province, China, the overburden stress is increasing, the spatial and temporal distribution of mining stress field is more complex to cause spatial structure of overlying strata seriously damaged, which often leads to mine water disaster. Therefore, the research on the law of surrounding rock stress and water-conducting fractured zone development has become an important topic for safe mining of gold mines. In this paper, based on the analysis of borehole data and profile map, three-dimensional geological model was established to predict the height of the water-conducting fracture zone by using Sufer17, Rhino 6, Griddle plug-in and FLAC3D software, and the mining process with the method of downward horizontal slice stoping-filling was simulated by using constitutive model. Results show that the maximum height of the water-conducting fractured zone is about 21.2 m during the whole mining at -700 level, the shape is from near horizontal to micro arch, the failure range of the plastic area near the fault is larger than that far away from the fault. The stress distribution on both sides of the fault is not continuous, which is larger in the hanging wall than that in the footwall. The stress concentration zone is formed in the front and back of the stope during mining process and increases with mining depth. This method can restore the original state of underground stress field to the greatest extent, and make up for the lack of empirical formula theory and the limitation of similar material method for deep mining, which is relatively more accurate and reliable.