Research On Mechanism Of Roadway Surrounding Rock Insability And Rockburst

The rockburst is one of the great dynamic disasters in the coal mining as well as deep underground engineering and also is the hot issue with widely attention in rock mechanics field. The frequency and harmfulness of rockburst become more serious with the depth of mine expanding, which needed to be solved as an important technology problem for domestic mining. With comprehensive application of physics-based simulation as well as theoretical analysis and numerical simulation, the systematic research of the mechanism of coal roadways surrounding rock instability and rockburst has been performed which concerned with the mechanism of coal roadways rockburst as well as its prevention and treatment. The main innovation achievements are as follows:(1) The roadways coal wall crack-layer plate mechanical model have been established which based on the characters of roadways surrounding deformation and failure. The stability features and catastrophe instability mechanism of coal wall crack-layer plate have been studied with elastic stability and nonlinear catastrophe theories. The Formation of coal wall crack-layer plate and its buckling instability rules have gained as well as the maximum instability critical load estimating formula and its influence relation with the roadways depth as well as rock properties and the geometry size of roadway.(2) In the study on influence of dynamic disturbances for the crack-layer plate structure stability, the roadsides crack-layer plate structure stability dynamic controlling equation have been obtained as well as its dynamic instability zone features. It reveals the rockburst inducement mechanism in the roadways surrounding rock with the influence rules of disturbance frequency and loading amplitude for the dynamic instability zone.(3) The systematic research on roadway surrounding rock stability features have been established with numerical simulation methods and relative software FLAC3D, it reveals the rules of stress as well as deformation and the plastic zone distribution changed with the roadway depth, rock properties, cross roadways included angles and dynamic disturbance.(4) The roadway surrounding rock energy accumulation zone concept and its determination method have been put forwards based on the results of numerical analysis. It reveals the energy accumulation features, energy density spatial distribution in the energy accumulation zone and the change law of average energy density and the distance distribution between energy accumulation zones and roadsides. The average energy density factor criterion for the rockbusrt has been established with introduction of the average energy density factork .(5) The roadway coal wall crack-layer plate structure formulation and instability failure rules have been successfully obtained with self-designed loading instrument and American electro-hydraulic serve controlled rock mechanics testing system for the coal wall crack-layer plate structure instability experiment simulation. The experiment reveals the crack development, propagation and the formulation mechanical mechanism.The study findings would provide important theoretical foundation for the mechanism of rockbusrt, forecasting methods and the control technology research.