Mechanism of formation of water-conducting fractured zones with deep mining in the Jiaojia gold mine, China

The deep resources within existing gold mines have great potential to prolong the life of mines such as the Jiaojia gold mine in Shandong province in China. However, with the increase of mining depth in the Jiaojia gold mine, the overburden stress is increasing and the spatial and temporal distribution of the mining stress field is becoming more complex. This in turn is causing the spatial structure of the overlying strata to be seriously damaged, which often leads to mine water disasters. In this paper, based on the analysis of borehole data and a profile map, a three-dimensional geological model was established to predict the height of the water-conducting fracture zone near a regionally significant fault. The effects of mining show that the maximum height of the water-conducting fractured zone is about 21.2 m during mining at the − 700 level. The shape of the fractures that are developed varies from nearly horizontal to micro arch-shaped. The failure range of the plastic area near the fault was found to be larger near the fault than that at a distance from the fault. The stress distribution on both sides of the fault was found to be not continuous, and to be larger in the hanging wall than that in the footwall. A stress concentration zone was found to be formed in the front and back of the stope during the mining process and to increase with mining depth. This method can restore the original state of the underground stress field to the greatest extent and make up for the lack of empirical formula theory and the limitation of the similar material methods for deep mining, which is relatively more accurate and reliable.