An Evaluation Method for the Bursting Characteristics of Coal Under the Effect of Loading Rate

Changes in loading rate can affect the strength performance and bursting characteristics of coal. Coal samples from the same source were subject to mechanical tests for multi-loading rates. These tests were carried out to determine changes in evaluation indicators for the law of bursting liability due to increases in the loading rate. The results show that indicators, including the uniaxial compressive strength and the bursting energy index, first increased and then decreased with the increase in loading rate. The value of the loading rate, which corresponds to the strength turning point, is named the “critical loading rate”. The results of evaluating the bursting liability of coal (from the same source) show all the possibilities. The critical loading rate corresponds to the highest bursting liability. The “loading rate sensitivity” is proposed to describe the comprehensive response of the bursting characteristics to the loading rate. This index, combined with the scale conversion method, makes the field application of laboratory experimentation possible. This method for evaluating the bursting liability of coal under the effect of loading rate was systematically established and shows good applicability.