Experimental Study On Deformation And Failure Characteristics And Instability Mechanism Of Muddy Roadway Under Dynamic Disturbance

Mudstone is a common rock type in coal mines,and the influence of mining or other dynamic load will lead to the slow release of deformation energy,which eventually cause the deformation of muddy roadway.With the increasing depth of coal mining,the stress environment of muddy roadway has changed greatly.Under higher stress environment,the dynamic load will induce rock mass deformation energy to release violently,which will lead to serious deformation and failure of roadway,seriously restricts the efficient production of coal mine.Therefore,studying the response characteristics of mudstone under high stress and different dynamic load disturbance,has great significance to study the roadway support and disturbance dynamic disaster.In this paper,the field investigation of roadway deformation and failure is monitored,combined with research method like theoretical analysis,laboratory test,and numerical simulation method,the deformation and failure characteristics and instability mechanism of roadway under dynamic disturbance are studied.Through the field observation of the roadway surface,it is found that there is a large roof fall phenomenon at the top of the roadway,the deformation of the top and bottom is more than 1 m,two ribs deformation is more than 1.5 m.Using drilling imaging at the site,according to the imaging results,the surrounding rock of roadway is mainly mudstone,and there are a large number of visible transverse and longitudinal cracks at the height of 0 ? 4 m.After drilling the rock samples in the roadway,the triaxial test of this samples was carried out by using dsz-1000 stress-strain controlled triaxial shear tester,the results show that the characteristic strength of rock increases with the increase of confining pressure and loading rate.The accumulation and evolution of elastic strain energy of the specimen is a composite function of the exponential function of the natural constant E.And the damage model of roadway support is discussed on this basis.According to the geological conditions,FLAC3 D software is used to establish a numerical model to simulate the influence of static mining and dynamic disturbance mining on the roadway,the results show that the deformation of surrounding rock under dynamic load disturbance is 1.8 ? 38.4 times of that under static load,and the development of plastic zone is more obvious under dynamic load disturbance.Finally,based on the 1200 transportation roadway in Shanjiaoshu Coal Mine,the paper puts forward the strong anchor grouting support scheme by using the dynamic step-by-step reinforcement principle,process control technology,support selection principle and strengthening support technology system,which can improve the plastic area of the roadway obviously.The field application shows that the roadway surface displacement of the strong bolt grouting support scheme meets the requirements of coal mine safety production.