DYNAMIC RESPONSE OF NONLINEAR BLOCKY ROCK MASSES AND ITS APPLICATION IN THE ANTI-IMPACT SUPPORT OF ROADWAY

With the increase of coal mining depth, the rockburst disaster is becoming more and more serious, so it is urgent to adopt new methods and theories to prevent. Pendulum-type waves are a new type of nonlinear waves discovered in deep rock masses, and make the rock masses appear different stress states of relative separation and compaction, which is closely related to the occurrence of rockburst disaster. Aiming at the nonlinear deformation characteristics of weak structural layers in rock masses, a nonlinear dynamic model of pendulum-type waves in blocky rock masses was established by introducing hyperbolic model, and the effects of physical and mechanical properties (maximum closure, initial stiffness and damping) of weak structural layers on the dynamic response of blocky rock masses were studied. Further, through the theoretical model of interaction between surrounding rocks and support systems, the influence of stiffness, capacity of yield position and energy absorption of support systems on dynamic deformation of roadway roof was studied and the force on support systems was analyzed without and considering the initial geostress, which provides a theoretical basis for the capacity of yield position and energy absorption of the new roadway hydraulic support equipment. The results show that the nonlinear dynamic model of blocky rock masses based on hyperbolic model can well limit the maximum deformation of weak structural layers between rock blocks. The larger the impact load is, the more significant the reduction in acceleration of rock blocks is when the maximum closure of weak layers is increased. Increasing the stiffness of the support systems, enhancing the capacity of yield position and energy absorption of the support systems can effectively reduce the acceleration amplitude of roadway roof, and weaken the impact of roadway surrounding rocks on the support systems, which is conducive to the safety of the roadway structure.