Experimental Research on Dynamic Failure of Rock-Cemented Material-Rock Interface Considering Strain Rate Effect

Due to the presence of natural joints and weak interlayer interfaces in the rock mass, the rock mass will be damaged or even deformed to high degree under the action of dynamic loads such as strong seismic activity, resulting in significant engineering safety accidents and casualties. In light of the aforementioned dynamic issues with rock discontinuities, complete rock samples and interface rock samples containing cemented material (gypsum) underwent a series of SHPB impact compressive and splitting tensile tests. To investigate the dynamic properties and change laws of rocks, theoretical analysis, high-speed camera systems, and "binary method" fracture extraction technology were employed. It was concluded that the peak strength of impact tension and impact compression of the samples increased with the increase of strain rate in a power function relationship. The cemented material (gypsum) interface causes stress wave and energy dissipation to be attenuated. When compared to an intact rock sample, the interface causes the number, area, and transmission coefficient of the cracks to decrease, preventing further crack development. However, the initial position and development direction of the crack and the overall stress loading of the sample are not affected. When the energy input is too much, the rock crack gradually changes from peritectic to transgranular, showing that the dissipative energy increases and reaches the peak strength. The findings can serve as a guide and a point of reference for major projects involving joined rock mass and broken rock mass in terms of safety design and operation. Peak strength of the rock sample increases as a power function of strain rate.Strain rate does not affect the initial position and development direction of the crack.The interface decreases the number, area, and transmission coefficient of the cracks.Cemented interface causes the stress wave and energy dissipation to be attenuated.Cracks will change from peritectic to transgranular as the input energy is too great.