Relationship between Local Deformation and Global Stability of Rock Using the Global–Local Dissipation Energy Time-Series Variation Coefficient

Abstract

The tension and slide of surrounding rock are highly inclined to cause dynamic disasters, thus seriously threatening the safety of mine resource recovery. This study proposes a novel method based on the global–local dissipation energy time-series variation coefficient in order to analyze the relationship between local deformation and global stability of rock. The localized light-force monitoring test method is used to analyze the tensile-sliding effect, and the evolution characteristics of the global–local dissipative energy time-series variation coefficient are compared. The results indicate that the strength reduction of rock is affected by the deformation accumulation of the loading displacement field. As for the stable damage specimen, the sliding displacement occurs 5.5 s earlier than tensile displacement, which is 4.4 s longer than the case of the transient damage specimen. The node spring model theory is further proposed to determine whether the global–local dissipation energy relationship of rock under load conformed to the linear function distribution. The global–local dissipation energy time-series variation coefficient range is always in the [1, 0.9] range. Rock instability can be predicted based on the slope and inflection point changes in the time-series variation coefficient curve, and increasing the number of effective monitoring points can significantly improve the monitoring effect and accuracy of the local time-series variation coefficient. As an important component of safe mining space, the roadway surrounding rock is prone to instability due to tensile and sliding failure, which seriously affects the safe and efficient mining of mine resources. Based on global–local energy, a new method of time-series variation coefficient is proposed in this study according to the local tensile and sliding deformation tests. By fitting the rock global–local energy relationship, the internal relationship between the local time-series variation index and the overall stability is determined. The result shows that the point measurement data in practical application are almost invariably local information because the rock deformation and stress data monitored in the roadway surrounding rock are almost reflected in the form of measuring points. Therefore, it is crucial to study the feedback of the local time-series variation coefficient on global stability, which provides an important index for early warnings of surrounding rock instability and failure. Meanwhile, it also points the direction for further improving the rock stability control theory in rock mechanics.