Study on the Control Mechanism of Key Strata on the Coordinated Open-Pit with Underground Mining Slope

Under the background of coordinated open-pit with underground mining engineering practice in PingShuo mining area, the stability of coordinated open-pit with underground mining slope influenced by key strata was studied by numerical modeling, in turn the key strata's control mechanism of coordinated open-pit with underground mining slope stability was analyzed. The study shows that the deformation and failure process of coordinated open-pit with underground mining slope influenced by underground mining disturbance is mainly divided into four stages under the condition of open-pit mining prior to underground mining, which are supergene transformation stage, structure modification stage, aging deformation stage, and finally instability or stable deformation stage, and two kinds key strata control the development of deformation and failure of the slope among those stage. General condition and criterion of coordinated open-pit with underground mining slope enter into the aging deformation stage, finally instability or stable deformation stage was put forward by building force model to analyze key strata's coupling mechanism of action, and then control measures of coordinated open-pit with underground mining slope stability based on the previous work.