Evaluation Method And Application Of Coal Burst Performance Under The Effect Of Loading Rate

The attribute of the medium would be notable iMPacted by the loadingenvironment, and the loading speed was the most important parameter. This paperfocused on the mechanical properties of coal under different loading speed. Based onthe analyzing of the field observation of the rate effect, various loading speed tests weretaken. It was found that when the loading speed was over some critical value, thestrength of coal would decrease with the increasing of the loading speed, and this wasnot the same with rock. The mechanism of this phenomenon was researched with theeffect of the development of the fracture and the breaking of the bearing structure onthe rate effect considered. It was pointed out that the mechanical properties of coal withrate effect was effected by both of the development of the fracture and the breaking ofthe bearing structure, and a constitutive relation which could reflect this kind of specialmechanical properties was created. This phenomenon was related with burst propertyof coal and rock, Given the current calculation method for the burst property index, itwas proved that the burst property of coal also had a rate effect and critical value, andit was pointed that coal under critical loading speed was in the most dangerous state. Inorder to use this conclusion, the conversion relation between the advanced speed of theworking face and loading speed was built. The method for evaluating the burst propertywith rate effect considered was put forward, and this method was useful for the safetyof coal mine by offering a early warning value. Artificial failure face increased byworkers could enhance the adaptability of working face to the advanced speed was also point out. The field observation showed that the mentioned method was positive forcoal mine safety production.