Theory And Application Research Of Rock Mass Dynamic Propagation On Pendulum-Type Waves

Rock burst is becoming more and more serious when deep mining. Base on the theory of pendulum-type waves dynamic propagation in rock mass, the occurs of rock burst in deep mining and the control of rock burst was studied.The relationship of characteristic phenomena of dynamic propagation in block rock mass and rock burst was analyzed in theory.The effect of block rock mass media to attenuation of the pendulum-type waves propagation was studied.The quasi-resonance and ultra-low friction phenomenon of block rock mass which can induce rock burst was analyzed. The instability effect of block rock mass and support on propagation of pendulum-type waves which can induce rock burst was studied.Energy transmission and dissipation of block rock mass were analyzed theoretically. Prevention of deep mining rock burst was analyzed in theory.The law of dynamic propagation in one-dimensional block rock mass on impact load was studied through experiment. Some conclusions were obtained:1 The main attenuation area of dynamic propagation was focused on the head of block rock mass but low-frequency and low-velocity propagation when pendulum-type waves occurs.The features of low-frequency and low-velocity propagation were more obvious when the scale of bock is small.Dynamic response amplitude of block was effect when viscidity variation in block partings.Amplitude was decrease obviously and response period increase when elasticity decrease in block partings.2 Quasi-resonance phenomenon of block rock mass was analyzed.The quasi-resonance equation of block rock mass is given on the propagation of pendulum-type waves and getting the resonance condition of block rock mass, Further we get the quasi-resonance of block rock mass which induced to rock burst.3 Ultra-low friction phenomenon of block rock mass was analyzed.Criterion of ultra-low friction is proposed by extreme value of relative displacement between the rocks on the propagation of pendulum-type waves, Further we get the ultra-low friction of block rock mass which induced to rock rupture rock burst.4 Instability of block rock mass and support on dynamic process was analyzed. Criterion of block rock mass and support instability on dynamic process is proposed,which induced to rock burst of block rock mass and support dynamic instability.5 Mathematical model of energy transmission and dissipation of block rock mass was proposed on propagation of pendulum-type waves. Conversion of kinetic energy and potential energy and the law of block rock mass energy dissipation were analyzed.6 To control of deep mining rock burst,rock mass and support unified energy absorption for anti-impact was proposed.Energy control equation of rock block close to support was proposed.Rock mass and support unified energy absorption should be rock mass energy absorption first and support energy absorption complementary7 The properties and thickness of block partings are all have great influence to velocity of pendulum-type waves by experiment and attenuation of block acceleration was obvious changed. At the same time the block frequency band center and extremum value of frequency were also changed obviously.8 Velocity of pendulum-type waves decrease when local block fracture and time-frequency response of block rock were also changed obviously by experiment.