Study of Deep In-Situ Stress Field Based on Geological Structures.

The deep in-situ stress field is the outcome of geological structure evolution, which also has a decisive influence on deep mining. Therefore, the characteristic of geological structure was analyzed first. Then, a new regional division method based on the geological structures was proposed. As a result, the Pingdingshan mining area was divided into three region units: the main control region of the Guodishan fault (D1 region), the main control region of the Likou syncline (Z1 region), and multi faults control region (D2 region). The results showed that the fold structures dominated by Likou syncline have the most significant impact on the deep in-situ stress field. In the Z1 region, the influence of fold structure on the deep in-situ stress field increased with the buried depth, while it was the opposite in the D1 and D2 regions. The analysis between geological structure and deep tectonic stress field indicated that the direction of tectonic stress field in each region obeyed the characteristics of regional geological, which also proved the logic of the proposed division method. The discussion of deep mining in each region demonstrated that the risk of instability and catastrophe of deep rock masses was greatest in the Z1 region, while it was lowest in the D1 region. Compared with the normal fault stress state and reverse fault stress state, the region belonging to the strike-slip fault stress state has the extreme challenge of surrounding rock deformation and instability. [ABSTRACT FROM AUTHOR]