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Abstract The dynamic compressive tests were carried out with ?75 mm split Hopkinson pressure bar(SHPB) on the plate-shape marble specimens(size of 60 mm×60 mm×15 mm) with a single circular or an elliptical hole in the center of the specimen. The dynamic strain signals in the incident bar and the transmitted bar were monitored with the ultra-dynamic strain indicator. The process of crack initiation，propagation and coalescence in the marble specimens was recorded with a high speed video camera. The dynamic strength，failure mode and crack propagation characteristics of the specimens were analyzed and discussed. It is found that the rock dynamic strength is influenced by the size，the shape and the spatial location of the water jet cut hole. The strength of the holed specimen is obviously smaller than that of the intact marble specimen. Axial tensile cracks parallel to the loading direction and X-type shear cracks surrounding the hole are the dominant factors for the failure of the specimens. With the increase of the diameter of the round hole，the speed of shear crack propagation increases while the speed of tensile crack propagation decreases. For the specimens containing an elliptical hole，the eccentricity and the angle between the loading direction and the long axes influence the cracking behavior and dynamic strength under impact loading. The average speed of dynamic crack propagation of the marble specimens is in the range of 100–450 m/s at the loading rate of 30–45 s－1.
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Received: 24 March 2014
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2015, Vol. 34 
