Response and Control of Surrounding Rock During Subsection Driving of Extra-large Section and Thick Coal Roof Open-off Cut

In order to study the mechanical behavior characteristics of the surrounding rock during the process of sub-section driving of large section open-off cut, the engineering of 5205 open-off cut of a coal mine in Shanxi province was elected as the study subject. The variation characteristics of both vertical stress and horizontal stress in surrounding rock mass were simulated, as well as the propagation process of both tension and shear plastic zone. The main transformation of destruction type, from shear failure to tensile failure, during the process of subsection driving of large section open-off cut, was elucidated. The design idea (the key positions are roof, the anchorage zone of top angle) and combination support technology of bolt, truss and anchor rope were proposed.