Practice Research on Small Coal Pillar Overall Coupling Yielding Support for Gob-side Entry Driving in Deep Mine

To counter the problems that the original support design for gob-side entry driving with small coal pillars can't meet the production requirements in Zhengtong Mine and the large deformation appears in the roof and two sides of the roadway, the main problems existing in the original supporting design and the key points of the roadway support were analyzed, and the overall coupling yielding support technique for roadways was put forward, which realized the deformation coupling of the rock bolt, the cable anchor and the surrounding rock, the deformation coupling of the rock bolt and the cable anchor and the yielding and coordinating stress of the rock bolt and the cable anchor. Based on these, a combined support system of the coupling yielding bolts + coupling yielding cable anchor + welding net+W steel belt was designed. The numerical simulation and the monitoring results in the roadway showed that the stable displacement values of the roof and two sides of the roadway with coupling yielding support were respectively 90 mm and 70 mm, which effectively controlled the deformation of the surrounding rockand met the requirementsfor safe production.