## 5 Conclusions  
To analyze the interlayer shear slip behavior of the hard rock strata above the coal seam goat during bending and subsidence, a three-point bending loading experiment was designed for the composite rock layers. Theoretical studies were conducted to discuss the conditions of the interlayer shear slip of the composite rock layers and the sequence of the fracturing of the upper and lower rock layers. In addition, a case study of the occurrence and prevention of coal mine tremors was conducted. The main conclusions of this study were as follows:  
The interface had a significant impact on the vertical and horizontal deformations of the rock specimens. As the bending deformation increased, the difference in the horizontal deformation between the two sides of the interface continued to increase, reaching a maximum of 0.13 mm. The fracturing of the upper and lower layers of the rock promoted a transient dislocation between the layers, with dislocation amounts reaching 0.2 and 0.35 mm, and maximum shear strains of 0.025 and 0.047.  
Rock bending led to an interlayer sliding deformation, while rock fracturing greatly promoted interlayer sliding. The change in the acceleration of the interlayer sliding exhibited intermittent characteristics during bending deformation, with a maximum interlayer sliding acceleration of 0.6 mm/s\({}^{2}\). During rock fracturing, the acceleration of the interlayer sliding suddenly increased, with a maximum value of 3.8 mm/s\({}^{2}\).  
The acoustic emission monitoring results indicated that the interlayer shear fracturing caused the rock to undergo mixed tensile-shear fracturing rather than pure tensile fracturing.  
Figure 20: Distribution of microseismic events with energies of greater than 10,000 J on working face 3106 at (**a**) 100 m, (**b**) 300 m, (**c**) 500 m, and (**d**) 700 m.  
ing. During the fracture deformation stage of the rock, the proportion of shear fractures was higher than that of tensile fractures, and acoustic emission events with long durations and a high amplitude continuously occurred.  
The mechanism of coal mine tremors in composite rock strata was that the increase in the area of the goaf led to the bending and subsidence of the thicker sandstone layers and interlayer shear slip. The tensile fracturing of the sandstone layer intensified the interlayer shear slip. The tensile fracturing of the sandstone released energy that generated longitudinal waves, while the interlayer shear slip released energy that generated transverse waves, causing the vibration of the roof rock strata and the surface.  
Conceptualization, Y.P. and X.G.; methodology, X.G.; experiment, T.Z. and W.W.; investigation, Y.X.; theoretical analysis, Y.S.; writing--original draft preparation, X.G.; writing--review and editing, Y.S.; visualization, L.D.; supervision, T.Z. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the National Key Research and Development Program of China (Grant No. 2022 YFC3004605).  
Not applicable.  
The raw data supporting the conclusions of this article will be made available by the authors on request.  
The authors declare no conflicts of interest.